Title:
Aggregate Passivation: Lithium Hydroxide Aggregate Treatment to Suppress Alkali-Silica Reaction
Author(s):
Craig W. Hargis, Maria C. G. Juenger, and Paulo J. M. Monteiro
Publication:
Materials Journal
Volume:
110
Issue:
5
Appears on pages(s):
567-576
Keywords:
aggregate; alkali-aggregate reaction; durability; expansion; lithium compounds
DOI:
10.14359/51685908
Date:
9/1/2013
Abstract:
Alkali-silica reaction (ASR) continues to be a concrete durability problem despite the many physical and chemical mitigation techniques known to successfully prevent it. The research presented herein tested a new method to limit ASR: aggregate passivation. A lithium silicate layer was created on reactive natural siliceous aggregate surfaces by treating the aggregates in a lithium hydroxide solution prior to use. A 4 M LiOH treatment was found to be superior to a 2 M LiOH treatment in producing a lithium silicate passivation layer and in reducing expansion due to ASR. The use of passivated aggregates greatly reduced expansion in accelerated mortar bar tests compared to nonpassivated aggregates and lithium-based admixtures.