Brick Ash

Fly ash is one of the residues produced in coal combustion. It is commonly captured from the chimneys of coal-fired power plants and is one of two types of ash collectively known as coal ash. The second, bottom ash, is removed from the bottom of the coal furnaces. Depending on the coal combustion source and makeup, the composition of fly ash varies considerably, but all fly ash contains significant amounts of silicon dioxide (SiO2) (both amorphous and crystalline) and calcium oxide (CaO ) are included.

Fly ash has been used to make concrete building blocks for over 50 years. They are widely used for the inner skin of cavity walls. They are naturally more thermally insulating than blocks made with other aggregates.

Fly ash bricks have been used in house construction since the 1970s. However, one problem with bricks is that they fail. This happens when the brick comes in contact with moisture and a chemical reaction occurs that causes the brick to expand.