Current studies on the expansion rate impact on the fracture performance of type I in ultra-hole performance fiber reinforced concrete (UHPFRC) remain relatively limited. This study aims to examine the effects of the stretching rate (load rates of 0.12, 1.2, 12 and 120 mm/min) and the steel fiber content (1.0 %, 1.5 %and 2.0 %) on the fracture properties of UHPFRC. Type-i fracturt tests were carried out on pre-locked UHPFRC copies, which were subjected to three points. The results showed that the nominal bending strength of UHPFRC was increased with increasing load rate. In particular for steel fiber content of 1.0 %, 1.5 %and 2.0 %, the nominal bending strength showed an increase of 16.20 %, 17.01 %and 10.69 %, since the load rate from 0.12 mm/min was increased to 120 mm/min. In addition, the increase in the fiber content significantly improved the bending and fracture properties of UHPFRC. With increasing load rate from 0.12 mm/min to 120 mm/min, the fracture energy of UHPFRC with steel fiber content of 1.0 %, 1.5 %and 2.0 %by 23.28 %, 19.41 %or. 18.98 %. In addition, with increasing load rate, the characteristic length of UHPFRC gradually decreases. Finally, a linear regression method was used to determine a predictive formula for the nominal bending strength and the fracture energy of UHPFRC, taking into account the combined effects of stretching rate and steel fiber content. This study will enrich the existing research of the stretching rate effect on the fracture performance of type I in UHPFRC.
Coupling effects of the expansion rate and steel fiber content on the fracture performance of fiber reinforcement concrete with ultraahohe performance
