Development of New Hybrid Composite Girders

A hybrid FRP bridge girder consisting of CFRP and GFRP has been developed in Japan. A number of tensile and compressive coupon tests were conducted to determine the material properties of hybrid FRP laminates which were used in the analytical investigations of the large-scale FRP beams. A series of beams with wide flange widths varying the volume content of CFRP in flanges were tested under four-points loading. The experimental investigations revealed that the failure mode of these beams was induced by the local buckling of the compressive flange. In order to avoid the

local buckling, stiffeners were installed in the flexural and shear span of beams. Although an appropriate installation of stiffeners can prevent effectively the local buckling, however the hybrid FRP beams failed prematurely due to stress concentration at the loading points. Analyses were carried out and showed a good correlation with experimental results.