Application of Grouted Mechanical Couplers in Accelerated Bridge Construction

Abstract

This paper presents two research projects that investigated the performance of the grouted coupler connection details developed for accelerated bridge construction applications. The goal of the first project was to conduct laboratory test and evaluation of the grouted rebar coupler connections similar to those utilized on the Keg Creek Bridge on US Highway 6, the first replacement bridge in Iowa constructed entirely with modular and accelerated bridge construction technologies. The connections of focus were between the pier column and the pier cap, and between the pier column and the drilled shaft. Laboratory specimens were fabricated such that they were representative of the pier column connections of the Keg Creek Bridge, and tested for their strength and durability, mainly resistance to crack initiation and propagation at the joints. The success of the first project led to a follow-up study that investigated the performance of three novel integral abutment connection details that were designed for mechanically splicing the integral diaphragm and cap beam. The test results showed that the grouted coupler connection details, if properly incorporated, would provide bridge owners and engineers with viable options for improving the constructability and durability of their bridges. Keywords: Accelerated bridge construction; connections; pier columns; integral abutment.