Assessment of the expansion related to alkali-silica reaction by the Damage Rating Index method

In this study, the DRI method enables a relatively good estimate of the amount of expansion of concrete prisms made with different aggregates. Results suggest that weighting factors used with the DRI method are appropriate. However, expansion and damage stem from combinations of factors that do not affect aggregates in the same manner. For concrete mixtures incorporating Potsdam sandstone, the most relevant petrograhic feature is the reaction rim surrounding reactive particles. For concrete mixtures incorporating Spratt limestone, almost every petrographic feature (e.g. cracks in aggregate particles and in cement paste) increases consistently with expansion. This study also showed that, in cube specimens made with high W/C ratio and low modulus of elasticity concrete, damage is more severe in the surface zone compared with inner zone. No such difference was observed in concrete cubes of lower W/C ratio higher modulus of elasticity.