INFLUENCE OF WEATHERING OF IRON SULFIDES CONTAINED IN AGGREGATES ON CONCRETE DURABILITY

The oxidation of pyrrhotite and pyrite initiates a series of weatherin g reactions in aggregates extracted from the Mont Palau quarry (Barcel ona, Spain). The lithotypes enclosing the sulfides, however, play an i mportant role in controlling the progress of weathering: whilst expans ive hydrated Fe-sulfates characteristic of acidic environments formed in the black shales, the neutralizing capacity of calcite dissolution prevents the formation of these harmful mineral phases in the limeston es.