"FRP Shear Transfer Mechanism for Precast, Prestressed Concrete Sandwich Load-Bearing Panels"

Abstract

Synopsis: This paper describes the structural behavior of precast prestressed concrete sandwich wall panels reinforced with carbon fiber reinforced polymer (CFRP) shear grid to achieve composite action. The study included testing of six full-scale sandwich wall panels, each measuring 20 ft (6.1 m) by 12 ft (3.7 m). The panels consisted of two outer prestressed concrete wythes and an inner foam core. The study included two types of foams and several shear transfer mechanisms with different CFRP reinforcement ratios to examine the degree of composite action developed between the two concrete wythes. All wall panels were simultaneously subjected to applied gravity and lateral loads. The paper also presents a general methodology to determine the behavior of fully and partial composite wall panels. The effects of imperfect connection between the two concrete wythes are considered by varying the total shear force transmitted through the shear connectors at the interface. The shear flow capacity of the insulating materials as well as the CFRP shear grid is determined using the proposed approach. The influence of the degree of the composite interaction on the induced curvature and slip-strain behavior is presented. A simple design chart for estimating the flexural capacity of the wall panels with different shear reinforcement ratios is proposed.