Behavior and design of ductile multiple-anchor steel-to-concrete connections

The connection of steel members to concrete is a common structural feature, with applications in both highway and building construction. A typical steel-to-concrete connection includes the following: a steel attachment consisting of a baseplate welded to the attached member; the anchors that actually do the connecting; and an embedment of the anchors into the concrete. The behavior and design of these connections is not well defined by existing design standards. Steel-to-concrete connections can be divided into two categories: connections whose strength is controlled by the strength of the anchor steel; and connections whose strength is controlled by the strength of the embedment.;Based on experimental research conducted at the University of Texas at Austin, the behavior and design of steel-to-concrete connections whose strength is controlled by the strength of the anchor steel is addressed. An analytical model for calculating the strength of these connections is presented. The model is developed from experimental results and is based on limit design theory. Experimental results are reported for 44 friction tests and 46 ultimate-load tests of multiple-anchor steel-to-concrete connections loaded monotonically by various combinations of moment and shear. Test specimens included steel attachments with rigid and flexible baseplates, connected to concrete with threaded cast-in-place or retrofit (undercut and adhesive) anchors. The results of this study are incorporated into a Design Guide for Steel-to-Concrete Connections.