天然气爆炸载荷作用下钢筋混凝土板毁伤试验研究

The damage characteristics of reinforced concrete slabs under the natural gas explosion load are studied experimentally. A semi-underground gas explosion loading device with a volume of 9. 8 m³ is constructed for the experimental research on the damage of reinforced concrete slabs with the thicknesses of 80 mm and 100 mm and the strengths of C30, C40 and C50 subjected to methane explosion loading. The distribution characteristics of quasi-static pressure, out-of-plane displacement of concrete slabs, and equivalent strain in the explosion space were obtained. The results reveal that the quasi-static pressure exhibits oscillatory features under the combined effect of explosion pressure accumulation and crack venting of reinforced concrete slabs in an enclosed space. The distribution of equivalent strain coincides with the crack pattern, displaying a symmetrical Y shape, and the equivalent strain has the distinct bimodal and trimodal characteristics. The two reinforced concrete slabs with different thicknesses exhibit significantly different failure modes: the reinforcement structure of 80mm-thick reinforced concrete slab remains intact, and the concrete cracked and dispersed, with localized concrete shearing failure, whereas the fracture of 100 mm-thick reinforced concrete slab occurred at the fixed joint, and the concrete slab is thrown as a whole, resulting in extensive shearing failure of the reinforced concrete composite.