Figure-1 shows the slump values of 13 different concrete mixes used in this experimental
investigation; for control mix it was obtained as 20 mm. When used engine oil was added
to 100% OPC concrete, the slump value increased to 35 mm. Similarly the slump of new
oil with 100% OPC concrete was obtained as 59 mm. SIKA superplasticiser which is
commercially produced to increase the fluidity of concrete, increased the slump value of
100% OPC concrete to 49 mm.
Usually fly ash when used as a partial replacement of OPC in concrete will increase
the slump of concrete and this hypothesis is found to be true in this experimental
investigation. Concrete mixes 40FA and 50FA made of 40% and 50% fly ash, yielded
higher value of slump i.e. 26 mm and 28 mm respectively. Used and new engine oils and superplasticiser significantly increased the slump value of fly ash based concrete by 1.5 to
2 times of the respective fly ash mix.