钢纤维橡胶自密实混凝土静态力学性能研究

钢纤维的桥联作用及其与橡胶颗粒的协同作用可显著改善混凝土性能，而针对钢纤维橡胶自密实混凝土的静态力学性能及其本构关系的研究较少。通过在10%、20%、30%橡胶颗粒掺量的橡胶自密实混凝土中分别外掺体积掺量为0.5%、1.0%、1.5%的钢纤维，制备出钢纤维橡胶自密实混凝土试件，进行棱柱体轴心抗压试验，探讨钢纤维掺量、橡胶颗粒掺量对试件的典型力学特征量的影响，建立钢纤维橡胶自密实混凝土轴心抗压强度的本构关系。结果表明：钢纤维橡胶自密实混凝土试件呈现延性破坏的同时，其完整性也较好；随着橡胶颗粒掺量的提高，试件轴心抗压强度逐渐降低；当钢纤维橡胶自密实混凝土中的橡胶颗粒掺量较高时(20%、30%),钢纤维对橡胶自密实混凝土轴心抗压强度无明显的增强效果；橡胶颗粒的掺入提高了试件的峰值应变，当橡胶颗粒掺量为10%时，达到最大值，增长幅度为10%;不同的钢纤维掺入量对钢纤维橡胶混凝土的峰值应变普遍有增强效果，但没有呈现出明显的规律性；轴心抗压本构关系能反映钢纤维橡胶自密实混凝土力学性能。

Research on static mechanical properties of self-compacting concrete mixed with steel fiber and rubber

The bridging effect of steel fiber and its synergistic effect with rubber particles can significantly improve the performance of concrete, but there are few studies on the static mechanical properties and constitutive relationship of self-compacting concrete mixed with steel fiber and rubber. To prepare self-compacting concrete specimens with steel fiber and rubber, the rubber concrete with 10%, 20%, and 30% rubber powder content were mixed with the steel fiber content of 0.5%, 1.0%, 1.5%, respectively. Prismatic axial compression tests were carried out to investigate the effects of steel fiber content and rubber powder content on the typical mechanical characteristics of specimens and the constitutive relationship of the axial compressive strength of the self-compacting concrete mixed with steel fiber and rubber was put forward. The results show that the failure of self-compacting concrete specimen mixed with steel fiber and rubber presents ductile failure, while its integrity is good. With the increase of rubber powder content, the axial compressive strength of the specimen gradually decreases. When the rubber powder content is high (20%, 30%), steel fiber has no obvious enhancement effect on the axial compressive strength of self-compacting concrete with rubber. The addition of rubber powder increases the peak strain of the specimen. The peak strain of the specimen reaches the maximum (an increase of 10%) when the amount of rubber powder is 10%. Different amounts of steel fiber can generally enhance the peak strain of self-compacting concrete mixed with steel fiber and rubber, but it does not show obvious regularity. The axial compressive constitutive relationship can reflect the mechanical properties of self-compacting concrete mixed with steel fiber and rubber powder.