Mechanical Properties of Steel Fiber Reinforced Silica Fume Concrete

Abstract

This paper presents the investigations towards developing a better understanding on the contribution of steel fibers on the compressive, flexural, and splitting tensile strengths of steel fiber reinforced silica fume concrete. An extensive experimentation was carried out with w/cm ratio ranging from 0.25 to 0.40, and fiber content ranging from zero to1.5 percent with an aspect ratio of 80 and silica fume replacement at 5% and 10%. The influence of fiber content in terms of fiber reinforcing index on the mechanical properties of high performance fiber reinforced concrete (HPFRC) with compressive, flexural, and splitting tensile strengths ranging from 55 to 86 MPa, 5.5 to 11 MPa, and 4 to 8.5 MPa respectively is presented. Based on the test results, equations are proposed using statistical methods to predict 28-day strength of HPFRC in terms of fiber reinforcing index for a wide range of w/cm ratios. Relationship between flexural and splitting tensile strengths has been developed using regression analysis. To examine the validity of the proposed model, the experimental results were compared with the values predicted by the model and by the equations of previous researchers, and the absolute variation obtained was within1.50 percent. Addition of 1.5 % volume fraction of crimped steel fiber resulted in 11 % increase in the compressive strength while modulus of rupture and splitting tensile strength increased by 38 % and 56 % respectively.