A Tribute of the Physical Properties of Hardened Portland Cement Paste

This paper deals mainly with data on water fixation in hardened Portland cement paste, the properties of water evaporable water, the density of the solid substance, and the porosity of the paste as a whole. The studies of the evaporable water include water-vapor absorption characteristics and the thermodynamics of adsorption. The discussions will include the following topics: (1) Theoretical interpretation of adsorption data; (2) The specific surface of hardened Portland cement paste; (3) Minimum porosity of hardened paste; (4) Relative amounts of gel-water and capillary water; (5) The thermodynamics of adsorption; (6) The energy of binding of water in hardened paste; (7) Swelling pressure; (8)Mechanism of shrinking and swelling; (9) Capillary-flow and moisture diffusion; (10) Estimation of absolute volume of solid paste in hardened paste; (11) Specific volumes of evaporable and non-evaporable water; (12) Computation of volume of solid phase in hardened paste; (13) Limit of hydration of Portland cement; (14) Relation of physical characteristics of past to compressive strength; (15) Permeability and absorptivity; and (16) Freezing of water in hardened Portland cement paste. The paper is composed on nine parts. Part 1 contains a review of previous work done in the field and discusses various experimental methods. Part 2 elaborates on the measurement of water-fixation and presents empirical aspects of the data. Part 3 presents theories upon which an interpretation of the data in Part 6 can be based. Part 4 is a discussion of the thermodynamics of moisture-content changes. Part 5 presents data pertaining to the volume of different phases in the paste. The relationship between the physical characteristics of the hardened cement paste and compressive strength of mortars is discussed in Part 6. Part 7 discusses permeability and absorptivity. A study of the freezing of water in hardened past is presented in Part 8. The properties of Portland cement paste as they appear in the light of these studies are described in Part 9.