Analyzing the load-displacement behavior and determining fracture parameters and bond strength of high-strength nonfibrous and fibrous SCC mixtures

This study aims to improve the ductility of high -strength SCC by adding hook -ended steel fibers and to analyze the effectiveness of this improvement using load -displacement responses and fracture parameters. Another objective of this study was to investigate the impact of steel fiber addition on the bond strength between the deformed steel bars and the high -strength SCC as well as the resultant failure mode. In this context, the high -strength nonfibrous and fibrous SCC mixtures were produced at a constant water -to -binder ratio of 0.37 and binder content of 385 kg/ m3. Portland cement, fly ash, metakaolin, and nano-SiO2 were used as binding agents to produce high -strength SCC mixtures. Briefly, it could be stated that this study examines, presents, and discusses the effects of the incorporation of metakolin and nano-SiO2 at various replacement levels and the addition of steel fiber on the load -displacement behavior of SCC beams subjected to a three-point flexural test, on the energy absorption capacity in terms of fracture energy, on the ductility by means of characteristic length, and on the bond strength determined by pull-out test. The present research has provided important insights into the fracture parameters, tensile and bond strength performance, and load -displacement curves of high -strength SCCs. The results leave no doubt that steel fiber addition is the most significant factor affecting both strength performance and fracture parameters of SCC mixtures while its efficiency depends on the degree of metakolin and nano-SiO2 used in the mixtures.