Time‐varying Leaching Depth Model of Concrete in Flowing Leaching Environment

Abstract The long‐term leaching of water transfer project leads to slurry spalling and aggregate exposure of concrete, which affects the safety of hydraulic structures. Therefore, it is of great significance to study the time‐varying law of concrete leaching depth in flow leaching environment. The change of the leaching depth of cement‐based materials with time was studied by using microhardness method and pH value in pore solution. The changes of hydration products at different depths were analyzed by thermogravimetry, and the change model of leaching depth with time was established. The results show that microhardness and pH decreases gradually with time at the same depth. The change trend of microhardness is consistent with the change trend of pH measured by pH value in pore solution. The mass loss rate increases with the increase of the distance from the leaching surface. Based on Ca 2+ concentration gradient, porosity and diffusion coefficient, a model of dissolution depth with time was established.