Pozzolan

Pozzolans are added to cement to increase set strength and reduce cement use.

Pozzolanic materials must be used in concrete in powder form, although lumps of hard material may be used as aggregate.

Upto 30% of portland cement may be replaced by pozzolan.

Pozzolanic cement mixes take longer to achieve full strength,

A simple way to grind lump pozzolans is to put them in a cement mixer with a brick.

List of Pozzolans

• Fly ash
• Coal ash
• Volcanic ash
• Silica fume
• Slag
• Brick dust
• Tile & crockery dust
• Clinker
• Some clays