Abstract

The fly ash of ‘C’ category was used as a raw material to partial replacement of clay for `making fly ash bricks. Not only the affectivity of fly ash with high replacement, but also the mechanical properties of bricks with different combination were studied. It is observed that the compressive strength of plain fly ash and treated fly ash bricks (FAB, FALB) increases linearly and found to be maximum with 5% coarse sand and 15% sand combination at 10% cement. This increase of compressive strength continues with the addition of 0.2% geo-fibre in FAB and FALB. The addition of 10% stone dust in FALSDB with and without geo-fibre shows the achievement in strength that is, maximum at 10% sand replacement. The combination of fibre reinforced fly ash lime stone dust brick (10FRFALSDB3´) was found to have highest compressive strength with 10% stone dust and sand combination at 10% cement.  It is found that when the amount of treated fly ash changes with respect to the stone dust and sand replacement, the compressive strength increases and was found to be maximum at 25% stone dust-sand combination with 50% treated fly ash. With this change the enhancement of compressive strength achieved maximum which is nearly close to Indian first class brick.

Key words: Fly ash, compressive strength, lime.