Binary Superposition Mix Design Method for SFRC Part I: Principle and Evaluation

Abstract

The binary superposition mix design method is constructed to quantitatively calculate the compositions of steel fiber reinforced concrete (SFRC), which brings into sufficient cement paste wrapping steel fibers to strengthen the boundary surfaces of steel fibers with base concrete. The principle of the method is firstly introduced. The experiments were carried out to evaluate the validity of the method. In the experiment, the cubic and axial compressive strength as well as the splitting tensile strength of SFRC affected by the fraction of steel fiber by volume and the average thickness of cement paste wrapping steel fibers were tested. The results are analyzed on the basis of former studies specified in the current technical specification for fiber reinforced concrete structures, which show that the larger strengths especial the splitting tensile strength of SFRC in grade CF50 can be got by the method, but the less splitting tensile strength of SFRC in grade of CF40 should be further studied.