Clay bricks or AAC blocks, which one is better in strength and economy?

Concrete AAC blocks are new age green building material that is it is easy to handle as compared to conventional breaks because they are light in weight. Though longer in dimension but still they are lighter in weight. They come in various sizes. The sizes are like 600 mm in length 200 to 250 mm in height and 100 to 300 mm in thickness. A standard AAC Block of size 600 x 250 x 150 mm is equivalent to about 8 clay bricks or red bricks.

Weight Comparison of Clay brick and AAC Block

Weight of a standard AAC Block after weighing we get 14 to 15 kgs. But when we compare clay bricks of the same volume of the AAC Block. The weight we got was 35 to 36 kgs. Further comparing AAC Block with fly ash brick of same volume the weight we got is 40 to 41 kgs.

Light Weight Experiment on Clay brick and AAC Block

The pours nature of the AAC Block makes them light in weight. When compared with fly ash and clay bricks they are dense and they are also heavy then AAC Block. When we emerge these three types of brakes in water, the fly ash and clay bricks sink to the bottom of the tank as they are dense and heavy. But AAC block magically floats on the surface of the water.

To keep AAC Block emerged in the water we have to keep bricks or any heavy load on it so that it stays in the water. We emerged these three types of bricks in the water for 6 hours. When we took out these samples after 6 hours it was clearly seen that the fly ash and clay bricks after breaking into two pieces the core of the bricks were wet and same thing we did with the AAC Block, after cutting this block into two pieces it was clearly seen that the core was still dry. So we can say that after curing process the self weight of the fly ash and clay bricks is increased.

Water Absorption Test on Clay brick and AAC block

In this we took a bucket half filled with water and then emerged 1 block vertically in that bucket. We kept that block in the water for 4 hours after taking out it was observed that the water rised was only 25mm. So it means that blocks does not absorb much water.

Working Process of Brick work or Block work

Initially, before starting a block work, the surface is to be chipped properly then it is cleaned by water. Then we need to spread a thick layer of concrete mix that is in the ratio of 1:6 on the surface. For the first layer of block work initially, two blocks are fixed at two corners and then it is checked with the tube level weather the blocks are horizontally perfect.

It is done to ensure the corner blocks kept are in a straight line. Then a plumb line is used to ensure the block placed is vertically alright. Then a thread line is tied to the corner blocks to ensure the block work is in a straight line. After applying mortar the blocks are then placed between the two corners. After the first layer of block work is complete there is no requirement of thick mortar.

The major advantage of AAC blocks is that we can use thin – layer mortar of cement based adhesive and water in the ratio of 3:1. Then this mix is applied on the block with the help of trovel and spread up to the thickness of 3mm. The same process is carried out for building further blockwork.

It is done to ensure the corner blocks kept are in a straight line. Then a plumb line is used to ensure the block placed is vertically alright. Then a thread line is tied to the corner blocks to ensure the block work is in a straight line. After applying mortar the blocks are then placed between the two corners. After the first layer of block work is complete there is no requirement of thick mortar.

The major advantage of AAC blocks is that we can use thin – layer mortar of cement based adhesive and water in the ratio of 3:1. Then this mix is applied to the block with the help of travel and spread up to the thickness of 3mm. Then the same process is carried out for building further blockwork.

Advantages of AAC blocks

• As compared with clay bricks or fly ash bricks one can build the wall more rapidly because it is easy to handle despite of its larger dimensions it is very light in weight. Another advantage of these AAC blocks is that it does not require much curing as it is required for bricks.
• With small number of blocks big wall can be constructed as the surface coverage area of these AAC block is more.
• Time required for constructing wall is half as compared with bricks.
• One can build wall with AAC blocks with a smaller number of joints.
• Mortar requirement is also very less.
• Labour requirement is also very less.

Size Uniformity Between Clay bricks and AAC blocks

In case of AAC blocks, size check is carried out time to time so we get a uniform size. But in case of Clay bricks, we do not get uniformity in size.

Plastering On Brick and Blocks walls

In case of clay bricks, they require regular curing and plastering is to be done for getting smooth surface. But in case of AAC blocks there is no requirement of plaster, we can directly apply gypsum on block surface. But for better protection if we are doing plastering for block as well, there is very less requirement of mortar as compared to clay bricks. Thickness of plaster on brick surface is 20mm and on block surface is 10mm so 50% material is saved.