RILEM Recommended Test Method AAR-0: Detection of Alkali-Reactivity Potential in Concrete -Outline guide to the use of RILEM methods in assessments of aggregates for potential alkali-reactivity

摘要

Petrographical examination (R1LEM AAR-1) should be carried out in all cases. On some occasions this will lead directly to definitive outcomes, either Class Ⅰ 'unlikely to be alkali-reactive', or Class Ⅲ 'very likely to be alkali-reactive'. In many cases, petrographical examination will lead to an indefinite outcome, Class Ⅱ 'potentially alkali-reactive', and further testing will be required. Siliceous aggregates (and carbonate aggregates with a significant siliceous content) may be assessed for ASR, usually using first the ultra-accelerated test (RILEM AAR-2) and ultimately the accelerated concrete prism test (RILEM AAR-3). The findings of the concrete prism test should always take precedence. The AAR-2 test cannot be used for Class II aggregates containing porous flint (chert) as a potentially reactive constituent. An ultra-accelerated concrete prism test (RILEM AAR-4) is being developed that it is hoped will eventually be suitable for acceptance testing on a project-by-project basis. Carbonate aggregates (and siliceous aggregates with a significant carbonate content) may be assessed using the AAR-5 methods currently being prepared by RILEM TC 191-ARP.