冲击荷载作用下橡胶混凝土动态力学性能研究

Study on Dynamic Mechanical Properties of Rubber Concrete under Impact Load

试验用直径100 mm霍普金森压杆(Split Hopkinson Pressure Bar,SHPB)对橡胶含量分别为0%、1%、2%、3%的橡胶混凝土进行动态冲击压缩试验,研究不同冲击气压下橡胶混凝土的破坏形态、抗压强度和能量吸收特性。结果表明:动态荷载作用下橡胶混凝土的破坏程度小于普通混凝土,破坏过程具有延性破坏特征,掺入橡胶提高了混凝土对应变率的敏感性,峰值抗压强度具有显著的应变率效应;相同橡胶掺量的混凝土,随着应变率的增加,动态抗压强度、峰值应变、动态增长因子(DIF)均增大;对于相同冲击气压,动态抗压强度随橡胶掺量的增加而降低。比能吸收分析表明,比能吸收值(SEA)随橡胶含量增加而增加,在高应变率下橡胶掺量为3%的橡胶混凝土增长速率最大,具有最佳的吸能效果,可为预测橡胶混凝土的动力性能提供参考。

The dynamic impact compression test was carried out with a 100 mm diameter Split Hopkinson pressure bar(SHPB) on rubber concrete with rubber content of 0%, 1%, 2% and 3% respectively, and the damage morphology, compressive strength and energy absorption characteristics of rubber concrete under different impact air pressure were studied. The results show that: the degree of damage of rubber concrete under dynamic loading is less than that of ordinary concrete, and the damage process has the characteristics of ductile damage;the incorporation of rubber improves the sensitivity of concrete to strain rate, and the peak compressive strength has a significant strain rate effect;the dynamic compressive strength, peak strain and dynamic growth factor(DIF) of concrete with the same rubber incorporation increase with the increase of strain rate;for the same impact pressure, the dynamic compressive strength decreases with increasing rubber admixture. The specific energy absorption analysis shows that the specific energy absorption(SEA) value increases with increasing rubber content, and the rubber concrete with 3% rubber admixture has the highest growth rate at high strain rates and has the best energy absorption effect, which can provide a reference for predicting the dynamic performance of rubber concrete.