Macro-micro mechanical properties and reinforcement mechanism of alkali-resistant glass fiber-reinforced concrete under alkaline environments

As a reinforced composite material, alkali-resistant glass fiber-reinforced concrete (AR-GFRC) has been exten-sively applied in large-scale projects due to its advantages such as strong corrosion resistance, high tensile and impact resistance, high elastic modulus and low cost. However, the mechanical properties and optimal ratio of AR-GFRC in complex environments such as strong alkaline along with their meso-damage and failure mechanism have not yet been fully understood. In order to investigate damage deformation and fiber reinforcement mechanisms of AR-GFRC under alkaline environments, the tensile performance of concretes with different fiber contents were investigated through splitting tensile tests, scanning electron microscopy (SEM) and numerical simulations. First, orthogonal design and splitting tensile tests were conducted to determine the optimum combination and ratio of each fiber content, while the effect on concrete strength was clarified. Second, the internal microstructure of AR-GFRC was evaluated using concrete SEM images, and the interaction of micro-structure and macro-properties as well as the strengthening mechanism and crack resistance of AR-GFRC were determined. Third, a randomly distributed fiber-reinforced concrete model was developed and a calculation method was proposed based on finite element numerical simulation results and the variations of AR-GFRC tensile damage was clarified. The obtained results could provide guidance and reference for safe engineering con-structions and further application of concrete in alkaline environments.