Journal Published Online: 01 June 2000
Volume 22, Issue 1

Quantitative Petrographic Technique for Concrete Damage Due to ASR: Experimental and Application

CODEN: CCAGDP

Abstract

An automatic petrographic test procedure for quantifying damage in concrete affected by alkali-silica reaction (ASR) is presented in this paper. A computer image analysis program was designed to quantify the degree of microcracking and the amount of silica gel resulting from ASR. The procedure involves the petrographic examination at a magnification of ×20 of polished concrete sections impregnated with fluorescent epoxy resin for cracking and uranyl acetate coated sections for the determination of their silica gel content. Also, the data were compared to the results obtained from a semi-quantitative petrographic method, i.e., the Damage Rating Index commonly used in Canada for evaluating the condition of concrete affected by ASR.

The petrographic examination was first carried out on laboratory sections cut and polished from concrete prisms incorporating two different aggregate types, the Spratt limestone and the Potsdam sandstone. Both methods were also applied to specimens prepared from a core collected from a large dam affected by ASR. Good correlation was obtained between analytical parameters derived from the image analysis method and the expansion levels of the laboratory test prisms; however, no explicit relation was found to date between the amount of gel as measured in this study and the expansion level.

This study shows that the quantitative petrographic method using the image analysis and the Damage Rating Index Method can be used to estimate the condition and current expansion of concrete specimens cored from concrete structures affected by ASR.

Author Information

Rivard, P
University of Sherbrooke, Sherbrooke, Canada
Fournier, B
International Centre for Sustainable Development of Cement and Concrete (ICON)/CANMET, Ottawa, Ontario, Canada
Ballivy, G
University of Sherbrooke, Sherbrooke, Canada
Pages: 10
Price: $25.00
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Details
Stock #: CCA10465J
ISSN: 0149-6123
DOI: 10.1520/CCA10465J