PVA纤维增强型水泥基复合材料高温后力学性能试验

Experiment on Mechanical Behaviors of PVA Fiber Reinforced Cementitious Composite After High Temperature

为了研究聚乙烯醇(PVA)纤维增强型水泥基复合材料高温后的力学性能,对30组共90个试件进行了力学性能试验,测得材料的立方体抗压强度、抗折强度、弹性模量、轴心抗压强度以及棱柱体单轴抗压应力-应变全曲线,并与相应基体的力学性能进行对比分析。结果表明:当加热温度低于200℃时,PVA纤维的掺入可有效改善水泥基复合材料的抗折强度和棱柱体单轴受压峰值荷载后的延性性能和韧性性能,降低弹性模量,对立方体抗压强度和棱柱体轴心抗压强度影响不大;温度高于200℃后,抗折强度、弹性模量和峰值荷载后的延性性能与韧性性能与基体接近,立方体抗压强度和轴心抗压强度均低于基体,轴心抗压强度下降幅度远远大于立方体抗压强度。

In order to study the mechanical behaviors of polyvinyl alcohol （PVA） fiber reinforced cementitious composite, 90 specimens divided into 30 groups after high temperature treatment were tested. The material cubic compressive strength, flexural strength, elasticity modulus, axial compressive strength and the prism uniaxial compressive stress-strain curves were obtained. The mechanical behavior of corresponding matrix was also tested for comparison. The results show that when the heating temperature bellows 200℃, flexural strength, ductility property and toughness property after the prism uniaxial compressive peak load of cementitious composite can effectively improve with PVA fiber mixing. Meanwhile, while elasticity modulus decreases, PVA fiber has little effect on cubic compressive strength and the prism axial compressive strength. When the heating temperature is higher than 200 ℃, flexural strength, elasticity modulus, ductility property and toughness property after the prism uniaxial compressive peak load of PVA fiber reinforced cementitious composite is close to the matrix. Cubic compressive strength and axial compressive strength of PVA fiber reinforced cementitious composite is lower than the matrix. Axial compressive strength decreases much more than the cubic compressive strength.