Investigation on crack extension resistance curve of aligned steel fiber-reinforced cement-based composites

In this study, an analytical method was proposed to predict the crack extension resistance curve (K-R curve) of aligned steel fiber-reinforced cement-based composites (ASFRC). The three-point bending tests were carried out on notched ASFRC specimens. Based on the predicted results, the influence of size effect and fiber dosage on K-R curves of ASFRC specimens was discussed. Finally, the relationship between K-R curves of ASFRC and steel fiber-reinforced cement-based composite (SFRC) specimens was investigated. The results show that the analytical results agree well with the experimental ones. The K-R curve of ASFRC specimen has size effect and increases with fiber dosage. The ASFRC specimen shows a 30% improvement in the crack extension resistance at peak load over the SFRC specimen when the fiber volume dosage is 0.8%, and the improvement becomes more pronounced with increasing fiber dosage. When the K-R curves of ASFRC and SFRC specimens are the same, the fiber consumption can be reduced by at least 40%.