SEDL / STP / STP1061-EB / STP23458S

Strained Quartz in Relation to Alkali-Silica Reaction

Cortelezzi, CR
Senior ResearcherSenior ResearcherResearch Assistant, CIC/LEMITCONICET in National UniversityCONICET/LEMIT, Buenos AiresBahía Blanca,

Maiza, P
Senior ResearcherSenior ResearcherResearch Assistant, CIC/LEMITCONICET in National UniversityCONICET/LEMIT, Buenos AiresBahía Blanca,

Pavlicevic, RE
Senior ResearcherSenior ResearcherResearch Assistant, CIC/LEMITCONICET in National UniversityCONICET/LEMIT, Buenos AiresBahía Blanca,

Pages: 14    Published: Jan 1990

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Abstract

Aggregates containing strained quartz crystals that have induced damage in concrete structures, are frequently mentioned in the literature. This kind of aggregate has generated economic as well as functional problems, with the consequent additional expenses for repair and maintenance. Samples of granitic, cataclastic migmatite aggregates from the Province of Buenos Aires were studied.

Percentages of strained quartz, based on its undulatory extinction angle, are presented and the results are compared to those obtained by the mortar-bar test, the accelerated evaluation method, and the staining method.

The reaction is ascribed to the polycrystallinity of the quartz grains, as shown by electron diffraction (TEM) and by X-ray diffractometry, both showing a disorder in the crystalline structure.