University of Idaho, Idaho Geologic Society
Keith Nottingham, Idaho Transportation Dept
Aggregate, alkali-silica reactivity, ASR, geology, Idaho
This project studied relationships between lithology (rock type) and alkali-silica reactivity (ASR) of 40 aggregate sources certified for concrete production by the Idaho Transportation Department (ITD) with the intention of identifying geologic units that are more (or less) susceptible to ASR. ASR refers to a chemical reaction between aggregate and alkalis in the cement. The reaction produces an expansive gel that causes damaging cracking in concrete and subsequent failure of the concrete before its projected lifespan. The research was a response to known issues of high ASR potential in many Idaho sources, particularly in southern Idaho where ASR-related deterioration required treatment and partial replacement of Interstate 84 (I-84) concrete near Mountain Home, Idaho.