The french standard methods for evaluating the reactivity of aggregates with respect to AAR: results of an inter-laboratory program

Abstract The objective of the working group was to check the consistency of the five standard test methods which were adopted in France three years ago. The authors present in this paper the results of an evaluation program concerning nine sands and 20 coarse aggregates. The P 18-585 (mortar bar test at 38°C), P 18-587 (concrete prism test), P 18-588 (microbar test), P 18-589 (kinetic test) and P 18-590 (autoclave test) were used. Emphasis was also put on the petrographic examination. The results have been analyzed by comparing the different procedures. Ultra-accelerated methods (P 18-588 and P 18-590) and the chemical test P 18-589 lead to similar conclusions as to the reactivity or non-reactivity of most of the aggregates tested. Special attention was paid to the aggregates containing more than 60% chert and likely to display a pessimum effect when used in concrete. Both P 18-588 and P 18-589 methods are helpful in recognizing their peculiar reactivity, while the P 18-585 does not produce any expansion. The P 18-587 Concrete test is not recommended for this type of aggregate because of possible misinterpretation of the small expansions observed in this test.