Petrographic Study of Gravel Used as Concrete Coarse Aggregate in Pavements in the Province of Río Negro (Argentine Patagonia).

PEDRO MAIZA; SILVINA MARFIL

Auckland

Congreso; 11th IAEG (International Association of Engineering Geology Congress).; 2010

IAEG

Gravels that are predominantly volcanic in composition cover a large areain Argentine Patagonia. They are frequently used as concrete aggregates. It is quite commonto find pavements that are deteriorated due to the development of the alkali-silica reaction.The main deleterious constituents are volcanic glass and cryptocrystalline silica. This workcomprises a study on the main gravel quarries in the Viedma area (province of Río Negro).A petrographic study of the different lithic components was conducted focussing on theidentification of the constituents that cause deleterious reactions in concrete, texture types,the presence of volcanic glass, alterations, and microgranular and amorphous cryptocrystallinesilica. The materials studied are considered potentially reactive with respect to thealkali-silica reaction from a petrographic point of view.