Title: Expansive Cement Produced from AFBC Ash by Alkali Sulphate Activation Approach

Author(s): W. Jiang and D. M. Roy

Publication: Symposium Paper

Volume: 153

Issue:

Appears on pages(s): 193-212

Keywords: alkali-aggregate reactions; chemical attack; expansive cements; fly ash; hydration; mix proportioning; porosity; strength; tests; Materials Research

DOI: 10.14359/1070

Date: 6/1/1995

Abstract:
Presents the results of exploratory experiments using AFBC ash to produce a new kind of expansive cement. The principles for design of the compositions and theoretical consideration are discussed. The tests were carried out to examine the XRD pattern and the pozzolanic activity of the AFBC ash used. The expansive properties of this cement and its effects on porosity, pore structure, heat evolution, setting time, resistance to chemical attack, leaching effect, and strength of hardened cement paste are analyzed in detail. A kind of warm-pressed AFBC ash expansive cement product is also presented. The present results indicate that the sulfoaluminate of AFBC ash can be used as an expansive component. This kind of expansive cement could be used to chemically induce compressive stress in the mortar and thereby reduce the size and amount of shrinkage cracks that frequently occur in portland cement concrete during drying. The results suggest an economically and environmentally acceptable approach.