Pore colmatation in case of liquid corrosion of concrete

Abstract

Abstract Pore colmatation plays a positive role, since a decrease in the permeability of cement concrete due to the deposition of insoluble corrosion products in the pores leads to a slowdown in corrosion processes. To test a mathematical model of pore colmatation of cement concretes under liquid corrosion, a study of mass transfer processes occurring when samples from Portland cement are exposed to a liquid aggressive medium was conducted. The article presents equations that allow us to determine the rate of pore colmatation and the thickness of the layer of colmatant formed in the pores during liquid corrosion of cement concretes. Based on the results of experimental studies of liquid corrosion of cement stone, the mass transfer parameters were determined in the investigated system «cement concrete – 2 % MgCl2 solution». Based on the obtained data, the values of the colmatation rate and the thickness of the layer of colmatant of cement concrete were calculated during liquid corrosion in a 2 % MgCl2 solution. It has been established that over time, the rate of mass transfer processes occurring in concrete decreases due to the difficulty of penetration of aggressive medium deep into concrete due to the deposition of corrosion products in the pores.