Background
ASCET is an international research project initiated by WGIAGE1 OECD2 / NEA3. WGIAGE4 Concrete subgroup is a working group within the OECD / NEA whose task is to address issues concerning
- the maintenance of the integrity of concrete structures,
- proposals for general principles to optimally handle the challenges of integrity, especially with regard to aging of concrete structures.
The aim of the ASCET project is to create a basis for general recommendations regarding management of ageing related concrete degradation in nuclear facilities.
Results
Phase 2 of the ASCET project consisted of a blind numerical simulation benchmark of a shear wall structure affected by concrete degradation, in this case ASR, tested under cyclic loading up to structural failure. The numerical simulations have been compared with experimental results.
The numerical result revealed for example that the shear friction capacity, calculated as per section 6.2.5 in EC2, exceeds the experimentally derived capacity of the studied wall. The numerical simulation confirmed that structures effected by ASR can have a higher ultimate shear capacity despite having nominally weaker material properties. That is because the concrete expansion caused by ASR is prevented due to the concrete reinforcement.
The results from this phase is important in order to create a basis for general recommendations regarding management of ageing related concrete degradation in nuclear facilities.
Objectives
Degradation of concrete structures important to safety has been identified by SSM as a potential problem area as the Swedish nuclear facilities are getting older. The results from this research project together with the next phase are therefore valuable when it comes to ageing management and radiation safety assessments of degraded concrete structures in nuclear facilities.