Challenges related to structural modelling and assessment of concrete structures affected by alkali-silica reactions

Abstract

Alkali-Silica Reaction (ASR) in concrete is a chemical process between dissolved alkali and hydroxyl ions from pore solutions in the cement paste, and reactive (amorphous) silica within the aggregates. The product of the chemical reaction is an alkali-silica gel that will increase in volume by water absorption. The result is expansion of the concrete and degradation of material properties. The deteriorating impact of ASR on concrete structures might be reduction in load bearing capacity, durability and service life. In this paper, the effects of ASR on concrete material are reviewed, and the challenges related to modelling the effects of ASR on the structural scale are addressed. Finally, plans for structural assessment on parts of an existing bridge in Norway are announced.