Effectiveness of Super-plasticizer on High Volume Slag (GGBS) Concrete

This research was conducted to determine the optimum dosage of super-plasticizer
for producing highly workable and high strength concrete using high volume of slag
(GGBS). Replacement of high volume slag in cement incorporating super-plasticizer
will contribute to increased strength; increased workability; reduced porosity and
permeability. Super-plasticized high - volume slag with 40% of Portland cement
replacement were produced by using different concentration of chemical admixtures
which is Naphthalene Formaldehyle Sulphonate also known as Sikament Nl. A
100% of Ordinary Portland Cement for control mix without super-plasticizer was
prepared. Seven mixes were using 60 per cent of high volume of GGBS and 40 per
cent of Ordinary Portland Cement (OPC) with different percentage of superplasticizer
from 0 per cent to 3 per cent; and constant water/cement (w/c) ratio of
0.40, course aggregate (14mm sieve) and sand. The measurement will be conduct
under workability, compressive strength, porosity and gas permeability of the
concrete. The duration or ages for measuring was divided in to 3-days, 7 -days, 28-
days and 90-days. There were 3 samples have to provide for each mix and each type
of sample. However, the conclusion of result is still pending due to the slow
development of compressive strength of concrete and further research with higher
dosage of super-plasticizer.