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APPENDIX A. PHOTOGRAPHS OF TEST SLABS
AT END OF OUTDOOR EXPOSURE AND AUTOPSIED BARS

 

Figure 45. Slab #1 front, rear, and top views with specifications
Figure 45. Slab #1 front, rear, and top views with specifications. Photos. (A) Slab number 1 front view shows the 1B label on the left and 1A on the right. The top has two green spots indicating bars and the bottom has four with no corrosion or staining. Wires connect to the top left and all four bottom bars.
a) Front View		 Figure 45. Slab #1 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and has only one wire in the top left bar with clean concrete and no corrosion.
b) Rear View
Figure 45. Slab #1 front, rear, and top views with specifications. Photos. (C) The top view is smooth and uncracked.
c) Top View
d) Slab specifications
Specimen ID 1A 1B
Top mat Coating D Coating D
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 46. Slab #1 extracted rebars condition. Photo. Before autopsy, the top mat bent ECRs are yellow-colored with several coating defects circled in red and black.
a) Top bars

Figure 46. Slab #1 extracted rebars condition. Photo. Before autopsy, the bottom mat straight black bars show corrosion on the right ends and white concrete residue adhered to the bar throughout.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 46. Slab #1 extracted rebars condition

Figure 47. Slab #1 after autopsy. Photo. After autopsy, the top mat bent ECRs are yellow-colored with the left (B-T) severally delaminated with corroded substrate showing.
a) Top bars

Figure 47. Slab #1 after autopsy. Photo. After autopsy, the cleaned bottom mat straight black bars show corrosion on the ends but otherwise are uniformly gray.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 47. Slab #1 after autopsy

Figure 48. Slab #2 front, rear, and top views with specifications
Figure 48. Slab #2 front, rear, and top views with specifications. Photos. (A) Slab number 2 front view shows the 2B label on the left and 2A on the right. The top has two green spots indicating bars and the bottom left bar has a corrosion spot while the concrete and the rest are clean. Wires connect the top and bottom bars of 2B and the same for 2A.
a) Front View		 Figure 48. Slab #2 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and clean with no wires.
b) Rear View
Figure 48. Slab #2 front, rear, and top views with specifications. Photos. (C) The top view is smooth and uncracked.
c) Top View
d) Slab Specifications
Specimen ID 2A 2B
Top mat Coating F Coating F
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Coating F
Coating defect (%) 0.004 0.5
Precracked No No

Figure 49. Slab #2 extracted rebars condition. Photo. Before autopsy, the top mat straight ECRs are shiny olive green. The second from the top ECR (B-T) shows deteriorated coating condition.

Figure 49. Slab #2 extracted rebars condition

Figure 50. Slab #2 after autopsy. Photo. After autopsy, a top mat ECR labeled B-T shows significant delamination and corrosion on the substrate. The right half of the fifth bar down (B-B1) shows a similar corrosion pattern. The remaining bars show good condition.

Figure 50. Slab #2 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 51. Slab #3 front, rear, and top views with specifications
Figure 51. Slab #3 front, rear, and top views with specifications. Photos. (A) Slab number 3 front view shows the 3B label on the left and 3A on the right. The top right bar and bottom 3B right and all 3As show corrosion. Wires connect the top and bottom bars of 3B and the same for 3A.
a) Front View		 Figure 51. Slab #3 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows no wires. Heavy corrosion shows around the top left bar that has seeped into the center.
b) Rear view
Figure 51. Slab #3 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and has a crack on the right side.
c) Top View
d) Slab specifications
Specimen ID 3A 3B
Top mat Coating C Coating C
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 52. Slab #3 extracted rebars condition. Photo. Before autopsy, the top mat straight ECR (A-T) looks mossy green with hairline cracks and coating blisters. The second ECR is spring green with hairline cracks in the center. The bottom mat four black bars show white concrete residue encrusted with rust.

Figure 52. Slab #3 extracted rebars condition

Figure 53. Slab #3 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated with corrosion spots, the second top mat ECR (B-T) is lime green with significant delamination and corrosion in the center, and the cleaned bottom mat four black bars look good with minimal corrosion damage.

Figure 53. Slab #3 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 54. Slab #4 front, rear, and top views with specifications
Figure 54. Slab #4 front, rear, and top views with specifications. Photos. (A) Slab number 4 front view shows the 4B label on the left and 4A on the right. The top two bars and the bottom and the third from the left on the bottom show corrosion. Wires connect the top and bottom bars of 4B and the same for 4A.
a) Front View		 Figure 54. Slab #4 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows one wire. The corrosion pattern is the same as the front, but heavier.
b) Rear View
Figure 54. Slab #4 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and has several cracks, mainly radiating from the right side.
c) Top View
d) Slab specifications
Specimen ID 4A 4B
Top mat Coating C Coating C
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 55. Slab #4 extracted rebars condition. Photo. Before autopsy, the top mat bent ECRs exhibit severe coating damage.
a) Top bars

Figure 55. Slab #4 extracted rebars condition. Photo. Before autopsy, the bottom mat straight black bars show minor dark discoloration and concrete residue adhered on the surface.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 55. Slab #4 extracted rebars condition

Figure 56. Slab #4 after autopsy. Photo. After autopsy, the top mat bent ECRs are completely delaminated and corroded.
a) Top bars

Figure 56. Slab #4 after autopsy. Photo. After autopsy, the cleaned bottom mat bars are dark-colored and show good performance with minimal corrosion damage.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 56. Slab #4 after autopsy

Figure 57. Slab #5 front, rear, and top views with specifications
Figure 57. Slab #5 front, rear, and top views with specifications. Photos. (A) Slab number 5 front view shows the 5B label on the left and 5A on the right. The top bars show corrosion and the first and second from the left on the bottom have corrosion with cracks throughout. Wires connect the top and bottom bars of 5B and the same for 5A.
a) Front View		 Figure 57. Slab #5 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled with cracks and corrosion on the top bars and cracks in the third from the left bar.
b) Rear View
Figure 57. Slab #5 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and has several vertical cracks with a large corrosion spot in the middle.
c) Top View
d) Slab specifications
Specimen ID 5A 5B
Top mat Black Black
Bar shape (straight/bent) Straight Straight
Coating defect (%) N/A N/A
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 58. Slab #5 extracted rebars condition. Photo. Before autopsy, the two top mat straight black bars (A-T and B-T,) exhibit severe corrosion. The bottom mat four black bars (A-B1, A-B2, B-B1 and B-B2) show minor corrosion with some concrete residue.

Figure 58. Slab #5 extracted rebars condition

Figure 59. Slab #5 after autopsy. Photo. After autopsy, two top mat black bars (A-T and B-T) reveal significant metal loss due to intensive corrosion The cleaned two bottom mat black bars (A-B1 and B-B2) show moderate pitting corrosion. The remaining two bottom black bars (A-B2 and B-B1) show shiny surfaces with generally good condition except for rust on the right end of B-B1.

Figure 59. Slab #5 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 60. Slab #6 front, rear, and top views with specifications
Figure 60. Slab #6 front, rear, and top views with specifications. Photos. (A) Slab number 6 front view shows the 6B label on the left and 6A on the right. The top right bar shows corrosion seeping to between the third and four bars on the bottom with minor cracks. Wires connect the top and bottom bars of 6B and the same for 6A.
a) Front View		 Figure 60. Slab #6 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled with minor cracks and the same corrosion pattern radiating into the cracks as the front view.
b) Rear View
Figure 60. Slab #6 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and has one prominent vertical crack.
c) Top View
d) Slab specifications
Specimen ID 6A 6B
Top mat Coating B Coating B
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 61. Slab #6 extracted rebars condition. Photo. Before autopsy, one of the top mat straight ECRs (B-T, mistakenly labeled for A-T) exhibits significant coating degradation due to corrosion. The other top mat ECR (A-T, mistakenly labeled for B-T) shows good condition. The bottom mat four black bars show no corrosion.

Figure 61. Slab #6 extracted rebars condition

Figure 62. Slab #6 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated with significant substrate corrosion and the other top mat ECR (B-T) still looks very good without noticeable coating damage. The cleaned bottom mat four black bars look good.

Figure 62. Slab #6 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 63. Slab #7 front, rear, and top views with specifications
Figure 63. Slab #7 front, rear, and top views with specifications. Photos. (A) Slab number 7 front view shows the 7B label on the left and 7A on the right. The top and bottom right bars show corrosion. Wires connect the top and bottom bars of 7B and the same for 7A.
a) Front View		 Figure 63. Slab #7 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled with a water dike and corrosion around all the bars except the top right.
b) Rear View
Figure 63. Slab #7 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and shows the two prominent vertical precracks.
c) Top View
d) Slab specifications
Specimen ID 7A 7B
Top mat Coating A Coating A
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes
Figure 64. Slab #7 extracted rebars condition. Photo. Before autopsy, the two top mat straight ECRs (A-T and B-T) exhibit hairline cracks and coating blisters with coating discoloration on the A-T. The bottom mat four black bars exhibit moderate corrosion .

Figure 64. Slab #7 extracted rebars condition

Figure 65. Slab #7 after autopsy. Photo. After autopsy, a top mat straight ECR (A-T) is completely delaminated due to extensive corrosion, and the second ECR(B-T) shows moderate coating delamination. The cleaned bottom mat four black bars look good without sign of corrosion.

Figure 65. Slab #7 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 66. Slab #8 front, rear, and top views with specifications
Figure 66. Slab #8 front, rear, and top views with specifications. Photos. (A) Slab number 8 front view shows the faint 8B label on the left and 8A on the right. Cracks show between the bars and with corrosion around them with the top left and third on the bottom the worst. Wires connect the top and bottom bars of 8A and on the bottom of 8B.
a) Front View		 Figure 66. Slab #8 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled with the water dike broken off. Cracks appear around all the bars, and the worst corrosion is around the top bars.
b) Rear View
Figure 66. Slab #8 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and has prominent corrosion marks in the lower right corner.
c) Top View
d) Slab specifications
Specimen ID 8A 8B
Top mat Coating F Coating F
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 67. Slab #8 extracted rebars condition. Photo. Before autopsy, the top mat bent ECRs exhibit corrosion.
a) Top bars

Figure 67. Slab #8 extracted rebars condition. Photo. Before autopsy, all the straight bottom mat bars exhibit severe corrosion.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 67. Slab #8 extracted rebars condition

Figure 68. Slab #8 after autopsy. Photo. After autopsy, the top mat bent ECRs are delaminated and severely corroded.
a) Top bars

Figure 68. Slab #8 after autopsy. Photo. After autopsy, the cleaned straight bottom mat black bars are severely pitted.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 68. Slab #8 after autopsy

Figure 69. Slab #9 front, rear, and top views with specifications
Figure 69. Slab #9 front, rear, and top views with specifications. Photos. (A) Slab number 9 front view shows the 9B label on the left and 9A on the right. The bars are pale green and the concrete looks clear and with no cracks. Wires connect the top and bottom bars of 9B; the same is true for 9A.
a) Front View		 Figure 69. Slab #9 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing the water dike with blue tape and some corrosion drips on the bottom bars.
b) Rear View
Figure 69. Slab #9 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with minor cracks.
c) Top View
d) Slab specifications
Specimen ID 9A 9B
Top mat Coating B Coating B
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Coating B
Coating defect (%) 0.5 0.004
Precracked No No

Figure 70. Slab #9 extracted rebars condition. Photo. Before autopsy, the straight ECRs show good condition except that a top map ECR (A-T) shows major blistering and significant coating deterioration.

Figure 70. Slab #9 extracted rebars condition

Figure 71. Slab #9 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated revealing severe corrosion of substrate, and the other top mat ECR (B-T) is still coated blue with one major delamination spot, but no corrosion underneath. The four bottom mat ECRs look good without coating deterioration.

Figure 71. Slab #9 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 72. Slab #10 front, rear, and top views with specifications
Figure 72. Slab #10 front, rear, and top views with specifications. Photos. (A) Slab number 10 front view shows the 10B label on the left and 10A on the right. The green bars and the concrete looks clear, with no cracks with the water dike prominent. Wires connect the top and bottom bars of 10B and the same for 10A.
a) Front View		 Figure 72. Slab #10 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing minor corrosion drips from the middle to the bottom.
b) Rear View
Figure 72. Slab #10 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with no visible cracks.
c) Top View
d) Slab specifications
Specimen ID 10A 10B
Top mat Coating A Coating A
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Coating A
Coating defect (%) 0.5 0.004
Precracked No No

Figure 73. Slab #10 extracted rebars condition. Photo. Before autopsy, all straight top and bottom mat ECRs look good.

Figure 73. Slab #10 extracted rebars condition

Figure 74. Slab #10 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is partially delaminated with minor substrate corrosion. The other five ECRs still look good.

Figure 74. Slab #10 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 75. Slab #11 front, rear, and top views with specifications
Figure 75. Slab #11 front, rear, and top views with specifications. Photos. (A) Slab number 11 front view shows the 11B label on the left and 11A on the right. The green bars and the concrete look clear with no cracks but major corrosion shows around the top and third from left bottom bars. Wires connect the top and bottom bars of 11A and the bottom bars for 11A.
a) Front View		 Figure 75. Slab #11 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing the water dike with minor visible cracks.
b) Rear View
Figure 75. Slab #11 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with a few visible cracks.
c) Top View
d) Slab specifications
Specimen ID 11A 11B
Top mat Coating B Coating B
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 76. Slab #11 extracted rebars condition. Photo. Before autopsy, the top mat two bent ECRs (A-T and B-T) exhibit moderate coating deterioration.
a) Top bars

Figure 76. Slab #11 extracted rebars condition. Photo. Before autopsy, the bottom mat four black bars look good.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 76. Slab #11 extracted rebars condition

Figure 77. Slab #11 after autopsy. Photo. After autopsy, a top mat bent ECR (A-T) is completely delaminated while the other top mat bent ECR (B-T) is partially delaminated showing some substrate corrosion.
a) Top bars

Figure 77. Slab #11 after autopsy. Photo. After autopsy, the cleaned bottom mat four black bars look good.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 77. Slab #11 after autopsy

Figure 78. Slab #12 front, rear, and top views with specifications
Figure 78. Slab #12 front, rear, and top views with specifications. Photos. (A) Slab number 12 front view shows the 12B label on the left and 12A on the right. The green bars and the concrete look clear, with one minor corroded crack. Wires connect the top and bottom bars of 12B; the same is true for 12A.
a) Front View		 Figure 78. Slab #12 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing minor discoloration but no visible cracks.
b) Rear View

Figure 78. Slab #12 front, rear, and top views with specifications. Photos. (C) The top view is severely mottled gray, with numerous visible cracks.
c) Top View
d) Slab specifications
Specimen ID 12A 12B
Top mat Coating C Coating C
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Coating C
Coating defect (%) 0.5 0.004
Precracked No No

Figure 79. Slab #12 extracted rebars condition. Photo. Before autopsy, the top mat two ECRs (A-T and B-T) show corrosion induced coating deterioration.. All of the bottom mat ECRs show good coating condition.

Figure 79. Slab #12 extracted rebars condition

Figure 80. Slab #12 after autopsy. Photo. After autopsy, both top mat ECRs (A-T and B-T) are completely delaminated and reveal severely corroded substrates. The cleaned bottom mat four ECRs still look good without significant coating deterioration.

Figure 80. Slab #12 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 81. Slab #13 front, rear, and top views with specifications
Figure 81. Slab #13 front, rear, and top views with specifications. Photos. (A) Slab number 13 front view shows the 13A label on the left and 13B on the right. The green bars and the concrete look clear with minor corrosion around the third on the bottom bar. Wires connect the top and bottom bars of 13B; the same is true for 13A.
a) Front View		 Figure 81. Slab #13 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing the water dike and clear concrete with no corrosion.
b) Rear View
Figure 81. Slab #13 front, rear, and top views with specifications. Photos. (C) The top view is clear gray with the two precracks.
c) Top View
d) Slab specifications
Specimen ID 13A 13B
Top mat Coating C Coating C
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 82. Slab #13 extracted rebars condition. Photo. Before autopsy, the top mat two straight ECRs (A-T and B-T) look good. The bottom mat four black bars are corrosion free except at the ends.

Figure 82. Slab #13 extracted rebars condition

Figure 83. Slab #13 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is significantly (more than 40 percent) delaminated and corroded substrate is revealed, while the other top mat ECR (B-T) remains the same. The cleaned bottom mat four black bars look good.

Figure 83. Slab #13 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 84. Slab #14 front, rear, and top views with specifications
Figure 84. Slab #14 front, rear, and top views with specifications. Photos. (A) Slab number 14 front view shows the 14A label on the left and 14B on the right. The green bars and the concrete have major cracks and corrosion around the bottom bars. Wires connect the top and bottom bars of 14B; the same is true for 14A.
a) Front View		 Figure 84. Slab #14 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing cracks connecting the bottom bars and minor discoloration.
b) Rear View
Figure 84. Slab #14 front, rear, and top views with specifications. Photos. (C) The top view is clear gray with the two precracks, the right one showing some corrosion.
c) Top View
d) Slab specifications
Specimen ID 14A 14B
Top mat Coating E Coating E
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 85. Slab #14 extracted rebars condition. Photo. Before autopsy, the top mat two ECRs (A-T and B-T) show blisters and some corrosion. The bottom mat four black bars (A-B1, A-B2, B-B1 and B-B2) are severely corroded.

Figure 85. Slab #14 extracted rebars condition

Figure 86. Slab #14 after autopsy. Photo. After autopsy, while a top mate ECR (A-T) exhibits minor corrosion with small coating disbondment, the other top mat ECR (B-T) suffers extensive coating deterioration and substrate corrosion. Most of the cleaned four bottom mat black bars exhibit severe corrosion damage.

Figure 86. Slab #14 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 87. Slab #15 front, rear, and top views with specifications
Figure 87. Slab #15 front, rear, and top views with specifications. Photos. (A) Slab number 15 front view shows the 15A label on the left and 15B on the right. The green bars and the concrete look clear with no corrosion. Wires connect the top and bottom bars of 15B; the same is true for 15A.
a) Front View		 Figure 87. Slab #15 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing clear concrete with no discoloration.
b) Rear View
Figure 87. Slab #15 front, rear, and top views with specifications. Photos. (C) The top view is clear gray with no discoloration.
c) Top View
d) Slab specifications
Specimen ID 15A 15B
Top mat Coating D Coating D
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 88. Slab #15 extracted rebars condition. Photo. Before autopsy, the top mat two straight ECRs (A-T and B-T) look good other than intentional coating defects. The bottom mat straight black bars show corrosion-free condition.

Figure 88. Slab #15 extracted rebars condition

Figure 89. Slab #15 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is unchanged without coating disbondment, but the other ECR (B-T) is moderately delaminated (more than 30 percent) with corroded substrate. The cleaned bottom mat black bars look good without pitting corrosion.

Figure 89. Slab #15 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 90. Slab #16 front, rear, and top views with specifications
Figure 90. Slab #16 front, rear, and top views with specifications. Photos. (A) Slab number 16 front view shows the 16A label on the left and 16B on the right. The green bars and the concrete look clear, with minor corrosion only on the top left and second from left bottom bars. Wires connect only between the top and bottom bars of 16B.
a) Front View		 Figure 90. Slab #16 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing clear concrete with minor discoloration on the bottom bars.
b) Rear View
Figure 90. Slab #16 front, rear, and top views with specifications. Photos. (C) The top view is clear gray, with no discoloration.
c) Top View
d) Slab specifications
Specimen ID 16A 16B
Top mat Stainless Steel Stainless Steel
Bar shape (straight/bent) Bent Bent
Coating defect (%) N/A N/A
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 91. Slab #16 extracted rebars condition. Photo. Before autopsy, the top mat bent stainless steel bars look clean.
a) Top bars

Figure 91. Slab #16 extracted rebars condition. Photo. Before autopsy, the bottom mat straight black bars show different levels of corrosion starting from no corrosion (A-B1) to moderate corrosion (B-B2).
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 91. Slab #16 extracted rebars condition

Figure 92. Slab #16 after autopsy. Photo. After autopsy, the top mat bent stainless steel bars remain unchanged.
a) Top bars

Figure 92. Slab #16 after autopsy. Photo. After autopsy, the cleaned bottom mat black bars exhibit minimal corrosion damage.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 92. Slab #16 after autopsy

Figure 93. Slab #17 front, rear, and top views with specifications
Figure 93. Slab #17 front, rear, and top views with specifications. Photos. (A) Slab number 17 front view shows the 17A label on the left and 17B on the right. The green bars and the concrete look clear with no corrosion Wires connect the top and bottom bars of 17B; the same is true for 17A.
a) Front View		 Figure 93. Slab #17 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing clear concrete with minor discoloration below the two middle bottom bars.
b) Rear View
Figure 93. Slab #17 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with no corrosion.
c) Top View
d) Slab specifications
Specimen ID 17A 17B
Top mat Coating D Coating D
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Coating D
Coating defect (%) 0.004 0.5
Precracked No No

Figure 94. Slab #17 extracted rebars condition. Photo. Before autopsy, all top mat and bottom mat ECRs look good without any noticeable coating deterioration other than the intentional coating defects.

Figure 94. Slab #17 extracted rebars condition

Figure 95. Slab #17 after autopsy. Photo. After autopsy, all the ECRs show the same condition, except that one top mat ECR (B-T) is partially delaminated with no noticeable corrosion underneath.

Figure 95. Slab #17 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 96. Slab #18 front, rear, and top views with specifications
Figure 96. Slab #18 front, rear, and top views with specifications. Photos. (A) Slab number 18 front view shows the 18A label on the left and 18B on the right. The top left green bar is completely corroded and stains the concrete around it and down to the lower level bars. The remaining bars show minor corrosion discoloration with drips onto the adjacent concrete. Wires connect the top and bottom bars of 18B; the same is true for 18A.
a) Front View		 Figure 96. Slab #18 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing almost total rust and corrosion on the right bars and the right side of the concrete. There are also discolored stains on the bottom bars and across the bottom of the concrete.
b) Rear View
Figure 96. Slab #18 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with no corrosion, with the water dike showing on the right and bottom.
c) Top View
d) Slab specifications
Specimen ID 18A 18B
Top mat Coating F Coating F
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 97. Slab #18 extracted rebars condition. Photo. Before autopsy, the two top mat straight ECRs (A-T and B-T) exhibit coating deterioration in the form of hairline coating cracks. The bottom mat black bars exhibit various levels of corrosion.

Figure 97. Slab #18 extracted rebars condition

Figure 98. Slab #18 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated and corroded, while the other top mat ECR (B-T) exhibits limited delamination with some substrate corrosion. The cleaned bottom mat bars exhibit either moderate pitting corrosion (A-B2 and B-B2) or no corrosion (A-B1 and B-B1).

Figure 98. Slab #18 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 99. Slab #19 front, rear, and top views with specifications
Figure 99. Slab #19 front, rear, and top views with specifications. Photos. (A) Slab number 19 front view shows the 19B label on the left and 19A on the right. Both top bars are completely corroded with rust running down to the lower bars and cracks between the lower bars. Wires connect the top and bottom bars of 19B; the same is true for 19A.
a) Front View		 Figure 99. Slab #19 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing corrosion on the right bar bleeding down to the lower level. Cracks connect the bottom bars and radiate out from the bars.
b) Rear View
Figure 99. Slab #19 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with corrosion from the precracking.
c) Top View
d) Slab specifications
Specimen ID 19A 19B
Top mat Coating F Coating F
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 100. Slab #19 extracted rebars condition. Photo. Before autopsy, the two top mat straight ECRs (A-T and B-T) show moderate coating deterioration in form of hairline cracks with minor corrosion stain. All the bottom mat black bars are severely corroded.

Figure 100. Slab #19 extracted rebars condition

Figure 101. Slab #19 after autopsy. Photo. After autopsy, both of the top mat ECRs (A-T and B-T) are almost completely delaminated with major substrate corrosion. The cleaned bottom mat black bars exhibit severe corrosion damage.

Figure 101. Slab #19 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 102. Slab #20 front, rear, and top views with specifications
Figure 102. Slab #20 front, rear, and top views with specifications. Photos. (A) Slab number 20 front view shows the 20B label on the left and 20A on the right. All bars show corrosion with bleeding and cracks in the concrete. Wires connect the top and bottom bars of 20B; the same is true for 20A.
a) Front View		 Figure 102. Slab #20 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing minor staining and huge cracks radiating from both top bars.
b) Rear View
Figure 102. Slab #20 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with corrosion from the precracking.
c) Top View
d) Slab specifications
Specimen ID 20A 20B
Top mat Black Black
Bar shape (straight/bent) Straight Straight
Coating defect (%) N/A N/A
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 103. Slab #20 extracted rebars condition. Photo. Before autopsy, both of the top mat black bars exhibit severe corrosion. The bottom mat black bars also show moderate to severe corrosion except the fourth bar from the top (A-B2).

Figure 103. Slab #20 extracted rebars condition

Figure 104. Slab #20 after autopsy. Photo. After autopsy, all of the clean black bars exhibit severe corrosion damage.

Figure 104. Slab #20 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 105. Slab #21 front, rear, and top views with specifications
Figure 105. Slab #21 front, rear, and top views with specifications. Photos. (A) Slab number 21 front view shows the 21B label on the left and 21A on the right. All bars show minor corrosion with the top right being the worst but with no bleeding onto the concrete. Wires are attached between the top and bottom bars of 21B; the same is true for 21A.
a) Front View		 Figure 105. Slab #21 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing clear concrete with no bar corrosion.
b) Rear View
Figure 105. Slab #21 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with precracked grooves showing darker color but no corrosion.
c) Top View
d) Slab specifications
Specimen ID 21A 21B
Top mat Coating D Coating D
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 106. Slab #21 extracted rebars condition. Photo. Before autopsy, the top mat two straight ECRs show either clean (B-T) or several coating defects circled in red. The bottom mat black bars show good condition without corrosion.

Figure 106. Slab #21 extracted rebars condition

Figure 107. Slab #21 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated and reveals corroded substrate whereas the other top mat ECR (B-T) remains unchanged. All of the cleaned bottom mat black bars look good.

Figure 107. Slab #21 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 108. Slab #22 front, rear, and top views with specifications
Figure 108. Slab #22 front, rear, and top views with specifications. Photos. (A) Slab number 22 front view shows the 22B label on the left and 22A on the right. The top left bar shows corrosion, and a major crack runs from the top right bar to the second lower bar with minor staining on the concrete. Wires connect the top left and bottom bars of 22B and just the lower bars for 22A.
a) Front View		 Figure 108. Slab #22 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing the water dike and clear concrete with corrosion and a thin drip of staining around the top right bar.
b) Rear View
Figure 108. Slab #22 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with a few prominent cracks.
c) Top View
d) Slab specifications
Specimen ID 22A 22B
Top mat Coating A Coating A
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 109. Slab #22 extracted rebars condition. Photo. Before autopsy, the top mat bent ECRs exhibit moderate coating deterioration and rust stains.
a) Top bars

Figure 109. Slab #22 extracted rebars condition. Photo. Before autopsy, the first bottom mat black bar (A-B1) looks clean, while the rest show moderate level of corrosion. .
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 109. Slab #22 extracted rebars condition

Figure 110. Slab #22 after autopsy. Photo. After autopsy, the bent top mat ECRs are completely delaminated and corroded.
a) Top bars

Figure 110. Slab #22 after autopsy. Photo. After autopsy, the cleaned bottom mat straight black bars exhibit minor corrosion damage.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 110. Slab #22 after autopsy

Figure 111. Slab #23 front, rear, and top views with specifications
Figure 111. Slab #23 front, rear, and top views with specifications. Photos. (A) Slab number 23 front view shows the 23B label on the left and 23A on the right. The top right bar shows severe corrosion and major cracks radiate from all the bars. Wires connect the top left and bottom bars of 23B and just the lower bars for 23A.
a) Front View		 Figure 111. Slab #23 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing the water dike and major corrosion on the left side and the bottom right bar with some cracks.
b) Rear View
Figure 111. Slab #23 front, rear, and top views with specifications. Photos. (C) The top view shows massive discoloration and corrosion with numerous cracks.
c) Top View
d) Slab specifications
Specimen ID 23A 23B
Top mat Black Black
Bar shape (straight/bent) Bent Bent
Coating defect (%) N/A N/A
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 112. Slab #23 extracted rebars condition. Photo. Before autopsy, both of the top mat bent black bars and all the bottom mat straight black bars are severely corroded.
a) Top bars

Figure 112. Slab #23 extracted rebars condition. Photo. Before autopsy, both of the top mat bent black bars and all the bottom mat straight black bars are severely corroded.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 112. Slab #23 extracted rebars condition

Figure 113. Slab #23 after autopsy. Photo. After autopsy, the cleaned top mat bent black bars and the bottom mat straight black bars exhibit severe corrosion damage.
a) Top bars

Figure 113. Slab #23 after autopsy. Photo. After autopsy, the cleaned top mat bent black bars and the bottom mat straight black bars exhibit severe corrosion damage.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 113. Slab #23 after autopsy

Figure 114. Slab #24 front, rear, and top views with specifications
Figure 114. Slab #24 front, rear, and top views with specifications. Photos. (A) Slab number 24 front view shows the 24B label on the left and 24A on the right. All the bars show minor corrosion with little concrete staining. Wires connect the top left and bottom bars of 24B; the same is true for 24A.
a) Front View		 Figure 114. Slab #24 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled showing the water dike and minor staining and corrosion only around the bottom right bar.
b) Rear View
Figure 114. Slab #24 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with no discoloration.
c) Top View
d) Slab specifications
Specimen ID 24A 24B
Top mat Coating A Coating A
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 115. Slab #24 extracted rebars condition. Photo. Before autopsy, the top mat two straight ECRs (A-T and B-T) look good with intentional coating defects circled. The bottom mat four black bars exhibit corrosion-free condition.

Figure 115. Slab #24 extracted rebars condition

Figure 116. Slab #24 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is completely delaminated and reveals corroded substrate. The other top mat ECR (B-T) remains unchanged. The cleaned bottom mat four black bars are shiny with minor pitting.

Figure 116. Slab #24 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 117. Slab #25 front, rear, and top views with specifications
Figure 117. Slab #25 front, rear, and top views with specifications. Photos. (A) Slab number 25 front view shows the 25A label on the left and 25B on the right. All bars show minor corrosion but the top right bar is completely corroded and stains the concrete around it down between the lower level of bars. The concrete on the lower level has some staining. Wires connect the top and bottom bars of 25B; the same is true for 25A.
a) Front View		 Figure 117. Slab #25 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled, showing rust and corrosion on the top left bar staining down to between the lower bars. There are also concrete cracks and minor corrosion drips near the lower bars.
b) Rear View
Figure 117. Slab #25 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with the groove line and cracks around it from the precracking.
c) Top View
d) Slab specifications
Specimen ID 25A 25B
Top mat Coating B Coating B
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 118. Slab #25 extracted rebars condition. Photo. Before autopsy, a top mat straight ECR (A-T) exhibits moderate coating deterioration and minor rust discoloration. The second bar top mat ECR (B-T) shows severe coating deterioration. The bottom mat four black bars exhibit minor corrosion.

Figure 118. Slab #25 extracted rebars condition

Figure 119. Slab #25 after autopsy. Photo. After autopsy, a top mat ECR (A-T) is mostly delaminated with moderate substrate corrosion, while the other top mat ECR (B-T) is completely delaminated with some severe corrosion spots on the substrate. The cleaned bottom mat four black bars show minor pitting.

Figure 119. Slab #25 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 120. Slab #26 front, rear, and top views with specifications
Figure 120. Slab #26 front, rear, and top views with specifications. Photos. (A) Slab number 26 front view shows the 26A label on the left and 26B on the right. All bars show minor corrosion, but the concrete is clean except for minor stains on the bottom right. Wires connect the top and bottom bars of 26B; the same is true for 26A.
a) Front View		 Figure 120. Slab #26 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows minor corrosion on the bars with no staining on the concrete.
b) Rear View
Figure 120. Slab #26 front, rear, and top views with specifications. Photos. (C) The top view is clear gray with the groove line of the precrack showing on the right side.
c) Top View
d) Slab specifications
Specimen ID 26A 26B
Top mat Stainless Steel Stainless Steel
Bar shape (straight/bent) Straight Straight
Coating defect (%) N/A N/A
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No Yes

Figure 121. Slab #26 extracted rebars condition. Photo. Before autopsy, a top mat straight stainless steel bar (A-T) show excellent condition while the other top mat stainless steel bar (B-T) exhibit some localized rust stains. The top mat bars have a diamond metal pattern instead of the usual spiral. All the bottom mat four black bars look good.

Figure 121. Slab #26 extracted rebars condition

Figure 122. Slab #26 after autopsy. Photo. After autopsy, all the cleaned bar exhibit excellent condition without any corrosion damage.

Figure 122. Slab #26 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 123. Slab #27 front, rear, and top views with specifications
Figure 123. Slab #27 front, rear, and top views with specifications. Photos. (A) Slab number 27 front view shows the 27A label on the left and 27B on the right. All bars show minor discoloration, but the concrete is clean. Wires connect the top and bottom bars of 27B; the same is true for 27A.
a) Front View		 Figure 123. Slab #27 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows the water dike with no corrosion but white staining on the concrete from the salt solution.
b) Rear View
Figure 123. Slab #27 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with the groove line of the precrack showing on the left side.
c) Top View
d) Slab specifications
Specimen ID 27A 27B
Top mat Stainless Steel Stainless Steel
Bar shape (straight/bent) Straight Straight
Coating defect (%) N/A N/A
Bottom mat Stainless Steel
Coating defect (%) N/A N/A
Precracked Yes No

Figure 124. Slab #27 extracted rebars condition. Photo. Before autopsy, all the top and bottom mat straight stainless steel bars show excellent condition. All bars have a diamond metal pattern instead of the usual spiral.

Figure 124. Slab #27 extracted rebars condition

Figure 125. Slab #27 after autopsy. Photo. After autopsy, all the cleaned stainless steel bars exhibit excellent condition.

Figure 125. Slab #27 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 126. Slab #28 front, rear, and top views with specifications
Figure 126. Slab #28 front, rear, and top views with specifications. Photos. (A) Slab number 28 front view shows the 28A label on the left and 28B on the right. All bars show corrosion discoloration but the top right bar stained and cracked the concrete. Wires connect the top and bottom bars of 28B; the same is true for 28A. The water dike is visible.
a) Front View		 Figure 126. Slab #28 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows the water dike with corrosion and cracks around the top left and some staining along the bottom.
b) Rear View
Figure 126. Slab #28 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray, with minor cracks on the right side.
c) Top View
d) Slab specifications
Specimen ID 28A 28B
Top mat Coating E Coating E
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 127. Slab #28 extracted rebars condition. Photo. Before autopsy, the two top straight ECRs (A-T and B-T) exhibit moderate coating degradation with minor corrosion. Two of the bottom mat straight black bars (B-B1 and B-B2) show moderate corrosion while the other bottom mat black bars (A-B1 and A-B2) are corrosion free.

Figure 127. Slab #28 extracted rebars condition

Figure 128. Slab #28 after autopsy. Photo. After autopsy, the top mat straight ECRs (A-T and B-T) show significant coating delamination and severe substrate corrosion. The cleaned bottom mat black bars exhibit either moderate corrosion damage (B-B1 and B-B2) or good condition (A-B1 and A-B2).

Figure 128. Slab #28 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 129. Slab #29 front, rear, and top views with specifications
Figure 129. Slab #29 front, rear, and top views with specifications. Photos. (A) Slab number 29 front view shows the 29A label on the left and 29B on the right. All bars show minor discoloration and minor concrete staining. Wires connect the top and bottom bars of 29B; the same is true for 29A. The water dike is visible.
a) Front View		 Figure 129. Slab #29 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows the water dike with minor staining near the bottom bars.
b) Rear View
Figure 129. Slab #29 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with cracks.
c) Top View
d) Slab specifications
Specimen ID 29A 29B
Top mat Coating E Coating E
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Coating E
Coating defect (%) 0.004 0.5
Precracked No No

Figure 130. Slab #29 extracted rebars condition. Photo. Before autopsy, a top mat straight ECR (B-T) shows moderate coating degradation and all the other straight ECRs show good condition except for intentional coating defects.

Figure 130. Slab #29 extracted rebars condition

Figure 131. Slab #29 after autopsy. Photo. After autopsy, the second ECR from the top (B-T) shows extensive coating delamination and substrate corrosion.

Figure 131. Slab #29 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 132. Slab #30 front, rear, and top views with specifications
Figure 132. Slab #30 front, rear, and top views with specifications. Photos. (A) Slab number 30 front view shows the 30A label on the left and 30B on the right. The top bars show major cracks and corrosion that stains the concrete down to the lower bars. Wires connect the top and bottom bars of 30B; the same is true for 30A.
a) Front View		 Figure 132. Slab #30 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows extensive corrosion staining on the top bars and bleeding to the bottom bars.
b) Rear View
Figure 132. Slab #30 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray and shows the precracks with minor cracks radiating from them.
c) Top View
d) Slab specifications
Specimen ID 30A 30B
Top mat Coating C Coating C
Bar shape (straight/bent) Straight Straight
Coating defect (%) 0.004 0.5
Bottom mat Black
Coating defect (%) N/A N/A
Precracked Yes Yes

Figure 133. Slab #30 extracted rebars condition. Photo. Before autopsy, the top mat two straight ECRs (A-T and B-T) exhibit severe coating deterioration with hairline cracks, coating blisters and major rust discoloration. The bottom mat four black bars exhibit different levels of corrosion, i.e., severe (B-B2 and A-B2), moderate (B-B1) and corrosion-free (A-B1).

Figure 133. Slab #30 extracted rebars condition

Figure 134. Slab #30 after autopsy. Photo. After autopsy, the top mat straight ECRs (A-T and B-T) experience complete coating delamination and reveal intensive substrate corrosion. The cleaned bottom mat two black bars (B-B1 and B-B2) exhibit moderate pitting damage and the other two bars (A-B1 and A-B2) exhibit intact condition.

Figure 134. Slab #30 after autopsy

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 135. Slab #31 front, rear, and top views with specifications
Figure 135. Slab #31 front, rear, and top views with specifications. Photos. (A) Slab number 31 front view shows the 31A label on the left and 31B on the right. The concrete surface shows minor cracks and corrosion drips. Wires connect the top and bottom bars of 31B and only the bottom bars for 31A.
a) Front View		 Figure 135. Slab #31 front, rear, and top views with specifications. Photos. (B) The rear view is unlabeled and shows minor discoloration drips on the lower half of the slab.
b) Rear View
Figure 135. Slab #31 front, rear, and top views with specifications. Photos. (C) The top view is mottled gray with no discoloration.
c) Top View
d) Slab specifications
Specimen ID 31A 31B
Top mat Coating E Coating E
Bar shape (straight/bent) Bent Bent
Coating defect (%) 0.5 0.004
Bottom mat Black
Coating defect (%) N/A N/A
Precracked No No

Figure 136. Slab #31 extracted rebars condition. Photo. Before autopsy, the top mat two bent ECRs show minor coating deterioration.
a) Top bars

Figure 136. Slab #31 extracted rebars condition. Photo. Before autopsy, the bottom mat four black bars show good condition except for rust on the ends.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 136. Slab #31 extracted rebars condition

Figure 137. Slab #31 after autopsy. Photo. After autopsy, the top mat bent ECRs show minor coating delamination and mild substrate corrosion.
a) Top bars

Figure 137. Slab #31 after autopsy. Photo. After autopsy, the cleaned bottom mat straight black bars exhibit good condition.
b) Bottom bars

*A-T: Top left bar, B-T: Top right bar, A-B1&B2: Bottom left bars, B-B1&B2: Bottom right bars

Figure 137. Slab #31 after autopsy

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