Orthogonal Experimental Study on Mechanical Properties of Hybrid Fiber Reinforced Concrete

Abstract:

In view of the influence of steel fiber（SF）, polypropylene fiber(PPF) and fly ash（FA） on the mechanical properties of C40hybrid fiber reinforced concrete(HFRC), orthogonal experimental design was carried out. Through the analysis of the extreme difference and the variance of the cube compressive strength, splitting tensile strength and axial compressive strength, the influence degree and significant factors of the three factors were obtained. The results show that the splitting tensile strength of concrete can be significantly improved by adding fiber, and the maximum increasing degree of steel fiber, polypropylene fiber and fly ash is 315%, 54% and 35% respectively. Also the experimental data indicate that the enhancement effect of fiber on the compressive strength is less significant than that of splitting tensile strength. Then, the mechanism analysis of the influence of the three factors on the mechanical properties of HFRC is implemented. Finally, the prediction models of cube compressive strength, splitting tensile strength and axial compressive strength of HFRC are established.