Abstract:
In this paper, Gum Arabic (GA) obtained from Acacia
Senegal trees found in northern Kenya and most of other semi
arid areas in Kenya was used in self compacting concrete as a
superplasticizer. The research sought to establish the effect of
Gum Arabic on concrete rheology at varying dosages and water-
powder ratio. Series of mix design trials were conducted based on
European Standard for design of self-compacting concrete
(EFNARC). The final optimum mix design ratio applied were:
water-powder ratio of 1.1, 1.0, 0.9 and 0.8 and Gum Arabic
dosages of 2%, 4%, 6%, 8%, 10% and 12% by weight of cement
while the coarse and fine aggregates content applied was 28%
and 45% respectively. The resultant mix was tested for passing
ability, flow ability and segregation resistance .The results show
that Gum Arabic is suitable for use as a superplasticizer in self
compacting concrete and a dosage of 8% by weight of cement for
water-powder ratio of 1.0, 0.9 and 0.8 by volume and aggregate
ratio of 28% coarse and 45% fine is recommended. It is also
noted that it has an advantage of being environment friendly.