Alkali-Silica Identification Handbook Now Available

The Alkali-Silica Reactivity Field Identification Handbook is now available from the Federal Highway Administration. This field identification handbook provides guidance in identifying alkali-silica reactivity (ASR) in concrete field structures, such as bridges and pavements. The handbook also provides fundamental information about ASR, including the requirements for ASR to take place and the chemical reaction that leads to the formation of ASR gel. It includes images to assist the reader in identifying ASR in the field under several scenarios, such as the effect of moisture on ASR-affected structures, ASR in combination with other concrete distresses and non-ASR related distresses as well as a  section on managing ASR-affected structures.

Two types of alkali-aggregate reaction are currently recognized; depending on the nature of the reactive mineral, these are ASR and alkali-carbonate reaction. Both types of reaction can result in expansion and cracking of concrete elements, leading to a reduction in the service life of concrete structures.