高温后钢管RPC的SHPB试验研究

摘要

采用φ75 mm分离式霍普金森压杆(Split Hopkinson Pressure Bar,SHPB)分别对常温、高温200℃和300℃后的钢管活性粉末混凝土(Reactive Powder Concrete-Filled Steel Tube,钢管RPC)及RPC进行冲击压缩试验,分析了应变率效应及温度效应对试件动态力学性能和破坏形态的影响.结果表明:高温作用后钢管RPC的韧性和相对韧性均随应变率的提高而增大,相同应变率下钢管RPC的韧性和相对韧性随过火温度提高而增大.冲击荷载作用下钢管RPC和RPC的破坏程度均随过火温度提高而降低,RPC发生脆性破坏而钢管RPC发生延性破坏.钢管RPC的吸收能随过火温度提高而增大,但RPC的吸收能受过火温度影响较小.钢管RPC和PRC的吸收能均随应变率的提高而增大.试件的吸能能力取决于能量吸收率的大小.%Impact tests on reactive powder concrete-filled steel tube (RPC-FST) and reactive powder concrete (RPC) specimens after exposure to high temperature (20 ℃,200 ℃,300 ℃) were performed by using a φ75 mm split Hopkinson pressure bar (SHPB).The strain rate effect and temperature effect on dynamic behaviors and failure modes of specimens were investigated.It is indicated that the toughness and specific toughness of RPC-FST increase as the strain rate increases.The toughness and specific toughness of RPC-FST under the same strain rate increase as the temperature increases.The failures of RPC-FST and RPC under impact loading tend to be unobvious as the temperature increases.Brittle failures are observed in RPC while ductile failures in RPC-FST.The absorbed energy of RPC-FST increases as the temperature increases,while the temperature has no great influence on the maximum absorbed energy of RPC.The absorbed energies of RPC-FST and RPC both increase as the strain rate increases.The capacity of energy absorption of the specimens is mostly dependent on the energy absorbency.