Evaluation of Test Methods for Testing Reactivity Related to AAR: RILEM AAR-2 and TI-B51 Assessment of the Methods in Relation to Fast and Slowly Reactive Rock Types

The RILEM AAR-2 method and the ASTM C 1260 method are nearly identical ultra-accelerated mortar bar test methods. The RILEM AAR-2 method has two versions AAR-2.1 for specimen size 25 × 25 × 285 mm and AAR-2.2 for specimen size 40 × 40 × 160 mm. The NORDTEST NT BUILD 295 method ‘Sand-alkali-silica reactivity accelerated test’ is equal to the Danish TI-B 51 method, which applies specimen size 40 × 40 × 160 mm in saturated NaCl solution at 50 °C up to 52 weeks. The TI-B 51 method has been used for 37 years for testing Danish sand (0–4 mm) with (fast reactive) porous opaline and porous calcedonian flint types. The argument for using saturated NaCl solution is that structures often are exposed to alkalis from sea water or de-icing salt (NaCl). In Denmark, many buildings from before 1987 contain a critical amount of fast reactive opaline flints, thus resulting in the structures being sensitive to exposure to NaCl.

The paper shows measurement results 1) by use of RILEM AAR-2.1 and AAR-2.2 test methods which by comparison of results gives a ratio for conversion in expansion recordings between the two test methods, and 2) a comparison of results between ASTM C 1260, RILEM AAR-2 and TI-B 51 test methods on both fast and slowly reactive rock types.