Research on the mechanical properties and impermeability mechanisms of sea sand glass fiber reinforced concrete

As construction projects increase globally, the scarcity of clean water and river sand resources has prompted the development and use of seawater sea sand concrete (SSC). This study aimed to investigate the mechanical and impermeability properties of seawater sea sand glass fiber reinforced concrete (GFRC-SS). Firstly, the effects of fiber content, fiber length, and fine aggregate type on the compressive strength, splitting tensile strength, and impermeability of GFRC were examined experimentally. Then, a comparative analysis was conducted between GFRC-SS and freshwater river sand glass fiber-reinforced concrete (GFRC-FRS) based on scanning electron microscopy and nuclear magnetic resonance analyses to establish the correlation between micro-deformation and macro-failure of GFRC. The results indicate that GFRC at the fiber content of 1 % achieved the most significant reduction in the proportion of detrimental pores and enhancement in mechanical and impermeability properties. For both GFRC-SS and GFRC-FRS, the addition of glass fibers can significantly increase the tensile strength of concrete, with the permeability coefficient reaching the order of 10 –8 cm/s. Above findings are expected to provide guidance and references for the research and application of glass fiber in SSC, as well as the determination of engineering requirements for permeability coefficients in GFRC-SS projects.