Precast Concrete Diaphragm Connector Performance Database

Abstract

A variety of connector details are used to provide integrity and force transfer between precast concrete panels in building floor diaphragms. To assess the adequacy of these connectors a large number of experiments have been conducted on discrete welded connectors used in precast concrete double-tee floor panels. A standard procedure for developing simplified response curves from original test data is used to generate simplified curves from each of the tests conducted. The calculated results of over 200 experiments are summarized in a comprehensive performance database. This database provides the stiffness, strength, and deformation properties of each connector detail examined. The connectors are divided into one of the following three displacement-based categories: low deformation element (LDE), moderate deformation element (MDE), and high deformation element (HDE), based on the performance measured in the experiments. A simplified pushover modeling approach is developed to estimate the in-plane maximum midspan flexural deflection and shear sliding of a diaphragm subjected to a static uniform load applied parallel to the span of the diaphragm system. This method begins with developing the shape functions of the joint moment-rotation and shear-sliding deformation responses by utilizing the information included in the performance database and then by estimating the in-plane flexural and shear resistance-displacement responses of the diaphragm system. Estimation of flexural and shear responses of the diaphragm designed with connectors in the LDE, MDE, and HDE categories are conducted as examples.