Evaluating elastic behavior for partially composite precast concrete sandwich wall panels

摘要

As energy codes become more stringent, the thermalefficiency of precast concrete sandwich wall panelswill be more important. Since the 1990s, sandwichpanel wythe connectors, often made of fiber-reinforcedpolymers (FRPs), have been used to provide both thermal and structural efficiency. However, designing suchpanels has been empirical and relies solely on connector properties provided by the connector companies,making the design process difficult for precast concreteengineers. This paper explains how data collected fromsmall, inexpensive push-off specimens can be used topredict elastic behavior of precast concrete sandwichwall panels. In this study, several different FRP connectors on component-scale push-off specimens underwent shear testing. The variables studied were wythethickness, insulation type, and insulation bond. Eightfull-scale specimens were fabricated with differentconnector types and configurations and tested to validate the proposed elastic analysis methodology. Theauthors created a generalized and simple beam-springmodel that uses beams to represent the concrete wythesand springs to model the shear deformation behaviorcreated by the rigid insulation and shear connectors.The beam-spring model provided measured-to-predicted ratios of 0.95 and 0.97 for cracking and deflections,respectively, validating its use as a generalized designtool.