自密实轻骨料混凝土压-剪复合受力力学性能

为探究自密实轻骨料混凝土压-剪复合受力力学性能，应用液压伺服机和材料压-剪试验机，对自密实轻骨料混凝土进行单轴受压、单轴劈裂抗拉和压-剪复合受力试验研究，通过试验得到不同加载工况下自密实轻骨料混凝土破坏形态和力-变形曲线，引用文献对普通混凝土和轻骨料混凝土压-剪复合受力研究数据，对比分析自密实轻骨料混凝土压-剪复合受力性能。研究结果表明：自密实轻骨料混凝土压-剪复合受力破坏形态与普通混凝土和轻骨料混凝土相类似，随着轴压比的提高，剪切破坏断面摩擦痕迹逐步明显，混凝土碎渣也逐步提高，自密实轻骨料混凝土剪切破坏强度、残余荷载和剪切破坏位移也随之提高；剪切破坏强度提高幅度高于普通混凝土和轻骨料混凝土，残余荷载受轴压比影响提高幅度高于普通混凝土，但略低于轻骨料混凝土。基于主应力空间结合普通混凝土和轻骨料混凝土压-剪试验数据，提出混凝土压-剪复合受力统一破坏准则，同时基于八面体应力空间，提出自密实轻骨料混凝土破坏准则，所提出的破坏准则具有良好的适用性。

Mechanical property of self-compacting lightweight aggregate concrete under combined compression-shear stress

In order to study the mechanical properties of self-compacting lightweight aggregate concrete under combined compression-shear loading, hydraulic servo machine and material compression-shear testing machine were used to study the uniaxial compression, uniaxial splitting tension and compression-shear composite loading of self-compacting lightweight aggregate concrete. The failure modes and force-deformation curves of aggregate concrete were compared with those of ordinary concrete and lightweight aggregate concrete under combined compression-shear loading. The results show that the failure modes of self-compacting lightweight aggregate concrete under combined compression-shear loading are different from those of ordinary concrete and lightweight aggregate concrete. Similarly, with the increase of axial compression ratio, the frictional trace of shear failure section is gradually obvious, and the concrete slag is also increased. At the same time, the shear failure strength, residual load and shear failure displacement of self-compacting lightweight aggregate concrete are gradually increased, and the shear failure strength affected by axial compression ratio is higher than that of ordinary concrete and concrete. While its residual load by axial compression ratio increases more than ordinary concrete, slightly lower than lightweight aggregate concrete. Based on the principal stress space and the compression-shear test data of ordinary concrete and lightweight aggregate concrete, the unified failure criterion equation of concrete under combined compression-shear loading was proposed, and the failure criterion of self-compacting lightweight aggregate concrete was proposed based on octahedron stress space. The proposed failure criterions have good applicability.