关键词: FRP网格, 水泥基复合材料, 单轴拉伸试验, 变形行为, 强度特性

Abstract: Traditionally, fabric-reinforced cementitious matrices are brittle matrices, which creates notable wide cracks and, consequently, limits the effective utilization of the grid strength of fiber-reinforced polymers(FRPs). To overcome this challenge, an engineered cementitious composite(ECC) is introduced as a substitute for the brittle matrix. A novel light-weight and high-strength material suitable for modern civil engineering applications is developed by incorporating ECC into a fabric-reinforced cementitious matrix(FRCM) and FRP grids. The mechanical properties of the composite panels of the FRCM are examined via uniaxial tensile tests. The investigation focuses on exploring the impact of FRP types and layers on the mechanical characteristics of FRCM, as well as their capacity to interact synergistically with ECC materials during its deformation. Two types of ECC materials, reinforced with different fiber grids, namely, carbon-fiber-reinforced polymers and basalt-fiber-reinforced polymers, are formulated for tensile testing. The tests assess the effects of the FRP grid layers and the matrix thickness on the composite material properties. By analyzing the deformation characteristics of the FRP grids and ECC materials, the effects of the FRP types, layers, and matrix thickness on the failure mode, initial elastic modulus, strain hardening modulus, crack initiation stress, peak stress, and strain of the composite materials are investigated. Under the test conditions, the results reveal the following trend: the tensile strength of the specimens initially increases with an increasing number of grid layers, reaching a peak at five layers, and declines with further addition of layers. Thus, the optimum strength is achieved with five layers of grids. Although matrix thickness has little effect on the mechanical behavior of the specimens during the elastic stage, it notably affects the modulus and peak strength during the strainhardening stage. The strengths and elongation rates of the two types of FRP grids vary, and their synergistic interaction with short fiber varies as well.

Key words: fiber-reinforced polymer grid, engineered cementitious composites, uniaxial tensile test, deformation behavior, intensive property