SEDL / STP / STP691-EB / STP36093S

Effect of Microstructure and Composition of Limestone, Marble, Basalt, and Quartzite Aggregate on Concrete Durability in Presence of Solutions of Calcium Chloride and Magnesium Sulfate

Gillott, JE
Professor, University of Calgary, Calgary, Alta

Pages: 12    Published: Jan 1980

Download this paper for $25 PDF (420K)          View License Agreement
Abstract

Aggregate long has been known to affect concrete durability. Unsound aggregate has been held responsible for pitting, popouts, spalling, map-cracking, D-cracking, bond-failure, and scaling. Sulfate and chloride solutions are a cause of concrete deterioration, Sulfates are common in groundwater and chlorides are commonly used as deicing agents; these ions are also present in seawater. Attack on aggregate and portland cement paste has been attributed to both physical and chemical processes. The scanning electron microscope has been used to examine rocks that have been immersed in sulfate and chloride solutions. Re-examination of the same areas after increasing times gives an indication of the resistance of the rocks to attack. The significance of the observations to the durability of concrete is discussed.