material saving

AAC Blocks vs red bricks – AAC blocks are also known as Autoclaved Aerated Concrete Blocks. They are lightweight, load-bearing, durable, and economical. AAC blocks can be manufactured to meet any requirements. AAC blocks are considered a green option instead of red bricks. They have enormous potential in terms of insulation, fire resistance, and thermal resistance. AAC blocks are environmentally friendly. They are a superior material compared to concrete, wood, brick, and stone. They can enhance the construction speed, reduce the costs, and unwanted wastage at construction sites.

Autoclaved Aerated Concrete blocks are superior to conventional red clay bricks in a lot of factors. Considering the impact and necessity of these factors we can easily make a choice.

AAC blocks vs red bricks

AAC blocks vs red bricks

AAC blocks are superior to red bricks in a lot of factors relating to quality, speed, workability, cost, and wastage. There is much to discuss about the advantages of AAC blocks. They hold benefits over Red bricks, fly ash bricks, Cement Concrete hollow blocks, and CLC blocks.

AAC blocks are manufactured from materials like sand, fly ash, lime, and cement. They are lightweight, eco-friendly, and energy-efficient. Their efficiency is due to 80% voids and the use of industrial waste.

AAC blocks are superior to conventional bricks for several reasons. They are lightweight and have eco-friendly properties. These blocks offer better insulation and energy efficiency. They also utilize waste materials like fly ash.

Let us have a comparison between AAC blocks and red bricks in terms of following parameters.

Availability of sizes
Technical Properties
Construction speed
Savings in labour
Material Savings

Availability of sizes.

Customization in size is the most important aspect in deciding the choice of bricks/blocks for a particular structure.

AAC blocks	Conventional red bricks
AAC blocks are available in varied sizes are can be customised for special requirements.	Mostly available in one or two standard sizes. No customisation is possible.

AAC blocks vs red bricks- Technical properties

AAC Blocks	Conventional Bricks

AAC blocks are available in 600 mm/625 mm (length) X 100–300 mm (height) X 230/240 mm (width).

Bricks are available in 225 mm (length) X 115 mm (width) X 75/70 mm (height).

The dimension tolerance of the AAC block is +/- 5 mm.

The dimension tolerance of brick is +/- 5 mm to +/- 15 mm or more.

Density ranges between 500-650 kg/cm³.

Density ranges between 1400-1900 kg/cm³.

The drying shrinkage of AAC blocks is 0.4%, which is very low compared to conventional bricks.

The drying shrinkage of bricks is 0.8%, which is comparatively high compared to AAC blocks.

AAC blocks vs red bricks – Construction speed

AAC blocks are considered cost-effective and economical in comparison with conventional bricks. The cost-effectiveness of AAC blocks is mostly related to the construction speed.
AAC blocks can enhance construction speed when compared to conventional bricks. This improvement is due to some unique characteristics detailed out in the following table.

Let us take a wall of 3mtr x 3 mtr size and 4 inch thickness

AAC Blocks	Conventional Bricks

Area of Block

Area of Brick

Area of block = 24 inch x 9 inch (600 mm x 230 mm) = 0.138 sqm

Area of brick = 9 inch x 3 inch (230 mm x 70 mm) = 0.0161 sqm

Wall area = 3m x 3m = 9 sqm

Wall area = 9 sqm

No. of blocks = 9 sqm / 0.138 sqm = 65 blocks (600 mm x 230 mm x 100 mm)

No. of bricks = 9 sqm / 0.0162 sqm = 555 bricks (230 x 110 x 70 mm)

Total Mortar Joints

85 rmt (approx)

170 rmt for 4-inch wall & 240-250 rmt for 9-inch wall

Weight

Weight of an AAC block (9 inch) = 16-17 kg

Weight of brick = 3-3.5 kg (approx)

1 no. 9 inch block = 14-15 bricks

Bricks are heavy

From the above comparisons, it is clear that the AAC blocks are lightweight and covers more area than bricks. Brick masonry got 3-4 times higher mortar joints and around 14-15 bricks constitute an AAC block. That is why Brick masonry is very slow.
AAC blocks are big, got fewer joints, and can be completed very fast.

Factors influencing construction speed

Factors Influencing Construction Speed	AAC Blocks	Bricks

Dimensional Accuracy

AAC blocks are factory-made and possess dimensional accuracy, making them easy to place and plumb.

Red bricks are locally made, irregular, and less dimensionally accurate, making them difficult to place, level, and plumb.

Number of Joints

AAC blocks have fewer joints, increasing construction speed.

Red bricks have 4 times more joints than AAC blocks, significantly reducing construction speed.

Coverage Area

AAC blocks cover a larger area.

Bricks cover a smaller area.

Skill Requirement

AAC blocks can be placed by semi-skilled workers due to their dimensional accuracy and shape.

Brickwork requires skilled masons because of inaccuracies and shape issues.

Mortar Joints

AAC blocks use ready-mix block adhesive with a joint thickness of 3-5 mm.

Brickwork uses site-mixed mortar with a minimum joint thickness of 10 mm.

Savings in labor

Savings in Labor	AAC Blocks	Bricks

Pre-curing and post-curing labor

AAC blocks do not require any pre-curing. AAC block masonry joints are air-cured and do not require any curing. Infrastructure and labor involved in the curing process can be eliminated.

Bricks must be soaked in water before use. Additionally, 7-day curing is required for brickwork, which demands curing infrastructure and labour involvement.

Labour saving in mortar mixing

Labour Saving in Mortar Mixing	AAC Blocks	Bricks

Mixing Process

AAC blocks use ready-mix bonding adhesive as jointing material, available in 25-30 kg packs and mixed with water before use.

Brickwork uses site-mixed mortar that involves handling, mixing, and conveying of raw materials and mortar.

Labour Cost

This can save substantial labour costs incurred for mortar mixing and conveying.

Extra labour costs involved for mortar mixing and conveying.

Conveying and re-handling labour

Conveying and Re-handling Labour	AAC Blocks	Bricks

Supply and Conveying

AAC blocks are supplied in pallets. They can be easily lifted and conveyed to work spots using cranes and tower cranes directly from the trucks.

Bricks are supplied loose and unloaded manually. They need to be filled in buckets for lifting to heights, requiring more labour.

Labour and Wastage

Saves labour in unloading, conveying, and lifting. Less handling generates zero wastage.

Brick shifting and conveying involve heavy labour and generate a large amount of wastage.

AAC block work rates are comparably less than brickwork due to the saving involved in the labour part. The rate per cum of AAC blocks will be around INR – 650/- to -750 /- per cum whereas brickwork is around INR 1400-1500/- per cum.

Saving in mortar

AAC blocks got fewer mortar joints of 3-5 mm thickness whereas brick masonry generates 3-4 times higher number of joints of 12 mm thickness. This can save substantially in terms of jointing material.

Analysis of Mortar for Brickwork

Description	Quantity	x	Rate (INR)	=	Cost (INR)
1 CUM Brickwork = 0.35 to 0.4 CUM mortar
Sand cost (Rs. 2500/- per CUM)	0.35	x	2500	=	875
Cement	1.3	x	300	=	390
Total cost per CUM of brickwork				INR	1265/-

Analysis of Block Adhesive

Description	Details
1 CUM block work	30 kg of block adhesive
Rate per kg	Rs. 12-15 per kg
Cost for 30 kg	Around INR 400/- per CUM

Conclusion:
Block adhesive costs approximately INR 400/- per CUM, whereas mortar costs around INR 1250/- per CUM.

Saving in plastering

AAC blocks are dimensionally accurate and both faces of the block-work look even without any undulations. The undulations can be levelled by providing a minimum plastering thickness of 10 mm inside and 12-15 mm outside. AAC blocks can even be painted by directly applying putty/Gypsum plaster over it.

Brickwork has a fair face and unfair face. To cover up undulations, a 12 mm plastering thickness is required for the fair face. A minimum of 18 mm thickness is needed for an unfair face.

AAC blocks offer other value-added benefits. They are superior in fire resistance, termite resistance, and thermal resistance. Additionally, they serve as a green building material. Please read ADVANTAGES OF AAC BLOCKS.

Also read : MANUFACTURING PROCESS OF AAC BLOCKS