Evaluation of Box Beam Stiffening of Unanchored Temporary Concrete Barriers
Cale Stolle, Karla Lechtenberg (Polivka), Ronald Faller, Dean Sicking, Bob Bielenberg, John Reid, John Rohde, Erin Allison, Ryan Terpsma
Temporary concrete barrier (TCB) systems that are not pinned into the pavement can be displaced during an impact and can result in workers being crushed between the barrier and objects within the workspace. Alternatively, the barrier could be moved far enough to fall off of the paved surface and onto workers in an excavation, below a bridge, or onto traffic under the bridge. The process for drilling holes in a bridge deck to anchor temporary concrete barriers is time-consuming, costly, and may ultimately result in damage to the bridge. Thus, a means for reducing the deflection of the barrier system is necessary and without the use of anchoring the barrier sections to the underlying pavements with pins, rods, or bolts. The primary objective of this study was to evaluate the potential for reducing barrier deflections through the use of box beam stiffening on New York State's TCBs. The secondary objective of the study was to evaluate stiffened and unstiffened versions of New York State's temporary concrete barrier system according to the Test Level 3 (TL-3) criteria set forth in the currently proposed Update to NCHRP Report No. 350. The research study included three full-scale vehicle crash tests with Dodge Quad Cab pickup trucks. The first system utilized 152-mm x 152-mm x 4.8-mm (6-in. x 6-in. x 0.1875-in.) box beam sections placed across three joints. The second system consisted of an unstiffened version of the temporary concrete barrier system. The final system utilized 152-mm x 203-mm x 6.4-mm (6-in. x 8-in. x 0.25-in.) box beam sections placed across six joints with the back side of the barriers placed 305 mm (12 in.) away from the bridge deck edge. Following the successful redirection of all three pickup trucks, the safety performance of the unstiffened and the two stiffened designs were determined to be acceptable according the TL-3 evaluation criteria specified in the currently proposed Update to NCHRP Report No. 350. Furthermore, the stiffened versions of the temporary concrete barrier system can be safely installed with a 305 mm (12 in.) gap between the bridge deck edge and the back side of the barriers.
Highway Safety, Roadside Appurtenances, Longitudinal Barriers, Temporary Barriers, Concrete Barriers, Box Beam Stiffener, Crash Test, Compliance Test, NCHRP 350 Update
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