超高性能混凝土RPC的抗冲击压缩特性

利用分离式Hopkinson 压杆试验装置,完成了超高性能混凝土RPC及其在钢管约束情况下的冲击压缩性能试验,比较了RPC材料在无约束和有约束2种受力状态下的变形和破坏特点,分析了RPC材料与C60自密实混凝土材料的应变速率效应的差异,给出了RPC材料与C60自密实混凝土的冲击破坏阈值.结果表明:在达到冲击破坏阈值的冲击荷载作用下,RPC材料呈现脆性破坏形态,对RPC侧向施加钢管约束可大大改善其抗冲击性能;RPC材料具有一定的应变速率效应,但RPC材料强度随加载速率提高的幅度比普通高强混凝土C60的要小,并且随着RPC材料强度等级提高应变速率效应逐渐减小.

Ultra high per formance concrete RPC under compressive impact loading

Impact compression tests of ultra high performance concrete RPC and the RPC confined inside a steel circular tube were performed with a modified right cone 74-mm-diameter SHPB. Deformation characteristics and failure modes of the RPC under impact loading were investigated compared with C60 self consolided concrete, and the failure critical impulses of impact loading to crush the RPC and the C60 are obtained. The results of the tests show that failure modes of the RPC and the C60 subjected to impact loading are brittle, and the behavior of the RPC or the C60 subjected to impact loading can be improved greatly by confining the RPC or the C60 inside a steel circular tube, the loading rate influences impact compressive characteristics of the RPC, and when the strain rate increases, the ultimate compressive strength and the peak strain increase. However, the RPC seems to be less affected by the loading rate than the C60 self consolided concrete.