WHAT ARE THE DIFFERENCE BETWEEN FLY ASH BRICK & RED BRICK

Building an own house is a dream for everyone. To build a house selection of building material is an important part. During the selection of building materials; Selection of  Brick  is to be done.

For the bricks, we have two major types of bricks in the market i.e. Fly ash Brick and Red brick.

Let us discuss them one by one and also compare them with their qualities and properties. 

1.       Fly Ash Brick: Fly ash brick is a very important building material. It is a lightweight building unit which is prepared from fly ash, sand, stone dust, gypsum, lime, cement. It has also self-cementing properties.  There are a number of compositions by which fly ash brick can be made.

Fly ash is residual gotten after ignition of pummeled coal. Fly ash comprises of oxides of silicon, aluminum, iron, magnesium, potassium, sodium, titanium and sulfur are available in limited quantity. Further Fly ash can be separated as class c and class F.

 

Sand is normally occurring aggregate, which is finer than 4.75 mm in size. Silica present in sand assists with holding the state of brick by preventing shrinkage, breaking and wrapping or brick. Additionally, high level of silica might lead the brick to be weak.

 

Gypsum is hydrated calcium sulfate (CaSo4.2H2o). Gypsum is included around 5%. Gypsum is added as a strength gainer in the brick.

 

Lime (CaCo3) is utilized as cover to join building units. Lime with water have glue property. Lime blends in with Fly ash in a customary temperature to have restricting property. Ooze lime or hydrated lime are utilized to stick the material into a spot.

Advantages of Using Fly Ash Brick:

• It is light in a weight. And hence it reduces dead load of the superstructure.
• It has strength ranging from 7.5-10MPa
• It gives a plain surface when used in masonry work which reduces the cost of plastering.
• These bricks have high fire insulation.

 

Disadvantages of Using Fly Ash Brick:

• It does not absorb heat due to which it is no use of the cold climate.
• It has low mechanical strength.
• They are only available in the modular size.

 

2. Red Clay Brick: It is also an important building unit which is made up of clay, sand, lime, and other ingredients in proportion.

1) Alumina (Al₂O₃): Alumina, Clay is a major composition of the Brick. Clay acts as a cementing material in the Brick. The plasticity of the brick is due to the presence of Clay. But an excessive quantity of clay can also shrink the brick, hence, deforming the shape of the brick.

2) Silica (SiO₂): These are oxides of silicon; it is used to manage the percentage of silica in brick. The main role of the silica is to defend the raw brick from wrapping, cracking, and shrinking.

The strength and durability of the brick lies upon the proportion of alumina and silica present in the brick. But the excess quantity of silica reduces the cohesive property of brick material making it weak and brittle.

3) Lime (CaCO₃): Lime is used in powder form, in small quantity only as a catalyst to fuse the silica at kiln temperature. For a good brick, a slight mix of silica is preferred.

4) Iron oxides: Metal oxides are used to color the material. They are used in very small quantity to give red color to the brick after burning. Other than this, it also makes brick impermeable.

 Advantages of Using Red Clay Brick:

• They can be used in load-bearing structures.
• The compressive strength of red clay brick is up to 10.3 MPa.
• All the compositions are locally available which reduces transportation charges.
• They provide thermal and sound insulation to the structure.
• Red Clay bricks are highly fire-resistant and easily reusable and recyclable.

 

FLY ASH BRICKS Vs RED CLAY BRICKS:

 

Fly Ash Brick                                 Red Clay Brick

They are made from cement, slag, fly ash.	They are manufactured from Clay Soil
It has a more uniform shape as they are cast in machine mold.	Do not have a uniform shape as they are hand mold-mad
has a Cement grey color	has the color red to light brown
has compressive strength – 75 to 100 kg/cm²	has compressive strength – 30 to 35 kg/cm²
Density: 1700-1850 kg/m3	Density: 1600-1750 kg/m3
wastage on site is around 2 – 5 %	wastage on site is more than 10 %
Water Absorption of about 6 -12 %	Water Absorption of about 20 – 25 %
Weight is 2.6 kg	Weight is 3.5 kg

 

 

CONCLUSION:

 

After thinking all aspects we can say that fly ash bricks are better than clay bricks. They are environment-friendly also because the maximum constituents are ash and fly ash bricks have greater strength as compared to red bricks.

So, we can choose fly ash brick which is the best brick for home construction from all aspects.

 

RELATED POST : What is a Brick? Composition & Function of Ingredients. Standard Brick Size.

                                : Masonry Works. Types of Masonry Work. Advantages & Disadvantages