ISSN: 1546-962X
Published Online: 3 January 2005
Page Count: 17

ASTM C 88 Test on Soundness of Aggregate Using Sodium Sulfate or Magnesium Sulfate: A Study of the Mechanisms of Damage
Haynes, H
Principal, Haynes & Associates, CA

(Received 22 December 2003; accepted 23 September 2004)

Abstract

In this study, the mechanisms of damage to aggregate particles by sodium sulfate and magnesium sulfate solutions were investigated. By using glass and aluminum containers to represent aggregate pore space and confining walls, test results showed that during soaking cycles crystal growth occurred that applied some bearing pressure on the container. This bearing pressure, however, was secondary to more damaging pressure that occurred during the oven drying cycles. During soaking cycles, mirabilite (Na²·SO⁴ 10H²O) applied bearing pressures up to about 0.6 MPa. During oven drying cycles, thenardite applied bearing pressures up to about 2.0 MPa. Magnesium sulfate salts produced bearing pressures about the same magnitude as that of the sodium sulfate salts.

Keywords:
ASTM C 88, force of crystallization, physical salt attack, magnesium sulfate, salt crystallization, salt hydration distress, salt weathering, sodium sulfate, soundness test

Paper ID: JAI12517
DOI: 10.1520/JAI12517
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