Importance of considering the coupling between transfer properties, alkali leaching and expansion in the modelling of concrete beams affected by internal swelling reactions

Alkali Aggregate Reaction (AAR) and Delayed Ettringite Formation (DEF) cause expansion of the affected concrete that generally leads to cracking and decrease of its mechanical properties. Consequently, these pathologies raise severe problems regarding serviceability, sustainable operation and structural integrity. Thus it is necessary to provide predictive models able to re-assess the mechanical state of the affected structures. Since cracking may alter diffusion properties of concrete, and since water and alkali content affects AAR and DEF progress, the necessity of taking full coupling of damage and water transfer is questioned for proper structural reassessment. Documented structural tests help evidence this necessity.