FINITE ELEMENT ANALYSIS OF WALLS WITH ALKALI-SILICA REACTION (ASR) SUBJECTED TO CONSTANT AXIAL AND CYCLIC LATERAL LOADINGS

摘要

Alkali Silica Reaction (ASR), a type of alkali aggregate Reaction (AAR), is observed in some concrete structures in eastern Canada and the eastern United States. The Canadian Nuclear Safety Commission (CNSC) is currently conducting research to develop regulatory guidelines for the assessment of existing concrete structures with AAR as well as the means to avoid this pathology in new builds. This paper describes the work conducted by the CNSC related to the prediction of the behaviour of an ASR wall subjected to constant axial and lateral cyclic loads. The objective of this work is to use the commercial finite element (FE) code LS-DYNA to model concrete walls with regular and reactive ASR concrete. The current work analyses the effect of ASR in a simple phenomenological model by substituting concrete expansion due to ASR with an identical thermal expansion. Cyclic loading with increasing amplitude is applied to both the ASR and regular walls until failure is achieved. The FE predictions are compared with available test results for both ASR and regular walls subjected to 240 days of accelerated aging. Based on good agreement between the FE predictions and the test results, additional FE analysis is conducted to perform a blind prediction of the behavior of the ASR wall after 900 days of accelerated aging.