The current status of AAR in Australia and mitigation measures

摘要

This paper describes the different stages in the development of research, testing and diagnosis of AAR in concrete structures in Australia. Most AAR cases here are a legacy of using inappropriate overseas test methods and criteria, developed for local aggregates there, and the consequent incorrect classification of reactive aggregates as innocuous. Appropriate Australian Standards for detecting reactive aggregates (AS1141-60.1, AMBT; AS1141-60.2 CPT; and AS1141.65, Petrography) were published in 2014 and early 2015. These, together with existing methods used by road authorities, will help in preventing future cases of AAR-induced damage to concrete structures. AAR mitigation by using suitable supplementary cementitious materials in concrete has been demonstrated in both laboratory testing and in actual structures. The updated Australian AAR guidelines (Handbook HB79) are due for publication in mid-2015. Australia is now well equipped to combat AAR in concrete, although incremental improvements will no doubt be achieved through further research.