PVA纤维增强水泥基复合材料拉伸特性试验研究

初步配制了PVA纤维水泥基复合材料,对使用原材料的性能、投料顺序和搅拌工艺进行了详细的描述;测定了各个配比的坍落扩展度,揭示掺加纤维后流动性减小的原因是由于PVA纤维有亲水性,纤维表面吸附了大量的自由水分子;利用外夹式单轴直接拉伸试验得到了硬化的应力-应变全曲线,观察到多条裂缝的出现,极限拉应变达到0.7%,大约是混凝土的70倍;根据试验数据得出基体和纤维掺量对极限拉应变、峰值应力和断裂能都产生影响,最后对假硬化的应力-应变全曲线进行了分析.所得结论为高韧性、高耗能材料的配制提供了大量的试验和理论依据.

Experimental research on tension property of polyvinyl alcohol fiber reinforced cementitious composites

Experimental research is undertaken to make polyvinyl alcohol fiber reinforced cementitious composites. The test material performance used, mixing method and mixing technology of test material are described in detail. The slump flow of each mix proportion is got. And the reason that the flowability is decreasing by the addition of the fiber is that fiber surface adsorbs amount of freed water molecules owing to the hydrophilic of PVA fiber. In addition, the pseudo-strain-hardening stress-strain curves are got in uniaxial direct tension, and multicracking appears. The ultimate tensile strain reaches O. 7 volume on slump % fl which is 70 times of the plain concrete. The influences of matrixs and the fiber ow, ultimate tensile strain, peak stress and fracture energy are analyzed by experimental data. At last, the pseudo-strain-hardening stress-strain curves are discussed. The analytical and experimental conclusions can provide a lot of experimental and theoretical bases for making the composites hold the high ductility and high energy consumption ability.