Abstract
The main objective of this study was to compare expansion and loss of concrete stiffness due to the adverse effect of Alkali-Silica Reactivity (ASR). Concrete cylinders made with four different aggregates were cured in water at 20 degrees C, and in 1N NaOH at 80 degrees C. The Loss In Stiffness (LIS) between water-and alkali-cured cylinders was determined at 28 and 180 days, and was correlated with the expansion of the mortar bars containing the companion aggregate source at the ages of 14, 28 and 56 days. The study revealed that the 28-day LIS of concrete cylinders showed no distinct correlation with the expansion of the mortar bars at the above mentioned ages. However, the 6-month LIS of the concrete cylinder showed a good correlation with the 14-, 28-and 56-day ASR-induced expansion. ASR classifications of the trial aggregates showed a perfect agreement based on the failure criteria of the mortar bars and alkali-cured prisms and those obtained from the loss in stiffness of the concrete cylinder.