ALKALI REACTIVITY OF GLASS AGGREGATE.

In order to look for a correlation between alkali reactivity and chemical composition of glass, nearly a hundred glass samples were made in the laboratory. The alkali reactivities of glass aggregates were determined by a rapid autoclave mortar-bar test developed by the authors. As the CaO and Al//2O//3 contents of the glass decrease, with a corresponding increase of the Na//2O and SiO//2 contents, the reactivities increase. It is shown that the aggregates are reactive if K less than 0. 1 or 0. 2, and are non-reactive if K greater than 0. 3. Furthermore, through regression analysis the relationship between the expansion of mortar bars and chemical composition of glass was established. This method is valid for predicting the alkali reactivities of aggregates made from some volcanic glass rocks and industrial wastes.