钢-PVA混杂纤维增强混凝土轴压力学性能试验研究

Experimental study on the axial pressure performance of steel-PVA hybrid fiber reinforced concrete under axial compression

混凝土中掺加纤维是改善混凝土脆性可选择的方法之一。为研究钢-聚乙烯醇(Polyvinyl Alcohol,PVA)混杂纤维增强混凝土轴心受压力学性能,设计了12组36个不同纤维掺量的标准棱柱体试块,通过测试试块的轴压荷载-变形曲线、观察试块破坏形态,分析了轴心抗压强度、峰值应变变化规律,提出了钢-PVA混杂纤维增强混凝土单轴受压本构方程,给出了相关参数的表达式。结果表明:钢-PVA混杂纤维增强混凝土轴心受压下表现为延性破坏,与钢纤维混凝土相比,其荷载-变形曲线与坐标轴包围面积较大;不同的钢纤维和PVA纤维掺量体积比对混杂纤维增强混凝土强度值的提高产生正负协同效应;PVA纤维掺量体积比较高时,混杂纤维增强混凝土峰值应变值显著提高。

Adding fiber to concrete is one of the alternative ways to improve the brittleness of concrete.Twelve groups with 36 standard test prisms were designed to study the compressive properties of steel-polyvinyl alcohol(PVA)hybrid fiber reinforced concrete with different fiber content.Based on the tested load-deformation curves and the observed failure modes of the test prisms,the axial compressive strength values and the peak strain value of the test prisms were analyzed.Furthermore,the uniaxial compression constitutive equation of the steel-PVA hybrid fiber reinforced concrete was proposed and corresponding parameters in the formula were given.The results show that the steel-PVA hybrid fiber reinforced concrete exhibits ductile failure obviously.And the area of its load-deformation curve around the abscissa is larger than the corresponding area of the steel fiber concrete.Different volume fractions of steel fiber and PVA fiber have positive and negative synergistic effect on the increase of strength value.When the volume fraction of PVA fiber increases,the peak strain of hybrid fiber reinforced concrete increases significantly.