ENHANCING CONCRETE PERFORMANCE BY USING ENVIRONMENT FRIENDLY FINELY DIVIDED MATERIALS

摘要

The present study focuses upon the performance of locally manufactured hydrated lime powder of type S and fly ash when added separately and in combination, termed cocktail in this paper, as 10% of the mass of cement to concrete mixes of 1:1.5:3.0 and 1:2.5:5.0 by mass with W/C=0.60. The selected mixes are traditionally considered rich and lean respectively. Compressive strength of lime modified concrete increases more for leaner mix than for richer mix with 10% lime addition in comparison to control concrete while fly ash modification increases the strength of richer mix more than the leaner one for the same parametric conditions. Almost similar trend is obtained when lime and fly ash cocktail admixture is added to concrete equal to 10% of cement mass with lime and fly-ash each sharing 5%. The workability of modified concrete enhances due to lime addition in comparison with control concrete while the reverse is true for fly-ash addition because of its higher water demand and higher surface area where it may be used effectively with some superplasticizers. Finally divided admixtures seem to enhance chemical resistance and water absorption of concrete.