Behavior Of Composite Girders Strengthened By CFRP Products

Abstract Composite structures are widely used in civil engineering projects. The present research consecrated to study the behavior of steel-concrete composite girders consisting from high strength concrete deck slab integrated with two steel I-beam by headed steel stud connectors. The present research implemented experimental and theoretical investigation. In the experimental investigation five models were constructed as test samples. The test samples designed to be tested and failed in flexure. The dimensions of deck slab for each sample are 1000200070mm widthlengththickness while the dimensions of each I-beam are 1422000mm depthlength.The test samples un-strengthened and strengthened externally by CFRP sheets with different manner and using and un-using CFRP bars instead of ordinary steel reinforcements.Theoretical investigation conducted by modeling the test samples numerically and analyzed using finite element method. The numerical models were carried out in three dimensions by software package ANSYS 12.1 2009. Verification of the numerical results was done by a comparison with experimental results. It is concluded that the strengthening of bottom face of concrete slab and bottom face of the bottom flanges of the steel beams by CFRP sheets increases the ultimate load values by 4 but there is no considerable enhancement in the deflection and slip values. There is a slight structural advantage in case of using CFRP bars instead of ordinary steel bars reinforcements.