ASR-Related Distress in Floor Coatings


Alkali-silica reaction (ASR) is a common distress mechanism associated with certain aggregates in portland cement concrete. ASR occurs when glassy, cryptocrystalline, microcrystalline, or physically strained silica (all chemically SiO2) reacts with the alkaline pore solution in the concrete and forms a gel that expands as it absorbs water. Small amounts of potentially ASR-reactive particles are common in many aggregates. These particles may or may not be destructive, depending on their reactivity, quantity and size, alkali contents in the mixture, and moisture exposure.

This article was originally published in Concrete International, the official publication of the American Concrete Institute.