Accelerated Tests of Concrete Expansion Due To Alkali Reaction
Roy W. Carlson
Appears on pages(s):
Reports length changes up to 2 years in mortars containing 22 different aggregates. Shows the ac- celerating effects of sodium hydroxide added to the mixing water and of storage temperatures of I 10 and 150 F. Although it appears that the main effect of the higher temperatures is to hasten the expansion due to reactive aggregates, it remains to be proved whether some aggregates such as quartz, which cause expansion at the higher temperatures, will ever cause expansion at 70 F or less. Among the aggregates tested, all those containing silica caused some expansion at the higher temperature, and conversely aggregates lacking in silica caused no expansion. in length was caused Greatest expansion of 2 percent b only 5 percent of an ag- gregate containing opa ine silica blended with 95 percent of a nonreactive aggregate.