Sri Sritharansri@iastate.edu email >
Faculty Affiliate, BEC
About the research
Many transportation organizations have embraced Accelerated Bridge Construction (ABC) to reduce both the traffic impacts and societal costs. One of the most common means to achieve ABC is to utilize prefabricated elements that are connected on site to construct a bridge. ABC will not be effective if the barrier requires cast-in-place construction. The purpose of this report is to present details of a precast barrier and two connection alternatives between the deck and precast barriers. In addition, a new connection between two adjacent prefabricated barriers was presented. All three connections were tested using full-scale precast barriers and a video summarizing the test can be found at https://youtu.be/up6sMEeqfaU.
One barrier-to-deck connection used inclined reinforcing bars with threaded ends that were connected to bar splicers embedded in the bridge deck. The other barrier-to-deck connection used U-shaped bars that were inserted into the barrier from the underside of the bridge deck overhang. Factors that were considered when designing the connections were minimal damage to deck, easy replacement of barrier, constructability, durability, and cost.
The barrier-to-barrier connection utilized headed reinforcement in the longitudinal and transverse directions. The connections were designed to meet TL-4 loads as per the Manual for Assessing Safety Hardware (MASH) and Load and Resistance Factor Design (LRFD) Bridge Design Specifications.
This report presents results from various tests and shows that all proposed connections are viable for accelerated construction of concrete barriers, although some refinement to the tested details will be needed.