Recommendations

RILEM Recommended Test Method AAR-1 'Detection of potential alkali-reactivity aggregates' Petrographic method

Title: RILEM Recommended Test Method AAR-1 'Detection of potential alkali-reactivity aggregates'
Petrographic method
Author(s): RILEM TC 191-ARP
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 36
Issue: 261
Issue date: 2003-08-01
Publication year: 2003
Pages: 480 - 496
Total Pages: 17
Nb references: 2
Language: English

Petrographic analysis shall always be the first step in the
assessment of the potential alkali-reactivity of concrete
aggregates as stated in RILEM AAR-0 entitled, ‘Outline
Guide to the Use of RILEM Methods in Assessments of
Aggregates for potential alkali-reactivity’.
This RILEM method specifies a general procedure for the
petrographic examination of concrete aggregates, to identify
rock types and minerals that might react with hydroxyl ions
from the concrete pore solution. The method, including
sampling, is intended to be used for the routine examination of
natural aggregates including sand, coarse gravel, all-in and
crushed rock aggregates, in testing laboratories, rather than by
expert petrographers for research purposes. The method can be
also used to quantify the amounts of various mineral and rock
types where required. The main objective of the RILEM
petrographic method is to determine a classification of a
particular aggregate in terms of alkali-reactivity. As a result of
undergoing the RILEM petrographic examination an aggregate
should be classified as one of the following:
- Very unlikely to be alkali-reactive - Class I
- Alkali-reactivity uncertain - Class II
- Very likely to be alkali-reactive - Class III
Acceptance and experience with reactive constituents differ
between countries, and thus, final assessment of reactive
constituents should where possible follow national or regional
experiences, recommendations and specifications. RILEM
AAR-0 also gives guidance on the further testing that may be
undertaken on the basis of the findings of the AAR-1
petrographical examination.
It is very important that the petrographic analysis is
carried out by a qualified geologist or petrographer with
experience of materials used for concrete and good local
knowledge of alkali-reactive aggregates and minerals.

Online publication: 2003-06-27
Classification: RILEM Technical Committees
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/14060