Which is better AAC or CLC block?

If you have been searching for the best block for your upcoming construction project, chances are that you have narrowed down your list to Autoclaved Aerated Concrete blocks (AAC) and Cellular Lightweight Concrete (CLC) blocks. These two types of blocks are among the most popular types of concrete used for building purposes both in commercial and residential buildings.

Is it difficult for you to choose between these two blocks? Then today you have come to the right place. In this article, we will compare and contrast these two types of blocks and tell you which one between the two is better. Make sure you read until the end so that you don’t miss any crucial information.

What is an AAC block?

Autoclaved aerated concrete is a lightweight precast sustainable construction material made from aggregates of quartz, lime, calcined gypsum, aluminum, Portland cement, and water. After blending and mixing, the concrete is autoclaved under high heat and pressure.

One of the top reasons why most people prefer this type of block is because of its excellent thermal insulation properties and high strength. They can be produced in a wide range of sizes and strengths. AAC blocks are widely used in the construction of commercial, residential, and industrial properties. Their immense strength makes them ideal for building high rise structures

What is a CLC block?

Cellular lightweight concrete is one of the most commonly used types of block for construction purposes. CLC blocks are cement-bonded materials that are made by blending cement, fly ash, sand, water, and preformed foam in varied proportions. 

The good thing about CLC blocks is that they don’t have to be transported to the constructed site. Instead, they can be produced at the construction sites using a special machine and molding device.

One of the most outstanding properties of CLC blocks is their self-compacting property which allows them to be pumped on major distances and heights. They are also incredibly stable and lightweight. CLC blocks are commonly used in Acoustic construction, precast exterior walls, low-cost housing, air-conditioned buildings, and much more.

ACC block VS CLC block

Properties	AAC block	CLC block
Raw material	Cement, gypsum, aluminium powder, sand or fly ash, aeration agent	Cement, sand or fly ash, foaming agent, water
Curing method	Steam curing in autoclave	Water curing or regular steam curing
Dry density	450kg/CBM to 1000kg/CBM	800kg /CBM to 1800  kg/CBM
Cost	Comparatively higher but affordable	Comparatively lower
Compressive strength（market common type）	3 to 5 N/mm2	2 to 5 N/mm2
Manufacturing scale	Manufactured in large scale	Manufactured in medium or small scale
Air voids percentage	50 to 60% of total volume	30 to 40% of total volume
Quality	Consistent, as production is mostly automated	Inconsistent, as the production is labour oriented
Water absorption	30%  for the block having density of 1000kg/CBM	12.5% for the blocks having density of 1000kg/CBM
Space for curing	Needs less space	Needs more space
Availability	Made in larger factories. So they may not be available locally	Made in smaller units. So they may be available locally
Environmental impact	Energy efficient and a lesser amount of CO2 is emitted while manufacturing	environmental friendly and helps in reducing solid waste for dumping

Which is better, CLC or AAC block?

Both blocks are unique in their own way and they both have their strengths and weaknesses. The best block is one that suits your individual needs. For instance, if you are looking for high compressive strength in a block then AAC blocks are better.

On the other hand, if you are looking for a lightweight block, then CLC blocks are the perfect option for you. We recommend that you choose a block type that suits your construction needs and budget.