不同维度玻璃纤维对GRC抗弯性能的影响

Influence of Glass Fibers with Different Dimensionality on Flexural Properties of GRC

采用一维短切玻璃纤维、二维玻璃纤维网格布、三维间隔连体玻纤织物(3D织物)对水泥基材料进行增强,得到不同维度玻璃纤维增强水泥(GRC);根据四点弯曲测试得到不同维度GRC试件的抗弯荷载挠度曲线,结合测试过程中的裂缝发展情况,分析不同维度玻璃纤维对水泥基材料抗弯性能的影响规律,并建立不同维度GRC试件的抗弯荷载挠度曲线拟合方程,计算其强度和韧性指标.结果表明:在弹性变形阶段和塑性变形阶段,不同维度GRC试件的荷载与挠度均有较好的线性关系,在弹塑性过渡阶段,3D织物GRC试件的抗弯荷载与挠度呈正弦函数关系;与纯水泥砂浆试件相比,一维短切玻璃纤维GRC试件、二维玻璃纤维网格布GRC试件、3D织物GRC试件的抗弯破坏强度分别提高53%、92%、193%,韧度指数分别达26.7、34.3、73.6;3D织物GRC使得GRC材料由低强度脆性破坏向高强、高韧性提升.

The cement-based materials were reinforced by one-dimensional chopped glass fiber,two-dimensional glass fiber mesh and three-dimensional glass fiber fabric(3D fabric)that was woven at intervals.Based on the examination of load-deflection curve from four-point bending test and the crack propagation in glass fiber reinforced cement(GRC)failure process,the bending performance of GRC reinforced by glass fibers with different dimensionality was analyzed.The fitted equations of bending load-deflection curve were established,and the strength and toughness indexes were used for quantitative characterization.The results show that,GRC reinforced by fibers with different dimensionality possesses good linear relationship between bending load and deflection in elastic deformation stage and plastic deformation stage.In the elastic-plastic transition stage,the bending load and deflection of GRC reinforced by 3D fabric shows a sine function relationship.The bending failure strength of GRC reinforced by chopped glass fiber,glass fiber mesh and 3D fabric is increased 53%,92%and 193%respectively compared with that of reference cement mortar,and the toughness index reaches 26.7,34.3 and 73.6 respectively compared with that of reference cement mortar(1.0).3D fabric reinforcement improves the strength and toughness of GRC from a low strength and brittle material.