Fly ash Bricks | Building Materials and Construction

Fly ash Bricks | An alternative Building Material

Fly ash bricks are masonry units that are used in the construction of buildings. They are considered to be a part of good and affordable building materials. They contain Class C fly ash and water.

Fly ash bricks are made by compressing Class C fly ash and water at 4000psi and then curing is carried on for 24 hours at a temperature of 66 degrees Celsius steam bath. Air entrainment agent is used to toughen the bricks.

Fly ash Bricks
Fly ash Bricks

Since the concentration of calcium oxide is very high in class C fly ash, the brick is described as self cementing.

It is considered to be a good alternative to traditional mud bricks since the method of manufacture of fly ash is energy efficient that is it helps save energy, brings about reduction of mercury pollution and plus it is cost effective.

Raw materials used for the manufacture of Fly ash Bricks:

  • Fly ash – which is the primary ingredient
  • Sand or Stone dust – as fine aggregate
  • Lime – source of calcium carbonate which results in the bricks being called “Self-cementing bricks”.
  • Gypsum – to enhance the fineness of the shape of the bricks
  • Cement – to increase bonding and strength

Types of Bonds in Brickwork | Stretcher and Header Bond

Bonds in Brickwork | Building Construction

In our previous articles, we discussed “what is a bond?” and “Rules for good Bonding”. Let us start our further discussion on types of bonds.

Different types of bonds are:

  1. Stretcher bond
  2. Header bond
  3. Facing bond
  4. English bond
  5. Flemish bond
  6. Dutch bond
  7. English cross bond
  8. Brick on edge bond
  9. Raking bond
  10. Zigzag bond
  11. Garden wall bond

Now we will proceed with our in depth discussion on “Stretcher bond” and “Header bond”.

What is a Stretcher Bond?

As the name itself suggests, stretcher bond is formed by laying bricks horizontally as stretchers on the faces of walls. The length of the bricks is along the horizontal direction of the wall.

Stretcher bond | Exposed Brickwork of a Restaurant
Stretcher bond | Exposed Brickwork of a Restaurant

Stretcher bond is used when walls of half brick thickness are to be constructed. The average size of the brick is 9cmx9cmx18cm. If the wall of thickness 9cm is to be constructed, then stretcher bond can be used.

Various types of wall constructions are done using this type of bond.

  • Sleeper walls
  • Partition walls
  • Division walls (internal dividers)
  • Chimney stacks