Shear bearing capacity of concrete cable duct reinforced with GFRP bars

The shear performance of the concrete cable ducts reinforced with glass fiber reinforced polymer (GFRP) bars was investigated. An appropriate calculation and design method was proposed based on the different countries' design codes. The crack growth mode, the distributions of the strain on the cross sections and the load-deflection curves were obtained by the shearing test on several small and full size specimens. The failure mechanism was revealed. The experimental results show that the shear bearing capacity increases with the increase of area-stirrup ratio and the longitudinal reinforcement ratio. The effect of stirrup on the shear bearing capacity can be neglected if the stirrup ratio is too small. The specimens still have relatively high shear bearing capacity under a small reinforcement ratio of longitudinal reinforcement. The proposed formula can preferably fulfill the requirements of security and economy for designing or fabricating the concrete cable ducts.