Postcracking residual strengths of fiber-reinforced high-performance concrete after cyclic loading

Abstract

The effect of fatigue loads on one of the main mechanical properties of fiber-reinforced high strength concrete (FRHSC) is studied in this work. In particular, this paper analyzes the variations in the residual tensile strength of steel fiber-reinforced concretes following cyclic flexural loading, which causes a predefined level of damage. To do so, a total of 40 prismatic specimens were tested. The specimens were not notched, but had previously been subjected to precracking. This has a similar effect to notching, but with a much smaller radius around the edge of the crack, which is therefore more vulnerable to fatigue. The results show that the damage provokes a progressive reduction in the residual traction strength. The study proposes two numerical expressions for the stress-crack width softening curves under tensile loads: an exponential formulation and a potential formulation. In both cases, the coefficients of both formulations depend on the damage that is induced. In addition, the proposal is to use fitted curves of the above-mentioned potential type.