经纬向纤维体积分数对耐碱玻璃纤维织物增强混凝土拉伸力学性能的影响

Influence of warp and weft fiber volume fractions on tensile mechanical properties of alkali-resistant glass textile reinforced concrete

为了研究经纬向纤维体积分数对耐碱玻璃纤维织物增强混凝土(ARG-TRC)拉伸力学性能的影响,通过万能试验机对不同经向纤维体积分数(0.24vol%、0.49vol%、0.73vol%和1.09vol%)和纬向纤维体积分数(0vol%、0.20vol%、0.48vol%和0.96vol%)的试件进行准静态拉伸试验,并结合数字图像相关分析得到拉伸状态下裂纹与应变分布。结果表明:ARG-TRC的拉伸力学性能和破坏形态主要取决于经向纤维体积分数,而纬向纤维体积分数对其影响不大;随着经向纤维体积分数的增加,极限强度、峰值应变和韧性明显增大,裂纹条数明显增加。对拉伸应力-应变曲线化进行三线性拟合,得到简化模型并与ACK模型进行对比。基于现有的裂纹间距计算模型和试验数据,修正了裂纹间距计算公式,其结果与文献数据吻合较好。该成果将有助于织物增强混凝土(TRC)中纤维织物的优化配置,提高纤维织物的利用率,对TRC的性能设计具有指导意义。

In order to study the influence of the warp and weft fiber volume fractions on the tensile mechanical properties of alkali-resistant glass textile reinforced concrete(ARG-TRC),quasi-static tensile tests were conducted on specimens with various volume fractions of warp yarn(0.24 vol%,0.49 vol%,0.73 vol%and 1.09 vol%)and weft yarn(0 vol%,0.20 vol%,0.48 vol%and 0.96 vol%)by a universal testing machine,and the crack strain distribution was obtained by digital image correlation(DIC)method.The results show that the tensile mechanical properties and failure modes of ARG-TRC mainly depend on the volume fractions of warp yarn,and the volume fractions of weft yarn do not show obvious effect.With the increase of the volume fractions of the warp yarn,the ultimate strength,peak strain and toughness increase significantly as well as the number of cracks.A trilinear model was obtained by fitting the experimental tensile stress-strain curves,and was compared with the ACK model.The crack-spacing calculation formula was modified based on the existing crack-spacing calculation model and experimental data,which show good consistency with the literature data.The findings will be helpful for the optimization of the configuration of textile in textile reinforced concrete(TRC),and for the improvement of the utilization efficiency of textiles,and be available for the performance design of TRC.