Title: Corrosion-Resistant Cements Based on Sulfated Clinkers

Author(s): S.V. Samchenko, O.V. Zemskova, and D.A. Zorin

Publication: Symposium Paper

Volume: 326

Issue:

Appears on pages(s): 31.1-31.8

Keywords: AFt and AFm phases, hardened cement paste resistance, structure of a hardened cement paste, chemical equilibrium

DOI: 10.14359/51711013

Date: 8/10/2018

Abstract:

This article is focused on the deterioration resistance of a hardened cement paste in terms of physical and chemical nature of this process. In terms of physics, the formation of solid firm crystalline texture determines the increased deterioration resistance of a hardened cement paste. The solid firm crystalline texture of a stone is formed due to mutual intergrowth of crystalline scaffold developing firstly ettringite it crystalline hydrates and poorly crystallized low-basic calcium hydrosilicates.

In terms of chemistry, the increased deterioration resistance of the hardened cement paste is due to reaching a chemical equilibrium between the deteriorative medium and the hardened cement paste, the hydrate phases of which containin their composition ions that are identical to ions of deteriorative medium. Moreover, it is necessary for the structure of the hardened cement paste to be formed involving AFt phases and excluding the content of AFm hydrates, which are the most susceptible to the influence of sulfate ions. This influence results in the complete decomposition of AFm hydrates within the structure of the stone followed by crystallization of AFt phases accompanied by calcium leaching from the structural components of the hardened cement paste.