Performance of Steel Fiber Reinforced Concrete under Different Cooling Methods at High Temperature

Abstract

To explore the tensile properties of steel fiber reinforced concrete under different cooling methods after high temperatures, this paper considers steel fiber reinforced concrete after five different temperatures, under natural cooling and rapid water cooling, conducting split-tension mechanical property studies. The failure form and splitting peak stress of steel fiber reinforced concrete under different working conditions are obtained by experiments, comparative analysis of cooling methods, influence of high temperature and steel fiber content on tensile properties of concrete splitting, the main conclusions are as follows: as the temperature rises, the failure pattern of steel fiber reinforced concrete developed from one main penetrating crack to several cracks on the specimen surface; the addition of steel fiber can effectively improve the plastic characteristics of concrete, the apparent cracks in the concrete also increase. As the temperature rises, the peak tensile stress of steel fiber reinforced concrete decreases gradually, the increase in temperature leads to some extent to a greater influence of steel fiber on the mechanical properties of concrete splitting; as the steel fiber dosage increases, significant increase in concrete splitting mechanical properties, concrete splitting peak stress after high temperature is relatively high. The peak stress of concrete splitting under natural cooling is lower than that under rapid water cooling. At the same time, mathematical modeling of the effect of steel fiber admixture and high temperature on the peak splitting tensile stress of concrete under two cooling methods is derived, and the force mechanism is discussed and analyzed. The results of the study provide a theoretical basis for the analysis and calculation of steel fiber concrete structures after fire.