Abstract
The influence of lithium nitrate on expansions due to delayed ettringite formation (DEF) and
alkali-silica reaction (ASR) has been investigated. Effects of the lithium salt were examined in
heat-cured mortars and concretes containing one or both damage mechanisms. The mortars and
concretes made using reactive and/or non-reactive aggregates were subjected to heat treatment
consisting of a hydration delay period of 4 hours at 23oC followed by steam-curing at 95oC and
then stored in limewater. Results showed that the lithium salt admixture was able to reduce the
occurrence of deleterious expansion due to delayed ettringite formation in addition to controlling
alkali-silica reaction in cementitious systems containing one or both mechanisms. In concretes
made using non-reactive limestone aggregates, incorporation of lithium nitrate in a proportion of
0.74 molar ratio of Li to (Na+K) was found to control delayed ettringite formation during the
one-year period of this study.
By analyzing the leaching properties of lithium and other alkalis from mortars during storage, it
was found that a substantial amount of lithium was retained in the cementitious system in a
slightly soluble form, and is expected to be responsible for reducing DEF.