High Temperature Performance of Lining Concrete for Subsea Tunnel

To study the physical and mechanical properties of tunnel lining concrete under high temperature combustion, concrete specimens were developed by consulting the concrete proportioning in Xiangan subsea tunnel lining. After combusting the specimens under high temperature, two types of cooling methods were used, namely, natural cooling and water spraying. The thermal expansion and deformation characteristics, compressive strength, elastic modulus, and anti-permeability of concrete after high temperature were analyzed. Results were as follows:(1) Water spray cooling had a significant effect on the thermal expansion of concrete at high temperature, and natural cooling greatly influenced the elastic modulus and anti-permeability level. (2) If the axial strain was the same, then the transverse strain increased with the increase in temperature when the temperature was below 600 ℃. However, when the temperature was higher than 600 ℃, the transverse strain decreased with the increase in temperature. (3) With the increase in temperature, a linear relationship existed between the compressive strength of concrete and the temperature under natural cooling condition. However, under the water spray cooling condition, a nonlinear relationship was observed.