Experimental Study On Flexural Toughness Of Steel Fiber Reinforced Concrete

According to the standard test methods for fiber reinforced concrete(CECS13: 2009), the performances of the cubic compressive strength, splitting tensile strength and flexure toughness are studied in this paper. The main achievements are as follows:1,The effects of fibers of different volume fractions, types(length-diameter ratio, manufacturing process and length) and concrete strength grade on cubic compressive strength are studied though the experiments on 150 steel fiber reinforced cements with the dimension of 150×150×150mm. The consequence of experiment indicates that the steel fiber volume has no obviously effect on the cubic compressive strength of SFRC. The cubic compressive strength of SFRC is even lower than plain concrete when the volume fraction is low. But the addition of the steel fiber greatly improve the failure pattern of the cement, which shifts the brittle failure of cement to certain plastic failure.2,The effects of fibers of different volume fractions, types(length-diameter ratio, manufacturing process and length) and concrete strength grade on splitting tensile strength are studied though the experiments on 150 steel fiber reinforced cements with the dimension of 150×150×150mm. And discusses the relationship between the splitting tensile strength and compressive strength. The consequence of experiment indicates that the splitting tensile strength of steel fiber concrete increases with the increase of volume fractions, length-diameter ratio, the length and concrete strength grade. The cold drawn steel fiber is superior to the mill steel fibers and shear steel fiber. The splitting tensile strength of SFRC increases with the rise of concrete strength grade, but their ratio drop off.3,The effects of fibers of different volume fractions, types(length-diameter ratio, manufacturing process and length) and concrete strength grade on flexure toughness are studied though the experiments on 138 steel fiber reinforced cements with the dimension of 100×100×400mm and 6 steel fiber reinforced cements with the dimension of 150×150×550mm. The flexural strength, the cracking bending strength, the flexural toughness indexes, the equivalent bending strength and the flexural toughness ratio are calculated and discussed. It is demonstrated that the flexural toughness indexes and the flexural toughness ratio of steel fiber concrete increase with the rise of volume fractions, length-diameter ratio and the length. The cold drawn steel fiber is superior to the mill steel fibers and Shear steel fiber. The brittle of SFRC increases with the rise of the concrete strength grade, and the flexural toughness indexes and the flexural toughness ratio are in descendent trend. The flexural toughness calculation method is discussed according to the test results and the flexural toughness indexe calculation method of low content fiber reinforced concrete is put forward by test results.