外掺氧化镁混凝土的变形特性研究

Study on deformation characteristics of concrete mixed with MgO

在混凝土中掺氧化镁可提高混凝土抗裂性。试验研究了外掺氧化镁混凝土的弹性模量、极限拉伸值、干缩率、自生体积变形等变形性能,并探讨分析了氧化镁对混凝土变形性能的影响机理。试验结果表明,外掺氧化镁的混凝土弹性模量与未掺的基本相当,极限拉伸值和干缩率小幅降低,自生体积变形从收缩转为微膨胀。总的来说,掺入氧化镁可以在一定程度上改善混凝土的变形特性,有利于提高混凝土的抗裂能力。

Incorporating MgO into concrete can improve its crack resistance.We carry out an experimental study on deformation properties of concrete mixed with MgO,including elastic modulus,ultimate tension,drying shrinkage and autogenous volume change,and discuss the influence mechanism of MgO on deformation properties of concrete.The results show that,the elastic modulus of mixed concrete is basically the same as the normal ones,and the ultimate tension and drying shrinkage show a slight decrease,while the autogeous volume change is transformed from shrinkage to slight expansion.Generally speaking,the incorporation of MgO into concrete can improve the deformation properties of concrete,and is favorable to increasing the crack resistance of concrete.