Ash Benefits & Uses
South Africa only produces siliceous (pozzolanic) fly ash
WHAT ASH IS AVAILABLE?
- Fly ash
- Classified fly ash
- Un-classified fly ash
- Clinker ash (old chain grate boilers)
- Cenospheres (limited availability)
- Bottom ash
- Disposed ash
South Africa produces in excess of 50 million tons of ash per annum with about a 10 % utilisation.
WHAT ARE ITS BENEFITS?
In Concrete
- Increased post 28 day strength gain
- Reduced the rate of chloride diffusion through the concrete
- Prevents or retards alkali-silica reaction
- Reduced heat of hydration by up to 20 %
- Reduction of shrinking due to lower water demand
- Increase in overall durability of the concrete
- Improves sulphate resistance
- Improves the workability of fresh concrete
- Reduction in bleed water
Environmental
- Reduction of CO² emission
- Reduces disposal volumes and neutralises waste
WHAT ARE ITS USES?
Typical uses of ash include:
- Cements and grouts
- Concrete Products & Bricks
- Ready mix concrete
- Artificial aggregates
- Road construction & soil stabilisation
- Soil conditioning
- Mine rehabilitation
- Agriculture