The National Academies Press

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Pages 340-356

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From page 340... ... 340 A p p e n d i x d introduction Phase III of SHRP 2 Renewal Project R04 required the construction of a demonstration bridge using the most-promising bridge details identified in earlier research and the modular systems being incorporated into accelerated bridge construction (ABC) standards. Read the entire page →
From page 341... ... 341 demonstration project innovative Features This demonstration project implements a series of innovations. It incorporates details drawn from diverse locations and applies them in a single demonstration project that was visited by Federal Highway Administration and department of transportation personnel from numerous states. Read the entire page →
From page 342... ... 342 increasing confidence among government and other stakeholders in recommending their use on other projects. demonstration project Construction The US-6 bridge, a three-span continuous structure that crosses Keg Creek near Council Bluffs, Iowa, is similar in size and length to a large majority of bridges across the United States and was replaced as a demonstration bridge in Phase III. Read the entire page →
From page 343... ... 343 tasks were bid at a much higher price than for a typical bridge. When mobilization ($25/ft2) Read the entire page →
From page 344... ... 344 Structural steel assembly was performed using bolted splice plates to connect adjacent modules at pier location. Although the spans were designed with sufficient moment capacity to function as simple spans, the transverse deck joints were also designed with sufficient capacity to provide continuity between adjacent spans with the impermeable UHPC bonded to the precast concrete to eliminate the intrusion of water into those joints. Read the entire page →
From page 345... ... 345 superstructure modules, as might be considered in a typical precast concrete plant. To create space for the joints between each module and permit separation of the pieces and future reassembly, the contractor constructed a grid of plywood blockouts that would allow the installation of the overlapping hairpin reinforcing but would also be easy to disassemble after the concrete was cured. Read the entire page →
From page 346... ... 346 during the ABC period, the precasting work had to be accurately measured and verified before placing concrete. Pier cap beams were formed and placed on temporary casting beds located beneath and immediately adjacent to the existing bridge on a temporary creek crossing. Read the entire page →
From page 347... ... 347 Contractor working hours during the ABC period were typically from 6:30 a.m. until 8:00 p.m. Read the entire page →
From page 348... ... 348 • Transport two abutment barrels and four wingwall units from the casting yard to the bridge site. • Lift and place precast abutment barrel and wingwall sections over the protruding steel H-piles. Read the entire page →
From page 349... ... 349 • Place grout bed at top of drilled shaft. • Install precast column on top of drilled shaft, and install guy wires. Read the entire page →
From page 350... ... 350 face of the column and anchored to an immovable object to maintain column position. The grouted couplers at the bottom of the column were injected with Dayton-Superior S-L grout in accordance with the manufacturer's specifications: Grout is injected with a hand pump through the port near the bottom of each coupler. Read the entire page →
From page 351... ... 351 the panel on the truck to maintain the center of gravity of the load between the wheel lines. Two cranes performed the lifting of the modules. Read the entire page →
From page 352... ... 352 component materials for each batch were provided in bulk packages: an 1,800-lb "super sack" of powder mix and three boxes of steel fibers. In addition to the dry ingredients, water and the required admixtures were carefully weighed with a digital scale. Read the entire page →
From page 353... ... 353 communicated to the contractor so that grinding of the deck concrete could be performed within the ABC schedule. Posttensioning of Superstructure Modules Installation of posttensioning rods was performed while the UHPC was curing, and stressing was completed after the UHPC had reached a minimum 14,000-psi compressive strength as verified by Iowa State University with specimen testing. Read the entire page →
From page 354... ... 354 during the installation of the superstructure. The approach pavement joints and the lifting pockets in the superstructure modules were filled with SCC in a straightforward operation. Read the entire page →
From page 355... ... 355 Travel Funding A limited number of travel scholarships were provided by the SHRP 2 program to encourage participation from state DOTs across the United States. A number of bridge owners were given financial support for travel expenses for the showcase. Read the entire page →
From page 356... ... 356 and a longer version, approximately 25 min, geared toward a more technical viewer such as a DOT bridge designer, consultant, or contractor. The videos will be made available online through a variety of sources, including SHRP 2 and FHWA websites. Read the entire page →

From page 340...

... 340 A p p e n d i x d introduction Phase III of SHRP 2 Renewal Project R04 required the construction of a demonstration bridge using the most-promising bridge details identified in earlier research and the modular systems being incorporated into accelerated bridge construction (ABC) standards.