Experimental investigation on flexural performance of polyester polyurethane concrete steel bridge deck composite structure

In this study, the results of an experimental investigation on the flexural behavior of composite specimens are presented, with the objective to simulate the performance of Polyester Polyurethane Concrete (PPUC)-steel bridge deck composite structures with different pavement layer thicknesses. Four groups of composite specimens with paving layer thicknesses of 20, 30, 40, and 50 mm are prepared, which are subjected to four-point bending tests with positive and negative moment loading, to obtain the failure mode, crack distribution, load-deflection relationship, and load-strain relationship. The test results indicate that under the action of a positive bending moment the specimens demonstrate two different failure modes, i.e. compressive failure and shear compression failure, whereas under the action of negative bending moment failure due to tensile failure occurs. Both the flexural stiffness and ultimate load-bearing capacity of the specimens increase with the increment of the paving layer thickness, in which the flexural stiffness under a positive bending moment loading state is higher than that under a negative bending moment loading state. Moreover, the specimens with lower stiffness can withstand a greater vertical displacement than those with higher stiffness. The strain of both PPUC and steel plates decreases with the increment of paving thickness, and this strain decrease is greater under the action of a negative bending moment compared to the strain under the action of a positive bending moment. Finally, the flexural performance of PPUC-steel plate composite structure is successfully simulated based on the cohesive zone model (CZM), which is verified by the test results. In addition, the parametric analysis, including the thickness of steel plate, the thickness of PPUC layer and the PPUC compressive strength, is conducted to reveal the flexural performance of PPUC-steel plate composite structure. This work can be used as a resource for the initial design of a PPUC-steel bridge deck.