ISSN: 0149-6123
Page Count: 3

Alkali Reactivity of Strained Quartz as a Constituent of Concrete Aggregate
Buck, AD
Geologist, Corps of Engineers, MS

Abstract

Some strained quartz may cause a deleterious alkali-silica reaction if present as a constituent of concrete aggregate in sufficient amounts. The criterion for reactive strained quartz is suggested to be more than 20% strained quartz with an average undulatory extinction angle greater than 15°. Length changes of mortar bars containing such strained quartz will be 0.025 and 0.040% or more at six and twelve months, respectively, when stored at a temperature of 60°C (140°F). Revisions to applicable ASTM standards may be appropriate.

Keywords:
alkalies, alkali aggregate reactions, petrography, alkalisilica reaction, concrete aggregate, strained quartz, length change data

Paper ID: CCA10264J
DOI: 10.1520/CCA10264J
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