Title: New Contribution in the Testing Methodology to Characterize Concrete Attacked by Alkali-Silica Reaction

Author(s): D. Bulteel, Y. Monnin, E. Garcia-Diaz, and P. Degrugilliers

Publication: Symposium Paper

Volume: 234

Issue:

Appears on pages(s): 485-494

Keywords: ASR; concrete; diagnose; flint aggregate; siliceous limestone; swelling mechanism

DOI: 10.14359/15954

Date: 3/22/2006

Abstract:
Different testing methodologies exist for the diagnosis of Alkali-Silica Reaction (ASR) in concrete. But the problem is to quantify the reaction because some methods are qualitative (petrographic method) and not always specific (accelerated swelling test could be biased by other expansive reaction as DEF).The aim of this study is to improve the diagnosis in concrete by following new parameters. This application supplements other methods. These new parameters are porous and absolute mass volume giving apparent mass volume which increase for the ASR. To obtain these parameters, the extraction of silica of the aggregate skeleton contained in concrete matrix is needed. The increase of apparent mass volume of silica from aggregate skeleton related the alteration of reactive silica which has for consequence the increase in swelling of concrete. These physical parameters are specific to ASR. They may be used for quantitative assessment of the alteration of reactive silica from aggregate which permit to follow ASR reaction degree responsible for the degradation of concrete. Encouraging results have been obtained on laboratory concrete for two different aggregates (flint aggregate or siliceous limestone) and also on field concrete.