An effective medium approach for predicting the intrinsic permeability of heated cement paste

Determination of the intrinsic permeability of heated cement paste is essential to fire spalling analysis of high-performance concrete. The purpose of this paper is to develop a three-scale scheme for predicting the intrinsic permeability of heated cement paste. In this scheme, cement paste is modelled as a multi-phase composite material and further represented by three two-phase composite constituents. By analysing the thermal decomposition, the variation of various constituents in cement paste is expressed as a function of the heating history. Based on effective medium theory, the intrinsic permeability of heated cement paste is obtained in terms of the volume fractions and permeabilities of various constituents of the cement paste. Finally, the validity of the three-scale scheme is preliminarily verified with experimental data obtained from the literature.