... ; 2,Manufacture of high permeability (≥ P30), waterproof concrete structure for the MTR, tunnels, the basement of high- ... ion permeability of concrete, erosion, avoid being reinforced concrete corrosion, thereby prolonging the life span of concrete; 4,Highway, bridge ... construction early strength, high strength concrete admixtures; tunnels, subways, large-scale structure in the course of construction ...