Title: Specific Volume of Evaporable Water in Hardened Portland Cement Pastes

Author(s): L. E. Copeland

Publication: Journal Proceedings

Volume: 52

Issue: 4

Appears on pages(s): 863-874

Keywords: no keywords

DOI: 10.14359/11654

Date: 4/1/1956

Abstract:
The mean specific volume of chemically free water in saturated hardened portland cement pastes was found to be 0.99, independent of the extent of hydration of the cement or the water-cement ratio of the paste. This implies that there is no difference between the specific volume of gel water and capillary water in saturated pastes. The total pore volume of a hardened paste is thus 0.99we. The conclusion of Powers and Brownyard that gel water was more dense than capillary water resulted from determining the specific volume of the solids in hardened pastes by a helium-displacement method. The specific volume of the hydration products, 0.398, determined in this work agrees well with the 0.392 obtained by Powers and Brownyard using the water-displacement method.The amount of water that a paste must absorb to remain saturated while the cement is hydrating is given by the equation: wt - wo = 0.25wn.