This paper is concerned with the reaction between the alkalies present in the pore fluids of the cementitious phases of concrete and certain siliceous aggregates. The reaction may be expansive and consequently deleterious. Maximum expansion occurs at some definite or ‘pessimum’ concentration of reactive aggregate for any given mortar. The nature of the reaction is discussed and formulae are given which describe the curve of expansion against proportion of reactive aggregate. The magnitude and significance of the coefficients of these expressions are discussed and suggestions are made for the limits to be set on the allowable expansion and other design parameters if the effects of the reaction are to be minimized.
- © 1980 The Geological Society