An innovative hybrid composite girder is being developed in Japan consisting of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP). The innovative feature of this girder is the optimum use of CFRP and GFRP in flanges to maximize structural performance while reducing the overall cost by using only GFRP in the web section. The flexural behavior of such hybrid FRP composite girders was investigated. Preliminary tests revealed that hybrid FRP girder failed due to local buckling and separation of laminates in the compression flange with the tensile strain much lower than the expected maximum strain. In view of improving its structural performance and practical application, concrete deck was provided on top of the hybrid FRP composite girder to avoid local brittle failure and to fully utilize the superior characteristics of the FRP materials. Different types of shear connection were trialed to provide composite action between the hybrid FRP girder and concrete deck. This paper will discuss the results of the experimental investigation on the combined section of concrete deck and hybrid FRP composite girder focusing mainly on issues related to the composite action of
such girders
