MICROSCOPIC OBSERVATION OF THE PRODUCTS OF THE ALKALI-SILICA REACTION IN THE DYED THIN SECTIONS OF CONCRETE CORES

Dyeing the products of the alkali-aggregate reaction made it possible to distinguish them from the components of the concrete under a microscopy. Cyanoacrylate mixed with a coloring substance was used to dye the alkali-silica gel red.Cyanoacrylate reacts readily with water contained in gel but not with the components of the concrete. Examination of dyed thin sections revealed a few concrete cores with expansion of alkali-silica reactive aggregates. This method appears to be useful for observing the alkali-aggregate reaction.