The effects of potassium and rubidium hydroxide on the alkali-silica reaction

Shomglin K., Turanli L., Wenk H., Monteiro P., Sposito G.

CEMENT AND CONCRETE RESEARCH, vol.33, no.11, pp.1825-1830, 2003 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 33 Issue: 11
  • Publication Date: 2003
  • Doi Number: 10.1016/s0008-8846(03)00204-7
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1825-1830
  • Keywords: alkali-aggregate reaction, aggregate, KOH, microstructure, SEM, SURFACE-CHARGE, WATER
  • Middle East Technical University Affiliated: Yes


Expansion of mortar specimens prepared with an aggregate of mylonite from the Santa Rosa mylonite zone in southern California was studied to investigate the effect of different alkali ions on the alkali-silica reaction in concrete. The expansion tests indicate that mortar has a greater expansion when subjected to a sodium hydroxide bath than in a sodium-potassium-rubidium hydroxide bath. Electron probe microanalysis (EPMA) of mortar bars at early ages show that rubidium ions, used as tracer, were present throughout the sample by the third day of exposure. The analysis also shows a high concentration of rubidium in silica gel from mortar bars exposed to bath solutions containing rubidium. The results suggest that expansion of mortar bars using ASTM C 1260 does not depend on the diffusion of alkali ions. The results indicate that the expansion of alkali-silica gel depends on the type of alkali ions present. Alkali-silica gel containing rubidium shows a lower concentration of calcium, suggesting competition for the same sites. (C) 2003 Elsevier Ltd. All rights reserved.