Foamed concrete or lightweight concrete as a material with a significantly lower density than conventional concrete can have an effective role in reducing the weight of buildings, especially in structural parts. .
Concrete with foam base with animal protein base is called concrete foam. In addition to the benefits of ordinary concrete, this type of concrete has the same properties as low specific gravity and high compressive strength. The lightness of this concrete in building structures reduces the dead load of the building, saving the excavation volume and the concrete used in the foundations, as well as reducing Earthquake loads. In order to increase the efficiency of this product in various projects, the amount of mixing and additives required will be adjusted according to the experience and standards of the countries of Germany, England and America, and will be made for final production and testing of resistance. For the production of this concrete, gravel, cement, air sand, concrete foam mortar (animal protein type) and authorized additives are used.  For optimal use of this product, first, the specific gravity and compressive strength of the intended use for the project are defined. Based on this, concrete is produced by mixing and adding additives according to previous instructions and experiences that are formulated by international standards of Germany, England and the United States during production.
1. Main applications
The most important applications of lightweight concrete include roof and wall blocks, as well as concrete floors and slopes.
Concrete is used as one of the most widely used building materials in a wide range of structural and non-structural applications in buildings. Lightweight concrete as a material with a significantly lower density than conventional concrete can have an effective role in reducing the weight of buildings, especially in structural parts. The main and most recent light concrete applications in Iran today are the ceiling and wall blocks, as well as concrete floors and slopes.
2. Make the ingredients
In the production of these concrete, mainly from industrial pigments and industrial materials or low-density minerals are used as stones or light fillers. In addition to concrete with light aggregates, some factories produce concrete blocks and concrete panels based on aerated concrete. The advantages of this type of concrete, in addition to lightness, high thermal insulation and the possibility of cutting with a saw, allows the nail and screw to nail and apply.
This type of concrete is divided into two types depending on the air bubble generation method:
In the production of gaseous concrete, a soft powder of aluminum is added to the mixture under special conditions to produce bubbles of hydrogen in the concrete through a chemical reaction with calcium hydroxide. The release of these bubbles causes the expansion of the mixture.
But in the production of inferior concrete, in contrast to gas concrete, air bubbles are produced by the use of a foaming agent and added to the concrete mix. The technology of inferior concrete production is simpler than the production of concrete concrete production, and it is possible to construct this type of concrete in construction workshops. The base materials used in the manufacture of insulating concrete are cement, water and foam from a foaming material. For the production of floor, usually a substance called foam is used. This material is first diluted with water and then turned into an oven in which the bubbles with a diameter of about a millimeter or less were produced by means of pressure from the air compressor or by rapid stirring. To create a stable insoles in the internal structure of the fossil material or independently, a foam stabilizing agent is used to produce stable bubbles. The purpose of the stabilization of bubbles is that the bubbles, by displacing and mixing, retain their shape and thus do not slip over the floor. Usually the resulting foam is creamy.
Foam materials can be classified structurally in two classes, including materials based on animal protein or propylene foam, and chemical foam or chemical foam.
Usually the foam of the protein-based material is volumetric, less stable and more stable than the foam from chemicals (chemicals with a specific gravity of about 40 grams per liter, with a froth of less than 2 hours, and increasing the volume of the floor It is about 25 times the size of the initial volume, while in the foam material the proteins with a density and stability of the floor are twice as large and the volume of the foam is about half that of the chemicals. The experience shows that chemicals for the manufacture of high density concrete 1000 are suitable, while protein materials can be used in the manufacture of concrete in a density of 500 to 1600 kg / m 3. The main.
It should be noted that (the stability of the floor should be such that, after the process of mixing the floor with the cement mortar and until the initial application of the mixture, maintains the floor of its stability, otherwise, the structure by placing and distributing the bubbles in Inside the mixture is broken down and the weight is increased due to the loss of part of the bubble before it cement first.
4. Water to cement
Usually the amount of water needed for concrete depends on the moisture content of the sand, but in general and averages per 100 kilograms of cement in the mixture of about 40 to 45 kilograms of water, but in the foam concrete, the amount of water used to make foam is water ratio Increasing the cement content up to 0.6% in total.
Density weights of 300 to 600 kg / m 3, made from cement and floor, is used as thermal insulation, especially in floors and roofs.
5. The production of foam concrete
To produce foam concrete, first, the cement and water are mixed with the desired amount for the desired density together in the mixer, then the foam material