Construction Cost Estimating


Basic differences among fly ash bricks & red bricks

In this civil engineering video, you will get some useful notes on the variations among red bricks and fly ash bricks.

The video focuses on the properties of both the bricks and which one is suitable for construction works.

In recent times, the fly ash bricks are gaining popularity among engineers, building professionals and workers for standard building construction as compared to red bricks.

Given below, the main points of differences:-

Construction Material: Fly ash bricks are formed with cement, slag, fly ash and construction rubbish. These waste materials are originated from the combustion of coal in thermal power plants. They are eco-friendly.

The clay bricks are mainly formed with clay that is obtained from fertile land or top soil.

Fly ash bricks generally use 65 kg cement for building up the one cubic meter of wall with large sized bricks as compared to red bricks.

Shape and size: Fly ash bricks come with identical shapes as they are cast in moulds. Whereas, the red bricks are built up by hand and consequently their shapes and sizes vary significantly.

To get the exact result, it is required to follow the steel manufacturer’s manual where the unit weight of the steel bars is cited.

Color: Fly ash bricks contain cement color. Red bricks are burnt and appeared as red to light brown in color based on the type of clay utilized for manufacture of the bricks.

Compressive Strength: The strength of fly ash bricks remain as 75 kg/cm2. Due to this high strength they are less permeable as well as stronger, consistent and thicker. Whereas the strength of red bricks remain as maximum of 35 kg/cm2.

Water Absorption: The water absorption capacity of fly ash brick is 6 to 12%. The water absorption capacity of red brick is 20 to 25%.

Cost: The cost of fly ash bricks is less as compared to red bricks.

Weight: The weight of fly ash bricks is light as compared to red bricks.

Thermal conductivity: The thermal conductivity of fly ash bricks is 0.90-105W/m2 degree. The thermal conductivity of red bricks is 1.25-1.35W/m2 degree.

Plastering: Fly ash bricks are available with very smooth finish. As a result, there are no requirements for the plastering and painting for the interior and exterior walls. When these bricks are used, the consumption of cement is decreased by 50%.

Plastering should be provided for red bricks.

Water consumption: Fly ash bricks consume less water with regards to red bricks.

Red bricks are effective for load bearing structure with regards to fly ash bricks. Fly ash bricks are useful for framed structure since the wall is used for providing partition only.

Basic differences among fly ash bricks & red bricks