COMPARISON OF LABORATORY PERFORMANCE TESTS USED TO ASSESS ALKALI-SILICA REACTIVITY

摘要

Alkali-silica reaction of certain concrete aggregates can lead to premature deterioration and maintenance problems in concrete structures. The CSA A23.1-14 A/ASTM C1293 concrete prism test (CPT) and the CSA A23.2-25A/ASTM C1260/ASTM C1567 accelerated mortar bar test (AMBT) are the two main procedures used in CSA and ASTM standards for examining the potential alkali-silica reactivity (ASR) of aggregates and also for assessing the effectiveness of supplementary cementing materials (SCMs) in suppressing ASR. The long testing duration of the CPT and the unreliability of the rapid AMBT have led to development and evaluation of a third method, the accelerated concrete prism test (ACPT). All three methods were performed using a range of different aggregates and SCM partial replacements of cement. Expansion data were compared with one another and with known field performance, where available. Results show good correlation between CPT and ACPT expansions and these tests appear to be good predictors of field performance. The AMBT, on the other hand, can be very misleading with certain aggregates.