高温后混凝土材料的动态压缩力学性能

摘要

利用直径φ100mm的SHP8(Split Hopkinson Pressure Bar)装置分别对常温和经历400℃、600℃、800℃高温后的混凝土材料试样进行应变率范围30～220s-1的动态压缩试验,混凝土材料的骨料尺寸为15～20mm.结果表明:经历高温后的混凝土材料,一方面具有温度软化效应,另一方面又具有应变率强化效应.其归一化强度随归一化温度对数的增大而近似线性地递减,相反却随应变率对数的增大而近似线性地递增.在应变率的强化效应及温度软化效应的耦合影响中,后者占主导地位.%Experiments were carried out by using SHPB (φ100mm) ( Split Hopkinson Pressure Bar) apparatus for concrete after exposure to 23 ～800℃. The diameters of coarse aggregates in the concrete ranged form 15mm to 20mm,and the SHPB experiments involve strain rates between 30s-1 and 220s-1. Results show that the heated concrete was weakened, and there was strain-rate effect on strength enhancement, with the normalized strength decreasing approximate linearly with the increase of the logarithm of the normalized temperature. Degradation of the compressive strength of the heated concrete was dominant.