Study on the relationship between the volume fraction of steel fiber and the increase of mechanical properties of concrete

Abstract

: In order to study the effect of different volume rates of new steel fiber materials on the basic mechanical properties of ordinary concrete, cubic specimens with length, width and height of 100 mm were used for testing and comparison, and the volume admixture of steel fiber was selected as 0.5%, 1.0%, 1.5% and 2.0%, with 3 specimens per experimental group, totaling 90 specimens, and cubic specimens with length of 400 mm, width and height of 100 mm were used for flexural testing. The flexural test was carried out with rectangular specimens of 400 mm in length, 100 mm in width and 100 mm in height, 3 specimens per experimental group, 45 specimens in total. After the specimens were cured for 28 d, the mechanical properties were tested according to CECS13:2009 "Test Methods for Steel Fiber Concrete". The results showed that the mechanical properties of steel fiber concrete were significantly improved compared with those of ordinary concrete, with a maximum increase of 11.5% in compressive strength, 49.0% in flexural strength and 45.6% in splitting strength. This paper analyzes the relationship between the volume rate of steel fiber and the mechanical properties of concrete through the test results, and proposes the relationship curve equation of the effect of volume rate of steel fiber on the mechanical properties of concrete, which can be used as a reference for engineering design.