Performance-based assessment of concrete resistance to leaching

Leaching of calcium and hydrates from concrete is likely to occur when concrete structures are immersed in pure or poorly mineralised water and acid environments. A performance-based test may be used to design concrete for such exposures, provided that it is representative, sensitive, and repeatable. In the experimental study a leaching test was performed on six vibrated concrete mixtures and five self-compacting concrete mixtures, varying aggregate type, water/binder ratio and mineral admixtures, such as fly ash, ground granulated blast-furnace slag and limestone filler. Two indicators have been used to assess damaged depth, taking limestone aggregates into account. Fly ash (20–30% of binder) and slag (60%) significantly improved behaviour of concrete, whereas leaching rate increased with an increase in limestone filler content.