道路再生骨料混凝土三轴强度及损伤分析

Damage analysis on recycled aggregate concrete under triaxial compression

为探究道路再生骨料对混凝土的多轴受压强度及损伤演变性能的影响,考虑两种类型粗骨料及6种围压值,设计完成了12组混凝土的常规三轴试验研究.通过试验,观察并对比了试件在单向轴压与三向轴压下破坏形态,获取了各围压荷载下试件的峰值应力、峰值应变,分析了三轴荷载作用下再生混凝土强度影响因素,并揭示了再生混凝土的损伤演变规律.研究结果表明:在围压荷载作用下,试件破坏形态发生了较大改变,骨料类型对试件破坏形态影响不大;围压值=0 MPa时,试件发生劈裂破坏;围压值>0 MPa时,发生具有一定延性的剪切斜压破坏;侧向围压荷载越大,再生混凝土的强度越大,变形能力越好;侧向围压荷载可有效约束再生混凝土损伤的发展,并延迟了初始损伤出现的时间.

In order to study the strength and damage evolution performance of road recycled aggregate concrete,12 groups specimens were designed and studied under 6 different confining pressures by taking confining pressures and coarse type as changing parameters.Through the conventional triaxial test study,the failure patterns of recycled concrete specimens were observed,the peak stress and peak strain of recycled concrete specimens under different confining pressures were obtained,the influencing factors of recycled concrete strength under triaxial load were analyzed,and the damage evolution rules of recycled concrete were revealed.The results show that the failure pattern of the specimens is mainly related to the confining pressure load.The higher the lateral confining load is,the stronger the recycled concrete is and the better the deformation capacity is.Lateral confining load can effectively restrain the development of the damage of recycled concrete and delay the time of the initial damage.