This study investigates chloride ingress into alkali-activated slag/fly ash (AA-S/F) concretes with various ratios of slag to fly ash (80/20, 60/40, 40/60 and 20/80). Alkaline activators were a mixture of sodium hydroxide and sodium silicate to obtain between 6-8% sodium hydroxide (NaOH) concentration by weight of cementitious material. The SiO2/Na2O ratios (silica modulus, Ms) of mixtures were 0.45, 1.0 and 1.25. Tests applied included typical fresh and hardened properties, air content, slump, compressive strength, bulk resistivity and non-steady state chloride migration. The results show that while attractive engineering properties can be achieved, the chloride ingress in the AA-S/F concretes studied here with ≥ 20% fly ash is moderate to high and this may make them unsuitable for use in reinforced concrete in chloride environments.
|Name||ACI Symposium Special Publications|
|Period||02/10/2017 → 04/10/2017|
Publication: ACI Special Publication, Volume: 320, p 35.1-35.14, 14p
- alkali activated slag/fly ash concretes
- bulk resistivity
- chloride migration coefficient
- compressive strength