Applications of diffusion theory to permeability tests on concrete Part I: Depth of water penetration into concrete and coefficient of permeability

The paper describes an application of diffusion theory to the penetration of water under pressure into concrete. The resulting second-order differential equation is non-linear, because the water-storage capacity of the open pores in concrete depends upon the counterpressure arising. Numerical computer analysis of the permeability equation leads to a formula for calculating the coefficient of permeability when the values of the test parameters and the depth of water penetration are known. The application of the final formula to a series of laboratory test results shows that there is a fairly good correlation between the values of the coefficient of permeability so calculated and those based on direct measurement of water flow through a concrete specimen.