Accession Number : AD0447240

Title :   CELL TEST METHOD FOR STUDY OF ALKALI-CARBONATE ROCK REACTIVITY,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF BUILDING RESEARCH

Personal Author(s) : Gillott, J. E.

Report Date : JUN 1964

Pagination or Media Count : 8

Abstract : Argillaceeous dolomitic limestone from Kingston, Ont., expands when placed in a strongly alkaline environment. Such expansion may disrupt concrete that contains aggregate made from this rock. A cell technique has been developed to test samples for reactivity. The apparatus is described and results are illustrated with reference to eight samples of concrete. Petrographic, mineralogical, and chemical analyses are given for the samples tested. The cell technique is discussed in relation to other test methods. It is possible to recognize potentially reactive carbonate rocks petrographically, but it is not possible to predict the amount of expansion a particular sample will produce. Linear measurements of concrete beams give reliable results, but the cell technique is more rapid. Dimensional change measurements of rock prisms soaked in alkali may give erroneous results if undetected microcracks develop. It is also difficult to allow for anisotropic properties of rocks, and many samples must be studied if the results are to be representative of a quarry. The cell technique eliminates these difficulties; powder is used and the expansive reaction may be smoothly followed to completion. (Author)

Descriptors :   *LIMESTONE, TEST METHODS, CONCRETE, CARBONATES, ALKALINE EARTH COMPOUNDS, PETROGRAPHY, CALCITE.

Distribution Statement : APPROVED FOR PUBLIC RELEASE