WATER ADSORPTION ISOTHERM OF CEMENT MATERIALS

Abstract

A new adsorption isotherm derived from the energy equilibrium on thermodynamics and characteristic of pore size distribution is proposed. In traditional terms, the equation has the form:

V =	ΩV0	,
	Ω−ln(h)

where V and h are the amount adsorbed per unit mass of the adsorbent and relative humidity, respectively. V₀ is the volume of adsorption under saturated conditions, which corresponds to the total pore volume. Ω is a constant reflecting the characteristics of the pore size distribution, temperature and the type of adsorbate. This equation can be used to express experimental data of the water adsorption isotherm over a wide range of humidity conditions with various cement materials.