High Performance Concrete Specifications and Practices for Bridges (2013) / Chapter Skim
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Pages 6-17
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From page 6... ...
6 The concept of HPC was first introduced in the 1980s and was often associated with high strength concrete for columns of high-rise buildings with measured compressive strengths as high as 19.0 ksi. During the same period, high strength concrete was used in limited bridge applications in the United States such as the East Huntington Bridge across the Ohio River (8.0 ksi design strength)
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From page 7... ...
7 The research determined that the specifications at that time had been formulated primarily from the knowledge of conventional materials. As such, some requirements may not be applicable to HPC and would serve as barriers to the acceptance of HPC for highway applications (Zia et al.
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8 not necessary to specify every characteristic or to specify the same grade for different characteristics. The intent was to select the characteristics and grades to match the intended application and its environment.
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9 State Bridge Name Specified Properties for Deck Concrete Compressive Strength, ksi Permeability, coulombs Alabama Highway 199 6.0 @ 28 days -- Colorado Yale Avenue 5.1 @ 28 days -- Georgia SR-920 7.3 @ 56 days 2000 @ 56 days Louisiana Charenton Canal Bridge 4.2 @ 28 days 2000 @ 56 days Nebraska 120th Street 8.0 @ 56 days 1800 @ 56 days New Hampshire Route 104, Bristol 6.0 @ 28 days 1000 @ 56 days New Hampshire Route 3A, Bristol 6.0 @ 28 days 1000 @ 56 days New Mexico Rio Puerco 6.0 @ 28 days -- North Carolina US-401 6.0 @ 28 days -- South Dakota I-29 Northbound 4.5 @ 28 days -- South Dakota I-29 Southbound 4.5 @ 28 days -- Tennessee Porter Road 5.0 @ 28 days 1500 @ 28 days1 Tennessee Hickman Road 5.0 @ 28 days 1500 @ 28 days1 Texas Louetta Road 4.0 and 8.0 @ 28 days -- Texas San Angelo 6.0 and 4.0 @ 28 days -- Virginia Route 40, Brookneal 4.0 @ 28 days 2500 @ 28 days1 Virginia Virginia Avenue,Richlands 5.0 @ 28 days 2500 @ 28 days 1 Washington State Route 18 4.0 @ 28 days -- Based on Russell et al.
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10 Performance Characteristic Standard Test Method FHWA HPC Performance Grade 1 2 3 4 Freeze-thaw Durability (x = relative dynamic modulus of elasticity after 300 cycles)
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11 occurred. The bridge geometry influenced the amount of concrete cracking.
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12 FIGURE 1 States' use of HPC in 2003–2004 survey. FIGURE 2 States' use of HPC in 2006–2007 survey.
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13 The most common procedure of specifying HPC was either by special provisions for a particular project (22 agencies) or a combination of special provisions and general specifications (22 agencies)
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14 immediately after finishing operations are complete on any portion of the placement. For bridge decks, the specification requires water curing for a minimum period of seven days irrespective of concrete strength.
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15 10 6 15 0 7 0 5 10 15 20 Combination of standard specifications and special provisions for specific projects Combination of standard specifications and special provisions for all projects Special provisions for specific projects Special provisions for all projects Standard specifications only No. of Agencies FIGURE 3 Number of agencies using standard specifications or special provisions for HPC.
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From page 16... ...
16 Overall, 67% of the agencies that reported on performance stated that the CIP HPC was performing better that the conventional CIP concrete. Only two agencies reported worse performance.
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17 time, revisions were made to the AASHTO LRFD Bridge Design Specifications and the AASHTO LRFD Bridge Construction Specifications to remove barriers to the use of HPC. As a result, state DOTs began to move away from the use of prescriptive specifications to the greater use of performance specifications and the use of HPC in bridges.
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