Experiments and prediction of direct tensile resistance of strain hardening fiber-reinforced concrete

This study investigates and predicts the direct tensile resistance of strain hardening steel fiber-reinforced concrete (SHSFRC). Three steel fiber types, namely, twisted, hooked, and smooth fibers, and three matrices with different compressive strengths of 28 MPa (M1), 84 MPa (M2), and 180 MPa (M3) were investigated in both single fiber pullout tests and direct tensile tests. In addition, a machine learning-based model was developed to predict the tensile resistance of SHSFRC. The experimental results showed that twisted fibers exhibited not only the highest pullout resistance but also the greatest tensile resistance in M1 and M2, whereas smooth fibers achieved the same results in M3. From the predicting outcomes, the proposed model achieved high efficiency and accuracy in estimating the tensile resistance of SHSFRC, with a correlation coefficient of 0.951.