Alkali-Silica Reaction Products in Concrete
Alkali-silica reaction gel in microcracks that are extended from the reactive aggregate particles into the paste. The width of the photo is 2.5 mm.
Alkali-silica reaction gel in an air void and in a neighboring crack along the periphery of a reactive aggregate particle. The width of the photo is 1.5 mm.
Thin-section photomicrograph of chalcedonic chert - a potentially alkali-silica reactive aggregate. The width of the photo is 1 mm.
Thin-section photomicrograph showing layered structure of alkali-silica reaction rim (isotropic gel and birefringent cryptocrystalline products) along the periphery of a limestone aggregate particle that contains reactive silica. The width of the photograph is 1.5 mm
Backscatter electron image in a scanning electron microscope showing alkali-silica reaction rim. The right photo is the enlarged view of the boxed area in the left photo. The energy-dispersive x-ray spectrum at the bottom is of the reaction rim of the small boxed area in the right photo.