Aerated concrete is classified as lightweight concrete produced from cement or lime, silica sand and sometimes Pozzolanic material.
Aerated concrete means concrete having an excessive amounts of air voids and they are designed to reduce the density of concrete and provide good thermal insulation.
It can be used for structural or non-structural purpose, air pores in aerated concrete are usually 0.1 to 1 mm in diameter.
Types of aerated concrete:
Based on the method of pore-formation it is classiﬁed into two types as follows:
Gas concrete is a mixture of water and cement, very good aggregate with the final addition of a pore-forming chemical that produces air-voids within the aqueous mixture at atmospheric pressure.
It makes expansion to a certain extent depending on the amount of gas produced inside the structure.
Aluminum powder gas is the most commonly used operating agent in concrete production.
It is a mortar combine by which air voids formed by adding a foaming agent that performs the function of making pores within the concrete without chemically reacting with the cement.
Detergents, resin soap, gum resins and siphoning are some foaming agents.
It is an extremely workable, low-density materials that may comprise up to 50% of entrained air.
Advantages of Aerated concrete:
- This concrete is made from a mixture of cement, fine sand and preformed foam having a lower density such as 400 – 1600 kg / m3.
- It is usually self-levelling, self-compacting and it can be pumped.
- They are cost-saving, faster completion and easier application compared to steel and wood.
- It has low density leads to a more economical design.
- It is non-combustible, fire resistance.
- Also has low construction costs and simple in construction work.
Disadvantages of Aerated concrete:
- During construction, care must be required so that the final surface of aerated concrete is not very smooth.
- As a result of excessive water absorption, finishes required to prevent environmental effects (weathering) on aerated concrete.
- Efflorescence harm occurs by excessive absorption and retention of water.
- Their strength decreases when wet and long-term exposure to moisture will cause the dissolution of the material.
Application of Aerated concrete:
- It can be used in almost every part of a building including wall panels and ceilings of the superstructure or substructure.
- Any standard panel or masonry units used for load and non-load bearing walls using regular concrete could be directly changed by concrete panels and units.
- It is vitally low-density concrete can be used as thermal, sound insulation panels, filtering media and floating blocks for phishing functions.
- Foamed concrete is good for filling redundant like displaced fuel tanks, sewer systems, pipelines and bridges.
- It may be used for house foundation and fireplace safety using its excessive thermal insulation functionality to the geotechnical, highway, bridge abutment and backfill.
- Foamed concrete will also be used for architectural functions, pottery, void filling, foundation raising and pouring elements for swimming pools.
- In highway development, foamed concrete could be applied as a soil fill for a sub-base, bridge abutment and bridge embankment.
- It is an acknowledged medium for substitute of temporary road trenches.
In Aerated concrete, air bubbles are introduced in such a way that air bubbles on drying act as open space for the expansion of concrete due to the increase in the surrounding air temperature.