传统纤维网格增强水泥基复合材料以脆性材料为基体，开裂后裂缝宽度较大导致FRP网格强度无法充分发挥。为解决该问题，使用高延性水泥基复合材料（ECC）作为水泥基替代脆性材料，与FRP网格结合制备出适用于新土木的新型轻质高强材料纤维网格增强水泥基复合材料（FRCM），并通过对FRCM复合板进行单轴拉伸试验研究FRP类型及层数对纤维网格增强水泥基复合材料力学性能影响机制及其与ECC材料协同受力变形的能力。设计2种不同类型纤维网格（碳纤维CFRP与玄武岩纤维BFRP）增强的ECC复合材料拉伸试验，2种试验均考虑FRP网格层数和基体厚度对复合材料性能的影响。基于FRP网格和ECC材料本身的变形特点，探究FRP类型、层数和基体厚度对复合材料破坏模式、初始弹性模量、应变硬化模量、开裂应力、峰值应力和应变的影响规律。结果表明： 1）在试验工况下，随着网格层数从1层增加到6层，试件的抗拉强度均表现出先增大后减小的特性，在配置5层网格时强度最高； 2）基体厚度对试件弹性阶段的力学行为影响较小，但对应变硬化阶段的模量和峰值强度影响较大； 3）2种FRP网格的强度和伸长率不同，且与短纤维的协同工作性能也存在差异，导致CFRP-ECC和BFRP-ECC复合材料的拉伸性能存在较大差异。
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 strainhardening stage. The strengths and elongation rates of the two types
of FRP grids vary, and their synergistic interaction with short fiber varies as
well.
