Title: Reactivity of Aggregate Constituents in Alkali Solutions

Author(s): Leonard Bean and J. J. Tregoning

Publication: Journal Proceedings

Volume: 41

Issue: 9

Appears on pages(s): 37-52

Keywords: none

DOI: 10.14359/8676

Date: 9/1/1944

Abstract:
The relative order of reactivity of I2 types of aggregate constituents to alkali hydroxide solutions was determined by an accelerated test at 122 C, to as follows: opal, chalcedony, pitchstone, rhyol basalt, magnesite, obsidian., calcite, limestone, dolomite, microcline, and ol igoclase. T h e carbonates were more reactive to KOH than NaOH. The feld spars and glass bearing rocks were more susceptible to attack by NaOH. Reactivity to carbonate sulfate solutions was found to be negligible un the conditions chosen. Quantitative data on solubility of the materials in hydroxide and carbon solutions at 21 C are given. These agree with results of the accelerated test. These data shed Iion alkali reactivity under the conditions of laboratory tests used, but make no attempt to dict expansion of concrete on the basis of the tests alone.