Effect of Size and Amount of Glass Aggregate on Alkali Silica Reaction

In this study, the potential alkali reactivity of glass aggregate was investigated in accordance with RILEM A.TC 106-2 standard. For this purpose two series of mortar mixtures were prepared. In the first series five different size fraction of non-reactive crushed limestone aggregate including 2-4 mm, 1-2 mm, 0.5-1 mm, 0.25-0.5 mm, and 0.125-0.25 mm were replaced with the corresponding particle size of flint glass. In the second series 25, 50, 75, and 100 % of the non-reactive aggregate was replaced with glass particles having the same gradation with that of the non-reactive aggregate. Regardless of the size and amount of the glass particles used in the mortar, it was observed that no considerable expansions were recorded within 14 days of exposure to 80 °C 1 N Na OH solution as prescribed by the standard. However, beyond this period a great amount of expansion was recorded in the mortar bars containing 2-4 mm and 1-2 mm glass size fractions. Although the 48-day expansion values of the glass-bearing mixtures in second series are well below 0.1% standard limit, the expansion figures of mixtures have still increasing trends. It seems that the RILEM A.TC 106-2 accelerated mortar bar method is conventionally used for rapid ASR assessment, but there is doubt about its suitability for determining the reactivity of glass aggregates

کلیدواژه ها:

Glass aggregate ، Alkali-silica-reaction ، RILEM A.TC 106-2 ، Expansion ، Aggregate Replacement