Pore Pressure Test And Experimental Studies On Explosive Spalling，for Concrete At High Temperature

High strength concrete’s risk of explosive spalling will increase significantly in the fire.Explosive spalling is a kind of suddenly instantaneous destruction phenomenon; it can causelarge losses to the structure of the bearing capacity. In this article, we make a formationmechanism analysis based on the mechanization of explosive spalling. Then we designed twotests which are targeted by the analysis, to analyze and summarize some problems, such as theexplosion influence of pore pressure inside the concrete, the pore pressure test. The specificcontent is as follows:1The study of high temperature concrete spalling mechanism were analyzed andsummarized in this paper. Based on the existing research results, we determine the test planand test objectives.2We design and manufacture a set of concrete pore pressure measuring under hightemperature equipment. We test the pore pressure values of ordinary concrete block andrubber concrete block respectively at high temperature. We analyzed the inner link oftemperature and pore pressure peak with the help of heating curves. This paper expounds themechanism of pore pressure to explain the intrinsic evolution process. Experiment proves thepore pressure exists in the concrete under high temperature，the existence of steam pressureinward migration law.3We designed a stamping experiment by embedded in the concrete block the pipe. Apump was used to exert the water pressure into the block. The damage phenomenon wasobserved. According to the different damage of punching shear position differences, indirectlyverified under the action of internal pressure, the phenomenon of spalling can observed in theconcrete.