EFFECT OF FIBER DOSAGE AND MATRIX COMPRESSIVE STRENGTH ON MSFRC PERFORMANCE

The design of MSFRC structural elements requires a proper knowledge of the relationship between fiber dosage and flexural residual strength. For this reason, the present study analyses the effect of fiber dosage and compressive strength of concrete on MSFRC cracked behavior. In particular, the influence of the aforementioned parameters was investigated through an experimental campaign, based on three-point bending tests, on specimens characterized by four different fiber dosages, ranging from 2 kg/m3 to 8 kg/m3 and three different concrete mixes, with strengths spanning from 33 MPa to 55 MPa. The analysis of the experimental results has highlighted that, for the macro-synthetic fibers considered, concrete compressive strength has no significant effect on residual flexural tensile strength. Moreover a very high correlation between residual flexural strength and number of fibers across the cracked specimens surface, has been observed. Finally, a strength predictive model was defined using the experimental data.