Development of a rational design methodology for precast concrete slender spandrel beams: Part 1, experimental results

Abstract

This paper summarizes test results of an extensive experimental program undertaken to develop a rational design procedure for precast concrete slender spandrel beams. Experimental research findings presented in this paper are used to propose a rational design procedure that will be presented in a forthcoming companion paper. The research introduced significantly simplified detailing requirements for the end regions of precast concrete slender spandrel beams. Such regions are often congested with heavy reinforcing cages when designed according to current procedures. In total, 16 full-scale precast concrete spandrel beams were tested to failure to study the limit state behavior. Each specimen was loaded through full-scale double-tee deck sections to mimic typical field conditions. Three of the specimens were designed and detailed with closed stirrups, according to current practice, and served as controls for the experimental program. The remaining thirteen specimens were designed with various configurations of open web reinforcement. Several specimens were specially configured with flexural, ledge/corbel, and hanger reinforcement in excess of what would be provided in a normal design. The enhanced reinforcement helped to delay typical midspan and local failure modes and allowed for observation and study of failure modes in the end region. The experimental results, combined with the analytical results and rational modeling in the companion paper, demonstrate that properly designed open web reinforcement is a safe, effective, and efficient alternative to traditional closed stirrups for precast concrete slender spandrel beams that have an aspect ratio of 4.6 or greater.