利用大直径（75 mm）分离式霍普金森拉杆（SHTB），对再生粗骨料取代率分别为0％、25％、50％、75％和100％的5组圆柱体再生混凝土试样进行应变率范围为100～102 s －1的动态直接拉伸实验，研究再生混凝土的动态直接拉伸力学性能及其破坏形态。试验结果表明，再生混凝土的抗拉强度随平均应变率的增加而增大，而再生混凝土的破坏形态与平均应变率有关，这表明再生混凝土具有明显的率敏感性。在相同水灰比下，再生混凝土准静态拉伸强度比普通混凝土低1．3％～15．9％，动态拉伸强度比普通混凝土低1．7％～29％，此研究为再生混凝土的工程应用提供一定的理论依据。%To study the direct tensile properties and fracture patterns of recycled aggregate concrete (RAC)with various replacement percentages (0%,25%,50%,75% and 100%)of recycled coarse aggregates,the dynamic direct tensile tests of RAC within a strain-rate range of 100 ~102 s -1 were conducted using large diameter (75 mm)split Hopkinson tensile bar (SHTB).Test results showed that the tensile strength of RAC increases with increase in the average strain-rate,and the average strain-rate affects the damage form of RAC,so RAC has an obvious rate sensitivity;under the same water cement ratio,the quasi-static tensile strength and dynamic tensile strength of RAC are 1.3% ~15.9% and 1.7% ~29% lower than those of ordinary concrete,respectively.This study provided a theoretical basis for engineering applications of RAC.
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