Laboratory short-term evaluation of ASR - A contribution

Accelerated tests were performed at 80 degreesC to evaluate alkali-silica r eactions (ASRs) in mortars made with alkali-enriched cement. Sodium salts ( NaCl, Na2SO4, and NaHCO3) and sodium hydroxide were used in the mortars, an d the microstructural alterations induced in the mortars by the alkaline co mpounds were investigated as their effect on mechanical properties. Data so far collected indicate that, at this temperature, the expansion of mortars without reactive aggregate is limited and, at least at the investigated al kali concentration, negligible compared to the expansion of mortars contain ing artificial reactive aggregates. Results show, however, that the extent of expansion can be influenced by the type of salt used to increase the alk ali concentration. (C) 2001 Elsevier Science Ltd. All rights reserved.