Abstract
•Proposed an empirical model to predict optimum Li dosages for suppressing ASR.•The predicted Li dosages were compared with experimental values at 14, 28 and 56days.•A good agreement existed between the optimum experimental and analytical Li dosages.•The model may be used to select a trial Li dosage to suppress excessive expansion of reactive aggregate.
The influence of various dosages of lithium nitrate salt to inhibit the ASR-induced expansions of six reactive aggregates was studied. ASTM C 1260 (commonly known as Accelerated Mortar Bar Test (AMBT)), and modified AMBT were used to measure linear expansions of control mortar bars containing no lithium content and those of the mortar bars treated with up to six dosages of lithium-to-alkali molar ratios of 0.59, 0.74, 0.89, 1.04, 1.19 and 1.33, respectively. An empirical model to predict the minimums dosages of lithium salt required to suppress the excess mortar expansion below the prescribed failure limits at 14, 28 and 56days was developed. The study revealed that a good correlation existed between the optimum lithium content obtained by the experimental procedures and that evaluated by the proposed model. It was also found that the amount of lithium nitrate salt needed to suppress ASR-induced mortar expansion varied depending upon the extent of aggregate reactivity, the mineralogy of the aggregates, and the test duration.