Experimental study on the mechanical properties of hybrid fiber rubber concrete

Abstract

Rubber concrete has a promising application due to its good ductility. However, how to solve the reduction of its strength is a key issue. In view of the inadequate mechanical properties of rubber concrete at present, this paper carried out a study of blending hybrid fibers (steel fiber-basalt fiber) into rubber concrete to improve the mechanical properties of the concrete. The effect of rubber powder, steel fiber and basalt fiber on the compressive strength and the flexural strength of concrete at different admixtures was studied experimentally using the method of orthogonal test design. The results show that the incorporation of rubber powder would reduce the compressive strength and flexural strength of concrete to some extent, but the reasonable incorporation of hybrid fiber could compensate for the loss of strength caused by rubber powder instead of fine aggregates. In this test, the maximum increase of compressive strength and flexural strength of the hybrid fiber rubber concrete(HFRC) after further incorporating with mixed fibers were 12.75% and 30.89%, respectively. Steel fiber(SF) is an important factor affecting the flexural strength of HFRC, and the improvement of the compressive strength by basalt fiber(BF) is not significant. The improvement of the flexural strength of HFRC by hybrid fiber was greater than that of the compressive strength. The combination of hybrid fiber and rubber concrete with optimal mechanical properties is obtained by extreme difference analysis, which provides a certain theoretical basis for the engineering application of blended fiber and rubber concrete.