Mechanical Properties of ASR/DEF Damaged Concrete Under External Restraints

Delayed ettringite formation (DEF) and alkali silica reaction (ASR) negatively affect the mechanical properties of concrete. This work investigated the compressive strength and dynamic elastic modulus variations of concrete to restrain the expansion progress owing to the internal swelling reaction (ISR) mechanisms (i.e., ASR and DEF). Two concrete mixtures are used to induce the damage in concrete cylinders owing to DEF and the combined effects of ASR and DEF. The expansion and dynamic elastic modulus of the free specimens (without restraints) are measured periodically during the storage period. The compressive strength and dynamic elastic modulus of restrained concrete cylinders are higher than the free specimens which have relatively lower expansion. The higher mechanical properties then gradually reduced with an increase of expansion but remained higher than that of specimens allowing free expansion.