High-temperature aged performance of waterproof gasket used in shield tunnel
YU Wei1, LIN Zanquan2, ZHU Binbin2, WANG Yuanye2, DING Wenqi3, QIAO Yafei3, ZHANG Xiaodong1, GONG Chenjie2*
1. China Railway Southern Investment Group Co., Ltd., Shenzhen 518054, Guangdong, China; 2. School of Civil Engineering, Central South University, Changsha 410075, Hunan, China; 3. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China
Abstract: In order to cope with the risk of sudden fire and reduce the damage caused by the fire, it was necessary to investigate the performance change trend of the gasket under high temperature, and then the mechanical properties and sealing performance of the gasket after high temperature were verified. The material selection and hole type selection of sealing gasket were investigated. In view of the influence of high temperature on gasket material, the thermal oxidizing aging test of rubber specimen was carried out under high temperature condition and the material property loss was measured. The main research findings were as follows: it was found that the engineering industry tends to adopt “Shesfield type” sealing gasket made of EPDM ma-terial, and the hole type was mostly circular double row hole. After aging at different temperatures, the overall material property of medium or low hardness(40 HA, 60 HA)EPDM materials showed a downward trend, while the tensile strength of 80 HA EPDM material had a high hardness increases first and then decreases. Under high temperature conditions, EPDM would have a large material loss, which would affect the sealing performance of the sealing gasket at the segment joint at the material level, and reduced the long-term waterproof reliability of the joint. The research results have guiding significance for the scientific evaluation of the service performance evolution of shield tunnel joint gaskets.
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