CIVIL ENGINEERING 365 ALL ABOUT CIVIL ENGINEERING



AbstractHighway bridge superstructures may be built using only precast concrete elements, such as deck bulb tees (DBTs). Formerly flange connections between those members have been made with welded steel inserts and grout keys, but these have not held up well under heavy truck traffic. Recently, agencies have started to investigate the use of alternative connections in which bars project laterally from the tee flanges and are connected by a narrow pour strip made from ultra-high-performance concrete (UHPC). They have shown better performance, but are typically made using proprietary UHPC, which is expensive. This paper reports tests and analyses of longitudinal joints between simulated DBTs connected using a nonproprietary UHPC. It includes an analysis of the deck to determine the force demands, material testing information including supplementary characteristics such as bond strength, and tests on full-scale panels simulating the deck portion of the tees. It was found that the strength demand is driven by a prescriptive requirement in the AASHTO LRFD specifications rather than by a specific force demand and that the nonproprietary UHPC was able to provide the required strength using a joint no more than 250-mm wide.



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *