PC Girder-to-RC Deck Connection: Interface Shear Transfer with GFRP Reinforcement

Abstract

In the case of bridge construction, the composite action between a precast, prestressed concrete (PC) girder and the reinforced concrete (RC) deck is typically of critical importance. When the PC girder is made with carbon FRP tendons and glass FRP (GFRP) auxiliary reinforcement, the possible contribution of GFRP to the interface shear resistance mechanism should be investigated and, if demonstrated reliable, should be accounted for in the design. Most of the research related to interface shear transfer has utilized steel bars as reinforcement, while FRP reinforcement as a shear transfer mechanism has received very little attention both experimentally and analytically. For this reason, the inclusion of GFRP to provide shear resistance across a given plane is an important topic. Furthermore, only a few design specifications include provisions for the calculation of the interface shear transfer design strength when using GFRP as the reinforcement. Therefore, experimental data are required to allow development and validation of the design approach for GFRP reinforcement as interface shear transfer reinforcement. In this project an experimental study was conducted on the contribution of GFRP to the mechanism of shear transfer by using push-off specimens; fabricated using a single concrete compressive strength; from the total number of samples, some included no reinforcement, some had steel stirrups, and some GFRP stirrups. The initial results of the experimental campaign are presented and discussed highlighting the differences between the two types of reinforcement.