The objective of the CSNI ASCET activity is to make general recommendations for ageing management of concrete nuclear facilities taking into account the effect of concrete pathologies on structural degradation. The ASCET Phase II is based on the recommendation of the workshop held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, United States, from 29 June to 1 July 2015, and the Phase I Report. Phase II of ASCET is defined as a blind simulation benchmark to predict the behaviour of structural elements with alkali aggregate reaction (AAR). This report describes the results of the ASCET Phase II benchmark and the Phase II workshop recommendations for further work, which are addressed in ASCET Phase III.
The benchmark was based on tests of walls conducted at the University of Toronto under a CNSC research programme. The results for two sets of two walls (one sound and one with AAR in each set) and one extra wall with AAR were provided for this benchmark. The results of one set of walls were provided to calibrate numerical tools and the results of the other set of walls were used to perform blind simulations. The analysis and comparison of analysis results of the ASCET Phase II were mainly focused on the ultimate wall shear capacity. It shall be noted that overall difference in ultimate shear capacity for five test walls was within 13%, which stays within uncertainties of test measurements.