Reliability of new Australian test methods in predicting alkali silica reaction of field concrete

- New Australian Standard test methods to test alkali-silica reactivity of aggregates.
- AS1141.60.1 classified most 'reactive' aggregates consistent with field performance.
- AS1141.60.1 is a poorer screening test for non-reactive aggregates than ASTM C1260.
- Both concrete prism tests were found to be more reliable than AMBT.

Two new Australian Standard methods to test alkali-silica reactivity (ASR) of aggregates - AS 1141.60.1 accelerated mortar bar test (AMBT) and AS 1141.60.2 concrete prism test (CPT) were published in September 2014. The methods adopted test procedures correspondingly from ASTM C1260 and ASTM C1293 with improved performance limits leading to a new class of slowly reactive aggregates. This paper examines the accuracy of these new testing methods in predicting the ASR of aggregates in field conditions based on international research data. AS 1141.60.1 was found to be a relatively good accelerated test which correctly classified 'slowly reactive' and 'reactive' aggregates consistent with field performance with few exceptions. It is however a poorer screening test for non-reactive aggregates than ASTM C1260. Both AS 1141.60.2 and ASTM C1293 concrete prism tests were found to be more reliable than AMBT as both correctly classified almost all 64 aggregates against known field performance.