煤矸石作为粗骨料对混凝土力学性能的影响

The Effects of Coal Gangue as Coarse Aggregate on Mechanical Property of Concrete

采用许昌煤矸石等质量取代混凝土中粗骨料配制了C30混凝土,测试了煤矸石掺量对混凝土力学性能的影响。结果表明,随煤矸石掺量增大,混凝土抗压和劈裂抗拉强度逐渐降低,当煤矸石掺量大于45%时,混凝土强度显著降低。混凝土的动态弹性模量和动态剪切模量随煤矸石掺量的增加显著降低,与煤矸石的掺量有较好的相关性。普通C30混凝土主要是界面区的破坏,而掺入煤矸石后,混凝土破坏除了界面区破坏外,还有由于煤矸石自身强度较低造成的骨料破坏。

Xuchang coal gangue was used to replace coarse aggregate to prepare C30 concrete. The influence of coal gangue on mechanical properties of concrete was investigated. Results show that with the increase of coal gangue,compressive strength and splitting tensile strength of concrete are on the decline.When the amount of coal gangue is more than 45%（ mass fraction） in concrete,the strength has been reduced obviously. With the increase of coal gangue,dynamic modulus of elasticity and dynamic shear modulus of concrete are on the obviously decline.These two modulus have good linear correlations with the content of coal gangue. As for the ordinary C30 concrete,most damage occurs in the interface transition zone（ ITZ） between aggregate and paste,but after addition of coal gangue the damage of concrete are not only due to the damage of ITZ,but also the damage of aggregate itself.