Influence of aggregate size and aggregate size grading on ASR expansion

摘要

The influences of aggregate size and aggregate sizegrading on ASR expansion in the Chinese autoclave test werestudied. The result shows that the effect of the addition of coarseaggregate on the expansion of mortar is complex. It may beinhibiting expansion, may have no effect, or may be promotingexpansion. Moreover, its effect will change with age. By theoreticanalysis of micromechanics, it is shown that the effect of coarseaggregate on the expansion of mortar depends on the relationbetween the free expansion of coarse aggregate εa and mortarεs.From the results of experimental and theoretic analyses, theauthors suggest that for the evaluation of the alkali-reactivity ofaggregate, single-size aggregate grading might be more reasonable.