An investigation on micro pore structures and the vapor pressure mechanism of explosive spalling of RPC exposed to high temperature

On the thermal spalling mechanism of reactive powder concrete exposed to high temperature: Numerical and experimental studies

“…1 demonstrates the experimental setup and instruments adopted for recording the spalling process of RPC subjected to high temperature of up to 500°C. According to our preliminary tests [1,29,28], when the RPC specimen was heated from room temperature to approximately 380°C, explosive spalling occurred and the specimen spalled into two parts. With continuous elevation of the ambient temperature, the spalled parts of the specimen gradually burst into a pile of small debris.…”

“…A high-definition CCD camera was erected outside the observation window made from anti-explosion tempered glass to capture the entire spalling process of RPC. Detailed information about the experimental device and setup can be found in the literature [29].…”

“…Table 1 lists the ingredients and the mixture ratio of raw materials adopted for RPC specimens. Table 2 lists the thermophysical properties of the materials that were measured in our preliminary tests [1,29]. Fig.…”

“…[72,70,29]. Porosity used to be taken as the characteristic parameter to describe the variation of the micro pore system under elevated temperatures.…”

“…Indeed, according to pioneer investigations, it is shown that various factors, such as the physical and/or mechanical properties of fibers [25][26][27][28] and concrete matrices [29][30][31], fiber fractions [32,33,22], specimen preparation and curing methods [34,35], heating procedures [36,37], temperature ranges [1,38], specimen sizes [33,39], etc., influence the thermal spalling performance of concrete in different ways. However, few analytical studies are available for quantitatively elaborating the governing mechanism of concrete spalling through which the aforementioned influencing factors take effect.…”