Title: Some Physical and Chemical Aspects of High Pressure Steam Curing

Author(s): George Verbeck and L. E. Copeland

Publication: Symposium Paper

Volume: 32

Issue:

Appears on pages(s): 1-14

Keywords: age; atmospheric pressure steam curing; autoclaving; calcium silicate hydrates; cement pastes; compressive strength; concretes; curing; high temperature;

DOI: 10.14359/6597

Date: 7/1/1972

Abstract:
The effect of temperature on the physical and chemical properties of hydrating cement is considered from the effect temperature has on both rate of hydration and on the composition of the hydration product. The increased rate of hydration produced by elevated temperature is discussed in terms of its apparent effect on the uniformity of distribution of the hydration product within the paste matrix and the significance of degree of uniformity of distribution on strength. The general chemical and physical nature of the hydration products formed below 212 F (1OOC) is essentially unaffected by curing temperature. In high pressure steam curing above 212 F the properties of the product can be considerably altered depening upon the temperature and the composition of the cement. The various phases produced for different temperatures and compositions are described in terms of the inherent nature of the basic calcium silicates. The strength of high pressure steam cured paste is shown to depend upon the phase composition of the product primarily through the influence fo the phase composition on its relative ability to reduce the capillary porosity of the paste.