Autoclaved aerated concrete (AAC) blocks are eco-friendly, lightweight, and all-weather construction materials that are designed to offer superior performance and durability. They are eight to nine times the size of a traditional red clay brick and provide better compressive strength across all construction projects. Although traditional red clay bricks have been used for decades in construction projects, AAC blocks are a viable alternative offering significant cost savings (20-25% in many cases) and better dead load reduction of the development as well.
Procurement teams can review the following differences when analysing which construction material is right for their project.
Compressive strength: AAC blocks provide greater strength
Red clay bricks are designed with a mixture of clay (alumina), sand, lime, iron oxide and magnesia, and is readily available across the country. AAC blocks are manufactured via a mixture of fly ash, cement, lime, gypsum, and aeration agents, and require specialized factories to design and develop.
While red clay bricks are easily available across regions, they do not offer superior compressive strength when compared to AAC blocks, which are designed to be more resilient to compressive loads. Red bricks offer a compressive strength of 2.5 to 3.5 N/mm2, while AAC blocks provide 3 to 4.5 N/mm2 of compressive strength.
Performance parameters: AAC blocks offer better performance
Light weight – AAC blocks are generally three to four times lighter than traditional bricks, making them cost-effective at-scale and easier to transport to the project site. (Dry density of close to 550-650 Kg/meter cube)
Water penetration – Red clay bricks generally absorb a lot of water, thereby limiting their utilization. AAC blocks absorb 10% of water max. by weight, making them ideal for any construction project.
Fire resistance – AAC blocks can offer fire resistance of up to 7 hours (8” wall), based on their core thickness. On the other hand, red clay bricks can provide close to 2 hours of fire resistance.
Sound insulation – AAC blocks offer sound insulation of about 42 dB, making them a superior choice over red clay bricks.
Thermal Insulation – AAC blocks offer excellent insulation to projects, which directly result in heating, ventilation, and air conditioning (HVAC) cost savings of close to 25-30%.
Earthquake resistance – AAC blocks are specifically manufactured to resist seismic activity, making them ideal for a wider range of projects across all regions.
Pest-resistance – AAC blocks are designed with inorganic materials and are highly resistant to termites and other common pests. This helps in lowering long-term maintenance costs for projects.
Storage – AAC blocks are readily available across seasons, and do not require special storage on-site. For red clay bricks, the monsoon season poses a significant challenge requiring special storage and handling.
Versatility – AAC blocks are lightweight and easy to use, which expands their utilization across any construction project. Red clay bricks, on the other hand, are bulky and not as effective at-scale. As AAC blocks are thinner, the available carpet area for the development increases.
Durability: Red clay bricks are not as durable as AAC blocks
AAC blocks are designed to be more durable and offer greater resistance to fire, seismic activities, moisture, termites, pests, etc. An AAC concrete block is also more uniform by design (generally 1.5 mm (+/-) variation), which strengthens the entire project significantly. Red clay bricks are more brittle than AAC blocks (roughly 10-12% breakage), which can lead to wastage on-site as well as faults within the overall construction. By using AAC blocks, developers can enhance the lifespan of the project and ensure that there is limited requirement for constant maintenance or repair work.
Workability: AAC blocks are easier to work with
The lightweight high-strength AAC blocks offer superior workability across all projects, and they require significantly lesser labour force on-site. This directly impacts labour costs per project, enabling greater cost savings at-scale. They also require lesser joints, resulting in a significant savings of mortar material while simultaneously boosting construction speeds. Additionally, for high-rise construction projects the overall dead weight of the development is lesser, which leads to greater savings in concrete and steel quantities used.
Sustainability: Red clay bricks are not as eco-friendly as AAC blocks
A single sq. ft. of clay brick walling (by carpet area) can consume close to 25kg of topsoil, which negatively impacts the environment long-term. On the other hand, AAC blocks are manufactured from fly ash, which is a thermal power plant waste product that is non-toxic in nature. Their manufacturing processes also ensure that any waste from the cutting process is recycled back into the raw materials for reuse. There are also no pollutants released when AAC blocks are manufactured.
Red clay bricks may be ideal for small scale projects that do not provide superior compressive strength or better handling & workability. However, for high-rise, industrial, commercial and infrastructure projects, AAC blocks offer greater performance benefits and better quality. An AAC blocks price in Delhi will also be consistent to that in Mumbai, Bangalore, as well as in Tier II/III cities, making them ideal for scale-driven adoption across multi-site projects.
Buyers can access a wide range of AAC block suppliers at BuildSupply and find the best AAC blocks price in the market. Developers can easily review product details, payment terms, and key benefits via the platform, and take advantage of the nation-wide support provided for all orders placed on the platform.