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

摘要:

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,通过四点弯曲的抗弯荷载-挠度曲线,结合玻璃纤维增强水泥(GRC)破坏过程中的裂缝发展变化情况,分析不同维度纤维对GRC抗弯性能的影响规律；建立不同维度玻璃纤维增强GRC抗弯荷载-挠度曲线拟合方程,应用强度和韧性指标进行定量表征。结果表明：不同维度玻璃纤维增强GRC在抗弯荷载作用下,弹性变形阶段和塑性变形阶段荷载与挠度均有较好的线性关系,3D织物增强GRC在弹塑性过渡阶段荷载与挠度呈正弦函数关系；短切玻璃纤维、玻璃纤维网格布、3D织物增强GRC比纯水泥砂浆抗弯破坏强度分别提高53%、92%、193%,相比纯水泥砂浆韧性指标1.0,分别提高到26.7、34.3、73.6；3D织物增强GRC 使得GRC材料由低强度脆性破坏向高强、高韧性提升。

Abstract:

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 flexural strength of GRC reinforced by chopped glass fiber, glass fiber mesh and 3D fabric was increased 53%, 92% and 193% respectively compared with that of pure cement mortar, and the toughness index reached to 26.7, 34.3 and 73.6 respectively compared with that of pure cement mortar (1.0). 3D fabric reinforcement improved the strength and toughness of GRC from a low strength and brittle material.