海底隧道非饱和混凝土中水分渗透研究

STUDY ON THE WATER PERMEABILITY IN NON-SATURATED CONCRETE OF SUBSEA TUNNEL

引入相对渗透率(饱和程度)kr描述非饱和与饱和状态的区别。基于Darcy定律考虑压力作用的方程,建立混凝土内各位置处压力及渗透深度随时间变化的理论模型。同时自制压力控制装置,研究压力水头下水分在非饱和混凝土中的迁移特性。对各种试验条件下的水分渗透深度进行理论分析,并同时与试验值进行比较。理论值与试验值能很好地吻合。得到渗透深度随时间的增加总是变大,且在后期的增加幅度小于前期。压力对水分渗透深度有促进作用,强度等级与水分渗透深度呈反比,而水灰比则与渗透深度呈正比。各种因素的讨论过程中,理论值与试验值都能很好的吻合。

The difference between unsaturated and saturated state is described with the introduction of relative permeability( saturation degree) kr. Theoretical models of pressure and penetration depth changes with time in concrete are built based on Darcy's law theoretical equation considering pressure and pressure model various with position in lining concrete. A self-made pressure control device is designed according to pilot program to study the migrations features moisture in concrete under the pressure head. It is analyzed penetration depth and compared with experimental value between which there is a good agreement. Penetration depth is always larger with the increase of time and the increasing degree is lower in the latter. Pressure has a promotion effect on penetration depth. Strength grade is inversely proportional to penetration depth. While water cement ratio is on the opposite. Theoretical values and experimental values are in good agreement during discussion of all the factors.