Title: Use of Fly Ash in Cement to Reduce Alkali-Silica Reactions

Author(s): Inger Meland

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 591-608

Keywords: alkali-aggregate reactions; cements; ceramic tiles; concretes; fly ash; mortars (material); silica.

DOI: 10.14359/10089

Date: 2/1/1986

Abstract:
This report presents results from an investigation where fly ash has been used in cement to try to reduce an observed alkali-silica reactivity in tile covered mortar and concrete constructions such as swimming pools and larger shower cabinets. Examinations of ceramic tiles showed that soluble silica formed when the material was exposed to sodium hydroxide solution. For testing according to ASTM C227-81 "Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-Bar Method)" concrete prisms were moulded using ordinary Portland cement or fly-ash cement with crushed ceramic tiles as aggregate. All the prisms showed changes in length; however, the changes are less in prisms made with fly-ash in cement. From these observations it seems that it is possible to reduce the damage caused by alkali-silica reactions in such structures by use of fly-ash in cement. Long term tests are being done on tile covered concrete slabs.