Effect of Non-reactive Limestone Aggregate on Alkali-Silica Reactivity of a Reactive Aggregate

The effect of limestone aggregate on alkali-silica reaction expansion was studied. A crushed reactive natural siliceous aggregate and a non-reactive crushed limestone aggregate were used. Both of the aggregates had roughly same angularity. In addition to control mixture consisting of neat reactive aggregate, two different series of aggregate mixture conforming to the grading requirements of ASTM C1260 were prepared. In series A, each reactive size fraction was replaced with non-reactive limestone of the same size. In series B, each size fraction of the limestone aggregate was replaced with the same size fraction of reactive aggregate. 12 different mortar mixtures were prepared and 14-day expansions were recorded in accordance with ASTM C1260. Except for the smallest size fraction, the expansion caused by individual reactive size fractions observed in series A mixtures were larger than corresponding values recorded in series B mixtures. This may be due to the interaction between the reactive size particles or the interaction between limestone and alkalis or cement.

کلیدواژه ها:

Mortar ، alkali-silica reactivity ، limestone aggregate ، ASTM C1260