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53 Figure 3.61. End zone cracks on the Platte River Bridge girders. 3.5.3 Virginia Department of shown in Figure 3.63. The spans over the Mattaponi River were Transportation (VDOT) made from pretensioned/post-tensioned VA 95-in.-deep new bulb tee girders, as shown in Figure 3.64. The research team, jointly with VDOT, selected two bridges The concrete girders were fabricated by Standard Concrete on Route 33 and one bridge on Route 614, for inspection. The Products (SCP), Inc. of Tampa, Florida, in October 2005. selected bridges were constructed between 2005 and 2007. According to the shop inspection reports, end zone cracking Girders of these bridges experienced end zone cracking at was reported in almost of all the girders. End zone cracking strand release. Some of the girders were repaired in the pre- in the web ranged from hairline to 0.016 in. at time of cast yard. release, and some of these cracks grew up to 0.020 in. at The two bridges on Route 33 are located in West Point, time of shipping. For web cracks 0.009 in. and under, the Virginia, and they are next to each other. The first bridge is precast producer sprayed on a penetrant sealer all along the over the Mattaponi River between King William and Queen crack. Sikagard 701W was used in this project. Web cracks Counties, and the second bridge is over the Pamunkey River that are 0.010 in. or greater were epoxy injected using the between New Kent and King William Counties. The third typical epoxy injection procedure given in the PCI Manual bridge is located on Route 614 (Hickory Fork Road) over for the Evaluation and Repair of Precast, Prestressed Concrete Carter's Creek, 1.6 miles west of Route 17, in Gloucester Bridge Products (11). Prime Rez 1100 High Mod LV was County, Virginia. used in this project. The bridge was open to traffic in September 2006. The 126.96.36.199 Bridge on Route 33 over Mattaponi River, inspection report that was generated by the district engineer at West Point, Virginia that time stated that "hairline diagonal cracks exist in the web of Spans `j through q.'" However, the report did not provide The bridge consists of 28 spans with 7 girders at 10 ft, 6 in. any detailed information on crack size, length, or number. and two overhangs, 3 ft, 8 in. long each, as shown in Figure 3.62. The research team inspected the bridge on July 1, 2008, and All girders were lightweight concrete of 120 pcf with a 28-day was looking for signs of distress such as delamination (which concrete strength of 8 ksi. Half-inch diameter, 270 ksi, low was inspected by tapping with a hummer on the girder at relaxation pretensioned strands were used in all spans. The the crack and its vicinity) and reinforcement corrosion. End eastbound and westbound approaches of the span were made zone cracks were visible in almost all of the girders on the from pretensioned VA 45-in.-deep new bulb tee girders, as bridge. The crack width ranged from 0.008 to 0.010 in. wide.
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54 Figure 3.62. Cross section of the bridge (eastbound and westbound approaches). Figure 3.63. Girder details of the eastbound and westbound approaches. Figure 3.64. Girder details of the spans over the Mattaponi River.
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55 Efflorescence could be seen around some of these cracks. The inspection engineer stated that the efflorescence was re- ported at the time when the bridge was opened to traffic in 2006 and, based on his experience, the amount of efflorescence did not increase with time. No signs of reinforcement corro- sion were reported, except in one girder in one of the spans of the eastbound approach, as shown in Figure 3.65. No delami- nation was reported in the girders that were inspected. 188.8.131.52 Bridge on Route 33 over Pamunkey River, West Point, Virginia The bridge consists of 49 spans. Girders of all spans were made of 120 pcf lightweight concrete with a 28-day concrete strength of 8 ksi. Half-inch diameter, 270 ksi, low relaxation strands were used in all spans. The bridge is made of eight VA Figure 3.65. Web end zone cracking (0.009 in.) show- New BT girders spaced at 9 ft, 6 in. to 11 ft, 6 in., as shown in ing some efflorescence, no delamination, and some Figure 3.66. Figures 3.67 and 3.68 show the cross section of signs of corrosion. Figure 3.66. Cross section of the bridge on Route 33 over the Pamunkey River. Figure 3.67. Girder details of the eastbound and westbound approaches.
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56 Figure 3.68. Girder details of the spans over the Pamunkey River. the girders used on the eastbound and westbound approaches It was evident that all of the girders have an almost identi- and the spans over Pamunkey River. cal pattern of end zone cracking. At each end of the girders, The bridge was opened to traffic in late 2007. The inspec- one end zone crack is formed where it extends from the top tion report that was generated by the district engineer at that of the flange and the member end to the top surface of the time stated that "hairline diagonal cracks exist in the web of bottom flange, as shown in Figure 3.72. Spans `j through q.'" However, the report did not provide It was evident that efflorescence exists on about 75% of any detailed information on crack size, length, or number. the cracks. Upon inspection, the concrete at the crack and The research team inspected the bridge on July 1, 2008, and in its vicinity looked very sound with no signs of delamina- was looking for signs of distress such as delamination and tion or reinforcement corrosion. The size of the crack ranges reinforcement corrosion. End zone cracks were visible in from 0.006 to about 0.009 in., with the majority of the cracks many exterior and interior girders on the bridge. The crack width ranged from 0.008 to 0.010 in. No efflorescence, signs of reinforcement corrosion, or delamination was reported in the inspected girders, as shown in Figure 3.69. 184.108.40.206 Bridge on Route 614 over Carter's Creek in Gloucester County, Virginia The third Virginia bridge is located on Route 614 (Hickory Fork Road) over Carter's Creek, 1.6 miles west of Route 17, in Gloucester Co. The bridge consists of 6 spans (82.5 ft each) with one expansion joint at the center pier. The cross section of the bridge consists of 6 girders at 7 ft, 4 in., which support 8-in.-thick cast-in-place concrete slab, as shown in Fig- ure 3.70. All of the girders are 54 in. deep AASHTO Type IV. The bridge crosses over a marsh land with a very humid environment. Also, the bridge has a very low profile that places trees in contact with the bottom flange of most of the Figure 3.69. Web end zone cracking (0.008 in.) spans, as shown in Figure 3.71. The bridge was opened to showing no efflorescence, no delamination, no traffic in 2006. signs of corrosion.
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57 (a) Cross Section of the Bridge (b) Girder Details Figure 3.70. Details of the bridge on Route 614 in Gloucester County, Virginia. Figure 3.72. End zone crack, Span 5, left side, exterior Figure 3.71. View of bridge over Carter's Creek girder, 0.006 to 0.008 in. wide, with efflorescence, no showing its low profile. delamination, no reinforcement corrosion.