Une nouvelle méthodologie de qualification des granulats siliceux vis-à-vis de l'alcali-réaction dans le béton

Title: Une nouvelle méthodologie de qualification des granulats siliceux vis-à-vis de l'alcali-réaction dans le béton
Author(s): M. Berra, T. Mangialardi, A. E. Paolini
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 36
Issue: 259
Issue date: 2003-06-01
Publication year: 2003
Pages: 302 - 310
Total Pages: 9
Nb references: 19
Language: French

Abstract: In this study, the reliability of both the French (AFNOR P18-542) [3] and the Canadian (CSA A23.
2-27A) [4] test methodologies for the qualification of aggregates susceptible of alkali-silica (A-S) reaction in concrete was verified on some Italian natural siliceous sands of known long-term field performance.
A new test methodology, based on the utilization of the petrographic examination (ASTM C295) [9], the mortar-microbar expansion test (AFNOR P18-588) [13] and a method of determination of the threshold alkali level, TAL, [8] was also developed.
It was found that the Canadian test methodology does not appear to be appropriate for evaluating the potential alkalireactivity of the tested sands.
Conversely, a correct diagnosis for the A-S reactivity of these sands is obtained through the use of the French test methodology.
However, both test methodologies do not appear suitable for strictly predicting the expansive behaviour of a given aggregate when subjected to variations of composition and/or environmental exposure conditions of concrete.
The proposed test methodology, which is essentially based on the use of the threshold alkali level, TAL, as a reactivity parameter, appears to be more appropriate for such a prediction, at least for the sands investigated.

Online publication: 2003-04-27
Classification: Technical Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/13868