再生混凝土与普通混凝土动态冲击强度对比研究

COMPARATIVE STUDY ON DYNAMIC IMPACT STRENGTH OF RECYCLED CONCRETE AND ORDINARY CONCRETE

为研究混凝土材料的动态抗压强度应变率效应,试验分别制作了水灰比为0.4的普通混凝土和再生粗骨料取代率为50%的再生混凝土试件,并分别做立方体静态抗压试验和霍普金森杆(SHPB)动态冲击压缩试验。试验结果表明,50%再生骨料取代率的再生混凝土的静力强度高于普通混凝土,在动态冲击下,两种混凝土的峰值应力和峰值应变均随应变率的增大而增大,表现出明显的应变率效应;普通混凝土在高应变率下抗压强度增幅及DIF增幅分别为34.4%和34.1%,均高于再生混凝土,说明普通混凝土的应变率敏感性要高于再生混凝土。

To study the strain rate effect of dynamic compressive strength of concrete materials,ordinary concrete with a water-cement ratio of 0.4 and recycled concrete with a recycled aggregate replacement rate of 50%were made respectively,and the cube static compressive test and the Hopkinson bar(SHPB)dynamic impact compression test were conducted respectively.The results show that the static strength of recycled concrete with 50%recycled aggregate replacement rate is higher than that of ordinary concrete.Moreover,under dynamic impact,the peak stress and peak strain of both kinds of concrete increase with the increase of strain rate,showing obvious strain rate effect.In addition,the increase of compressive strength and DIF of ordinary concrete at high strain rate are 34.4%and 34.1%respectively,both of which are higher than that of recycled concrete,indicating that the strain rate sensitivity of ordinary concrete is higher than that of recycled concrete.