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Effects of corrosion on steel reinforcement

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Title:
Effects of corrosion on steel reinforcement
Physical Description:
Book
Language:
English
Creator:
Ostrofsky, David
Publisher:
University of South Florida
Place of Publication:
Tampa, Fla.
Publication Date:

Subjects

Subjects / Keywords:
Corrosion
Tensile
Stress
Piles
Prestress steel
Dissertations, Academic -- Civil Engineering -- Masters -- USF   ( lcsh )
Genre:
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

Notes

Abstract:
ABSTRACT: Corroded steel in concrete is a structural issue that plaques concrete structures in coastal regions. Traditionally corroded steel strength is calculated from a distributed area loss due to corrosion over the entire surface of the steel and reducing the capacity accordingly. In reality, corrosion attacks localized regions creating pits and reducing the cross section in a small region which amplifies the effects of corrosion. Stress concentrations at the corrosion pitting damage may further reduce the tensile capacity of the steel. A study of corrosion damage and strength associated with pitting damage can assist in understanding the ultimate tensile capacity of corroded steel strands, better correlations are needed to estimate actual strength of damaged steel. The focus of this thesis is on seven-wire prestress steel strands with various stages of induced corrosion. Each strand has been documented, profiled, and measured in order to correlate physical damage with ultimate capacity.
Thesis:
Thesis (M.S.)--University of South Florida, 2007.
Bibliography:
Includes bibliographical references.
System Details:
System requirements: World Wide Web browser and PDF reader.
System Details:
Mode of access: World Wide Web.
Statement of Responsibility:
by David Ostrofsky.
General Note:
Title from PDF of title page.
General Note:
Document formatted into pages; contains 211 pages.

Record Information

Source Institution:
University of South Florida Library
Holding Location:
University of South Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 001935424
oclc - 226045341
usfldc doi - E14-SFE0002258
usfldc handle - e14.2258
System ID:
SFS0026576:00001


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Effects Of Corrosion On Steel Reinforcement by David Ostrofsky A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering Department of Civil & Envirnmental Engineering College of Engineering University of South Florida Major Professor: Austin Mullins, Ph.D. Rajan Sen, Ph.D. William Carpenter, Ph.D. Date of Approval: November 14, 2007 Keywords: corrosion, tensile, stre ss, piles, prestress steel Copyright 2007 David Ostrofsky

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Ac kn ow le dg me nts I would like to thank Kristin Dunathan f or standing by me in ever y thing I do, Dr. Austin Mulli ns for a llowing me to join his rese arc h team, Dr Rajan Sen for additional g uidance also Dr. Micha el Stokes, Mr. Danie l Wi nters, and Mr J ulio Aguilar for taking the time to assist me. I would like to thank my friends w ho helped my when I neede d a ha nd B y ro n D e lon g fo r g ivi ng his tim e wh e n I ne e de d h e lp. F ina lly I tha nk my fa mil y members that a ssisted me in my educa tional goa ls.

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i Tabl e of Contents L i s t o f T a b l e s .......................................................... iii L i s t o f F i g u r e s .......................................................... v A b s t r a c t ............................................................ xviii C h a p t e r 1 I n t r o d u c t i o n .................................................... 1 1 1 O v e r v i e w ..................................................... 1 1 2 S c o p e o f P r o j e c t ................................................ 4 1 3 O r g a n i z a t i o n o f t h e R e p o r t ........................................ 4 C h a p t e r 2 C o r r o s i o n B a c k g r o u n d ........................................... 6 2 1 C o r r o s i o n i n S t r u c t u r e s .......................................... 6 2 1 1 C o s t t o I n d u s t r y ......................................... 6 2 2 C a u s e s o f C o r r o s i o n ............................................ 10 2 2 1 C h e m i c a l P r o c e s s ...................................... 10 2 3 Q u a n t i f y i n g C o r r o s i o n D a m a g e ................................... 11 2 3 1 I n s p ec t i n g an d M o n i t o ri n g C o rr o s i o n Da m age . . . . . . . . 12 2 3 2 P re v en t i n g C o rr o s i o n Da m age . . . . . . . . . . . . . . 13 C h a p t e r 3 S p e c i m e n H i s t o r y .............................................. 18 3 1 E x p e r i m e n t a l S c e n a r i o .......................................... 18 3 2 O v e r v i e w o f S i m u l a t e d S e t u p .................................... 18 3 3 O b s e r v e d C o r r o s i o n ........................................... 19 3 4 S u m m a r y o f T r e n d s ............................................ 19 C h a p t e r 4 I m a g i n g P r o c e s s................................................ 32 4 1 I m a g i n g ..................................................... 32 4 1 1 P r o c e d u r e ............................................ 32 4 1 2 D o c u m e n t a t i o n o f D a m a g e ............................... 33 4 2 I m a g i n g O b s e r v a t i o n s .......................................... 33 4 2 1 C o n d i t i o n o f S t e e l ...................................... 33 4 2 2 S u m m a r y o f T r e n d s ..................................... 34 C h a p t e r 5 S t r a n d P r o f i l e r ................................................. 44 5 1 T h e o r y ...................................................... 44

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ii 5 2 P r o f i l e r S e t u p ................................................. 45 5 3 P r o c e d u r e .................................................... 46 5 4 I n i t i a l T e s t i n g o f P r o c e s s ........................................ 46 5 5 E r r o r ........................................................ 47 5 6 D a t a P r o c e s s i n g ............................................... 48 5 7 S u m m a r y o f D a t a .............................................. 48 C h a p t e r 6 T e n s i o n T e s t .................................................. 63 6 1 S t a n d a r d s .................................................... 63 6 2 P r o c e d u r e .................................................... 63 6 3 I n i t i a l T e s t i n g o f P r o c e s s ........................................ 64 6 4 O b s e r v a t i o n s ................................................. 65 6 5 D a t a P r o c e s s i n g ............................................... 65 6 6 S u m m a r y o f D a t a .............................................. 65 C h a p t e r 7 S u m m a r y a n d C o n c l u s i o n s ....................................... 81 7 1 G r a v i m e t r i c L o s s a n d A c t u a l L o s s ................................. 81 7 2 P i t t i n g C o r r o s i o n .............................................. 81 7 3 U l t i m a t e C a p a c i t y ............................................. 82 7 4 S t r e s s C o n c e n t r a t i o n ........................................... 82 7 5 S u m m a r y o f R e s u l t s ............................................ 84 R e f e r e n c e s ............................................................ 97 A p p e n d i c e s ............................................................ 98 Ap p en d i x A C ri t i ca l C o rr o s i o n I m age s an d Ob s er v ed Da m age . . . . . . 99 A p p e n d i x B P r o f i l e d S t r a n d R e s u l t s ................................. 119 A p p e n d i x C T e n s i o n T e s t R e s u l t s ................................... 162

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iii List of Tabl es T a b l e 2 1 C o s t o f C o r r o s i o n t o I n d u s t r y ....................................... 7 T a b l e 3 1 S a m p l e o f C r a c k S u r v e y ......................................... 20 Ta ble 3. 2 G ra vim e tr ic Te st R e su lts of Con tr ols . . . . . . . . . . . . . . . 23 Table 3.3 G ravimetric Test Results of CFRP W rappe d Specimens . . . . . . . . 24 Ta ble 3. 4 G ra vim e tr ic Te st R e su lts of GF RP Wr a pp e d Sp e c ime ns . . . . . . . . 25 T a b l e 4 1 O b s e r v e d D a m a g e S c a l e ......................................... 35 T a b l e 5 1 P r o f i l e d S t r a n d R e s u l t s .......................................... 51 Table 6.1 Te nsion Test Results I nstant Fa ilure . . . . . . . . . . . . . . . . 67 Table 6.2 Te nsion Test Results Epox y Fa ilure . . . . . . . . . . . . . . . . 67 Table 6.3 Te nsion Test Results Ulti mate Capa city After I nitial Failure . . . . . . 68 Table 6.4 Te nsion Test Results Ty pical F ailure . . . . . . . . . . . . . . . . 69 Ta ble 6. 5 T e ns ion Te st R e su lts Un da ma g e d Co ntr ols . . . . . . . . . . . . . 72 Ta ble 6. 6 T e ns ion Te st R e su lts Mo dif ie d Co ntr ols . . . . . . . . . . . . . . 72 T a b l e 7 1 S u m m a r y o f R e s u l t s C F R P ....................................... 85 T a b l e 7 2 S u m m a r y o f R e s u l t s G F R P ....................................... 87 Ta ble 7. 3 Su mma ry of Re su lts Ou tdo or Con tr ols . . . . . . . . . . . . . . . 89 Ta ble 7. 4 Su mma ry of Re su lts I nd oo r C on tr ols . . . . . . . . . . . . . . . . 90 T a b l e A 1 D e s c r i p t i o n o f D a m a g e C F R P ................................... 112

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iv T a b l e A 2 D e s c r i p t i o n o f D a m a g e G F R P ................................... 113 Ta ble A. 3 D e sc ri pti on of Da ma g e Ou tdo or Con tr ols . . . . . . . . . . . . . 114 Ta ble A. 4 D e sc ri pti on of Da ma g e I nd oo r C on tr ols . . . . . . . . . . . . . . 114 T a b l e A 5 O b s e r v e d D a m a g e S c a l e ........................................ 115 Ta ble A. 6 O bs e rv e d Co rr os ion Da ma g e CF RP . . . . . . . . . . . . . . . 116 Ta ble A. 7 O bs e rv e d Co rr os ion Da ma g e GF RP . . . . . . . . . . . . . . . 117 Ta ble A. 8 O bs e rv e d Co rr os ion Da ma g e Ou tdo or Con tr ols . . . . . . . . . . . 118 Ta ble A. 9 O bs e rv e d Co rr os ion Da ma g e I nd oo r C on tr ols . . . . . . . . . . . 118

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v List of F igures F i g u r e 1 1 S e v e r e C o r r o s i o n D a m a g e ........................................ 1 Fi gu re 1 2 T y p i ca l “S p l as h Zo n e” C o rr o s i o n Da m age . . . . . . . . . . . . . 3 F ig ur e 2. 1 Co rr os ion in R e inf or c e d Co nc re te . . . . . . . . . . . . . . . . 15 Fi gu re 2 2 R u s t S t ai n s Fr o m C o rr o s i o n Da m age . . . . . . . . . . . . . . . 16 F i g u r e 2 3 S a c r i f i c i a l A n o d e .............................................. 17 Fig ure 3.1 Strand a nd Side Nomenclatur e . . . . . . . . . . . . . . . . 19 F i g u r e 3 2 C r a c k P a t t e r n : L ) 3 9 R ) 4 9 ...................................... 21 Fig ure 3.3 Cra ck Pattern: A) 38, B) 44, C) 45, D) 46 . . . . . . . . . . . . . 22 Fig ure 3.4 Simulated Environment Set-Up . . . . . . . . . . . . . . . . . 26 Fig ure 3.5 Simulated Environment Ne twork of Sensors . . . . . . . . . . . . 26 F i g u r e 3 6 T i d a l S c h e d u l e a n d P u m p s ....................................... 27 Fig ure 3.7 I nitial Rust Stains in S plash Z one . . . . . . . . . . . . . . . . 27 F ig ur e 3. 8 Re mov a l of Pile s F ro m Sim ula te d E nv ir on me nt . . . . . . . . . . . 28 Fig ure 3.9 Corr osion Damag e: 38c, 39c d, 44d, 46d . . . . . . . . . . . . . . 29 Fig ure 3.10 Corr osion Damag e: 53a, 58c 42d, 48b . . . . . . . . . . . . . . 30 F i g u r e 3 1 1 R e m o v a l o f C o n c r e t e C o v e r ..................................... 31 F i g u r e 3 1 2 E x p o s e d P i l e C o r e ............................................ 31 Fig ure 4.1 Micr oscope I nteg rate d I nto Camera . . . . . . . . . . . . . . . . 36

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vi Fig ure 4.2 Spec imen L ighting Configur ation . . . . . . . . . . . . . . . . 37 F i g u r e 4 3 I m a g e C a p t u r e A r e a ............................................ 38 Fig ure 4.4 Tr iang ular Chuck Sec ured to B ar . . . . . . . . . . . . . . . . . 39 F i g u r e 4 5 I m a g e P r o c e s s i n g S t a t i o n ........................................ 40 F i g u r e 4 6 I m a g i n g S o f t w a r e I n t e r f a c e....................................... 41 Fig ure 4.7 I mag e of Pitting Da mag e to Multiple W ires . . . . . . . . . . . . . 42 Fig ure 4.8 I mag e of Pitting Da mag e Sever ing Wire . . . . . . . . . . . . . . 43 F i g u r e 5 1 P r o f i l e r T e s t S e t u p ............................................. 50 F i g u r e 5 2 P r o f i l e o f E m p t y T u b e .......................................... 57 F i g u r e 5 3 S a m p l e P r o f i l e o f S t r a n d......................................... 57 Fig ure 5.4 Prof ile of Strand without Calibration . . . . . . . . . . . . . . . 58 Fig ure 5.5 Prof ile of Strand with Calibration . . . . . . . . . . . . . . . . 58 Fig ure 5.6 Prof ile of Aluminum Bar with Varie d Cross Section . . . . . . . . . 59 F i g u r e 5 7 P r o f i l e C a l i b r a t i o n ............................................. 59 F i g u r e 5 8 S t r a n d C l a m p e d a t L o w e r T u b e ................................... 60 F i g u r e 5 9 U p p e r a n d L o w e r T u b e .......................................... 60 Fig ure 5.10 F luid in Upper Tube a nd Attache d Measur ing T ape . . . . . . . . . 61 Fig ure 5.11 Piezometer, Clamp, and Copper Tubing . . . . . . . . . . . . . 61 F i g u r e 5 1 2 P i e z o m e t e r a n d F l o w V a l v e s .................................... 62 F i g u r e 5 1 3 P r o f i l e T e s t S t a t i o n ............................................ 62 F i g u r e 6 1 T y p i c a l S t r a n d F a i l u r e .......................................... 73 F i g u r e 6 2 A l l S t r a n d s F a i l e d a t O n c e ....................................... 73

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vii Fig ure 6.3 U ltimate Capacity at Second Wire F ailure . . . . . . . . . . . . . 74 Fig ure 6.4 U ltimate Capacity at Third Wire F ailure . . . . . . . . . . . . . . 74 F i g u r e 6 5 T e n s i o n T e s t S e t u p ............................................. 75 Fig ure 6.6 Te nsion Test After Strand Fa ilure . . . . . . . . . . . . . . . . 76 F i g u r e 6 7 T e n s i o n T e s t S t a t i o n ............................................ 77 F i g u r e 6 8 T e n s i o n T e s t C o n t r o l P a n e l s ...................................... 78 F i g u r e 6 9 T e n s i o n T e s t I n t e r f a c e .......................................... 79 F i g u r e 6 1 0 P r e s t r e s s A n c h o r s ............................................. 80 F i g u r e 7 1 A c t u a l v s G r a v i m e t r i c L o s s ...................................... 91 Fig ure 7.2 Er ror Pre dicting U ltimate Capacity w/o 45cd . . . . . . . . . . . . 92 F ig ur e 7. 3 Pr of ile Er ro r v s U lti ma te Ca pa c ity . . . . . . . . . . . . . . . . 93 F i g u r e 7 4 B a r A r e a v s C a p a c i t y ........................................... 94 F i g u r e 7 5 I n v e r s e T a n g e n t R e l a t i o n s h i p ..................................... 95 F ig ur e 7. 6 St re ss C on c e ntr a tio n v s Ca pa c ity . . . . . . . . . . . . . . . . . 96 F i g u r e A 1 C r i t i c a l C o r r o s i o n I m a g e 3 8 c d .................................... 99 F i g u r e A 2 C r i t i c a l C o r r o s i o n I m a g e 3 9 d a .................................... 99 F i g u r e A 3 C r i t i c a l C o r r o s i o n I m a g e 4 0 c d ................................... 100 F i g u r e A 4 C r i t i c a l C o r r o s i o n I m a g e 4 2 b c ................................... 100 F i g u r e A 5 C r i t i c a l C o r r o s i o n I m a g e 4 3 a b ................................... 101 Fig ure A .6 Critical Corrosion I mag e 43bc . . . . . . . . . . . . . . . . . 101 F i g u r e A 7 C r i t i c a l C o r r o s i o n I m a g e 4 5 b c ................................... 102 F i g u r e A 8 C r i t i c a l C o r r o s i o n I m a g e 4 7 a b ................................... 102

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vii i F i g u r e A 9 C r i t i c a l C o r r o s i o n I m a g e 4 8 b c ................................... 103 Fig ure A .10 Critical Corrosion I mag e 48cd . . . . . . . . . . . . . . . . . 103 Fig ure A .11 Critical Corrosion I mag e 49da . . . . . . . . . . . . . . . . . 104 Fig ure A .12 Critical Corrosion I mag e 50ab . . . . . . . . . . . . . . . . . 104 Fig ure A .13 Critical Corrosion I mag e 50da . . . . . . . . . . . . . . . . . 105 Fig ure A .14 Critical Corrosion I mag e 52ab . . . . . . . . . . . . . . . . . 105 Fig ure A .15 Critical Corrosion I mag e 52bc . . . . . . . . . . . . . . . . . 106 Fig ure A .16 Critical Corrosion I mag e 52da . . . . . . . . . . . . . . . . . 106 Fig ure A .17 Critical Corrosion I mag e 53ab . . . . . . . . . . . . . . . . . 107 Fig ure A .18 Critical Corrosion I mag e 54ab.1 . . . . . . . . . . . . . . . . 107 Fig ure A .19 Critical Corrosion I mag e 54ab.2 . . . . . . . . . . . . . . . . 108 Fig ure A .20 Critical Corrosion I mag e 54bc . . . . . . . . . . . . . . . . . 108 Fig ure A .21 Critical Corrosion I mag e 54cd . . . . . . . . . . . . . . . . . 109 Fig ure A .22 Critical Corrosion I mag e 54da . . . . . . . . . . . . . . . . . 109 Fig ure A .23 Critical Corrosion I mag e 55ab . . . . . . . . . . . . . . . . . 110 Fig ure A .24 Critical Corrosion I mag e 57ab . . . . . . . . . . . . . . . . . 110 Fig ure A .25 Critical Corrosion I mag e 57da . . . . . . . . . . . . . . . . . 111 Fig ure A .26 Critical Corrosion I mag e 58bc . . . . . . . . . . . . . . . . . 111 F i g u r e B 1 P r o f i l e o f 3 8 a b ............................................... 119 F i g u r e B 2 P r o f i l e o f 3 8 c d ............................................... 119 F i g u r e B 3 P r o f i l e o f 3 8 d a ............................................... 120 F i g u r e B 4 P r o f i l e o f 3 9 b c ............................................... 120

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ix F i g u r e B 5 P r o f i l e o f 3 9 c d ............................................ 121 F i g u r e B 6 P r o f i l e o f 3 9 d a ............................................ 121 F i g u r e B 7 P r o f i l e o f 4 0 a b ............................................... 122 Fig ure B .8 P r o f i l e o f 4 0 b c ............................................ 122 F i g u r e B 9 P r o f i l e o f 4 0 c d ............................................... 123 F i g u r e B 1 0 P r o f i l e o f 4 0 d a .............................................. 123 F i g u r e B 1 1 P r o f i l e o f 4 1 a b .............................................. 124 F i g u r e B 1 2 P r o f i l e o f 4 1 b c .............................................. 124 F i g u r e B 1 3 P r o f i l e o f 4 1 c d .............................................. 125 F i g u r e B 1 4 P r o f i l e o f 4 1 d a ............................................ 125 F i g u r e B 1 5 P r o f i l e o f 4 2 a b ............................................ 126 F i g u r e B 1 6 P r o f i l e o f 4 2 b c .............................................. 126 F i g u r e B 1 7 P r o f i l e o f 4 2 c d .............................................. 127 F i g u r e B 1 8 P r o f i l e o f 4 2 d a ............................................ 127 F i g u r e B 1 9 P r o f i l e o f 4 3 a b .............................................. 128 F i g u r e B 2 0 P r o f i l e o f 4 3 b c ............................................ 128 F i g u r e B 2 1 P r o f i l e o f 4 3 c d .............................................. 129 F i g u r e B 2 2 P r o f i l e o f 4 3 d a .............................................. 129 F i g u r e B 2 3 P r o f i l e o f 4 4 a b .............................................. 130 F i g u r e B 2 4 P r o f i l e o f 4 4 b c ...................................... 130 F i g u r e B 2 5 P r o f i l e o f 4 4 c d ............................................ 131 F i g u r e B 2 6 P r o f i l e o f 4 4 d a .............................................. 131

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x F i g u r e B 2 7 P r o f i l e o f 4 5 a b ............................................ 132 F i g u r e B 2 8 P r o f i l e o f 4 5 b c ............................................ 132 F i g u r e B 2 9 P r o f i l e o f 4 5 c d .............................................. 133 F i g u r e B 3 0 P r o f i l e o f 4 5 d a .............................................. 133 F i g u r e B 3 1 P r o f i l e o f 4 6 a b .............................................. 134 F i g u r e B 3 2 P r o f i l e o f 4 6 b c .............................................. 134 F i g u r e B 3 3 P r o f i l e o f 4 6 c d .............................................. 135 F i g u r e B 3 4 P r o f i l e o f 4 6 d a .............................................. 135 F i g u r e B 3 5 P r o f i l e o f 4 7 a b .............................................. 136 F i g u r e B 3 6 P r o f i l e o f 4 7 b c ............................................ 136 F i g u r e B 3 7 P r o f i l e o f 4 7 c d ............................................ 137 F i g u r e B 3 8 P r o f i l e o f 4 7 d a .............................................. 137 F i g u r e B 3 9 P r o f i l e o f 4 8 a b .............................................. 138 F i g u r e B 4 0 P r o f i l e o f 4 8 b c .............................................. 138 F i g u r e B 4 1 P r o f i l e o f 4 8 c d ............................................ 139 F i g u r e B 4 2 P r o f i l e o f 4 8 d a ............................................ 139 F i g u r e B 4 3 P r o f i l e o f 4 9 a b ............................................ 140 F i g u r e B 4 4 P r o f i l e o f 4 9 b c .............................................. 140 F i g u r e B 4 5 P r o f i l e o f 4 9 c d .............................................. 141 F i g u r e B 4 6 P r o f i l e o f 4 9 d a ............................................ 141 F i g u r e B 4 7 P r o f i l e o f 5 0 a b .............................................. 142 F i g u r e B 4 8 P r o f i l e o f 5 0 b c .............................................. 142

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xi F i g u r e B 4 9 P r o f i l e o f 5 0 c d ............................................ 143 F i g u r e B 5 0 P r o f i l e o f 5 0 d a .............................................. 143 F i g u r e B 5 1 P r o f i l e o f 5 1 a b .............................................. 144 F i g u r e B 5 2 P r o f i l e o f 5 1 b c ............................................ 144 F i g u r e B 5 3 P r o f i l e o f 5 1 c d .............................................. 145 F i g u r e B 5 4 P r o f i l e o f 5 1 d a .............................................. 145 F i g u r e B 5 5 P r o f i l e o f 5 2 a b .............................................. 146 F i g u r e B 5 6 P r o f i l e o f 5 2 b c ............................................ 146 F i g u r e B 5 7 P r o f i l e o f 5 2 c d .............................................. 147 F i g u r e B 5 8 P r o f i l e o f 5 2 d a .............................................. 147 F i g u r e B 5 9 P r o f i l e o f 5 3 a b .............................................. 148 F i g u r e B 6 0 P r o f i l e o f 5 3 b c .............................................. 148 F i g u r e B 6 1 P r o f i l e o f 5 3 c d .............................................. 149 F i g u r e B 6 2 P r o f i l e o f 5 3 d a .............................................. 149 F i g u r e B 6 3 P r o f i l e o f 5 4 a b .............................................. 150 F i g u r e B 6 4 P r o f i l e o f 5 4 b c .............................................. 150 F i g u r e B 6 5 P r o f i l e o f 5 4 c d .............................................. 151 F i g u r e B 6 6 P r o f i l e o f 5 4 d a .............................................. 151 F i g u r e B 6 7 P r o f i l e o f 5 5 a b ...................................... 152 F i g u r e B 6 8 P r o f i l e o f 5 5 b c .............................................. 152 F i g u r e B 6 9 P r o f i l e o f 5 5 c d .............................................. 153 F i g u r e B 7 0 P r o f i l e o f 5 5 d a .............................................. 153

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xii F i g u r e B 7 1 P r o f i l e o f 5 6 a b .............................................. 154 F i g u r e B 7 2 P r o f i l e o f 5 6 b c .............................................. 154 F i g u r e B 7 3 P r o f i l e o f 5 6 c d .............................................. 155 F i g u r e B 7 4 P r o f i l e o f 5 6 d a ............................................ 155 F i g u r e B 7 5 P r o f i l e o f 5 7 a b .............................................. 156 F i g u r e B 7 6 P r o f i l e o f 5 7 b c .............................................. 156 F i g u r e B 7 7 P r o f i l e o f 5 7 c d .............................................. 157 F i g u r e B 7 8 P r o f i l e o f 5 7 d a .............................................. 157 F i g u r e B 7 9 P r o f i l e o f 5 8 a b ............................................ 158 F i g u r e B 8 0 P r o f i l e o f 5 8 b c .............................................. 158 F i g u r e B 8 1 P r o f i l e o f 5 8 c d .............................................. 159 F i g u r e B 8 2 P r o f i l e o f 5 8 d a .............................................. 159 F i g u r e B 8 3 P r o f i l e o f 5 9 a b .............................................. 160 F i g u r e B 8 4 P r o f i l e o f 5 9 b c .............................................. 160 F i g u r e B 8 5 P r o f i l e o f 5 9 c d .............................................. 161 F i g u r e B 8 6 P r o f i l e o f 5 9 d a .............................................. 161 F i g u r e C 1 T e n s i o n T e s t 3 8 a b ............................................ 162 F i g u r e C 2 T e n s i o n T e s t 3 8 c d ............................................ 162 F i g u r e C 3 T e n s i o n T e s t 3 8 d a ............................................ 163 F i g u r e C 4 T e n s i o n T e s t 3 9 a b ............................................ 163 F i g u r e C 5 T e n s i o n T e s t 3 9 b c ............................................ 164 F i g u r e C 6 T e n s i o n T e s t 3 9 d a ............................................ 164

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xiii F i g u r e C 7 T e n s i o n T e s t 4 0 a b ............................................ 165 F i g u r e C 8 T e n s i o n T e s t 4 0 b c ............................................ 165 F i g u r e C 9 T e n s i o n T e s t 4 0 c d ............................................ 166 F i g u r e C 1 0 T e n s i o n T e s t 4 0 d a ........................................... 166 F i g u r e C 1 1 T e n s i o n T e s t 4 1 a b ........................................... 167 F i g u r e C 1 2 T e n s i o n T e s t 4 1 b c ........................................... 167 F i g u r e C 1 3 T e n s i o n T e s t 4 1 c d ........................................... 168 F i g u r e C 1 4 T e n s i o n T e s t 4 1 d a ........................................... 168 F i g u r e C 1 5 T e n s i o n T e s t 4 2 a b ........................................... 169 F i g u r e C 1 6 T e n s i o n T e s t 4 2 b c ........................................... 169 F i g u r e C 1 7 T e n s i o n T e s t 4 2 c d ........................................... 170 F i g u r e C 1 8 T e n s i o n T e s t 4 2 d a ........................................... 170 F i g u r e C 1 9 T e n s i o n T e s t 4 3 a b ........................................... 171 F i g u r e C 2 0 T e n s i o n T e s t 4 3 b c ........................................... 171 F i g u r e C 2 1 T e n s i o n T e s t 4 3 c d ........................................... 172 F i g u r e C 2 2 T e n s i o n T e s t 4 3 d a ........................................... 172 F i g u r e C 2 3 T e n s i o n T e s t 4 4 a b ........................................... 173 F i g u r e C 2 4 T e n s i o n T e s t 4 4 b c ........................................... 173 F i g u r e C 2 5 T e n s i o n T e s t 4 4 c d ........................................... 174 F i g u r e C 2 6 T e n s i o n T e s t 4 4 d a ........................................... 174 F i g u r e C 2 7 T e n s i o n T e s t 4 5 a b ........................................... 175 F i g u r e C 2 8 T e n s i o n T e s t 4 5 b c ........................................... 175

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xiv F i g u r e C 2 9 T e n s i o n T e s t 4 5 c d ........................................... 176 F i g u r e C 3 0 T e n s i o n T e s t 4 5 d a ........................................... 176 F i g u r e C 3 1 T e n s i o n T e s t 4 6 a b ........................................... 177 F i g u r e C 3 2 T e n s i o n T e s t 4 6 b c ........................................... 177 F i g u r e C 3 3 T e n s i o n T e s t 4 6 c d ........................................... 178 F i g u r e C 3 4 T e n s i o n T e s t 4 6 d a ........................................... 178 F i g u r e C 3 5 T e n s i o n T e s t 4 7 a b ........................................... 179 F i g u r e C 3 6 T e n s i o n T e s t 4 7 b c ........................................... 179 F i g u r e C 3 7 T e n s i o n T e s t 4 7 c d ........................................... 180 F i g u r e C 3 8 T e n s i o n T e s t 4 7 d a ........................................... 180 F i g u r e C 3 9 T e n s i o n T e s t 4 8 a b ........................................... 181 F i g u r e C 4 0 T e n s i o n T e s t 4 8 b c ........................................... 181 F i g u r e C 4 1 T e n s i o n T e s t 4 8 c d ........................................... 182 F i g u r e C 4 2 T e n s i o n T e s t 4 8 d a ........................................... 182 F i g u r e C 4 3 T e n s i o n T e s t 4 9 a b ........................................... 183 Fig ure C.44 Te nsion Test 49bc ........................................... 183 F i g u r e C 4 5 T e n s i o n T e s t 4 9 c d ........................................... 184 F i g u r e C 4 6 T e n s i o n T e s t 4 9 d a ........................................... 184 F i g u r e C 4 7 T e n s i o n T e s t 5 0 a b ........................................... 185 F i g u r e C 4 8 T e n s i o n T e s t 5 0 b c ........................................... 185 F i g u r e C 4 9 T e n s i o n T e s t 5 0 c d ........................................... 186 F i g u r e C 5 0 T e n s i o n T e s t 5 0 d a ........................................... 186

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xv F i g u r e C 5 1 T e n s i o n T e s t 5 1 a b ........................................... 187 F i g u r e C 5 2 T e n s i o n T e s t 5 1 b c ........................................... 187 F i g u r e C 5 3 T e n s i o n T e s t 5 1 c d ........................................... 188 F i g u r e C 5 4 T e n s i o n T e s t 5 1 d a ........................................... 188 F i g u r e C 5 5 T e n s i o n T e s t 5 2 a b ........................................... 189 F i g u r e C 5 6 T e n s i o n T e s t 5 2 b c ........................................... 189 F i g u r e C 5 7 T e n s i o n T e s t 5 2 c d ........................................... 190 F i g u r e C 5 8 T e n s i o n T e s t 5 2 d a ........................................... 190 F i g u r e C 5 9 T e n s i o n T e s t 5 3 a b ........................................... 191 F i g u r e C 6 0 T e n s i o n T e s t 5 3 b c ........................................... 191 F i g u r e C 6 1 T e n s i o n T e s t 5 3 c d ........................................... 192 F i g u r e C 6 2 T e n s i o n T e s t 5 3 d a ........................................... 192 F i g u r e C 6 3 T e n s i o n T e s t 5 4 a b ........................................... 193 F i g u r e C 6 4 T e n s i o n T e s t 5 4 b c ........................................... 193 F i g u r e C 6 5 T e n s i o n T e s t 5 4 c d ........................................... 194 F i g u r e C 6 6 T e n s i o n T e s t 5 4 d a ........................................... 194 F i g u r e C 6 7 T e n s i o n T e s t 5 5 a b ........................................... 195 F i g u r e C 6 8 T e n s i o n T e s t 5 5 b c ........................................... 195 F i g u r e C 6 9 T e n s i o n T e s t 5 5 c d ........................................... 196 F i g u r e C 7 0 T e n s i o n T e s t 5 5 d a ........................................... 196 F i g u r e C 7 1 T e n s i o n T e s t 5 6 a b ........................................... 197 F i g u r e C 7 2 T e n s i o n T e s t 5 6 b c ........................................... 197

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x vi F i g u r e C 7 3 T e n s i o n T e s t 5 6 c d ........................................... 198 F i g u r e C 7 4 T e n s i o n T e s t 5 6 d a ........................................... 198 F i g u r e C 7 5 T e n s i o n T e s t 5 7 a b ........................................... 199 F i g u r e C 7 6 T e n s i o n T e s t 5 7 b c ........................................... 199 F i g u r e C 7 7 T e n s i o n T e s t 5 7 c d ........................................... 200 F i g u r e C 7 8 T e n s i o n T e s t 5 7 d a ........................................... 200 F i g u r e C 7 9 T e n s i o n T e s t 5 8 a b ........................................... 201 F i g u r e C 8 0 T e n s i o n T e s t 5 8 b c ........................................... 201 F i g u r e C 8 1 T e n s i o n T e s t 5 8 c d ........................................... 202 F i g u r e C 8 2 T e n s i o n T e s t 5 8 d a ........................................... 202 F i g u r e C 8 3 T e n s i o n T e s t 5 9 a b ........................................... 203 F i g u r e C 8 4 T e n s i o n T e s t 5 9 b c ........................................... 203 F i g u r e C 8 5 T e n s i o n T e s t 5 9 c d ........................................... 204 F i g u r e C 8 6 T e n s i o n T e s t 5 9 d a ........................................... 204 F i g u r e C 8 7 T e n s i o n T e s t C 1 ............................................ 205 F i g u r e C 8 8 T e n s i o n T e s t C 2 ............................................ 205 F i g u r e C 8 9 T e n s i o n T e s t C 3 ............................................. 206 F i g u r e C 9 0 T e n s i o n T e s t C 4 ............................................ 206 F i g u r e C 9 1 T e n s i o n T e s t C 5 ............................................. 207 F i g u r e C 9 2 T e n s i o n T e s t C 6 ............................................. 207 F i g u r e C 9 3 T e n s i o n T e s t C 7 ............................................ 208 F i g u r e C 9 4 T e n s i o n T e s t S 1 ............................................. 208

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xvii F i g u r e C 9 5 T e n s i o n T e s t S 2 ............................................ 209 F i g u r e C 9 6 T e n s i o n T e s t S 3 ............................................ 209 F i g u r e C 9 7 T e n s i o n T e s t S 4 ............................................. 210 F i g u r e C 9 8 T e n s i o n T e s t S 5 ............................................ 210 F i g u r e C 9 9 T e n s i o n T e s t S 6 ............................................ 211

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xviii Effec ts of C or r os ion on St e e l R e infor c e m e nt Da vid Ost r ofsky ABSTRACT Cor ro de d s te e l in c on c re te is a str uc tur a l is su e tha t pl a qu e s c on c re te str uc tur e s in coasta l reg ions. Traditionally corr oded stee l streng th is calculate d from a distributed a rea los s d ue to c or ro sio n o ve r t he e nti re su rf a c e of the ste e l a nd re du c ing the c a pa c ity acc ording ly I n rea lity corr osion attacks loca liz ed re g ions crea ting pits and re ducing the cross sec tion in a small reg ion which amplifies the e ffe cts of cor rosion. Stress conce ntrations at the cor rosion pitting damag e may further reduc e the te ns ile c a pa c ity of the ste e l. A stu dy of c or ro sio n d a ma g e a nd str e ng th a sso c ia te d w ith pitting damag e ca n assist in understanding the ultimate tensile ca pacity of cor roded stee l strands, better corr elations are neede d to estimate ac tual streng th of damag ed stee l. The foc us of this thesis is on s evenwire pr estress stee l strands with various stag es of induce d corr osion. Each stra nd has bee n documented, pr ofiled, and me asure d in order to corre late phy sical dama g e with ultimate capa city

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1 Chapter 1 Introduction 1.1 Overview I n this thesis we will ex plore the e ffe cts of cor rosion damag e and the structura l c a pa c ity of se ve n w ir e pr e str e ss s tr a nd s th a t ha ve be e n a ff e c te d b y c or ro sio n. Cor ro sio n is an ele ctroc hemical r eac tion, which require s a potential diffe renc e to cr eate an e le c tr oc he mic a l c e ll. I n c oa sta l r e g ion s c or ro sio n d a ma g e c a us e s se ve re da ma g e du e to the pre sents of excess chloride s, Fig ure 1.1 shows e x tensive dama g e to a br idge pile. F igure 1.1 Sever e Cor rosion Dam age

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2 Corrosion cause s billi ons of dollars a y ear in damag e, and is a threa t to the structural integ rity of a struc ture. Structure s in direct conta ct with salt water experience an acc eler ated r ate of corr osion due to the abunda nce of chlorides, c arbons, a nd ox y g en. Concrete structure s are reinfor ced w ith steel to provide additional streng th, this st eel corr odes and e x pands ca using c rac ks in the concr ete, whic h further acc eler ates the corr osion until eventua lly the conc rete spalls off or the structure fails. Reinforc ed concr ete is desig ned to fa il in tension allowing fa ilure modes to be g radua l and visible, but corrosion da mag e fa ilure ca n be sudden a nd dang erous. Steel is used to provide te ns ile str e ng th a nd is c ri tic a l to a str uc tur e s c a pa c ity Wh e n c or ro sio n o c c ur s it e ff e c ts the tensile streng th of the steel it attac ks and a me asure of the re maining c apac ity of co rr o d ed s t ee l i s n ee d ed t o b et t er an al y z e e x i s t i n g s t ru ct u re s I n co as t al re gi o n s b ri d ge piles are in direct c ontact with salt wate r and a re a ffe cted a dverse ly Tidal cy cles a nd wa ve s c a us e a re g ion of br idg e pil e s to be e xpos e d to sa ltw a te r b ut n ot c omp le te ly submerg ed, this are a is known as the spla sh zone, Fig ure 1.2 shows ty pical splash zone damag e.

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3 F igure 1.2 Typical “S plash Zone” C orrosion Dam age T h e s p l as h z o n e i s t y p i ca l l y t h e a re a a ff ec t ed m o s t b y co rr o s i o n v i s i b l e d am age i n cl u d es cr ac k s ru s t s t ai n s an d ev en s p al l i n g o f c o n cr et e. I n s p ec t i o n o f c o rr o s i o n d am age shows conce ntrated e ffe cts, wher e stee l damag e is localized and not eve nly distributed. Corrosion damag e ca n form into pits and eventua lly reduc es the stee l cross sec tion entirely When steel loss is concentra ted the ef fec ts on capa city is drastic, if cor rosion damag e is not addre ssed structura l failure is possible. As se ssi ng the str uc tur a l c a pa c ity of da ma g e d s tr uc tur e s a llo ws e ng ine e rs to a dd re ss safe ty conce rns and de sign r epair s to rehabilitate e x isting structure s. When determining the ef fec ts of corr osion mathematically Arrhe nius equation ca n predic t metal loss but the c a lc ula tio ns a ssu me c or ro sio n o c c ur s si mul ta ne ou sly on the e nti re su rf a c e a t th e sa me

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4 rate observa tions show concentr ated da mag e due to the va riations in local exposure co n d i t i o n s T h e f o cu s o f t h e e x p er i m en t at i o n i s t o an al y z e l o ca l i z ed co rr o s i o n d am age a nd the e ff e c ts i t ha s o n th e ult ima te c a pa c ity of re inf or c e d c on c re te str uc tur e s. 1.2 Scope of Proj ect Th e pu rp os e of thi s th e sis is t o d e te rm ine the str e ng th o f c or ro de d s te e l a nd to c or re la te the re su lts wi th m e a su re d d a ma g e to b e tte r p re dic t th e c a pa c ity of ste e l in e xistin g str uc tur e s. Spe c if ic a lly we wi ll p e rf or m te ns ion te st o n s e ve n w ir e pr e str e ss strands that have been c orrode d in a simulated environment. The simulated environment e xpos e d r e inf or c e d c on c re te to t ida l c on dit ion s c re a tin g a “ sp la sh zon e ” wh ic h is ty pic a lly the mos t da ma g e d a re a A ft e r t he str a nd s a re c or ro de d th e y a re re mov e d f ro m th e c on c re te piles, profiled, a nd tested for their tensile ca pacity When analy zing exist ing c orrosion, traditional methods use an ide alized model that assumes conditions that do not ex ist. Due to faulty equations and the inability to ext ensively examine the damag e, a sta tisti cal method of ana ly sis based on obser vable da ta is neede d. The a im is t o better c alculate the capa city of dama g ed stee l using e x perimenta l data conve y ed in a usa ble proba bility based fo rm a t. 1.3 Organization of the Re port The re port is org anized into seven cha pters, The first cha pter g ives a brie f over view, the sc op e of the pr oje c t, a nd a su mma ry of the or g a niza tio n. Cha pte r 2 pr ov ide s a backg round into corr osion, causes of corr osion, and industry examples. Chapter 3 discusses the spec imens history by explaining the simulated sce nario a nd the spec imens orig in. Chapter 4 explains the imag ing pr ocess whic h documents the samples to be tested.

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5 Cha pte r 5 dis c us se s th e the or y be hin d th e pr of ili ng of the c or ro de d s tr a nd s, the te st proce dure, a nd a summary of the re sults and trends. Chapter 6 disc usses the tension testing, the test proce dure, summar y of the tension test data and a summar y of the observe d trends. Chapter 7 g ives the experimental conc lusions, an overa ll summ ary of the data, a nd prac tical applica tions of the results of the testing

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6 Cha pt e r 2 C or r os ion Bac kgr ound 2.1 Corr osion i n Structures Cor ro sio n o f s te e l in c on c re te str uc tur e s c a n d a ma g e the str uc tur a l in te g ri ty a nd c a us e failure s. Marine e nvironments and the use of deicing salts in colder c limates cause s chloride induc ed cor rosion. Carbonation cor rosion is another mec hanism that can f urther deg rade the steel c ausing acc eler ated da mag e. The re a re multiple modes of c orrosion and t y p es o f c o rr o s i o n d am age C h l o ri d e i n d u ce d co rr o s i o n an d t h e a s s o ci at ed p i t t i n g d am age will be the foc us of the re sear ch. 2.1.1 Cost to Industry There is a signif icant cost a ssociated with cor rosion damag e and the repa irs and monitoring re quired to ensur e integ rity and saf ety Cost can be the de ciding fac tor in a structura l desig n, but considering the expected life span of a structure and the c ost of reha bilitating cor rosion damag e, initial cost to prevent c orrosion should be included. Tools for re pairing and ana ly zing cor rosion damag e ar e also ne eded to r educe cost of repa ir. A structura l eng ineer must be confident in the r epair s nece ssary to reha bilitate a structure When deciding to replac e or r epair damag ed structur al components, the confide nce in the integ rity of the struc ture is most important. Providi ng tools for interpre ting the c apac ity of dama g ed structur es and the possible viable re pairs ca n save the industry the cost assoc iated with excess re pairs and unne eded r eplac ement, this can

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7 a lso g ive a sta nd a rd fo r d e a lin g wi th r e ha bil ita tio n, Se e Ta ble 2. 1 f or c os t a sso c ia te d w ith corr osion. Tabl e 2.1 Cost of Corr osion to In dus try Reg ion / I ndustry Cost of Corrosion Refer ence Aircr aft I ndustry (North Ame rica ) $13 billion per y ear IA R Fly er, Sp ri ng 20 0 0 E d i t i o n, N R C I ns t i t ut e f or Aer ospace Rese ar ch (C a n a d a ). V S. Ag ar wa l a: "Cor r os i on D e te c tio n a n d M o n ito rin g A Rev i ew ", Pape r N o. 271, Cor r os i on 2000, N ACE I n t er n at i on al 2000. Aircr aft, Military (United States of Americ a) $ 3 billion per y ear V S. Ag ar wa l a: "Cor r os i on D e te c tio n a n d M o n ito rin g A Rev i ew ", Pape r N o. 271, Cor r os i on 2000, N ACE I n t er n at i on al 2000. Ai rc ra ft (l os t reve nue whe n g rounded for c orrosion ma int e na nc e /r e pa ir s) $100,000 per da y IA R Fly er, Sp ri ng 20 0 0 E d i t i o n, N R C I ns t i t ut e f or Aer ospace Rese ar ch (C anad a). A ir F o rc e a n d N a v y A u stra lia >$ 50 mi l l i on per y ear W eb s i t e o f D ef ense Sci ence and Te c h n o l o g y Or g a n i z a t i o n ( DS TO, A us t r al i a) A r m y US $1 0 bi l l i on per y ear ( es t i mat e) M Y ou s on : "I n v i s i bl e Ene my ", Eng i n ee r i n g Se pt embe r 2003. A r m y US $2 bi l l i on per y ear r el at ed t o pai nt i ng an d pai nt r emo val ( es t i mat e) M Y ou s on : "I n v i s i bl e Ene my ", Eng i n ee r i n g Se pt embe r 2003. Au t om ob i l e s ( U SA ) $ 2 3 .4 b i l l i o n p er yea r co st t o Amer i ca n c on s u mer s du e t o: i nc rea sed m an ufac t uring c o st s, r epai r s an d m ai nt ena nce deprec i at i on. ( C ost s of r educe d s af et y n ot i n cl u ded) w w w c or r os i on c os t c om Corr osi on Costs and Prev enti ve St ra te gi es in the Unite d State s Rep or t by CC Technol og ie s L abor at or ie s, I nc. t o F edera l Highway A d m in istration (FHW A ), Of f ice of I n f rastru ctu re Re s e a r c h a nd De v e l o pme nt Re po r t F HWARD01156, Se pt ember 2001.

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8 Tabl e 2. 1 ( Co nt inue d) Reg ion / I ndustry Cost of Corrosion Refer ence B ri dg e s ( USA Hi g hw a y B ri dg e s) $30 billion (1999 do lla rs ) t o r e me dia te corr osion-induced structura l deficie ncies Materia ls Performanc e, Marc h 2002, p.31. Coast Guard, U nited States, Aircr aft $20 milli on per y ear L e e An n T e g tme ie r: U. S. Coast Guard Tr eads in De ep Wat e r" O ve rh a ul & Maintenanc e Mag azine (May 1, 2002). Eiffe l Tower ( Paris) 1989 r ef u r bi s h men t c os t s of 200 mi l l i on FF. Abou t 5060 to n s o f p a int a re a p p lied e v e ry 7 y ear s by s om e 25 pai nt er s as c or r os i on pr ot e c t i on f or t h e > 7 t hous and t on s t eel s t r uct ur e. Cor r os i on da mag e i s a ma j or cons i dera t i on i n t he mai nt ena nce / refurb i shm en t req uirem en t s. A rtic le s b y A R o ith, U n ive rs ity B ay r eu t h a n d M M ar t i n I ZA p ub l i shed at www.uni b ayr eut h. d e and ww w. i za com G as P i p el i ne Indust ry ( N ort h Ameri ca) $80 milli on per y ear pu rc ha se d in c oa tin g s to coat ne w pipelines and rec oat exist ing pipe lines (1993 re fer ence ). P C avass i and M C o rnago: T he C ost of Co r r osi on i n t he O i l an d G as I n du s t r y ", J PC L, M ay 1999, pp3040. (B a c k g ro u n d S e c tio n o n p .3 4 w ith a d d iti o n a l re fer e n c e s.) H e l i c op t e r s US Ar my ( 19 98 es t i mat e) $ 4 bi l l i on s pen t on corr osi on r epai r s ( es t i mat e) M T T C N ews V ol ume 8, I s s ue 9 (A u g u st 1 9 2 0 0 3 ), u n d e r a rtic le "Cor r os i on c os t s e at u p D O D bu dg et ". M i l i t ar y U SA mo r e t han $ 20 bi l l i on per y e a r ( a s r e p o r t e d b y GA O) M T T C N ews V ol ume 8, I s s ue 9 (A u g u st 1 9 2 0 0 3 ), u n d e r a rtic le "Cor r os i on c os t s e at u p D O D bu dg et ". N a v y USA A r ound 25 % of t ot al f l eet mai nt ena nce budget ( es t i mat e) s pen t on c or r os i on pr ev en t i on an d c on t r ol U ni t ed St at es G ene r al A c c o u n t i n g Of f i c e R e p o r t No GA O03753, 2003.

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9 Tabl e 2.1 (C ontinu ed ) Reg ion / I ndustry Cost of Corrosion Refer ence Power G en er at i on ( U SA ) $5 billion $10 bil lion a nn ua lly fo r t he U. S. elec tric powe r industry (E PRI e sti ma te ). I n s te a me le c tr ic g e ne ra tin g pla nts corr osion costs ex cee ded 10 % o f t ota l po we r c os t. Up to 50% of outag es attributable to cor rosion. InT ech M agazine O nl i ne pu bl i s h ed at w ww i s a. or g O ct ober 1, 1998. R oads S i de w a l k s Br i dg es T oront o (Cana da) $ 1 1 0 m i l l i o n i s t o be s p ent by t h i s c i t y on t h e r epa i r of ro a d s, sid e w a lks a n d b rid g e s in 2005 . w i t h a ba ck l og of $235 mi l l i on def er r ed due t o budget co nstraint s. K M cG r an' s ar t i cl e "O n t he r oad t o r u i n ?", T or on t o St ar Fe br u ar y 5, 2005, pB 4B 5. Stat ue o f Li b ert y (U SA ) > $200 mi l l i on r es t or at i on p ro je c t (1 9 8 6 ), la rg e ly n ec es s i t at ed du e t o c or r os i on dam age wi t h s i gn i f i can t i nt er nal gal van i c c orr osi on damage. B aboi an R. e t a l : "T h e St at u e of Li be r t y Re s t or a t i on ", NACE I n t er n at i on al H ou s t on 1990. U n i t ed St at es of A meri ca Approxim ately $300 billion per y ear for metallic cor rosion (about 4% of GN P or >$1000 per person) More than one third of costs consider ed avoidable using exis ting k n o w h o w a n d t e c h n o l o g y. B at el l e n ew s r el ea s e, 1996.

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10 2.2 Causes of Corrosion Ma ny fa c tor s c a n c on tr ibu te to a c or ro siv e e nv ir on me nt. Re inf or c e d c on c re te is a common structura l element in which the c ompositi on of the c oncre te and the e x posure of the eleme nts are ma jor fac tors in the steels environme nt and susceptibility to corrosion. Th e pe rm e a bil ity of c on c re te is d ir e c tly re la te d to the tim e it t a ke s f or e xter na l f a c tor s to penetr ate the c oncre te cove r and a ffe ct the stee l. I n coasta l reg ions chlorides infiltrate the c on c re te a nd c a us e c or ro sio n d a ma g e tha t de bil ita te s st ru c tur e s. Pitt ing c or ro sio n is a mode wher e a bulk of the surfa ce r emains undama g ed and the corr osion is concentra ted causing a loca l loss of steel cross sec tion. Pi tting fa ilures occ ur unexpectedly and ar e us ua lly hid de n ma kin g a da ng e ro us fa ilu re mod e O nc e the ste e l ha s b e g un to c or ro de it expands and ca uses cr acks in the c oncre te. This can c ause the concr ete to spall off leaving the steel e x posed, which le aves the steel vulnera ble to continued cor rosion. Once the steel is exposed the corr osion rate incr ease s exponentially and risk of f ailure of the damag ed compone nt drastically incre ases. 2. 2. 1 C he m ic al P r oc e ss Corrosion is an elec troche mical re action, whe re a curr ent of e lectrons f low betwee n a potential differ ence causing a dete rioration of the atomic structure of the stee l. Metal atoms lose elec trons and bec ome ions. Galvanic corr osion is a model based on dissimilar me ta ls t ha t a re c on ne c te d e le c tr ic a lly a nd e xpos e d to a n e le c tr oly te I n r e inf or c e d c on c re te the potential diffe renc e is prese nt due to varia tions in environmental conditions, and the concr ete is the e lectroly te medium. The stee l reinfor ceme nt is a path for the elec troche mical re action that occ urs betwe en the potential diff ere nces in the c oncre te. The

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11 hy dration re action in conc rete cause s the pore solution to be an a lkaline. I n this condition the steel tends to be in a passive state a nd corr osion is neglig ible, but due to the porous na tur e of c on c re te c or ro siv e e le me nts c a n b e int ro du c e d to the e nv ir on me nt a nd c a us e corr osion. Chloride induced cor rosion and ca rbonation ar e two mec hanism of cor rosion tha t a re a re su lt o f e xter na l f a c tor s, re inf or c e d c on c re te str uc tur e s in ma ri ne e nv ir on me nts are prone to both of these mecha nisms of corrosion, for a diag ram of the corr osion proce ss in reinforc ed conc rete see F igur e 2.1. 2.3 Quan tifyin g Corr osion Damage Assessment of the e x tent of cor rosion damag e ca n be a dif ficult proce ss, embedded pr ob e s c a n a ssi st i n mo nit or ing bu t r e qu ir e a n e xten siv e ne tw or k o f p ro be s f or a c c ur a te monitoring. Visual sig ns are prese nt throug hout the differ ent stag es of the c orrosion proce ss, in reinforc ed conc rete cra cks and r ust stains are the initial sig ns of cor rosion damag e and c an indicate the seve rity of the c orrosion, see Fig ure 2.2 f or an e x ample of rust stains on concr ete. Scientific models convey the elec troche mical re action that take s pla c e du ri ng the c or ro sio n p ro c e ss b ut c a lc ula tio ns a ssu me a n e ve nly dis tr ibu te d e ff e c t, wh ic h is no t th e ob se rv e d e ff e c t. T he su rf a c e a re a s a nd c on dit ion s o f t he e le me nts involved in the corr osion reac tion are r equire d to predict loca l ga lvanic cur rent flow, e mpi ri c a l mo de ls a re no t a ble to p re dic t lo c a l c ur re nt f low fo r p itt ing da ma g e in reinfor ced c oncre te bec ause the irreg ularities in the conc rete make the c onditions unmeasura ble. To better quantify the af fec t of corr oded stee l, an inspection base d method is neede d wher e site spec ific conditions and loca liz ed dama g ed ca n be conside red a nd visual evidenc e collec ted. Ther e ar e some tools available to quantify damag e using visual

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12 inspections but there is a ne ed for a more acc urate method of asse ssing c apac ity for damag ed re inforce d concr ete. Ty pical cor rosion damag e is localized and e mpirical calc ulations have diff iculty predic ting a ctual loca liz ed stee l loss. A statist ical method of d et er m i n i n g an ap p ro x i m at e c ap ac i t y o f d am age d co m p o n en t s b y ca l cu l at i n g an av er age amount of loca l critical stee l loss, which considers the pr obability and seve rity of pitting damag e for the conditions prese nt and ac counts for the number of stra nds that are damag ed, with a g iven amount of visual evide nce, c an be a power ful tool in estimating the ca pacity of dama g ed structur es. 2.3.1 Insp ect ing an d Monitoring Corrosion Dam age Modern struc tures ca n be conf igur ed with probe s and sensors tha t can indica te the status of key elements. I nspections and sc heduled monitoring for c orrosion ca n extend the service life of struc tures throug h maintenanc e and timely repa irs. Risk based inspections consider the likelihood of failure and the c onsequenc e of f ailure, this identifies the sever ity of the proble m and the urg ency of the situation. Corrosion can be monitored by extensive sy stem of embedde d probes a nd can be inh ibi te d b y a nu mbe r o f p re ve nti ve sy ste ms. Du e to t he e xten siv e c os t in vo lve d w ith corr osion damag e, monitoring the status of structura l elements is becoming a nec essar y step in preve nting c ritical dama g e. Monitoring allows for a timely repa ir which c an sig nif ic a ntl y re du c e the c os t of c or ro sio n mi tig a tio n. Ev a lua tin g re inf or c e d c on c re te prese nts inherent issues, direc t inspection of the stee l is not poss ible unless spalling ha s occur red, w hich limits the ability to conduct a c omplete inspection. Concre te does not ac t as a homog eneous me dian for the corr osion process, this makes zones that may be prone

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13 to l oc a lize d d a ma g e Cr a c ks a re a n in dic a tio n o f c or ro sio n d a ma g e bu t c a n b e dif fi c ult to interpre t with out the presenc e of r ust or other sig ns of cor rosion. An elec tro potential differ ence can be measure d with sophisti cate d equipment, showing zones where corr osion will occur. Core samples ca n be extracte d to measure car bonation penetr ation which shows the per meability of conc rete and the stag e of c arbona tion. Chl oride c oncentr ations due to environme nt or local e x posure c an indicate zones that are vulne rable to corrosion. Pr e ve nti ng e xten siv e c or ro sio n d a ma g e by re pa ir ing the c or ro sio n d a ma g e in a tim e ly manner can g rea tly reduc e the c ost of reha bilitation and ex tend the ser vice life of a structure Scheduled inspec tions are c ritical for proper maintenanc e of struc tures whe n safe ty and the se rvice life of the struc ture a re ke y objectives. 2.3.2 P reve nting Corrosion Dam age Preventing corr osion should be initi ated in the de sign stag e, the use of the prope r materia ls can e x tend servic e life c onsiderably There are many solutions for preve nting corr osion and ea ch sce nario c an have a unique solution. The use of sacr ificial anode s can control the mode of corr osion and provide a solution for easier maintenanc e by providing an ea sily chang eable element, F igur e 2.3 shows a ty pical sac rificial a node. I n some ca ses sacr ificial anode s are embedde d and desig ned to last the ser vice life of the struc ture. Probes ca n be installed to monitor the state of the inter nal structure providing a tool that c a n in dic a te zon e s th a t a re e xpe ri e nc ing a po ssi ble c or ro sio n r e a c tio n. Th e a bil ity to m o n i t o r c o rr o s i o n al l o ws fo r e ar l y d et ec t i o n wh i ch ca n p re v en t ex t en s i v e d am age t h ro u gh intervention in the ea rly stag es. I nduced c urre nt can be used to control the elec troche mical re action of c orrosion. I nduced c urre nt acts as a rene wable a node which

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14 preve nts the corr osion reac tion from occur ring by providing a strea m of elec trons into the str uc tur e T he re a re ma ny fo rm s o f c or ro sio n mi tig a tio n, us ing pr e ve nti ve me tho ds to control cor rosion can be very expensive. Repairs ar e also c ostly and the c ost rises e xpon e nti a lly wi th t he e xten t of c or ro sio n. Ul tim a te ly pr e ve nti ng c or ro sio n c a n b e le ss expensive then repa irs over a n extended life span, a nd is for nec essar y to ensure the service life and sa fety of the struc ture.

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15 F igure 2.1 Corr osion i n Reinf orce d Concret e

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16 F igure 2.2 Rust Stains Fr om Corr osion Damage

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17 F igu r e 2. 3 Sa c r ific ial Ano de

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18 Chapter 3 Specim en History 3. 1 Ex pe r im e nt al S c e nar io Cor ro sio n o f s te e l in c on c re te str uc tur e s c a n d a ma g e the str uc tur a l in te g ri ty a nd c a us e failure s. Marine e nvironments and the use of deicing salts in colder c limates cause s chloride induc ed cor rosion. Carbonation cor rosion is another mec hanism that can de g rade the steel. Oc ean br idge piers experienc e extensive corr osion damag e and r epair s are routine. Simulating the c ondition of piles ex posed to oce an salt wa ter c an provide insight into the corrosion that oc curs a nd the damag e done to the ste el in the piles. 3. 2 Ov e r vie w of Sim ula te d Se tu p To simulate bridg e pier s in a marine e nvironment, twenty -two individual five foot long squa re piles we re c ast with four seve n-wire prestre ss strands in eac h pile. The piles wer e exposed to simulated tides to crea te a splash zone, which is ty pical for the environment e mulated. The w ater had a 3.5% salt content and the water level wa s chang ed eve ry six hours to simulate ocea n exposure. After 1,160 day s the piles wer e remove d from the tanks a nd the strands we re r emoved a nd weig hed to provide g ravimetric data. Ea ch piled wa s cut with an ele ctric sa w then the c oncre te was c hipped awa y Three fee t of the strands we re c ut away from the tar g et zoned clea ned and measure d.

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19 3. 3 Ob se r ve d Co r r os ion The piles display ed cr acks a nd rust stains in the splash zone, which is ty pical in the corr osion mode simulated. At around 300 da y s, cra cks appe are d and cor rosion stains fo rm e d a ro un d th e c ra c ks So me of pil e s w e re wr a pp e d w ith F RP ( fi be r r e sin po ly me rs ) to protect a g ainst corr osion providing a rang e of c orrosion dama g e to ana ly ze. Additional information conc erning the re sults of the FRP testing ha ve also be en docume nted [1] 3. 4 Sum m ar y o f Tr e nds The stra nds were car efully remove d from the piles a nd clea ned, ea ch strand w as weig hed and numbe red f or later proce ssing. Cra ck loca tion were monitored and re corde d t o c o r r e l a t e c r a c k d a m a g e w i t h w e i g h t l o s s a n d c a p a c i t y. F igure 3.1 Strand and Sid e Nom enclature

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20 Tabl e 3.1 Sam ple of Crac k Su rvey [ 1] N a me M ax. C racks A B CD O u t door C o n tro ls #38 W id th ( mm) No 0 .4 0 .7 5 0 .4 L e n g th (in .) 3 26 20 #44 W id th ( mm) 0. 75 0. 75 0. 3 0. 25 L e n g th (in .) 20. 5 20. 5 6. 5 17 #45 W id th ( mm) No 0 .4 0 .3 0 .5 L e n g th (in .) 9 17 18 #46 W id th ( mm) 0 .2 0 .2 0 .3 0 .2 L e n g th (in .) 6. 5 11. 5 16. 5 10 I n door C o n tro ls #39 W id th ( mm) No No 0 .5 0 .2 L e n g th (in .) 35 11 #49 W id th ( mm) No 0 .4 No 0 .4 L e n g th (in .) 18. 5 14

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21 F igure 3.2 Crac k Pat ter n: L) 39, R) 49 [1]

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22 F igure 3.3 Crac k Pat ter n: A) 38, B) 44, C) 45, D) 46 [1]

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23 Tabl e 3.2 G ravim etr ic Test Re sults of Controls [1] Speci men St r an d / T ie (F ig. 6 38) B re a k in Str and W i re O ri gi nal W ei ght (g) Lo st W ei ght (g) P ercent L o ss #38 O u t door A B 0 1 6 8 .8 7 .4 4 .4 B C 3 1 6 8 .8 1 7 .5 1 0 .4 C D 0 1 6 8 .8 1 0 5 .9 D A 0 1 6 8 .8 7 .9 4 .7 tie 1 3 3 2 .3 3 8 .9 1 1 .7 #44 O u t door A B 0 1 6 8 .8 8 .3 4 .9 B C 0 1 6 8 .8 1 6 .4 9 .7 C D 0 1 6 8 .8 1 1 .4 6 .8 D A 3 1 6 8 .8 1 5 .4 9 .1 tie 2 3 3 2 .3 3 2 .7 9 .8 #45 O u t door A B 0 1 6 8 .8 6 .2 3 .7 B C 2 1 6 8 .8 8 .9 5 .3 C D 4 + 1 1 6 8 .8 1 9 .8 1 1 .7 D A 0 1 6 8 .8 8 .1 4 .8 tie 1 3 3 2 .3 3 2 .2 9 .7 #46 O u t door A B 0 1 6 8 .8 9 .8 5 .8 B C 0 1 6 8 .8 8 .2 4 .9 C D 0 1 6 8 .8 1 4 .5 8 .6 D A 0 1 6 8 .8 7 .3 4 .3 tie 2 3 3 2 .3 3 0 .1 9 .1 #39 I n door A B 0 1 6 8 .8 7 .1 4 .2 B C 0 1 6 8 .8 8 .3 4 .9 C D 6 1 6 8 .8 2 1 .2 1 2 .6 D A 0 1 6 8 .8 7 .2 4 .3 tie 2 3 3 2 .3 3 3 .1 1 0 .0 #49 I n door A B 0 1 6 8 .8 8 .8 5 .2 B C 1 1 6 8 .8 1 4 .3 8 .5 C D 0 1 6 8 .8 8 .6 5 .1 D A 1 1 6 8 .8 1 3 .2 7 .8 tie 1 3 3 2 .3 2 6 .2 7 .9 N o t e: W here t he cent ral wi re i n a 7-wi re s t rand wa s b roken, i t i s repo rt ed i n t he f o rm a+ 1 wh ere a signif i es the n um b er o f o t he r wires b ro ke n. A l l such b rea ks occur r ed i n t he mi dd l e r egi on of t he s peci men

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24 Tabl e 3.3 G ravim etr ic Test Re sults of CF RP Wrapped Sp ecim ens [1] N o of Lay er s Speci men S tra n d / T ie ( Fi g 6. 38) B re a k in Str and W i re O r i gi nal W ei ght (g) Lo st W ei ght (g) P ercent L o ss 1 #54 A B 0 1 6 8 .8 6 .1 3 .6 B C 0 1 6 8 .8 6 .2 3 .7 C D 0 1 6 8 .8 5 .6 3 .3 D A 0 1 6 8 .8 4 .9 2 .9 T ie 0 3 3 2 .3 2 2 .6 6 .8 #58 A B 0 1 6 8 .8 4 .4 2 .6 B C 0 1 6 8 .8 7 .4 4 .4 C D 0 1 6 8 .8 6 .4 3 .8 D A 0 1 6 8 .8 6 .2 3 .7 T ie 0 3 3 2 .3 2 4 .4 7 .3 2 #55 A B 1 1 6 8 .8 5 .6 3 .3 B C 0 1 6 8 .8 5 .8 3 .4 C D 0 1 6 8 .8 4 .8 2 .8 D A 0 1 6 8 .8 4 .7 2 .8 T ie 0 3 3 2 .3 2 0 .3 6 .1 #42 A B 0 1 6 8 .8 4 .7 2 .8 B C 0 1 6 8 .8 5 .5 3 .3 C D 0 1 6 8 .8 5 .6 3 .3 D A 0 1 6 8 .8 5 .4 3 .2 tie 0 3 3 2 .3 1 7 .3 5 .2 3 #56 A B 0 1 6 8 .8 5 .3 3 .1 B C 0 1 6 8 .8 5 .1 3 .0 C D 0 1 6 8 .8 6 .7 4 .0 D A 0 1 6 8 .8 5 .5 3 .3 tie 0 3 3 2 .3 2 2 .2 6 .7 #59 A B 0 1 6 8 .8 7 .3 4 .3 B C 0 1 6 8 .8 5 .5 3 .3 C D 0 1 6 8 .8 5 .2 3 .1 D A 0 1 6 8 .8 5 .8 3 .4 tie 0 3 3 2 .3 2 3 .6 7 .1 4 #57 A B 0 1 6 8 .8 5 .1 3 .0 B C 0 1 6 8 .8 5 .4 3 .2 C D 0 1 6 8 .8 5 .9 3 .5 D A 0 1 6 8 .8 6 .7 4 .0 tie 0 3 3 2 .3 2 5 .5 7 .7 #43 A B 0 1 6 8 .8 5 .3 3 .1 B C 0 1 6 8 .8 5 .2 3 .1 C D 0 1 6 8 .8 6 3 .6 D A 0 1 6 8 .8 5 3 .0 tie 0 3 3 2 .3 2 0 .2 6 .1

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25 Tabl e 3. 4 G r av im e tr ic Te st Re sult s o f G F RP Wr appe d Spe c im e ns [1] Lay er Speci men S tra n d /T ie Fi g 6. 38 B reak i n Str and W i re O r i gi nal W ei ght (g) L o st W ei ght (g) P ercent L o ss 1 #48 A B 0 1 6 8 .8 5 .7 3 .4 B C 0 1 6 8 .8 6 .5 3 .9 C D 0 1 6 8 .8 6 3 .6 D A 0 1 6 8 .8 5 .4 3 .2 T ie 0 3 3 2 .3 2 1 .3 6 .4 #52 A B 0 1 6 8 .8 6 .5 3 .9 B C 0 1 6 8 .8 6 .5 3 .9 C D 0 1 6 8 .8 5 .5 3 .3 D A 0 1 6 8 .8 5 .9 3 .5 T ie 0 3 3 2 .3 2 2 .9 6 .9 2 #47 A B 0 1 6 8 .8 5 .2 3 .1 B C 0 1 6 8 .8 6 .1 3 .6 C D 0 1 6 8 .8 6 .2 3 .7 D A 0 1 6 8 .8 5 .2 3 .1 T ie 0 3 3 2 .3 2 0 .1 6 .0 #40 A B 0 1 6 8 .8 5 .1 3 .0 B C 0 1 6 8 .8 5 .7 3 .4 C D 0 1 6 8 .8 6 3 .6 D A 0 1 6 8 .8 5 .2 3 .1 T ie 0 3 3 2 .3 2 0 .9 6 .3 3 #50 A B 0 1 6 8 .8 6 .2 3 .7 B C 0 1 6 8 .8 6 .3 3 .7 C D 0 1 6 8 .8 6 .6 3 .9 D A 0 1 6 8 .8 5 .9 3 .5 T ie 0 3 3 2 .3 2 1 .2 6 .4 #53 A B 0 1 6 8 .8 6 .2 3 .7 B C 0 1 6 8 .8 5 .8 3 .4 C D 0 1 6 8 .8 4 .9 2 .9 D A 0 1 6 8 .8 5 .3 3 .1 T ie 0 3 3 2 .3 1 8 .1 5 .4 4 #51 A B 0 1 6 8 .8 6 3 .6 B C 0 1 6 8 .8 6 .3 3 .7 C D 0 1 6 8 .8 6 .6 3 .9 D A 0 1 6 8 .8 5 .9 3 .5 T ie 0 3 3 2 .3 2 1 .2 6 .4 #41 A B 0 1 6 8 .8 4 .9 2 .9 B C 0 1 6 8 .8 4 .7 2 .8 C D 0 1 6 8 .8 6 .3 3 .7 D A 0 1 6 8 .8 4 .5 2 .7 T ie 0 3 3 2 .3 2 1 .9 6 .6

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26 F igure 3.4 Sim ulated En vironm ent SetUp [1] F igure 3.5 Sim ulated En vironm ent Ne twork of Sensors [1]

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27 F igure 3.6 Tidal Schedul e and Pum ps [1] F igure 3.7 Initial Rus t Stains in Spl ash Zone [1]

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28 F igure 3.8 Rem oval of P iles F rom Simulated Environme nt [1]

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29 F igure 3.9 Corr osion Damage : 38c, 39c d, 44d, 46d [1]

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30 F igure 3.10 Corr osion Damage : 53a, 58c, 42d, 48b [1]

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31 F igure 3.11 Rem oval of Concre te C over [ 1] F igure 3.12 Exposed Pile Cor e [1]

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32 Cha pt e r 4 I m ag ing P r oc e ss 4. 1 I m ag ing I n order to document the phy sical dama g e, the stee l strands wer e photog raphe d using a came ra integ rate d into a microscope The g oal of imag ing the steel is to document the extent of corr osion and to corr elate the failure mode with the ty pe of c orrosion and extent of corrosion. 4.1.1 P roce dure To photog raph the damag e in an or g anized way the strands whe re imag ed using the following proce dure. F irst, the strands ar e mar ked at the e nd that was identified a s the bottom. The mark is place d on a sing le exterior strand to indicate side one. The steel su rf a c e wa s d ivi de d in to t hr e e sid e s in or de r t o im a g e the e nti re su rf a c e of the sp e c ime ns Once indicating the sides, a mid zone of intere st was deter mined throug h visual inspection and the mid zone was mea sured a nd marke d with permane nt marker Pictures are taken with the white dot to the lef t and starting with side one, then the w hite dot was rotated 120 de g ree s clockwise to photog raph side 2, a nd ag ain for side 3, making a total of three sides. Optimum locations were individually captur ed to ensure place s of conc ern we re do c ume nte d. I ma g e s w e re ma g nif ie d f or c la ri ty a nd e a c h p ic tur e c a ptu re d a le ng th of a pp ro xima te ly a ha lf inc h a nd the fu ll w idt h o f t he str a nd s. I ma g e Pr o w a s u se d to

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33 captur e the pictur e and the proce ss was controlled thr oug h the softwar e and ope rate d using a windows based c omputer. 4.1.2 Docum entation of Damage I n the proc ess of imag ing the strands, notes we re a lso taken to provide a dditional rec ords that ca n help classify the strands to later compar e with fa ilure modes. The extent of surfa ce c orrosion, pitting da mag e, and pitting fre quency was a lso recor ded. The loc a tio ns a nd the size of the pit s w ill be us e fu l da ta in c or re la tin g the fa ilu re mod e s w ith the ph y sic a l da ma g e I n a dd iti on to p hy sic a l de sc ri pti on s, g e ne ra l no te s w e re a lso rec orded. 4. 2 I m ag ing Obse r va ti ons The stra nds display ed var ious stage s of cor rosion and collec tively exhibi ted the initial st ag es of surf ace corr osion through e x treme pits that could dra stically reduc e tensile ca pacity to strands that had be en complete ly deter iorated. Pitting da mag e wa s the most common form of damag e obser ved, some a rea s showed conc entra ted damag e and o t h er s s h o we d a m o re d i s t ri b u t ed d am age co v er i n g v ar i o u s l en gt h s S i n ce p i t t i n g d am age is l oc a lize d th e ste e l c a pa c ity c a n b e sig nif ic a ntl y re du c e d w ith a sma ll p e rc e nt o f o ve ra ll steel loss. The extent of the pitting da mag e and the various modes of c orrosion will vary the expected tensile c apac ity and will be re flec ted in the tensile testing results. 4.2.1 Condition of S tee l Di str ibu te d c or ro sio n d a ma g e in r e inf or c e d c on c re te c a us e s sp a lli ng of c on c re te beca use of the e x pansion of the stee l corrosion produc t, in the proce ss of spalling the concr ete c rac ks and the a rea around the cra cks may be stained showing the initial signs of

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34 damag e. I nitial corrosion beg ins as surfa ce oxidation and is a passive for m of corr osion that occur s from exposure to ox y g en. The next obs erve d corr osion stage occur s when the steel is in the concr ete. the c orrosion af fec ts a g ener al ar ea a nd rese mbles scaling Once the sca ling ha s initi ated, loca l conditions are pr one to pitting and de pending on the local e nv ir on me nt t he pit s c a n v a ry in s ize E xtre me pit tin g wi ll e ve ntu a lly de te ri or a te the c ro ss se c tio n a nd se ve r t he ste e l st ra nd s. 4. 2. 2 Sum m ar y o f Tr e nds The c ondition of the steel var ied from ne g ligible da mag e to the seve ring of strands. I nitial scaling cover ed var ious area s from loca liz ed to the majority of the specimen. The observe d data ha s been summar ized into t hree cate g ories to help quantify the observa ble data. T he surf ace corr osion indicates the per cent of the surfa ce tha t has experience d corr osion damag e. Pitting damag e re fer s to the siz e of pits observe d, pitting fre quency indicates how ma ny of the pits are prese nt. See Appendix A for sample imag es of c ri tic a l c or ro sio n d a ma g e d oc ume nte d to c or re la te wi th t he te ns ion te sti ng re su lts descr iptive notes, and the obser ved pitting da mag e for eac h bar. Ta ble 4.1 list the para meters use d to classify the strands, see Fig ures 4.14.8 for pictur es of the imag ing proce ss and samples of pitting damag e. See A ppendix A for strand cla ssification and imag es.

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35 Tabl e 4. 1 Ob se r ve d Da m ag e Sc ale Sur f ace Cor r osi on Li ght t o no ne 030% M edi um t o l i ght 3060% H eav y t o m edi um >60% Pi t t i ng Dam age S m a l l p i ts < 1 / 8" M e d i u m p i ts 1/ 4" 1/ 8" L a rg e p i ts >1/ 4" Pi t t i ng Fr equen cy Li ght t o no ne 0 t o 5 M edi um t o l i ght 6 t o 15 H eav y t o m edi um >15

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36 F igure 4.1 Micr oscope Integr ated Into Cam era

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37 F igu r e 4. 2 Spe c im e n Lig ht ing Co nfigur at ion

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38 F igure 4.3 Im age Capture Are a

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39 F igure 4.4 Triangul ar Chuck Secured to Bar

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40 F igure 4.5 Im age P roce ssing S tation

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41 F igure 4.6 Im aging S oftw are Inte rface

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42 F igure 4.7 Im age of Pit ting Dam age to M ultip le Wires

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43 F igure 4.8 Im age of Pit ting Dam age Sever ing Wire

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44 Chapter 5 Strand P rofiler 5.1 Theory I n order to profile the stra nds and estimate the c ross sectional a rea along the le ng th o f t he ba rs s imp le fl uid me c ha nic s w a s a pp lie d. Us ing Pa sc a l’ s L a w, fl uid pr e ssu re is d ir e c tly re la te d to de pth ; The hy drostatic pre ssure: P = ( *h (Eq. 5.1) P = hy drostatic pre ssure (psf ) ( = fluid density (#/ft^3) h = he ig ht o f f lui d a bo ve (f t) An open sy stem of a homog eneous f luid will have uniform surfa ce he ight a t equilibrium. Using these basic c oncepts a method for mea suring the strands c ross section can be develope d. A sy stem of valves c onnecting two g lass tubes are used to cre ate a c on tin uo us c on du it. Ea c h g la ss t ub e ha s a pie zome te r a t th e ba se to m e a su re the fl uid pressure One tube is e levated a nd filled with fluid, the second tube of the same diameter has a stee l specimen plac ed in it. Once a valve is opene d the fluid from the uppe r tube beg ins to fill t he lower tube to rea ch equilibrium. The pr essure measure ments are made a t a ra te of ten times a se cond at e ach tube the data is c onverte d to chang e in fluid heig ht for e ach c olumn. Si nce the g lass tubes are the same dia meter, the differ ence in heig ht chang e of f luid in the tubes is due to the volume of steel pre sent in the lower tube Using

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45 the ba sic pr inc ipl e of vo lum e tr ic fl ow the c ha ng e in f lui d v olu me in t he up pe r t ub e is equal to the c hang e in volume of the lowe r tube; Volume Flow ( from upper tube) = Volume Flow ( into lower tube) ( Eq. 5.2) h1 *A 1 = h2 *A 1 h2 *A s h1 = fluid heig ht chang e at uppe r tube (in) A1 = tube c ross sectional a rea (in^2) h2 = fluid heig ht chang e at lowe r tube (in) As = a vera g e stee l cross sec tional are a (in^2) Using the cha ng es in heig hts and the known tube a rea the steel a rea for the loc al re g ion c a n b e c a lc ula te d. Th e sma lle r t he c ha ng e in h e ig ht t he c los e r t he a ve ra g e c ro ss section re prese nts the actua l cross sec tion of steel. 5. 2 P r ofil e r Se tu p The prof iler wa s set up using two ide ntical g lass tubes that are eac h a half inch inner diame ter c onnecte d by a ser ies of two valve s and coppe r tubing The fir st valve from the uppe r tube c ontrolled the flow r ate a nd the sec ond valve is used to start a nd end the flow. The piezometers wer e installed inline at the ba se of e ach tube at the coppe r tub ing a nd c on ne c te d to a Op tim Me g a Da c tha t pr oc e sse d th e da ta ta kin g me a su re me nts ten times a sec ond. Test Control Software w as used to interf ace with the Meg a Da c and start the test. The g lass tubes wer e cla mped to a stee l frame with measuring tape a ttached to take ca librating measure ments. Ace tone was the fluid used for the liquid medium after testing the possible fluids choices. Ac etone ha s low viscosity and low surf ace tension which make s it a fluid with desirable pr operties f or the prof iling proc ess.

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46 5.3 P roce dure Th e pr of ile r i s o pe ra te d u sin g fl uid fl ow a nd e le c tr on ic se ns or s. Th e fi rs t st e p is to verify the sy stem is sealed a nd does not leak. A fter c onfirming the sy stem is closed, the e xce ss a ir tha t ma y be tr a pp e d is ble e d o ut b y c y c lin g the sy ste m. O nc e the e xce ss a ir is re mov e d th e va lve is c los e d a nd the up pe r t ub e is f ill e d le a vin g the low e r t ub e wi th f lui d just below the start of the ste el. The stee l strands are clamped a nd hung just above the fl uid le ve l in the low e r t ub e le a vin g the tub e op e n f or a ir fl ow so the fl uid c a n f low fr e e ly once the valve is opene d. After the spec imens are in place a nd the fluid is filled to the p ro p er h ei gh t s t h e p re s s u re re ad i n gs fr o m t h e p i ez o m et er s ar e b al an ce d u s i n g t h e M ega Da c int e rf a c e to m a ke a da tum fo r d a ta pr oc e ssi ng T he fl uid he ig ht f or e a c h tu be is rec orded, a nd then the ele ctronic r ecor dings a re star ted and the va lve is opened to star t the fl uid fl ow Pr e ssu re s a re me a su re d a nd re c or de d te n ti me s a se c on d c re a tin g a log of da ta to be stored a nd later pr ocesse d. Once the fluid has prof iled the bar the valve is c losed and the f inal fluid heig hts are r ecor ded. Using the elec tronic data and the r ecor ded measure ments the cross se ctional ar ea of the steel is ca lculated a long the leng th of the bar. 5. 4 I nit ial Te st ing of P r oc e ss To verif y the testing proce ss functioned prope rly sample bar s were tested and the re su lts e xami ne d f or a c c ur a c y A so lid smo oth su rf a c e a lum inu m ba r w ith a va ri e d c ro ss section wa s profiled a nd the re sults were c onsistent with the measured da ta, see Fig ure 5. 6 a nd F ig ur e 5. 7 f or re su lts of c a lib ra tio n te st. Sa mpl e se ve n w ir e str a nd s w e re a lso tested and the results wer e consistent with the mea sured ba rs, but less acc urate than for

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47 the clea n aluminum bar, this may be due to the w icking eff ect of fluids or other e x terna l fac tors, see F igur e 5.3 for a sample pr ofile of a damag ed bar Mineral spirits and a cetone wer e tested a nd the ac etone wa s more consistent and mor e ac cura te than other fluids considere d. After assuring the test produce d reliable data the te st specimens we re profiled. 5.5 Error El e c tr on ic a nd e xpe ri me nta l da ta c a n h a ve va ri ou s so ur c e s o f e rr or T he da ta produce d from the pr ofiling pr ocess ha d an inher ent amount of noise a nd neede d to be pr oc e sse d in to u sa ble da ta T he pr e ssu re re a din g s sh ow e d v isi ble no ise tha t se e me d to fluctuate d a consistent amount, see Fig ure 5.4. When the da ta was a vera g ed over a fe w da ta po int s th e g e ne ra l tr e nd s w e re un ve ile d, se e F ig ur e 5. 5. Us ing the ov e ra ll c ha ng e in fluid heig ht, the elec tronic data was c alibrate d to adjust for the spec ific fluid prope rties and to re flec t actual da ta. The stee l frame that the profiler was c lamped to has a natura l fre quency and ca n cause vibrations that the piezometers ar e sensitive enoug h to detect causing a cy clic er ror a nd could be the sour ce of the consistent noise. The se nsitivi ty of the sensors a lso detecte d the minor bumps and movements of the se nsors cre ating spikes in the data, making it important not t o disturb the sy stem during testing. Strands tha t were no t c omp le te ly str a ig ht a nd tou c he d th e g la ss o r c a me c los e to t he g la ss a llo we d th e fl uid to c lim b th e g la ss d ue to t he fl uid s su rf a c e te ns ion th is w ic kin g a c tio n c ou ld a lso c a us e fluctuations in the data. T he er ror will be a ccounte d for whe n the final re sults are summarized and will be one of the source s of deviation in the proba bility based interpre tation of the re sults.

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48 5. 6 D at a P r oc e ssi ng The da ta is capture d ten times a sec ond and stored f or proc essing The files cre ated a re c ompatible with Ex cel a nd easily imported. Eac h specimens da ta was individually proce ssed and c alibrate d to refle ct the ac tual measure d loss of the specimen so that the profiled c ross sections would be a ccur ate. I nitial and final fluid positions are enter ed along with the position of the bar into an Excel template to produc e the g raphs a nd da ta ne e de d. Spi ke s in da ta a nd oth e r i rr e g ula ri tie s w e re re mov e d f ro m th e ste e l lo ss c a lc ula tio ns bu t r e ma in i n th e g ra ph e d d a ta T he pr of ile d g ra ph s d isp la y thr e e da ta se ts, the per cent stee l loss is g raphe d in y ellow and is ty pically the lowest data set. The pr ofiled strand ar ea is g raphe d in pink, and the cor rec ted strand a rea is gr aphed blue see Appendix B for the profiled stra nds g raphic al re sults. 5.7 Summ ary of Data Profiling the stra nds provides a me thod of repr esent the phy sical cr oss section of the steel stra nds numerica lly The prof iling data for the stra nds exhi bited the anticipate d cross sec tional are a with minor fluctuations that ar e ca librated to match the phy sical specimen. Spikes in the data are still visible and are noticeable as external noise. F igur e 5. 1 il lus tr a te s th e pr of ile r s e tup T a ble 5. 1 h a s th e su mma ry of the nu me ri c a l r e su lts measure d weig ht loss and perc ent loss are the g ravimetric results of the study The profiled we ight loss was c alculate d using the data obtaine d from prof iling ea ch strand, summing the a rea under the g raphe d curve of the stra nd data g ives the volume of the strand. The volumetric data can be used to ca lculate we ight loss and ve rify the ac cura cy of the prof iling proc ess. The ma x imum localiz ed per cent loss and the minimum bar a rea

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49 can be seen on the g raphic al re prese ntation of the data The re sults are e asier to inter pret using a g raphic al method which a llows y ou to see the a ctual tre nds in the data. The g ra ph s sh ow ob vio us sp ike s in da ta a nd oth e r n ois e le a vin g int e rp re ta tio ns of the re su lts open to scrutiny The e stimated capa city is calcula ted using the minimum bar are a obtained fr om profiling the strand and the known ultimate stress of the stee l. Fig ure 5.25.7 shows profiles of c ontrols and a sa mple profile of a strand. F igur e 5.8-5.13 shows imag es of the pr ofiler se tup. Appendix B contains the g raphic al re sults of the strand profiling See Chapter 7 for a summary of the re sults and for tre nds in the data.

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50 F igu r e 5. 1 P r ofil e r Te st Se tu p

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51 Tabl e 5.1 P rofiled S trand Results M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % % er r or M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 4 3 A B 8 .3 3 3 .0 1 8 .4 2 1 .1 2 8 .6 0 .0 5 5 1 4 .7 B C 7 .7 5 2 .8 1 7 .4 1 4 .3 5 1 1 .8 0 .0 5 3 1 4 .2 C D 9 .0 3 3 .2 7 9 .1 8 1 .7 0 1 6 .7 5 0 .0 5 0 1 3 .4 D A 7 .0 7 2 .5 7 7 .2 1 2 .0 1 1 5 .7 0 .0 5 0 1 3 .6 5 9 A B 9 .3 7 3 .4 0 9 .3 5 0 .1 9 1 2 .2 0 .0 5 2 1 4 .1 B C 9 .0 1 3 .2 5 8 .8 5 1 .7 4 1 6 .6 0 .0 5 0 1 3 .4 C D 8 .2 3 2 .9 8 8 .5 4 3 .8 1 1 7 .3 0 .0 4 9 1 3 .3 D A 8 .8 3 3 .2 0 8 .9 8 1 .7 3 1 3 .5 0 .0 5 2 1 3 .9 4 2 A B 7 .2 5 2 .6 3 7 .4 3 2 .5 2 1 0 .4 0 .0 5 3 1 4 .4 B C 8 .0 5 2 .9 2 8 .3 4 3 .6 4 8 .8 0 .0 5 4 1 4 .7 C D 8 .6 3 3 .1 2 8 .3 3 3 .4 4 1 1 .1 0 .0 5 3 1 4 .3 D A 7 .9 5 2 .8 8 7 .8 9 0 .7 2 1 4 .6 0 .0 5 1 1 3 .8 5 8 A B 7 .4 3 2 .6 9 7 .5 1 1 .1 2 6 .3 0 .0 5 6 1 5 .1 B C 9 .9 5 3 .6 1 9 .5 4 .5 0 9 .8 0 .0 5 4 1 4 .5 C D 8 .9 5 3 .2 4 8 .5 9 3 .9 9 8 .4 0 .0 5 5 1 4 .8 D A 8 .7 5 3 .1 7 8 .5 2 .8 3 1 2 .9 0 .0 5 2 1 4 .0

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52 Tabl e 5. 1 ( Co nt inue d) M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % % er r or M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 5 7 A B 8 .1 3 2 .9 4 8 .2 1 1 .0 2 9 .6 0 .0 5 4 1 4 .6 B C 8 .4 3 3 .0 5 8 .7 2 3 .4 8 1 3 .5 0 0 5 2 1 3 .9 C D 8 .9 3 3 .2 3 9 .0 4 1 .2 7 1 2 .9 0 .0 5 2 1 4 .0 D A 9 .7 3 3 .5 2 9 .3 8 3 .5 7 9 .3 0 .0 5 4 1 4 .6 5 6 A B 7 .8 5 2 .8 5 7 .6 7 2 .2 6 1 0 .9 0 .0 5 3 1 4 .4 B C 8 .1 3 2 .9 4 8 .0 2 1 .3 2 1 8 .5 0 .0 4 9 1 3 .1 C D 9 .2 5 3 .3 5 9 .3 9 1 .5 4 9 .7 5 0 .0 5 4 1 4 .5 D A 8 .5 3 3 .0 9 8 .8 6 3 .9 1 1 5 .5 0 .0 5 0 1 3 .6 5 5 A B 8 .6 3 3 .1 2 8 .8 2 .0 1 8 .3 0 .0 5 5 1 4 .8 B C 8 .3 5 3 .0 3 8 .4 6 1 .3 5 9 .8 0 .0 5 4 1 4 .5 C D 7 .8 3 2 .8 3 7 .5 9 3 .0 3 7 .6 0 .0 5 5 1 4 .9 D A 7 .2 5 2 .6 3 7 .2 0 .6 5 7 .4 0 .0 5 5 1 4 .9 5 4 A B 8 .6 5 3 .1 4 9 .3 3 7 .8 9 1 0 .5 0 .0 5 3 1 4 .4 B C 9 .2 3 3 .3 4 8 .8 8 3 .7 6 1 4 .1 0 .0 5 1 1 3 .8 C D 8 .6 3 3 .1 2 8 .0 7 6 .4 6 1 2 .7 0 .0 5 2 1 4 .1 D A 7 .9 3 2 .8 7 7 .8 1 .6 0 1 2 .9 0 .0 5 2 1 4 .0

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53 Tabl e 5. 1 ( Co nt inue d) M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % % er r or M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 4 1 A B 7 .4 5 2 .7 0 7 .5 6 1 .5 1 8 .9 0 .0 5 4 1 4 .7 B C 7 .7 3 2 .8 0 7 .5 2 .9 4 9 .7 5 0 .0 5 4 1 4 .5 C D 8 .8 5 3 .2 1 8 .4 3 4 .7 2 1 2 .1 6 0 .0 5 2 1 4 .1 D A 7 .5 3 2 .7 2 7 .7 6 3 .1 0 1 3 .3 0 .0 5 2 1 4 .0 5 3 A B 8 .7 5 3 .1 7 8 .4 2 3 .7 4 1 6 .6 0 .0 5 0 1 3 .4 B C 1 8 .4 6 .6 5 1 8 .3 0 .1 5 1 3 .8 0 .0 5 1 1 3 .9 C D 7 .9 3 2 .8 7 7 .7 2 .8 6 9 .5 0 .0 5 4 1 4 .6 D A 8 .3 3 3 .0 1 8 .8 8 6 .6 4 1 5 .5 0 .0 5 0 1 3 .6 4 0 A B 7 .6 5 2 .7 7 7 .5 8 0 .8 8 1 1 .1 0 .0 5 3 1 4 .3 B C 8 .2 5 2 .9 9 8 .2 6 0 .1 5 6 .5 0 .0 5 6 1 5 .1 C D 8 .5 5 3 .1 0 8 .1 4 4 .7 7 1 0 .8 0 .0 5 3 1 4 .4 D A 7 .6 5 2 .7 7 7 .8 4 2 .5 2 1 0 .4 0 .0 5 3 1 4 .4 5 2 A B 8 .5 7 3 .1 1 8 .2 2 4 .0 6 7 .8 0 .0 5 5 1 4 .9 B C 9 .0 5 3 .2 8 9 .5 5 5 .5 6 9 .2 0 .0 5 4 1 4 .6 C D 8 .0 5 2 .9 2 8 .6 4 7 .3 6 1 2 .7 0 .0 5 2 1 4 .1 D A 8 .4 5 3 .0 6 8 .1 4 3 .6 4 1 9 .6 0 .0 4 8 1 2 .9

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54 Tabl e 5. 1 ( Co nt inue d) M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % % error M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 5 1 A B 8 .5 5 3 .1 0 8 .7 1 .7 9 1 2 .9 0 .0 5 2 1 4 .0 B C 8 .5 3 3 .0 9 8 .6 9 1 .9 1 1 2 .9 0 .0 5 2 1 4 .0 C D 8 .1 3 2 .9 4 8 .6 6 6 .5 6 1 1 .3 0 .0 5 3 1 4 .3 D A 8 .6 5 3 .1 4 8 .6 6 0 .1 5 9 .1 0 .0 5 4 1 4 .6 5 0 A B 8 .7 5 3 .1 7 8 .0 7 7 .7 4 1 1 .4 0 .0 5 3 1 4 .3 B C 8 .8 5 3 .2 1 9 .4 9 7 .2 6 1 2 .5 0 .0 5 2 1 4 .1 C D 9 .1 5 3 .3 2 9 .4 6 3 .4 2 1 3 .6 0 .0 5 2 1 3 .9 D A 8 .4 5 3 .0 6 8 .8 7 5 .0 0 1 3 .3 0 .0 5 2 1 4 .0 4 7 A B 7 .7 5 2 .8 1 8 .4 8 9 .4 6 8 .3 0 .0 5 5 1 4 .8 B C 8 .6 5 3 .1 4 8 .3 1 3 .9 0 8 .1 0 .0 5 5 1 4 .8 C D 8 .7 5 3 .1 7 8 .6 2 1 .4 6 1 1 .8 0 .0 5 3 1 4 .2 D A 7 .7 5 2 .8 1 7 .4 9 3 .3 2 8 .3 0 .0 5 5 1 4 .8 4 8 A B 8 .2 5 2 .9 9 8 .3 9 1 .7 3 1 0 .2 0 .0 5 4 1 4 .5 B C 9 .0 5 3 .2 8 9 .6 8 6 .9 9 2 5 .9 0 .0 4 4 1 1 .9 C D 8 .5 5 3 .1 0 8 .6 8 1 .5 5 7 .8 0 .0 5 5 1 4 .9 D A 7 .9 5 2 .8 8 7 .5 5 .6 3 7 .9 0 .0 5 5 1 4 .8

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55 Tabl e 5. 1 ( Co nt inue d) M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % er r or M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 3 8 A B 7 .4 3 2 .6 9 7 .5 9 2 .2 0 7 .5 0 .0 5 5 1 4 .9 C D 1 0 .0 3 .6 3 1 0 .2 1 .7 3 1 3 .9 0 .0 5 1 1 3 .9 D A 7 .4 5 2 .7 0 7 .4 8 0 .4 4 1 4 .3 0 .0 5 1 1 3 .8 4 4 A B 7 .8 5 2 .8 5 7 .8 8 0 .4 2 1 1 .4 0 .0 5 3 1 4 .3 B C 1 6 .4 5 .9 5 1 5 .3 6 .7 4 4 5 .7 0 .0 3 2 8 .7 C D 1 1 .4 4 .1 4 1 1 .5 1 .2 5 1 8 .3 0 .0 4 9 1 3 .2 D A 1 5 .4 5 .5 8 1 5 .5 0 .9 9 2 7 .5 0 .0 4 3 1 1 .7 4 5 A B 5 .7 5 2 .0 8 5 .9 2 .6 6 8 .2 0 .0 5 5 1 4 .8 B C 8 .9 3 3 .2 3 8 .6 9 2 .6 5 1 9 .5 0 .0 4 8 1 3 .0 C D 1 9 .3 7 .0 2 1 7 .5 9 .2 4 5 5 .5 5 0 .0 2 7 7 .2 D A 1 7 .6 6 .4 0 1 7 .8 1 .1 5 1 7 .7 5 0 .0 4 9 1 3 .2 4 6 A B 9 .3 5 3 .3 9 9 .9 5 .9 1 9 .2 0 .0 5 4 1 4 .6 B C 8 .2 3 2 .9 8 7 .9 4 3 .4 9 7 .8 0 .0 5 5 1 4 .9 C D 1 4 .5 5 .2 6 1 3 .4 7 .4 8 2 8 .5 0 .0 4 3 1 1 .5 D A 7 .3 3 2 .6 5 7 .2 6 0 .9 1 7 .8 0 .0 5 5 1 4 .9

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56 Tabl e 5. 1 ( Co nt inue d) M easur ed W ei ght l oss ( g) % l oss Pr of i l ed W ei ght l oss ( g) % er r or M ax Local i z ed Loss % M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) 3 9 A B 7 .1 3 2 .5 8 6 .9 5 2 .4 8 1 1 .9 0 .0 5 3 1 4 .2 B C 7 .8 5 2 .8 5 7 .5 2 4 .1 7 1 0 .7 0 .0 5 3 1 4 .4 C D 2 1 .2 7 .6 8 2 1 .4 0 .8 2 3 3 0 .0 4 0 1 0 .8 D A 7 .2 3 2 .6 2 7 .5 8 4 .8 9 1 3 .6 0 .0 5 2 1 3 .9 4 9 A B 8 .3 5 3 .0 3 8 .0 8 3 .2 0 1 2 .1 0 .0 5 2 1 4 .2 B C 1 3 .8 5 .0 2 1 3 .8 0 .2 4 2 1 .7 0 .0 4 7 1 2 .6 C D 8 .6 3 3 .1 2 8 .7 8 1 .7 7 1 0 .2 0 .0 5 4 1 4 .5 D A 1 3 .2 4 .7 9 1 2 .8 2 .7 7 2 0 .2 0 .0 4 8 1 2 .9

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57 F igu r e 5. 2 P r ofil e of Em pt y Tub e F igu r e 5. 3 Sa m ple P r ofil e of St r and

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58 F igure 5.4 P rofile of Strand w ithout Calib ration F igure 5.5 P rofile of Strand w ith Calib ration

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59 F igure 5.6 P rofile of Alum inu m Bar wi th Varied Cr oss Section F igu r e 5. 7 P r ofil e Ca libr at ion

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60 F igu r e 5. 8 St r and C lam pe d at Lowe r Tube F igu r e 5. 9 U ppe r and L owe r Tube

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61 F igu r e 5. 10 F luid i n Up pe r Tube and A tt ac he d M e as ur ing Tape F igu r e 5. 11 P ie z om e te r C lam p, a nd C oppe r Tubing

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62 F igure 5.12 P iezom ete r and Flow Valves F igure 5.13 P rofile Test Station

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63 Cha pt e r 6 Te nsio n Te st 6. 1 St anda r ds Eac h specimen w as tested f or the tensile c apac ity using A ASHTO and A STM standards a nd proce dures The standard me thod of test used is from “Me chanic al Testing of Steel Products”, A ASHTO desig nation T 244-92, ASTM desig nation A 370-92. Specifica lly section A7 of the proce dure “ Method of Te sting Unc oated Seve n-Wire Stress-Relieved Strand f or Prestre ssed Concre te” wa s ref ere nced f or the test proc edure [2]. T he str a nd s a re 36 wh ic h is g re a te r t ha n th e 24 min imu m st ipu la te d. Th e loa d r a te is displacement contr olled and set a s 125 :g /sec, using the 24" minimum a strain r ate of 0.18 in/min was used for the te nsion test. 6.2 P roce dure The tension test is perf ormed using the MTS 810 Material Te st Sy stem in the structure s lab of the Unive rsity of South Florida. F irst the ends of the stra nds were coate d with epoxy to preve nt slip failure modes. Sikadur 32 Hi-Mod two pa rt epoxy is applied on the end two to thre e inche s of ea ch end of the steel stra nds. Prestress stee l anchor s are us e d a t e a c h e nd to s e c ur e the ste e l du ri ng te ns ile te sti ng T he a nc ho rs a re pla c e d in blocking sleeve s and the stra nd is inserted into the anc hor we dg e to sec ure the top end. Next the test pist on is positi oned to insert the bottom end of the strand into the bottom anchor Once the steel is in position, t he stee l is loaded in tension to approxi mately ten

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64 perc ent of the e x pecte d capa city in acc ordanc e with the AASHTO proce dures. The expected ca pacity of the stra nds is approxi mately 16 kips and the test was star ted at about 1. 5 k ips A ft e r t he ini tia l lo a d is a pp lie d th e te st i s r un wi th a c on sta nt d isp la c e me nt r a te of 0.18 in/min unti l eac h strand fa ils, the epox y fails, or the te st reac hes a ma x displaceme nt of 3.5 inches. Af ter the te st is completed, photos are ta ken to document the failure mode of the stra nds. Finally the strands a re r emoved a nd the anc hors ar e cle aned for the ne x t specimen, c leaning the anc hors re duces the possibili ty of slip failure in the g rips. 6. 3 I nit ial Te st ing of P r oc e ss Control strands were tested first to ensure the test proce dure w ould produce the desired r esults. The first strands te sted without epox y experience d various slip failed modes, most common failure wa s slip at the first wire r upture. Af ter the e pox y was used the slip failure mode was c orre cted a nd the spec imens failed in tension as de sired. Con tr ol s tr a nd s w e re te ste d to g ive the ult ima te c a pa c ity of the un da ma g e d s tr a nd s w ith no corr osion. Additional control bars we re a ltered to c ompare the re sults of the altere d strands with the experimental strands. U niform ar ea w as re moved taking the same a rea fr om e a c h e xter na l st ra nd to r e du c e the ov e ra ll c ro ss s e c tio n w ith ou t c utt ing a ny str a nd s. Other c ontrol bars we re te sted with sever ed strands to test contr ols with one and two sever ed strands. The controls tested will provide da ta that ca n be used f or compa rison wi th t he te st r e su lts to b e tte r i nte rp re t th e c a pa c ity of c or ro de d s te e l.

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65 6. 4 Ob se r va ti ons Th e e po xy us e d to se c ur e the e nd s su pp lie d th e re sis ta nc e ne e de d to pr e ve nt s lip failure Test wer e ra n until each of the seve n strands we re br oken, due to the twist in the seven w ires whe n a strand w ould brea k the re maining stra nds would be straig hten out showing elong ation of the spec imens with relatively low loads until the specimen wa s ta un t a nd the e xpe c te d s tr e ss s tr a in w ou ld r e su me un til the ne xt str a nd wo uld br e a k, thi s is a ls o v is ib le in th e g r a p h e d d a ta s e e A p p e n d ix C f o r p lo ts o f te n s io n te s t r e s u lt s E p o xy failure was limited and occ urre d during about five pe rce nt of the test, in some ca ses the e p o xy b r o k e a t t h e e xp e c te d c a p a c it y w it h th e f ir s t w ir e r u p tu r e Se e T a b le 6 2 f o r e p o xy failure results. 6. 5 D at a P r oc e ssi ng The MTS 810 rec ords var ious data for later a naly sis, specifica lly forc e, displaceme nt, and time wer e re corde d and proc essed using Ex cel. The strands consist of seven w ires, af ter the f irst wire bre aks the c ross section is reduc ed. Due to the reduc tion of c ro ss s e c tio n a ft e r w ir e br e a ks f or c e dis pla c e me nt c ur ve s w e re us e d in ste a d o f s tr e ss curve s to more ac cura tely display the data, se e Appe ndix C for g raphic al re sults of the tensile testing. 6.6 Summ ary of Data The seve n-wire strands we re stre ssed to ultimate capa city Eig hty -six strands we re tensile tested. Thre e strands f ailed all wire s at once and ea ch excee ded their e x pecte d capa city see Ta ble 6.1. Epoxy failure s are listed in Table 6.2, some strands we re not aff ecte d by the epoxy failure beca use the e pox y failed w hen the f irst wire ruptur ed, which

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66 is ty pically the ultimate capa city Some strands rea ched ultimate a fter the first wire br oke, the se str a nd s c oll e c tiv e ly ha d a low e r c a pa c ity the n e xpe c te d d ue to t he los s o f c ro ss section prior to ultimate ca pacity see Ta ble 6.3 for r esults. Ty pical fa ilures ar e su mma ri zed in T a ble 6. 4. Str a nd 45 c d h a d a g re a tly re du c e d c ro ss s e c tio n a nd is a statistical outlier in the data set, it has be en re moved from some g raphs a nd is noted when excluded. Table 6.56.6 are tensile test results of contr ols strands tested for compar ison. Fig ure 6.16.4 shows forc e displace ment curve s for sample stra nd failure s, and F igur e 6.5-6.10 shows imag es of the te nsion test and testing e quipment.

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67 Tabl e 6.1 Tension T est Re sults In stant F ailure Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or I ns t an t F ai l ure 43 DA 13. 58 15. 66 13. 29 1 s t b r e a k o n ly 42 AB 14. 43 16. 09 10. 32 1 s t b r e a k o n ly 40 D A 14. 42 16. 19 10. 92 al l st r and f ai l ed a t once Tabl e 6.2 Tension T est Re sults Ep oxy F ailure Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or E po x y F ai l ure 53 AB 13. 43 12. 63 6. 31 ep ox y fai l ure 50 C D 13. 92 12. 42 12. 05 ep ox y fai l ure 44 D A 11. 64 4. 63 151. 45 ep ox y fai l ure 44 BC 8. 75 8. 78 0. 33 epoxy f ai l ur e, 1 br eak 55 AB 14. 75 8. 17 80. 54 e p o x y f a i l u r e 2 b r e a ks 53 C D 14. 58 12. 50 16. 60 e p o x y f a i l u r e 4 b r e a ks 46 D A 14. 85 9. 45 57. 15 epoxy f ai l ur e, ul t @ 2nd br eak

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68 Tabl e 6.3 Tension T est Re sults Ultim ate C apacity After Initial F ailure Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or U l t i m at e Capaci t y Af t er I ni t i al W i re F ai l ure 57 D A 14. 61 8. 91 63. 96 ul t @ 2nd br eak 47 AB 14. 78 10. 97 34. 74 ul t @ 3r d br eak 52 D A 12. 94 9. 44 37. 04 ul t @ 3r d br eak 52 BC 14. 60 9. 92 47. 19 ul t @ 3r d br eak 41 AB 14. 65 9. 33 57. 07 ul t @ 3r d br eak 49 BC 12. 61 5. 75 119. 29 ul t @ 4t h br eak 56 BC 13. 12 11. 87 10. 50 ul t @ secon d br eak 42 C D 14. 32 12. 45 15. 04 ul t @ secon d br eak 44 C D 13. 15 10. 90 20. 64 ul t @ secon d br eak 51 AB 14. 04 11. 35 23. 71 ul t @ secon d br eak 59 AB 14. 13 11. 01 28. 37 ul t @ secon d br eak 48 C D 14. 84 10. 31 43. 98 ul t @ secon d br eak 47 BC 14. 79 10. 17 45. 42 ul t @ secon d br eak 55 BC 14. 54 10. 00 45. 43 ul t @ secon d br eak 41 C D 14. 13 9. 44 49. 72 ul t @ secon d br eak 49 D A 12. 86 8. 51 51. 13 ul t @ secon d br eak 58 BC 14. 53 9. 56 52. 00 ul t @ secon d br eak 54 BC 13. 82 8. 66 59. 64 ul t @ secon d br eak 45 C D 7. 19 1. 22 489. 26 ul t @ t hi r d br eak

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69 Tabl e 6.4 Tension T est Re sults Typ ical F ailure Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or T y pi c al F ai l ure 43 C D 13. 41 14. 72 8. 88 t y pi cal 59 BC 13. 43 14. 36 6. 48 t y pi cal 41 D A 13. 97 14. 61 4. 40 t y pi cal 39 AB 14. 18 14. 79 4. 10 t y pi cal 51 BC 14. 02 14. 49 3. 24 t y pi cal 43 BC 14. 20 14. 52 2. 20 t y pi cal 49 C D 14. 47 14. 78 2. 07 t y pi cal 50 D A 13. 98 14. 00 0. 15 t y pi cal 58 D A 14. 04 14. 02 0. 11 t y pi cal 40 AB 14. 31 14. 14 1. 21 t y pi cal 53 D A 13. 60 13. 44 1. 22 t y pi cal 38 AB 14. 91 14. 67 1. 62 t y pi cal 50 BC 14. 09 13. 82 1. 95 t y pi cal 56 D A 13. 61 13. 31 2. 25 t y pi cal 46 BC 14. 86 14. 51 2. 42 t y pi cal 40 BC 15. 05 14. 41 4. 45 t y pi cal 39 D A 13. 90 13. 30 4. 55 t y pi cal 50 AB 14. 27 13. 61 4. 87 t y pi cal 42 D A 13. 74 13. 03 5. 48 t y pi cal 56 C D 14. 53 13. 71 5. 98 t y pi cal

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70 Tabl e 6.4 (C ontinu ed) Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or T y pi c al F ai l ure 40 C D 14. 36 13. 52 6. 21 t y pi cal 54 D A 14. 04 13. 21 6. 26 t y pi cal 58 C D 14. 75 13. 84 6. 58 t y pi cal 57 C D 14. 04 13. 13 6. 91 t y pi cal 55 C D 14. 88 13. 88 7. 24 t y pi cal 38 D A 13. 80 12. 85 7. 40 t y pi cal 52 C D 14. 05 12. 79 9. 87 t y pi cal 45 D A 13. 26 11. 97 10. 76 t y pi cal 56 AB 14. 34 12. 90 11. 20 t y pi cal 55 D A 14. 92 13. 34 11. 85 t y pi cal 57 BC 13. 92 12. 41 12. 18 t y pi cal 45 AB 14. 78 12. 98 13. 85 t y pi cal 59 D A 13. 92 11. 90 17. 01 t y pi cal 53 BC 13. 87 11. 79 17. 67 t y pi cal 41 BC 14. 55 12. 32 18. 07 t y pi cal 48 DA 14. 85 12. 49 18. 92 t y pi cal 4 6 AB 14 61 11. 52 26. 85 t y pi cal 57 AB 14. 56 11. 31 28. 71 t y pi cal 54 AB 14. 42 9. 94 45. 08 t y pi cal 54 C D 14. 05 9. 31 50. 95 t y pi cal

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71 Tabl e 6.4 (C ontinu ed) Est i m at ed T e n s ile C a p a c i ty ( k) U l ti m a te T e n s ile C a p a c i ty ( k) Pr of i l e Bar Ar ea % Er r or T y pi c al F ai l ure 49 AB 14. 15 13. 60 4. 04 t y pi cal 2 st r ands f a ile d @ u lt 59 C D 13. 32 14. 50 8. 13 t y p i c a l 4 b r e a ks 51 C D 14. 29 14. 64 2. 37 t y p i c a l 4 b r e a ks 39 BC 14. 37 14. 62 1. 71 t y p i c a l 4 b r e a ks 42 BC 14. 68 14. 76 0. 54 t y p i c a l 4 b r e a ks 47 D A 14. 76 14. 68 0. 56 t y p i c a l 4 b r e a ks 47 C D 14. 22 14. 13 0. 60 t y p i c a l 4 b r e a ks 52 AB 14. 86 13. 89 7. 01 t y p i c a l 4 b r e a ks 45 BC 12. 96 10. 04 29. 09 t y p i c a l 4 b r e a ks 46 C D 11. 53 7. 62 51. 25 t y p i c a l 4 b r e a ks 51 D A 14. 64 14. 09 3. 88 t y p i c a l 5 b r e a ks 58 AB 15. 09 13. 90 8. 54 t y p i c a l 5 b r e a ks 44 AB 14. 27 12. 88 10. 81 t y p i c a l 5 b r e a ks 43 AB 14. 72 12. 93 13. 83 t y p i c a l 5 b r e a ks 48 BC 11. 94 9. 05 31. 95 t y p i c a l 5 b r e a ks 38 C D 13. 87 10. 48 32. 38 t y p i c a l 5 b r e a ks 48 AB 14. 45 8. 71 65. 85 t y p i c a l 5 b r e a ks

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72 Tabl e 6. 5 Te nsio n Te st Re sult s U ndam ag e d Co nt r ols M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) U l ti m a te C a p a c i ty ( k) % Er r or U ndam aged C ont r ol s S1 0. 0597 16. 1 15. 39 4. 66 cl ean bar t y pi cal S2 0. 0597 16. 1 15. 45 4. 25 cl ean bar t y pi cal S3 0. 0597 16. 1 14. 42 11. 70 cl ean bar t y pi cal S4 0. 0597 16. 1 15. 16 6. 25 cl ean bar t y pi cal S5 0. 0597 16. 1 13. 94 15. 54 cl ean bar t y pi cal S6 0. 0597 16. 1 15. 53 3. 71 cl ean bar t y pi cal Tabl e 6. 6 Te nsio n Te st Re sult s M odi fie d Co nt r ols M i n Bar Ar ea ( i n2) Est i m at ed C a p a c i ty ( K) U l ti m a te C a p a c i ty ( k) % Er r or M o d if ie d C o n tr o ls C1 0. 0450 12. 2 11. 13 9. 16 2 s t ran ds sa nd ed ul t @ 3rd br eak C2 0. 0511 13. 8 13. 30 3. 80 1 st r and cut t y pi cal C3 0. 0511 13. 8 11. 91 15. 92 1 st r and cut t y pi cal C4 0. 0426 11. 5 10. 85 6. 04 2 st r ands cut t y pi cal C5 0. 0426 11. 5 11. 33 1. 54 2 st r ands cut t y pi cal C6 0. 0426 11. 5 10. 88 5. 74 al l ext er i or st r ands sanded t y pi cal C7 0. 0426 11. 5 10. 66 7. 93 al l ext er i or st r ands sanded t y pi cal

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73 F igure 6.1 Typical S trand F ailure F igure 6.2 All Strands Failed at Once

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74 F igure 6.3 Ultim ate C apacity at Second Wire F ailure F igure 6.4 Ultim ate C apacity at Third Wire F ailure

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75 F igu r e 6. 5 Te nsio n Te st Se tu p

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76 F igure 6.6 Tension T est After Strand Failure

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77 F igure 6.7 Tension T est Station

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78 F igu r e 6. 8 Te nsio n Te st Co nt r ol P ane ls

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79 F igure 6.9 Tension T est Inter face

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80 F igure 6.10 P rest ress Anchors

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81 Cha pt e r 7 Sum m ar y a nd C onc lusi ons 7. 1 G r av im e tr ic Los s a nd A c tu al L os s Gra vimetric loss assumes distributed damag e and is a n inacc urate estimate of stee l loss, pitt ing da mag e ca uses ac tual steel loss to be localized not distributed, see F igur e 7.1 for a compar ison of g ravimetric and ac tual local stee l loss. Figur e 7.1 shows that the actua l local loss is approxi mately four times g rea ter than the g ravimetric estimations of los s. Ac tua l lo c a l st e e l lo ss e sti ma tio ns of c a pa c ity a re mor e a c c ur a te tha n g ra vim e tr ic estimates of stee l capa city When calcula ting c apac ity of cor roded stee l using e stimated g ra vim e tr ic los s, a dd iti on a l c on sid e ra tio ns sh ou ld m a de fo r l oc a l pi tti ng ste e l lo ss. F ig ur e 7. 2 il lus tr a te s th e e rr or in p re dic tin g ult ima te c a pa c ity A s th e ult ima te capa city reduc es the e rror in estimating c apac ity incre ases. The data is sepa rate d into the differ ent fa ilure modes to show the e rror associate d with eac h failure mode. All failure modes fall into an exponential rela tionship and shows a strong corr elation. 7. 2 P it ti ng C or r os ion Cor ro sio n p itt ing da ma g e a ff e c ts t he e sti ma te d c a pa c ity a c c ur a c y s tr a nd s w ith la rg e r a mou nts of ste e l lo ss d isp la y e d g re a te r e rr or wh ic h ma y be du e to s tr e ss conce ntration. I ncre ased e rror in estimating c apac ity at g rea ter stee l loss can be obse rved from F igur e 7.3, the e rror incre ases e x ponentially with reduc ed ultimate ca pacity and shows a strong trend that may be due to stre ss conce ntration.

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82 Strands that rea ched ultimate c apac ity afte r the fir st wire fa ilure experienc e a re du c e d c ro ss s e c tio n p ri or to u lti ma te c a pa c ity E xpe c te d a re a fo r u lti ma te c a pa c ity is lost causing a re duction in possible capac ity this is an additional affe ct of c orrosion damag e that re duces e x pecte d capa city and spec ifically aff ects multiple wire stra nd, additional considera tion should be give n to multi ple wire strands whe n estimating the e f f e c t s o f c o r r o s i o n d a m a g e o n u l t i m a t e c a p a c i t y. 7.3 Ultim ate C apacity The re lationship between the ultimate capa city of cor roded stra nds and the minimum bar a rea is gr aphed in F igur e 7.4 and show s a nonlinear trend. The straig ht line in Fig ure 7.4 shows the expected ca pacity if the ca pacity is linearly rela ted to the bar are a a nd sh ow s th a t th e a c tua l c a pa c ity fo llo ws a dif fe re nt t re nd T he pin k c ur ve d li ne in Fig ure 7.4 is an inve rse tang ent func tion and the best fit trend line f or the da ta. Fig ure 7.5 shows the cor rela tion of the data g raphe d in Fig ure 7.4 w ith the inverse tang ent func tion by g ra ph ing X/ Y v s Y of the da ta fr om F ig ur e 7. 4, wh ic h c re a te s a str a ig ht l ine if the da ta has an inve rse tang ent re lationship. The ultimate capa city and the minimum bar ar ea ha ve a strong inverse ta ng ent cor rela tion accor ding to F igur e 7.5 and this trend is visible on Fig ure 7.4 be tween the data points and the inve rse tang ent line. A more acc urate trend line can be develope d with additional data points at lower c apac ities. 7.4 Stress Conce ntration The nonlinea r trend of the ca pacity may be due to stre ss conce ntrations cause d by pits and sharp tra nsitions i n cross sec tional are a. Ty pical stress c oncentr ation fac tors rang e fr om one to three and depe nd on the cha ng e in cr oss sectional ar ea a nd the

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83 transition betwee n the cha ng e in ar eas. Stress c oncentr ation fac tors can be calc ulated from experimental da ta throug h the re lationship of expected ca pacity to actual c apac ity A stress conc entra tion factor ha s been c alculate d for e ach stra nd and g raphe d ag ainst ultim ate c apac ity in Fig ure 7.6 a nd a dire ct cor rela tion can be se en in the data The stre ss conce ntration fac tors have the same ra ng e as ty pical stress c oncentr ation fac tors and follow a simil ar tre nd. The c orre lation betwee n the stress conc entra tion factor and the ultimate ca pacity is related to e stimated capa city since the c orre lation is related to estimated ca pacity it is also related to the prof ile perc ent er ror a nd is another repr esenta tion of the trend be tween pr ofile per cent e rror and ultimate ca pacity Th e da ta re c or de d in the ima g ing pr oc e ss w a s c or re la te d to the str e ss conce ntration fac tors for c omparison. Strand 44da ha d larg e pits with a hig h fre quency of pit s a nd ha s a str e ss c on c e ntr a tio n f a c tor of 2. 5. Str a nd 49 bc ha d la rg e pit s w ith a me diu m fre quency of pits and has a stress conc entra tion factor of 2.2. Strand 55bc ha d medium pits with a low freque ncy of pits and has a stress conc entra tion factor of 1.5. Strand 54da had small pits with a low freque ncy of pits and has a stress conc entra tion factor of 1.1. There is a strong corr elation of da ta that shows that stress conc entra tions have an a ffe ct on the ultimate tensile ca pacity of steel a nd that the stress conc entra tion factor inc rea ses exponentially as the a mount of damag e incr ease s.

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84 7.5 Summ ary of Results Gr a vim e tr ic e sti ma tio ns of c a pa c ity ov e rs ta te the str e ng th o f s tr a nd s a nd ne e d to be modified for more a ccur ate c apac ity predic tions. The actua l loss is approximately four times the g ravimetric loss, and stress conc entra tions rang e fr om one to three making the actua l capa city four to twelve times less than the g ravimetric capa city Ex tensive corr osion will ex hibit a gr eate r loss in capa city and a la rg er r eduction should be used f or extensive damag e than use d for e arly stag es of c orrosion, this makes the c apac ity of steel exponentially reduc ed for extensive corrosion. Ta ble 7.1-7.4 summarizes the re sults of the testing g ravimetric capa city is calcula ted using distributed damag e, estimated capa city is calcula ted using the minimum bar are a obtained f rom the prof iler, and the ultimate capa city is the ultim ate load f rom the tensile testing

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85 Tabl e 7.1 Sum m ary of Results CF RP G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 43 AB 1 5 .6 1 4 .7 1 2 .9 1. 14 B C 1 5 .7 1 4 .2 1 4 .5 0. 98 C D 1 5 .6 1 3 .4 1 4 .7 0. 91 D A 1 5 .7 1 3 .6 1 5 .7 0. 87 59 A B 1 5 .6 1 4 .1 1 1 .0 1. 28 B C 1 5 .6 1 3 .4 1 4 .4 0. 94 C D 1 5 .6 1 3 .3 1 4 .5 0. 92 D A 1 5 .6 1 3 .9 1 1 .9 1. 17 42 A B 1 5 .7 1 4 .4 1 6 .1 0. 90 B C 1 5 .6 1 4 .7 1 4 .8 1. 00 C D 1 5 .6 1 4 .3 1 2 .5 1. 15 D A 1 5 .6 1 3 .8 1 3 .0 1. 06 58 A B 1 5 .7 1 5 .1 1 3 .9 1. 09 B C 1 5 .5 1 4 .5 9 .6 1. 52 C D 1 5 .6 1 4 .8 1 3 .8 1. 07 D A 1 5 .6 1 4 .0 1 4 .0 1. 00

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86 Tabl e 7. 1 ( Co nt inue d) G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 57 A B 1 5 .6 1 4 .6 1 1 .3 1. 29 B C 1 5 .6 1 3 .9 1 2 .4 1. 12 C D 1 5 .6 1 4 .0 1 3 .1 1. 07 D A 1 5 .5 1 4 .6 8 .9 1. 64 56 A B 1 5 .6 1 4 .4 1 2 .9 1. 11 B C 1 5 .6 1 3 .1 1 1 .9 1. 11 C D 1 5 .6 1 4 .5 1 3 .7 1. 06 D A 1 5 .6 1 3 .6 1 3 .3 1. 02 55 A B 1 5 .6 1 4 .8 8 .2 1. 81 B C 1 5 .6 1 4 .5 1 0 .0 1. 45 C D 1 5 .7 1 4 .9 1 3 .9 1. 07 D A 1 5 .7 1 4 .9 1 3 .3 1. 12 54 A B 1 5 .6 1 4 .4 9 .9 1. 45 B C 1 5 .6 1 3 .8 8 .7 1. 60 C D 1 5 .6 1 4 .1 9 .3 1. 51 D A 1 5 .6 1 4 .0 1 3 .2 1. 06

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87 Tabl e 7.2 Sum m ary of Results GF RP G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 41 A B 1 5 .7 1 4 .7 9 .3 1. 57 B C 1 5 .7 1 4 .5 1 2 .3 1. 18 C D 1 5 .6 1 4 .1 9 .4 1. 50 D A 1 5 .7 1 4 .0 1 4 .6 0. 96 53 A B 1 5 .6 1 3 .4 1 2 .6 1. 06 B C 1 5 .0 1 3 .9 1 1 .8 1. 18 C D 1 5 .6 1 4 .6 1 2 .5 1. 17 D A 1 5 .6 1 3 .6 1 3 .4 1. 01 40 A B 1 5 .7 1 4 .3 1 4 .1 1. 01 B C 1 5 .6 1 5 .1 1 4 .4 1. 05 C D 1 5 .6 1 4 .4 1 3 .5 1. 06 D A 1 5 .7 1 4 .4 1 6 .2 0. 89 52 A B 1 5 .6 1 4 .9 1 3 .9 1. 07 B C 1 5 .6 1 4 .6 9 .9 1. 47 C D 1 5 .6 1 4 .1 1 2 .8 1. 10 D A 1 5 .6 1 2 .9 9 .4 1. 37

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88 Tabl e 7. 2 ( Co nt inue d) G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 51 A B 1 5 .6 1 4 .0 1 1 .4 1. 24 B C 1 5 .6 1 4 .0 1 4 .5 0. 97 C D 1 5 .6 1 4 .3 1 4 .6 0. 98 D A 1 5 .6 1 4 .6 1 4 .1 1. 04 50 A B 1 5 .6 1 4 .3 1 3 .6 1. 05 B C 1 5 .6 1 4 .1 1 3 .8 1. 02 C D 1 5 .6 1 3 .9 1 2 .4 1. 12 D A 1 5 .6 1 4 .0 1 4 .0 1. 00 47 A B 1 5 .7 1 4 .8 1 1 .0 1. 35 B C 1 5 .6 1 4 .8 1 0 .2 1. 46 C D 1 5 .6 1 4 .2 1 4 .1 1. 01 D A 1 5 .7 1 4 .8 1 4 .7 1. 01 48 A B 1 5 .6 1 4 .5 8 .7 1. 66 BC 1 5 .6 1 1 .9 9 .1 1. 32 C D 1 5 .6 1 4 .9 1 0 .3 1. 44 D A 1 5 .6 1 4 .8 1 2 .5 1. 19

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89 Tabl e 7. 3 Sum m ar y o f Re sult s Out doo r Co nt r ols G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 38 A B 1 5 .7 1 4 .9 1 4 .7 1. 02 BC te s t b re a k te s t br eak C D 1 5 .5 1 3 .9 1 0 .5 1. 32 D A 1 5 .7 1 3 .8 1 2 .9 1. 07 44 A B 1 5 .6 1 4 .3 1 2 .9 1. 11 B C 1 5 .1 8 .7 8 .8 1. 00 C D 1 5 .4 1 3 .2 1 0 .9 1. 21 D A 1 5 .2 1 1 .7 4 .6 2. 52 45 A B 1 5 .8 1 4 .8 1 3 .0 1. 14 B C 1 5 .6 1 3 .0 1 0 .0 1. 29 C D 1 5 .0 7 .2 1 .2 5. 87 D A 1 5 .1 1 3 .2 1 2 .0 1. 11 46 A B 1 5 .6 1 4 .6 1 1 .5 1. 27 B C 1 5 .6 1 4 .9 1 4 .5 1. 02 C D 1 5 .3 1 1 .5 7 .6 1. 51 D A 1 5 .7 1 4 .9 9 .5 1. 57

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90 Tabl e 7. 4 Sum m ar y o f Re sult s In doo r Co nt r ols G r a v im e tr ic C a p a c ity ( K) Est i m at ed C a p a c i ty ( k) U l ti m a te C a p a c i ty ( k) St r ess C oncent r at i on Fact or 39 A B 1 5 .7 1 4 .2 1 4 .8 0. 96 B C 1 5 .6 1 4 .4 1 4 .6 0. 98 C D 14. 9 10. 8 dat a er r or D A 1 5 .7 1 3 .9 1 3 .3 1. 05 49 A B 1 5 .6 1 4 .2 1 3 .6 1. 04 B C 1 5 .3 1 2 .6 5 .8 2. 19 C D 1 5 .6 1 4 .5 1 4 .8 0. 98 D A 1 5 .3 1 2 .9 8 .5 1. 51

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91 F igu r e 7. 1 A c tu al v s G r av im e tr ic Los s

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92 F igure 7.2 Error P redict ing Ultimat e Capacity w/o 45cd

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93 F igure 7.3 P rofile Error vs Ultim ate C apacity

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94 F igure 7.4 Bar Ar ea vs Capacity

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95 F igu r e 7. 5 I nve r se Tang e nt Re lat ion ship

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96 F igure 7.6 Stre ss Concentrat ion vs Cap acity

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97 Refere nces [1] Suh, K.S, Mul lins, G., Sen, R., and Wi nters, D. Use of F RP for Corrosion Str e ng the nin g Ap pli c a tio ns in a Ma ri ne En vir on me nt. F ina l Re po rt su bmi tte d to Florida / US Depar tment of Tra nsportation, Tallaha ssee, F L ,2005,Oct., 406 pp. [2] FDO T Structures Rese arc h Center. Te nsile Test results of Post Tensioning Ca bles from the Midbay Br idge Thomas E. B eitelman, Oc tober 2000 [3] R.C. Hibbeler. Mec hanics of Ma terials. 5 ed. Uppe r Saddle River: Pea rson th Educa tion, 2003 [4] Donald R. Askeland, a nd Pradee p P. Phul e. The Science and Eng ineer ing of Materia ls. 4 ed. Pacif icGrove : Bill Steinquist 2003 th [5] Volz, S J eff ery ; Penn State University “F atig ue Streng th of Corroded Prestressing Strands” ACI Convention. Denver Colorado. 7 Nov 2006

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98 Append ices

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99 Append ix A Critic al Corrosion Im ages and Ob serve d Dam age F igure A.1 Cr itical Corr osion Image 38cd F igu r e A. 2 C r it ic al C or r os ion Im ag e 39 da

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100 Append ix A (Continued) F igure A.3 Cr itical Corr osion Image 40cd F igu r e A. 4 C r it ic al C or r os ion Im ag e 42 bc

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101 App e ndix A ( Co nt inue d) F igure A.5 Cr itical Corr osion Image 43ab F igu r e A. 6 C r it ic al C or r os ion Im ag e 43 bc

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102 App e ndix A ( Co nt inue d) F igure A. 7 C r it ic al C or r os ion Im ag e 45 bc F igure A.8 Cr itical Corr osion Image 47ab

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103 App e ndix A ( Co nt inue d) F igu r e A. 9 C r it ic al C or r os ion Im ag e 48 bc F igure A.10 Cr itical Corr osion Image 48cd

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104 App e ndix A ( Co nt inue d) F igu r e A. 11 Cr it ic al C or r os ion Im ag e 49 da F igure A.12 Cr itical Corr osion Image 50ab

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105 App e ndix A ( Co nt inue d) F igu r e A. 13 Cr it ic al C or r os ion Im ag e 50 da F igure A.14 Cr itical Corr osion Image 52ab

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106 App e ndix A ( Co nt inue d) F igu r e A. 15 Cr it ic al C or r os ion Im ag e 52 bc F igu r e A. 16 Cr it ic al C or r os ion Im ag e 52 da

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107 App e ndix A ( Co nt inue d) F igure A.17 Cr itical Corr osion Image 53ab F igure A.18 Cr itical Corr osion Image 54ab.1

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108 App e ndix A ( Co nt inue d) F igure A.19 Cr itical Corr osion Image 54ab.2 F igu r e A. 20 Cr it ic al C or r os ion Im ag e 54 bc

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109 App e ndix A ( Co nt inue d) F igure A.21 Cr itical Corr osion Image 54cd F igu r e A. 22 Cr it ic al C or r os ion Im ag e 54 da

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110 App e ndix A ( Co nt inue d) F igure A.23 Cr itical Corr osion Image 55ab F igure A.24 Cr itical Corr osion Image 57ab

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111 App e ndix A ( Co nt inue d) F igu r e A. 25 Cr it ic al C or r os ion Im ag e 57 da F igure A.26 Cr itical Corr osion Image 58bc

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112 App e ndix A ( Co nt inue d) Tabl e A.1 De scription of Dam age CF RP CF RP Bar D escr i pt i on 43 AB scal i ng, m i ddl e st age cor r osi on BC scal i ng, m i ddl e st age cor r osi on C D l i ght cor r osi on d i st r i but ed D A l i ght cor r osi on d i st r i but ed 5 9 A B s in g le la r g e p it BC l i ght cor r osi on d i st r i but ed C D l i ght cor r osi on d i st r i but ed D A l i ght cor r osi on d i st r i but ed 42 AB l i ght cor r osi on d i st r i but ed BC l i ght cor r osi on d i st r i but ed C D s in g le la r g e p it D A l i ght scal i ng, ear l y cor r osi on 58 AB l i ght scal i ng, ear l y cor r osi on B C h e a v y c o rr o s i o n w i th m u l ti p l e l a rg e p i ts C D l i ght scal i ng, m i ddl e st age cor r osi on, di st r i but ed D A scal i ng, m i ddl e st age cor r osi on CF RP Bar D escr i pt i on 57 AB l i ght scal i ng, conce nt r at ed co r r osi on BC l i ght scal i ng, ear l y cor r osi on C D l i ght scal i ng, ear l y cor r osi on D A l i ght scal i ng, conce nt r at ed co r r osi on 56 AB l i ght scal i ng, ear l y cor r osi on BC l i ght scal i ng, ear l y cor r osi on C D l i ght scal i ng, ear l y cor r osi on D A l i ght scal i ng, ear l y cor r osi on 5 5 A B c o n c e n tr a te d c o r r o s io n la r g e p it BC m edi um cor r osi on, m edi um scal i ng, conce nt r at ed C D di st r i but ed co r r osi on, ear l y st age D A ear l y cor r osi on, l i t e da m age 54 AB scal i ng, conce nt r at ed p i t s, m i ddl e st age BC scal i ng, m i ddl e st age cor r osi on C D scal i ng, m i ddl e st age cor r osi on D A ear l y st age

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113 App e ndix A ( Co nt inue d) Tabl e A.2 De scription of Dam age G F RP GFRP Bar D escr i pt i on 41 AB concent r at ed d am age wi t h scal i ng, m edi um st age BC ear l y di st r i but ed co r r osi on C D c o n c e n tra te d d a m a g e s c a l i n g w i th p i ts D A ear l y st age, di st r i but ed co r r osi on 53 AB di st r i but ed co r r osi on, m edi um scal i ng BC di st r i but ed co r r osi on, l i ght scal i ng C D ear l y st age, l i ght scal i ng D A ear l y st age, di st r i but ed co r r osi on 40 AB ear l y st age BC l i ght l y di st r i but ed co r r osi on C D concent r at ed d am age D A ear l y cor r osi on 5 2 A B e a r ly c o r r o s io n c o n c e n tr a te d a t m id d le B C lig h t s c a lin g e a r ly c o r r o s io n c o n c e n tr a te d p it C D m e d i u m s c a l i n g tu rn i n g to p i ts D A l i g h t c o rr o s i o n c o n c e n tra te d a t p i ts GFRP Bar D escr i pt i on 51 AB di st r i but ed co r r osi on, ear l y st age BC di st r i but ed co r r osi on, ear l y st age C D ear l y st age, di st r i but ed co r r osi on D A di st r i but ed co r r osi on, ear l y st age 50 AB di st r i but ed co r r osi on, m edi um scal i ng BC di st r i but ed co r r osi on, l i ght scal i ng C D di st r i but ed co r r osi on, m edi um scal i ng D A di st r i but ed co r r osi on, m edi um scal i ng 47 AB concent r at ed d am age BC m edi um cor r osi on, m edi um scal i ng C D ear l y scal i ng D A ear l y st age di st r i but ed co r r osi on 48 AB ear l y di st r i but ed co r r osi on BC concent r at ed l ar ge p i t s, hea v y cor r osi on C D ear l y cor r osi on, conce nt r at ed d am age D A ear l y conce nt r at ed d am age

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114 App e ndix A ( Co nt inue d) Tabl e A. 3 D e sc r ipt ion of D am ag e Out doo r Co nt r ols O ut door C ont r ol Bar D escr i pt i on 38 AB di st r i but ed co r r osi on BC heav y scal i ng, cr i t i cal l y dam aged C D heav y scal i ng, di st r i but ed co r r osi on D A di st r i but ed co r r osi on 44 AB di st r i but ed e ar l y cor r osi on B C h e a v y s c a l i n g l a rg e p i ts C D di st r i but ed co r r osi on, m edi um scal i ng D A h e a v y s c a l i n g l a rg e p i ts 45 AB ear l y st age, di st r i but ed co r r osi on BC concent r at ed d am age, hea v y scal i ng C D heav y scal i ng, cr i t i cal l y dam aged D A di st r i but ed co r r osi on 46 AB di st r i but ed co r r osi on, l i ght scal i ng BC di st r i but ed d am age C D di st r i but ed, hea v y scal i ng D A di st r i but ed co r r osi on, l i ght scal i ng Tabl e A. 4 D e sc r ipt ion of D am ag e Indo or Co nt r ols I ndoor C ont r ol Bar D escr i pt i on 39 AB ear l y st age BC ear l y st age, l i ght scal i ng C D heav y scal i ng, l ar ge p i t s, cr i t i cal l y dam aged D A ear l y st age, l i ght scal i ng 49 AB ear l y di st r i but ed co r r osi on, l i ght scal i ng B C l a te c o rr o s i o n h a e v y s c a l i n g l a rg e p i ts C D di st r i but ed co r r osi on, ear l y st age D A heav y scal i ng, di st r i but ed d am age

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115 App e ndix A ( Co nt inue d) Tabl e A. 5 Ob se r ve d Da m ag e Sc ale Su r f ac e Cor r os i on Li ght t o no ne 030% M edi um t o l i ght 3060% H eav y t o m edi um >6 0% Pi t t i ng Dam age Sm al l pi t s < 1/ 8" M edi um pi t s 1/ 4" 1/ 8" Lar ge p i t s >1 / 4" Pi t t i ng Fr equen cy Li ght t o no ne 0 t o 5 M edi um t o l i ght 6 t o 15 H eav y t o m edi um >1 5

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116 App e ndix A ( Co nt inue d) Tabl e A.6 Observe d Corrosion Dam age CF RP CF RP Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 43 AB l i ght m edi um l i ght BC l i ght m edi um l i ght C D m edi um sm al l l i ght D A l i ght sm al l l i ght 59 AB m edi um l ar ge l i ght BC m edi um sm al l l i ght C D m edi um sm al l l i ght D A m edi um m edi um l i ght 42 AB l i ght sm al l l i ght BC m edi um sm al l l i ght C D l i ght l ar ge l i ght D A l i ght m edi um l i ght 58 AB l i ght m edi um l i ght B C he avy l arg e he avy C D heav y sm al l m edi um D A m ed i um s m al l he avy C FR P Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 57 AB l i ght l ar ge l i ght BC m edi um sm al l l i ght C D l i ght sm al l l i ght D A l i ght l ar ge l i ght 56 AB l i ght m edi um l i ght BC l i ght sm al l l i ght C D l i ght m edi um l i ght D A l i ght sm al l l i ght 55 AB l i ght l ar ge l i ght BC m edi um m edi um l i ght C D m edi um sm al l l i ght D A l i ght m edi um l i ght 54 AB m edi um l ar ge l i ght BC m edi um l ar ge l i ght C D m edi um l ar ge m edi um D A l i ght sm al l l i ght

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117 App e ndix A ( Co nt inue d) Tabl e A.7 Observe d Corrosion Dam age G F RP GFRP Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 41 AB l i ght l ar ge m edi um BC m edi um sm al l l i ght C D m edi um l ar ge m edi um D A l i ght sm al l l i ght 53 AB m edi um l ar ge l i ght BC m edi um m edi um l i ght C D l i ght sm al l l i ght D A m edi um sm al l l i ght 40 AB l i ght sm al l l i ght BC l i ght m edi um l i ght C D m edi um l ar ge l i ght D A l i ght sm al l l i ght 52 AB l i ght m edi um l i ght BC l i ght l ar ge l i ght C D l i ght m edi um m edi um D A l i gh t m ed i um he avy GFRP Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 51 AB m edi um m edi um m edi um BC m edi um m edi um m edi um C D m edi um sm al l l i ght D A m edi um m edi um l i ght 50 AB l i ght m edi um l i ght BC m edi um m edi um l i ght C D m edi um m edi um l i ght D A m edi um m edi um l i ght 47 AB l i ght l ar ge l i ght BC l i ght m edi um l i ght C D m edi um sm al l l i ght D A l i ght sm al l l i ght 48 AB m edi um m edi um l i ght BC m edi um l ar ge m edi um C D l i ght l ar ge l i ght D A l i ght m edi um l i ght

PAGE 138

118 App e ndix A ( Co nt inue d) Tabl e A. 8 Ob se r ve d Co r r os ion Da m ag e Out doo r Co nt r ols O ut door C ont r ol Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 38 AB l i ght sm al l l i ght B C m ed i um l arg e he avy C D m edi um l ar ge m edi um D A l i ght sm al l l i ght 44 AB l i ght sm al l l i ght B C m ed i um l arg e he avy C D m edi um l ar ge m edi um D A m ed i um l arg e he avy 45 AB l i ght sm al l l i ght BC l i ght l ar ge l i ght C D m edi um l ar ge m edi um D A l i ght sm al l l i ght 46 AB m edi um m edi um l i ght BC m edi um sm al l l i ght C D m ed i um l arg e he avy D A l i ght m edi um l i ght Tabl e A. 9 Ob se r ve d Co r r os ion Da m ag e Indo or Co nt r ols I ndoor C ont r ol Sur f ace Cor r osi on Pi t t i ng Dam age Pi t t i ng Fr equen cy 39 AB l i ght m edi um l i ght BC l i ght sm al l l i ght C D m ed i um l arg e he avy D A l i ght m edi um l i ght 49 AB m edi um sm al l m edi um BC m edi um l ar ge m edi um C D m edi um sm al l l i ght D A l i ght l ar ge m edi um

PAGE 139

119 Append ix B Pr ofi led Strand Results F igure B.1 P rofile of 38ab F igure B.2 P rofile of 38cd

PAGE 140

120 App e ndix B ( Co nt inue d) F igu r e B.3 P r ofil e of 38 da F igu r e B.4 P r ofil e of 39 bc

PAGE 141

121 App e ndix B ( Co nt inue d) F igure B.5 P rofile of 39cd F igu r e B.6 P r ofil e of 39 da

PAGE 142

122 App e ndix B ( Co nt inue d) F igure B.7 P rofile of 40ab F igu r e B.8 P r ofil e of 40 bc

PAGE 143

123 App e ndix B ( Co nt inue d) F igure B.9 P rofile of 40cd F igu r e B.1 0 P r ofil e of 40 da

PAGE 144

124 App e ndix B ( Co nt inue d) F igure B.11 P rofile of 41ab F igu r e B.1 2 P r ofil e of 41 bc

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125 App e ndix B ( Co nt inue d) F igure B.13 P rofile of 41cd F igu r e B.1 4 P r ofil e of 41 da

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126 App e ndix B ( Co nt inue d) F igure B.15 P rofile of 42ab F igu r e B.1 6 P r ofil e of 42 bc

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127 App e ndix B ( Co nt inue d) F igure B.17 P rofile of 42cd F igu r e B.1 8 P r ofil e of 42 da

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128 App e ndix B ( Co nt inue d) F igure B.19 P rofile of 43ab F igu r e B.2 0 P r ofil e of 43 bc

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129 App e ndix B ( Co nt inue d) F igure B.21 P rofile of 43cd F igu r e B.2 2 P r ofil e of 43 da

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130 App e ndix B ( Co nt inue d) F igure B.23 P rofile of 44ab F igu r e B.2 4 P r ofil e of 44 bc

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131 App e ndix B ( Co nt inue d) F igure B.25 P rofile of 44cd F igu r e B.2 6 P r ofil e of 44 da

PAGE 152

132 App e ndix B ( Co nt inue d) F igure B.27 P rofile of 45ab F igu r e B.2 8 P r ofil e of 45 bc

PAGE 153

133 App e ndix B ( Co nt inue d) F igure B.29 P rofile of 45cd F igu r e B.3 0 P r ofil e of 45 da

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134 App e ndix B ( Co nt inue d) F igure B.31 P rofile of 46ab F igu r e B.3 2 P r ofil e of 46 bc

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135 App e ndix B ( Co nt inue d) F igure B.33 P rofile of 46cd F igu r e B.3 4 P r ofil e of 46 da

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136 App e ndix B ( Co nt inue d) F igure B.35 P rofile of 47ab F igu r e B.3 6 P r ofil e of 47 bc

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137 App e ndix B ( Co nt inue d) F igure B.37 P rofile of 47cd F igu r e B.3 8 P r ofil e of 47 da

PAGE 158

138 App e ndix B ( Co nt inue d) F igure B.39 P rofile of 48ab F igu r e B.4 0 P r ofil e of 48 bc

PAGE 159

139 App e ndix B ( Co nt inue d) F igure B.41 P rofile of 48cd F igu r e B.4 2 P r ofil e of 48 da

PAGE 160

140 App e ndix B ( Co nt inue d) F igure B.43 P rofile of 49ab F igu r e B.4 4 P r ofil e of 49 bc

PAGE 161

141 App e ndix B ( Co nt inue d) F igure B.45 P rofile of 49cd F igu r e B.4 6 P r ofil e of 49 da

PAGE 162

142 App e ndix B ( Co nt inue d) F igure B.47 P rofile of 50ab F igu r e B.4 8 P r ofil e of 50 bc

PAGE 163

143 App e ndix B ( Co nt inue d) F igure B.49 P rofile of 50cd F igu r e B.5 0 P r ofil e of 50 da

PAGE 164

144 App e ndix B ( Co nt inue d) F igure B.51 P rofile of 51ab F igu r e B.5 2 P r ofil e of 51 bc

PAGE 165

145 App e ndix B ( Co nt inue d) F igure B.53 P rofile of 51cd F igu r e B.5 4 P r ofil e of 51 da

PAGE 166

146 App e ndix B ( Co nt inue d) F igure B.55 P rofile of 52ab F igu r e B.5 6 P r ofil e of 52 bc

PAGE 167

147 App e ndix B ( Co nt inue d) F igure B.57 P rofile of 52cd F igu r e B.5 8 P r ofil e of 52 da

PAGE 168

148 App e ndix B ( Co nt inue d) F igure B.59 P rofile of 53ab F igu r e B.6 0 P r ofil e of 53 bc

PAGE 169

149 App e ndix B ( Co nt inue d) F igure B.61 P rofile of 53cd F igu r e B.6 2 P r ofil e of 53 da

PAGE 170

150 App e ndix B ( Co nt inue d) F igure B.63 P rofile of 54ab F igu r e B.6 4 P r ofil e of 54 bc

PAGE 171

151 App e ndix B ( Co nt inue d) F igure B.65 P rofile of 54cd F igu r e B.6 6 P r ofil e of 54 da

PAGE 172

152 App e ndix B ( Co nt inue d) F igure B.67 P rofile of 55ab F igu r e B.6 8 P r ofil e of 55 bc

PAGE 173

153 App e ndix B ( Co nt inue d) F igure B.69 P rofile of 55cd F igu r e B.7 0 P r ofil e of 55 da

PAGE 174

154 App e ndix B ( Co nt inue d) F igure B.71 P rofile of 56ab F igu r e B.7 2 P r ofil e of 56 bc

PAGE 175

155 App e ndix B ( Co nt inue d) F igure B.73 P rofile of 56cd F igu r e B.7 4 P r ofil e of 56 da

PAGE 176

156 App e ndix B ( Co nt inue d) F igure B.75 P rofile of 57ab F igu r e B.7 6 P r ofil e of 57 bc

PAGE 177

157 App e ndix B ( Co nt inue d) F igure B.77 P rofile of 57cd F igu r e B.7 8 P r ofil e of 57 da

PAGE 178

158 App e ndix B ( Co nt inue d) F igure B.79 P rofile of 58ab F igu r e B.8 0 P r ofil e of 58 bc

PAGE 179

159 App e ndix B ( Co nt inue d) F igure B.81 P rofile of 58cd F igu r e B.8 2 P r ofil e of 58 da

PAGE 180

160 App e ndix B ( Co nt inue d) F igure B.83 P rofile of 59ab F igu r e B.8 4 P r ofil e of 59 bc

PAGE 181

161 App e ndix B ( Co nt inue d) F igure B.85 P rofile of 59cd F igu r e B.8 6 P r ofil e of 59 da

PAGE 182

162 Append ix C Tension Test Re sults F igu r e C. 1 Te nsio n Te st 38 ab F igu r e C. 2 Te nsio n Te st 38 c d

PAGE 183

163 App e ndix C ( Co nt inue d) F igure C.3 Tension T est 38da F igu r e C. 4 Te nsio n Te st 39 ab

PAGE 184

164 App e ndix C ( Co nt inue d) F igure C.5 Tension T est 39bc F igure C.6 Tension T est 39da

PAGE 185

165 App e ndix C ( Co nt inue d) F igu r e C. 7 Te nsio n Te st 40 ab F igure C.8 Tension T est 40bc

PAGE 186

166 App e ndix C ( Co nt inue d) F igu r e C. 9 Te nsio n Te st 40 c d F igure C.10 Tension T est 40da

PAGE 187

167 App e ndix C ( Co nt inue d) F igu r e C. 11 Te nsio n Te st 41 ab F igure C.12 Tension T est 41bc

PAGE 188

168 App e ndix C ( Co nt inue d) F igu r e C. 13 Te nsio n Te st 41 c d F igure C.14 Tension T est 41da

PAGE 189

169 App e ndix C ( Co nt inue d) F igu r e C. 15 Te nsio n Te st 42 ab F igure C.16 Tension T est 42bc

PAGE 190

170 App e ndix C ( Co nt inue d) F igu r e C. 17 Te nsio n Te st 42 c d F igure C.18 Tension T est 42da

PAGE 191

171 App e ndix C ( Co nt inue d) F igu r e C. 19 Te nsio n Te st 43 ab F igure C.20 Tension T est 43bc

PAGE 192

172 App e ndix C ( Co nt inue d) F igu r e C. 21 Te nsio n Te st 43 c d F igure C.22 Tension T est 43da

PAGE 193

173 App e ndix C ( Co nt inue d) F igu r e C. 23 Te nsio n Te st 44 ab F igure C.24 Tension T est 44bc

PAGE 194

174 App e ndix C ( Co nt inue d) F igu r e C. 25 Te nsio n Te st 44 c d F igure C.26 Tension T est 44da

PAGE 195

175 App e ndix C ( Co nt inue d) F igu r e C. 27 Te nsio n Te st 45 ab F igure C.28 Tension T est 45bc

PAGE 196

176 App e ndix C ( Co nt inue d) F igu r e C. 29 Te nsio n Te st 45 c d F igure C.30 Tension T est 45da

PAGE 197

177 App e ndix C ( Co nt inue d) F igu r e C. 31 Te nsio n Te st 46 ab F igure C.32 Tension T est 46bc

PAGE 198

178 App e ndix C ( Co nt inue d) F igu r e C. 33 Te nsio n Te st 46 c d F igure C.34 Tension T est 46da

PAGE 199

179 App e ndix C ( Co nt inue d) F igu r e C. 35 Te nsio n Te st 47 ab F igure C.36 Tension T est 47bc

PAGE 200

180 App e ndix C ( Co nt inue d) F igu r e C. 37 Te nsio n Te st 47 c d F igure C.38 Tension T est 47da

PAGE 201

181 App e ndix C ( Co nt inue d) F igu r e C. 39 Te nsio n Te st 48 ab F igure C.40 Tension T est 48bc

PAGE 202

182 App e ndix C ( Co nt inue d) F igu r e C. 41 Te nsio n Te st 48 c d F igure C.42 Tension T est 48da

PAGE 203

183 App e ndix C ( Co nt inue d) F igu r e C. 43 Te nsio n Te st 49 ab F igure C.44 Tension T est 49bc

PAGE 204

184 App e ndix C ( Co nt inue d) F igu r e C. 45 Te nsio n Te st 49 c d F igure C.46 Tension T est 49da

PAGE 205

185 App e ndix C ( Co nt inue d) F igu r e C. 47 Te nsio n Te st 50 ab F igure C.48 Tension T est 50bc

PAGE 206

186 App e ndix C ( Co nt inue d) F igu r e C. 49 Te nsio n Te st 50 c d F igure C.50 Tension T est 50da

PAGE 207

187 App e ndix C ( Co nt inue d) F igu r e C. 51 Te nsio n Te st 51 ab F igure C.52 Tension T est 51bc

PAGE 208

188 App e ndix C ( Co nt inue d) F igu r e C. 53 Te nsio n Te st 51 c d F igure C.54 Tension T est 51da

PAGE 209

189 App e ndix C ( Co nt inue d) F igu r e C. 55 Te nsio n Te st 52 ab F igure C.56 Tension T est 52bc

PAGE 210

190 App e ndix C ( Co nt inue d) F igu r e C. 57 Te nsio n Te st 52 c d F igure C.58 Tension T est 52da

PAGE 211

191 App e ndix C ( Co nt inue d) F igu r e C. 59 Te nsio n Te st 53 ab F igure C.60 Tension T est 53bc

PAGE 212

192 App e ndix C ( Co nt inue d) F igu r e C. 61 Te nsio n Te st 53 c d F igure C.62 Tension T est 53da

PAGE 213

193 App e ndix C ( Co nt inue d) F igu r e C. 63 Te nsio n Te st 54 ab F igure C.64 Tension T est 54bc

PAGE 214

194 App e ndix C ( Co nt inue d) F igu r e C. 65 Te nsio n Te st 54 c d F igure C.66 Tension T est 54da

PAGE 215

195 App e ndix C ( Co nt inue d) F igu r e C. 67 Te nsio n Te st 55 ab F igure C.68 Tension T est 55bc

PAGE 216

196 App e ndix C ( Co nt inue d) F igu r e C. 69 Te nsio n Te st 55 c d F igure C.70 Tension T est 55da

PAGE 217

197 App e ndix C ( Co nt inue d) F igu r e C. 71 Te nsio n Te st 56 ab F igure C.72 Tension T est 56bc

PAGE 218

198 App e ndix C ( Co nt inue d) F igu r e C. 73 Te nsio n Te st 56 c d F igure C.74 Tension T est 56da

PAGE 219

199 App e ndix C ( Co nt inue d) F igu r e C. 75 Te nsio n Te st 57 ab F igure C.76 Tension T est 57bc

PAGE 220

200 App e ndix C ( Co nt inue d) F igu r e C. 77 Te nsio n Te st 57 c d F igure C.78 Tension T est 57da

PAGE 221

201 App e ndix C ( Co nt inue d) F igu r e C. 79 Te nsio n Te st 58 ab F igure C.80 Tension T est 58bc

PAGE 222

202 App e ndix C ( Co nt inue d) F igu r e C. 81 Te nsio n Te st 58 c d F igure C.82 Tension T est 58da

PAGE 223

203 App e ndix C ( Co nt inue d) F igu r e C. 83 Te nsio n Te st 59 ab F igure C.84 Tension T est 59bc

PAGE 224

204 App e ndix C ( Co nt inue d) F igu r e C. 85 Te nsio n Te st 59 c d F igure C.86 Tension T est 59da

PAGE 225

205 App e ndix C ( Co nt inue d) F igure C.87 Tension T est C1 F igure C.88 Tension T est C2

PAGE 226

206 App e ndix C ( Co nt inue d) F igure C.89 Tension T est C3 F igure C.90 Tension T est C4

PAGE 227

207 App e ndix C ( Co nt inue d) F igure C.91 Tension T est C5 F igure C.92 Tension T est C6

PAGE 228

208 App e ndix C ( Co nt inue d) F igure C.93 Tension T est C7 F igure C.94 Tension T est S1

PAGE 229

209 App e ndix C ( Co nt inue d) F igure C.95 Tension T est S2 F igure C.96 Tension T est S3

PAGE 230

210 App e ndix C ( Co nt inue d) F igure C.97 Tension T est S4 F igure C.98 Tension T est S5

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211 App e ndix C ( Co nt inue d) F igure C.99 Tension T est S6


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Effects of corrosion on steel reinforcement
h [electronic resource] /
by David Ostrofsky.
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[Tampa, Fla.] :
b University of South Florida,
2007.
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ABSTRACT: Corroded steel in concrete is a structural issue that plaques concrete structures in coastal regions. Traditionally corroded steel strength is calculated from a distributed area loss due to corrosion over the entire surface of the steel and reducing the capacity accordingly. In reality, corrosion attacks localized regions creating pits and reducing the cross section in a small region which amplifies the effects of corrosion. Stress concentrations at the corrosion pitting damage may further reduce the tensile capacity of the steel. A study of corrosion damage and strength associated with pitting damage can assist in understanding the ultimate tensile capacity of corroded steel strands, better correlations are needed to estimate actual strength of damaged steel. The focus of this thesis is on seven-wire prestress steel strands with various stages of induced corrosion. Each strand has been documented, profiled, and measured in order to correlate physical damage with ultimate capacity.
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Thesis (M.S.)--University of South Florida, 2007.
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Includes bibliographical references.
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Text (Electronic thesis) in PDF format.
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Advisor: Austin Mullins, Ph.D.
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Corrosion.
Tensile.
Stress.
Piles.
Prestress steel.
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Dissertations, Academic
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x Civil Engineering
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t USF Electronic Theses and Dissertations.
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u http://digital.lib.usf.edu/?e14.2258