Experimental Study and Analysis on the Durability of Concrete in Underground Engineering

The underground environment is much more complicated than the overground environment. Concrete in underground engineering bears complex environmental effects such as soil stress, water penetration stress, and soil salt erosion. The durability of concrete directly determines the service life of underground engineering. In this paper, considering the soil stress, the chloride ion, sulfate attack and permeability resistance of concrete were tested in the laboratory. The results show that fly ash has excellent resistance to sulfate attack, and when fly ash content is 20% or 30%, the concrete specimens have the best chloride ion penetration resistance and water penetration resistance. Under the effect of preload stress, when the preload stress level is less than 20%, the capacity of concrete stress cannot be reduced greatly, but when the preload stress level is greater than 20%, the concrete durability performance decreases rapidly.