片麻岩骨料混凝土基本力学性能及其换算关系研究

为了研究片麻岩机制砂骨料混凝土的劈裂抗拉强度、轴心抗压强度和弹性模量与立方体抗压强度之间的关系,选取水胶比、机制砂砂率和机制砂石粉含量为配比参数,制备11组C50片麻岩骨料混凝土进行不同龄期的基本力学性能试验。根据试验结果,探讨了片麻岩骨料混凝土各力学性能受各配比参数变化的影响规律,采用数理统计回归的方法,对立方体抗压强度与其他力学性能指标之间的换算关系进行了分析。结果表明:片麻岩骨料混凝土力学性能中受配比参数变化影响最大的是劈裂抗拉强度,其次是立方体抗压强度和轴心抗压强度,最小的是弹性模量; 拟合的片麻岩骨料混凝土劈裂抗拉强度、轴心抗压强度、弹性模量与立方体抗压强度之间换算关系式,较GB 50010—2010中相应的关系式能更准确地反映片麻岩骨料混凝土立方体抗压强度与其他力学性能指标之间的关系; 片麻岩骨料混凝土试块回弹值与立方体抗压强度的相关性很小。

Study on basic mechanical properties and conversion relationship of gneiss aggregate concrete

In order to study the relationship between splitting tensile strength, axial compressive strength, elastic modulus and cubic compressive strength of gneiss machine-made aggregate concrete,the basic mechanical properties of 11 groups of C50 gneiss aggregate concrete were tested at different ages by selecting the water binder ratio, the rate of machine-made sand and the stone powder content in machine-made sand as the mixing parameter variables. Based on the test results, the influence of the mixing ratio parameters on the mechanical properties of gneiss aggregate concrete was discussed, and the conversion relationship between the cubic compressive strength and other mechanical properties was analyzed by using the mathematical statistics regression method. The results show that among the mechanical properties of gneiss aggregate concrete, the splitting tensile strength is the most affected by the change of proportioning parameters, the cubic compressive strength and axial compressive strength are the second, and the elastic modulus is the smallest. The fitted conversion relationship between splitting tensile strength, axial compressive strength, elastic modulus and cubic compressive strength of gneiss aggregate concrete can more accurately reflect the relationship between the cubic compressive strength of gneiss aggregate concrete and other mechanical performance indicators than the corresponding relationship in GB 50010—2010. The rebound value of gneiss aggregate concrete test block has little correlation with the cubic compressive strength.