Title:
Suitability of Alkali Activated GGBS/Fly Ash Concrete for Chloride Environments
Author(s):
Dali Bondar, Sreejith V. Nanukuttan, Marios N. Soutsos, P.A. Muhammed Basheer and John L. Provis
Publication:
Symposium Paper
Volume:
320
Issue:
Appears on pages(s):
35.1-35.14
Keywords:
alkali activated slag/fly ash concretes, bulk resistivity, chloride migration coefficient, compressive strength, workability
DOI:
10.14359/51701073
Date:
8/1/2017
Abstract:
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.
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