Cellular concrete is one of the most widely used materials in construction. This is due to its versatility, as it can be used in innumerable sectors.
Although it may be visually unattractive, it can be easily cladded with many materials.
In this article we are going to understand a little more about one of the members within the special concretes.
What is cellular concrete?
Cellular concrete is a white material used in construction. It’s obtained by a mixture of water, limestone, silica sand and cement, to which an expanding agent is incorporated in the final phase of mixing. This reacts with the mix, generating air bubbles inside the dough.
It was invented and patented by J.A. Ericsson in 1924. Ericsson was a Swedish architect who was looking for a material that would present the same construction benefits as wood (workability, strength and insulation) and eliminate its inconveniences (need for maintenance, brittleness and ignitability).
At the beginning of the 60s, as a consequence of the growth experienced within the construction sector, the need arose to obtain a product to use in ceilings and slabs that was lightweight and acted as a thermal insulator.
“In certain European countries such as Germany or Austria, cement mortar began to be manufactured by adding foams. This can be considered the beginning of cellular concrete.”
Since then, it has been improved and its use has become widespread internationally.
Now it is one of the most used materials in the world, especially in Europe. It’s used in the construction of thousands of houses.
Also known as foam concrete, it is made in the form of concrete blocks or panels.
Advantages of cellular concrete
Cellular concrete has great physical qualities that combine insulation and resistance. It has a multitude of benefits that have made it one of the best alternatives in construction materials.
These are some of the benefits it offers.
Its low density and lightness allow to increase installation speed. It is also easy to work with because it is not a complicated material to cut.
It varies depending on the density of the material. Obviously, its resistance will be higher the higher its density. You can even build multi-level collective housing with it.
Resistant to water absorption
This type of concrete has a structure that absorbs water much slower. It is as a humidity regulator, absorbing any excess humidity or softening dry air. This way, it creates a pleasant atmosphere at home.
As we mentioned before, it maintains a pleasant and cool indoor environment, both in winter and in summer.
Thus, during cold seasons, the interior will be kept warm, whilst in summer we will be able to keep a cool interior. This leads to significant savings in air conditioning and heating costs.
Cellular concrete weighs between 10% and 87% less than conventional concrete. This drastic weight reduction represents a significant saving when building foundations and structures.
Being a light material, weighing half of what similar materials weigh. This allows transportation tasks to be much easier, as well as working with it (cutting, nailing, sawing, etc.).
Cellular concrete that ages very well throughout time. It is as durable as a rock and does not decompose.
Only a very small part is absorbed by the concrete, most of it bounces back to the place of origin. The noise that actually reaches the interior is minimal.
It’s a very versatile material when it comes to shapes and forms. It can be easily manufactured into anything: arches, pyramids, angles, etc. Thus, it increases the aesthetic impact of a building.
Due to its low thermal conductivity, the heat flux of cellular concrete is very low. It’s an ideal material to be used in industrial, agricultural or administrative buildings.
It is essential in areas that have a high seismic risk. If an earthquake occurs, the fractured walls will fall, but these won’t cause as much damage as other traditional materials would.
When to use cellular concrete?
Cellular concrete is advisable to use in:
- 1. Cold climates: It is perfect for places that are exposed to low temperatures, where thermal materials are required to prevent heat from escaping the building.
- 2. Hot climates: It also prevents the entry of heat into a building.
- Temperate climates, or extremes such as winter or summers.
Elements that are manufactured with cellular concrete
These are some of the products that are manufactured with cellular concrete:
- Roof slabs
- Partition walls
- Building blocks
- Base slabs for paving
It is also widely used as a filler in between brick walls, as a thermal insulating material for roofs or floors, as an acoustic insulator or as a rigid floor such as tennis courts.
Types of cellular concrete
Bellow, are going to explain some of the different types of cellular concrete.
Pure cellular concrete
Portland cement, water, and prepared foam or gas are used. It has no solid aggregates. When manufactured, water and cement are mixed first and, later, a chemical agent or foam is incorporated, which has to be mixed correctly to achieve a cellular consistency.
Sanded cellular concrete
It contains cement, water, the chosen foaming aggregate and sand which has a maximum diameter of 4 mm.
Lightweight aggregate concrete
Composed by pumice stone, tezontle, etc., which replaces sand. These aggregates must be very resistant, to increase the resistance to compression.
Cellular concrete with expansive aggregates
The addition of these aggregates has been shown to help retain water when curing concrete in hot climates.
It’s also a protection element for metal structures against fire.
Cellular concrete with dispersant additives
The dispersing action of the additives help expose cement particles to hydration, improves resistance to compression and increases the fluidity as a consequence of the decrease in the cement /water ratio of the mixture.
Manufacturing cellular concrete
The most important phases when manufacturing cellular concrete are the following:
- Gathering, preparing, dosing and mixing of raw materials: water, cement, limes and sand. The appropriate proportions are: 500 g of aluminum oxide, 15 kg of plaster, 40 kg of lime and 90 kg of cement, for every 200 kg of sand.
- Preparing the molds.
- Cutting blocks or special geometries.
- Curing the concrete.
- Palletizing and packaging.
At least 90% of the reduced waste left over from manufacturing can be reused. Manufacturing cellular concrete requires little energy, and water can also be reused.
We could say that the uses of cellular concrete are limited by human imagination. It is such a versatile material that allows you to create all kinds of elements in any shape or size.
“It has so many benefits that manufacturing this material has become a new and very attractive alternative for any entrepreneurs within the construction sector.”
Research on using it to build housing is showing spectacular results. It does not burn, nor does it rot, and it resists termites.
This concrete has the peculiarity of breathing. That is, it lets through water vapour emitted by the household occupants or by daily tasks such as cooking. This is essential to avoid damage caused by condensation and moisture, such as mould.
It can be installed easily and quickly, due to the easy assembly of the manufactured pieces. Also, the weight and shape of its blocks facilitate highly effective work.
Everything previously explained in this article, motivates us to think that the opportunity has already been reached to demonstrate the benefits that this material can bring to the construction industry.
These are some of the sources we have used to the write this article: