Title:
Alkali Silica Reaction Processes: The Conversion of Cement Alkalies to Alkali Hydroxide
Author(s):
Sidney Diamond and Michael Penko
Publication:
Symposium Paper
Volume:
131
Issue:
Appears on pages(s):
153-168
Keywords:
alkalies; alkali-silica reactions; ettringite; gypsum; pore solutions; porosity; sulfates; Materials Research
DOI:
10.14359/1206
Date:
3/1/1992
Abstract:
Among the important stages of the overall SR process as it occurs in concrete is the conversion of alkali sulfate dissolved from the cement to alkali hydroxide. The results of laboratory studies are presented to provide an understanding of this process and its effects. This conversion process depends on continued formation of ettringite and does not take place until the cement gypsum is exhausted. Provision of a large excess of gypsum or interference with early ettringite production by high-temperature exposure may postpone or prevent it, thus reducing the OH - ion concentration and the possibility of ASR reaction.