AERATED CONCRETE-A SUSTAINABLE BUILDING

MATERIAL

What is Aerated Concrete?

Developed in Sweden in the 1920s in response to increasing demands on timber supplies, AC is a lightweight manufactured building stone.

Comprised of all natural raw materials, AC is used in a wide range of commercial, industrial, and residential applications.

AC products include blocks, wall panels, floor and roof panels, and lintels.

It is recommended by Indian Green Building Council (IGBC) as for material of choice for LEED certification and offers cost savings up to 40% due to huge savings in structural costs and increase in floor space area.

CLOSE–UP VIEW OF AC

Manufacturing Process

AC is a precast product manufactured by combining silica (either in the form of sand, or recycled fly ash), cement, lime, water, and an expansion agent - aluminium powder, and pouring it into a mould.

In structurally reinforced AC products like lintels or roof panels, steel rebar or mesh is also placed in the mould.

Once added to the concrete, the aluminium powder reacts with the silica, resulting in the formation of millions of microscopic hydrogen bubbles. The hydrogen bubbles cause the concrete to expand to roughly five times its original volume.

The hydrogen subsequently evaporates, leaving a highly closed-cell aerated concrete, then cut into which are further steam and pressure cured in an autoclave.

Properties of AC

Improved thermal efficiency reduces the heating and cooling load in buildings.

Porous structure allows for superior fire resistance. Workability allows ACurate cutting, which minimizes the

generation of solid waste during use. Resource efficiency gives it lower environmental impact in all

phases of its life cycle, from processing of raw materials to the disposal of waste.

Light weight saves cost & energy in transportation, labour expenses, and increases chances of survival during seismic activity.

Larger size blocks leads to faster masonry work. Quick Assembly:  Since it is a lightweight material and easy

to work with, the assembly is much quicker and smoother.

Properties of AC

Environmentally Friendly:  Helps to reduce at least 30% of environmental waste as opposed to going with traditional concrete. There is a decrease of 50% of greenhouse gas emissions.

Energy Saver:  It is an excellent property that makes it an excellent insulator and that means the interior environment is easier to maintain.

Great Acoustics:  Aerated concrete has excellent acoustic performance. It is able to be used as a very effective sound barrier.

Fire Resistant:  Just like with regular concrete, AC is fire resistant. This material is completely inorganic and not combustible.

Non-Toxic:  There are no toxic gases or other toxic substances in autoclaved aerated concrete. It does not attract rodents or other pests nor can it be damaged by such.

Properties of AC

Great Ventilation:  This material is very airy and allows for the diffusion of water. This will reduce the humidity within the building. AC will absorb moisture and release humidity; this helps to prevent condensation and other problems that are related to mildew.

Lightweight:  Concrete blocks that are made out of AC weigh about one-fifth of typical concrete. They are also produced in sizes that are easy to handle for quick construction.

Accuracy:  The panels and blocks made of autoclaved aerated concrete are produced to the exact sizes needed before they even leave the factory. There is less need for on-site trimming.

Long Lasting:  The life of this material is extended because if is not affected by harsh climates or extreme changes in weather conditions. It will not degrade under normal climate changes either.

Disadvantages

Scarcity of Manufacturing Plants.Projects far from manufacturing facilities will suffer from higher initial costs.

Familiarity with ProductFew contractors are a currently familiar with the product, and trained masons must adjust to using thin-set mortar as opposed to traditional cement-based mortar, which requires less precision in its application.

THANK YOUSubmitted by:-

Durga Prasad Gupta(2011barc013)

Vijayant Lakra(2011barc019)