混掺精细钢纤维/PVA纤维水泥基复合材料单轴拉伸试验及本构关系

Uniaxial tensile test and constitutive relation of reinforced cement-based composites with fine steel fiber and PVA fiber

为了研究精细钢纤维与聚乙烯醇(polyvinyl alcohol,PVA)纤维掺量对纤维水泥基复合材料抗拉力学性能的影响,进行了4组12个精细钢纤维/PVA纤维混杂水泥基材料试件的单轴抗拉试验,测得其应力-应变曲线及相关抗拉力学性能指标。试验和分析结果表明,含0.8%精细钢纤维试件的初裂强度为3.70 MPa,峰值强度为4.16 MPa,分别略低于最大值4.44 MPa与4.86 MPa,但峰值应变为最大值0.858%,材料韧性优于其他试件。过多的精细钢纤维不利于纤维发挥其增韧作用。基于试验数据建立了适用于混掺精细钢纤维/PVA纤维水泥基材料的单轴拉伸应力应变本构模型,模型拟合结果与试验曲线吻合良好。

In order to study the effect of the content of fine steel fiber and polyvinyl alcohol(PVA) fiber on the tensile properties of fiber-cement based composites,4 groups of 12 fine steel fiber/PVA fiber cement-based composites were tested under uniaxial tension,and their stress-strain curves and related tensile properties were measured.The experimental results and data analysis show that the initial cracking strength and peak strength of the specimen with 0.8% fine steel fiber are 3.70 MPa and 4.16 MPa,which are slightly lower than the maximum values of 4.44 MPa and 4.86 MPa,respectively.But it has the highest peak strain of 0.858%,showing the best toughness than other specimens.It is found that excessive fine steel fibers have negative effect on the material's toughness.Furthermore,a tensile stress-strain constitutive model for the cement-based material with fine steel fibers and PVA fibers was proposed,with the fitting results compared favorably with experimental data.