Foam concrete as material for constructionprovides good thermal insulation properties for residential buildings and structures of economic value. The presence of many small air chambers isolated from each other makes the walls of this material light. Such rooms have good sound insulation and high fire safety. In order for the mixture of sand and cement to acquire such properties, it is necessary to add a frother for foam concrete to it.
The solution is obtained by air, the amount of the mixture increases without weight gain. The proportion of air can fall to 80% of its total volume.
The main components are:Portland cement М400 or М500, sand, water and frother for foam concrete. In some cases, the addition of expanded clay is possible as a lightweight aggregate. A concrete mix can have a different density depending on the ratio of components (cement / sand: 1 / 1-1 / 3), it can be from 600 to 1600 kg / m³. For lighter foam concrete sand is not used.
Water is used drinking, and sand without strangersimpurities. To obtain a material of a given density, the water-cement ratio of the solution must be at least 0.38. Reducing this value will cause the cement for the reaction to take some of the water out of the foam.
From frother quality and complianceThe technology of its application depends on the number of air bubbles. This affects the density and strength of the finished material. Properly prepared white foam is easily held in a bucket if it is turned upside down.
To be sure of the quality of the aerated concrete,attention should be paid to the uniform distribution of the cement in the mixture. To achieve this, it is best to mix it with dry sand to a uniform color and only then dilute with water.
Recently, besides the classical scheme,when foam is added to the ready-mixed concrete solution and mixed at low speed, porous and barotechnology are used. Their difference lies in the way air is drawn into the process of the formation of the finished mixture.
Porization - the use of high-speed mixersmall volume. Foaming agent for foam concrete is added in the process of mixing. Air is drawn into the mixture due to the forces of turbulence. Barotechnology - the use of a sealed chamber and pressure during short-term mixing of components. You can add a foaming agent to the water or already ready foam in the required amount.
Builders back in the XIX century to create a cellularthe structures of the concrete were mixed into the solution with bovine blood. At the beginning of the 20th century, they began to use the soap root for these purposes. Now you can buy ready-made foam for foam concrete. Its price will depend on the manufacturer, the country of the manufacturer and the type of active ingredient. Domestic concentrate can be bought from 70 ("Neoplast-5") to 100 rubles per kilogram ("PB-Lux"). Foreign protein compounds will cost an average of 1.5 times more expensive. For example, GreenFroth in packaging of 230 kg (a metal barrel) costs 125 rubles, and the cost of a canister (10 liters) will be 185 rubles per kilogram.
Such formulations are usually made ready for use.using marketable products. According to the recipe, they need only be diluted with water. Next, the solution is fed into the foam generator, where it passes through a special filler. Under the action of the air flow supplied under pressure, a stable foam is formed, consisting of a large number of small bubbles.
Other option of use of frother -This is the addition of concentrate directly to water when mixed at high speeds. Under the influence of turbulence, foam is formed. Then cement and sand are added to this mixture with constant mixing. The quality of this foam concrete is slightly lower than that prepared according to the classical scheme.
In the technological scheme use organic andsynthetic components. Protein or protein foaming agents are made by hydrolysis from raw materials of animal origin based on blood. Also used for these purposes vegetable woody resin after saponification.
Natural frother for foam concreteIt is considered the most appropriate option in the manufacture of material used in the construction of residential buildings. This is primarily environmental and sanitary standards. The other side of the issue is the “neutrality” of the reaction of the finished product.
Синтетические пенообразователи более дешевые.The disadvantage of their use is the inability to produce low density foam concrete (less than 300 kg / m³). In addition, the strength of the finished wall blocks is inferior to analogues made on the basis of protein foam.
Ready concentrate for the manufacture of cellularConcrete is usually sold in bulk. It is not always possible to purchase it in the required quantity. For private construction, it is possible to prepare a frother for foam concrete at home. To do this, you need pine rosin, carpentry bone glue, caustic soda (caustic soda).
Kleekanifolny concentrate allowsreceive up to 500 liters of foam from 1 kg. The porosity of the material is uniform. Foam weight is about 90 g / l. With the observance of technology, the bubbles are small - from 0.1 to 0.4 mm. The concentrate is prepared in about 2 hours. It can be stored for 2-4 weeks. Working temperature ranges from 5 to 30 ° C.
Работа проводится в два этапа.At first the basis is prepared - rosin soap. For foam concentrate to prepare 1 m³ of cellular concrete, you will need: caustic soda (caustic soda) - 0.016 kg, and gum rosin - 0.06 kg. Then in the composition to increase the viscosity and durability injected joiner bone glue - 0.063 kg.
Soda is diluted with water to a solution density of 1.2kg / dm³. This mixture is boiled and rosin (no more than 5 mm) of rosin is gradually added there. For 1 liter of soda solution you will need 1.5 kg of rosin. On a boiling water bath, the mixture is kept for 1.5 to 2 hours, stirring constantly until complete dissolution of the components.
Joiner's glue (tiled) is prepared in advance.It is pre-crushed and filled with water for a day (1:10). Heating the composition to 60 ° C, by stirring to achieve complete dissolution of the particles. After the components are ready, the cooled soap solution is poured into the glue in small portions and mixed. The ratio of glue and “soap” solutions is 6: 1.
