Abstract:
In order to investigate the flexural behaviors and the calculation method of the flexural capacity of steel fiber reinforced concrete(SF/concrete) beams with hybrid glass fiber reinforced polymer composites(GFRP) and steel bars, the proposed formula of the boundary reinforcement ration and the flexural capacity of hybrid reinforced SF/concrete beams were derived on the basis of considering the tensile strength of concrete in the tension zone. Based on this, three kinds of SF/concrete beams with different reinforcement methods were designed and fabricated, and the influence of the hybrid reinforcement ration and the area ratio of GFRP bars to steel bars(
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As) on the failure modes and the flexural capacity of test beams were mainly discussed. At the same time, the variation characteristics of the flexural behaviors of the hybrid reinforced concrete beams under different concrete strengths were compared and analyzed by relying on relevant test data. The results of the test and the comparative analysis show that the cross section of the hybrid reinforced SF/concrete beams still conform to the flat section assumption. The flexural capacity and the mid-span deflection of the hybrid reinforced SF/concrete beams under the same reinforcement form increase with the increase of the area ratio of GFRP bars to steel bars
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As. The flexural capacity of the concrete beams with single-layer reinforcement is larger than that of the double-layer reinforcement. Reasonably increasing the concrete strength can further improve the flexural capacity of the hybrid reinforced concrete beams while fully satisfying the tensile effect of GFRP bars. The reliability of the failure modes of the hybrid reinforced concrete beams predicted by the theory of boundary reinforcement ration is higher. The predicted values of the proposed calculation formula of the flexural capacity are in good agreement with the experimentally measured values, and it has good applicability.