About AAR & Concrete Durability

A wide variety of aggregate types in common use across the world, particularly those with a siliceous composition, are vulnerable to attack by the alkaline pore fluid in concrete. This attack, which in wet conditions produces a hygroscopic and hydraulic gel, can cause cracking and disruption of the concrete. The deterioration mechanism is termed Alkali Aggregate Reaction (AAR) or, more specifically for siliceous aggregates, Alkali Silica Reaction (ASR).

AAR is recognised as a durability problem in most regions of the world. The problem is both associated with the concrete mix design of new concrete, and as a durability problem in existing structures. Many consultants around the world are aware of the problem, but only a few have expert experience and credentials.

We realise that concrete durability is of major importance, as the investment of concrete structures worldwide is enormous and will continue. It is our ambition that our services might lead to safer, more robust concrete structures, a decrease in future maintenance costs, and more optimal use of aggregate resources.

Uncertainties of design and production of non-alkali reactive concrete are still of great concern in most parts of the world. It has been stated that, “Concrete durability is a multibillion-dollar opportunity”. A large number of vital concrete structures around the world suffer from the effects of deleterious AAR. Structural assessment, remedial work, monitoring and managements of diagnosed structures are of great importance regarding the rehabilitation and prolonged service life of these structures.