One of the highest quality and durable thermal insulation materials is considered to be foam glass. Due to its truly unique characteristics, this material has found its application not only in individual construction, but even in the construction of industrial facilities. However, for all its merits, the insulator is not as popular as other heat insulators, and there are reasons for this. In addition to the mass of positive properties and characteristics, foam glass also has significant drawbacks. Let's see what shortcomings of foam glass prevent it from becoming the first among heat-insulating materials.
The problem is that the production of this material uses cheap raw materials, such as broken glass fragments or sintered rocks, but the manufacturing technology itself is quite expensive. In order to obtain granulated foam glass, a temperature of the order of 800-900 degrees and heat-resistant steel molds are required.
- The manufacturing process consists first of heating and softening the glass powder obtained from the raw material.
- Then it is foamed by incinerationgasifier - usually hard coal.
- After the material is slowly cooled, resulting in foam glass.
The production of insulation is a rather complicated and long process, due to which the cost of seemingly cheap raw materials increases significantly.
Foam glass products
The end result of production are blocks with a cellular structure and granular foam glass. Due to the use of special shapes, block products have a higher cost than the same amount of material in the form of granules.
Subsequently, the blocks are cut into slabs, which are used as thermal insulation on complex objects. For example, on roofs with a large area or structures of complex geometric shapes, as well as for thermal insulation of underground structures. It is convenient to use foam glass plates as thermal insulation for swimming pools, bathtubs and other buildings that operate in difficult temperature conditions, and all thanks to the special resistance of the material to water vapor.
Granulated foam glass is used, as a rule, as bulk free thermal insulation on roofs or backfill under the screed. The second use of this material is as a filler for various mortars to obtain light screeds, plasters or foundation blocks.
Both products have the composition and characteristics of ordinary glass, so the advantages and disadvantages of foam glass are based on the propertiesthis material.
Strength properties of foam glass
This insulation is one of the most durable of all types of thermal insulation. However, we are only talking about compressive strength, which is important for heat-insulating materials, since it is this load that the insulator, as a rule, is subjected to. The special value of this parameter is due to the fact that with strong compression, the insulation may lose some of its properties: its moisture resistance is violated, and the insulator begins to conduct heat.
Unlike styrofoam and fibrous materials, which are designed for only small internal forces, which significantly limits their use in some situations, foam glass is completely incompressible, which allows it to take on part of the load.
Foam glass does not deform under the influence of gravity, which eliminates its sagging, shrinking or shrinkage. Due to this, the insulation does not require mandatory fastening to metal anchors or pins, which can create cold bridges. The material can be easily bonded to hot bitumen, polymer or concrete mastics and specialized adhesives.
But not all strength characteristics of insulation are so ideal. The disadvantages of foam glass are based primarily on the properties of the original raw material, which has a low resistance to mechanical impact. Therefore, the blocks are quite easy to break or damage. Moreover, even small surface defects can lead to a decrease in moisture resistance andincrease in thermal conductivity.
Explosive life of foam glass
The service life of the insulation is at least 100 years, which significantly exceeds the service life of most buildings without major repairs, where it can be used.
Foam glass was created back in the 30s of the last century, so today we can talk about the resistance to aging of this material. Experts conducted experimental studies that showed that foam glass blocks did not lose their properties over a period of 50 years and remained practically unchanged.
However, this advantage is irrelevant in private construction, as low-rise buildings need to be reconstructed no later than 50 years later. Therefore, it is more expedient to use less durable, but cheaper heat-insulating materials than to use foam glass, the price of which is quite high (16,000 rubles/m3).
In this case, we are talking about various kinds of influences of both chemical and biological nature. Thermal insulation materials made of foam glass are not destroyed by chemicals, the only exception is hydrofluoric acid. But this can hardly be considered a disadvantage, since this reagent can only be found in chemical production.
Since foam glass consists only of higher oxides of various elements, it is not affected by the oxygen contained in the surrounding air, and hence, by oxidation.
Thanks to the same featurethe heater is not subject to combustion. When exposed to high temperatures, it melts like ordinary glass, while not releasing, unlike most thermal insulation materials, harmful gases and substances.
There is another factor that affects the fire safety of the material - this is the lack of absorbency. Foam glass fully possesses this property and is not an absorbent material.
Thanks to this characteristic, it does not affect the insulation and water, no matter whether it is fresh or s alty, since there are no soluble components in the composition, and the foam glass structure is a closed cell into which moisture is simply not able to get. Due to these qualities, the material does not collapse under the influence of low temperatures. Therefore, insulation is often used as a waterproofing material.
In addition, foam glass, whose characteristics are identical to those of ordinary glass, has a low coefficient of thermal expansion, which means that it can easily withstand seasonal temperature changes, regardless of the region of application. Another positive property of the material is high-quality sound insulation, and all thanks to the dense structure of foam glass.
FOAMGLAS foam glass
However, the non-hygroscopicity and density of the material also causes some disadvantages of foam glass, in particular, its rather large weight in comparison with other heat insulators. This significantly complicates the transportation of insulation, due to whichsignificantly increases the selling price of the material. Yes, and installation becomes a rather problematic event.
However, modern production allows us to correct this shortcoming. For example, Pittsburg Corning Corporation produces foam glass FOAMGLAS, which is characterized by extraordinary lightness, while retaining all the properties inherent in this material.
Therefore, today foam glass is mainly mounted on building mixtures, which simplifies the fastening of the insulation. In addition, good adhesion of the material is also due to the good adhesion of foam glass.
First of all, we note that foam glass is absolutely resistant to decay, mold and fungi, since it simply does not contain a favorable environment for their reproduction. This factor is especially important in construction, when heat-insulating materials are often used in confined spaces. This property of foam glass makes it possible to avoid destruction of both the heat insulator and the surface it protects, be it a roof, a wall, or a foundation.
It is also important that the foam glass cannot be damaged by plant roots. And also it is absolutely inaccessible to penetration of insects and rodents, thanks to abrasive properties. This feature of the material has found its application in the arrangement of granaries, warehouses and food refrigeration, when foam glass insulation is also an ideal protection against various biological forms.
What other advantages anddisadvantages of foam glass?
In addition to the main characteristics listed above, the material has several other distinctive properties.
Foam glass is very easy to process and give it the desired shape using conventional cutting tools. This allows this insulator to be used for buildings of any geometric shape. But the industrial production of blocks is a rather complicated process, leading to a significant increase in the cost of the material.
Insulation-foam glass is an absolutely environmentally friendly material that does not have any harmful effects on human he alth. And more recently, it was produced according to technology, where hydrogen sulfide was used as a gas generator. Its smell was transferred to the finished material, so the use of insulation in private construction was rather limited due to the unpleasant smell of "rotten eggs".
Due to its environmental friendliness, foam glass is becoming one of the most popular thermal insulation materials today, moreover, after use, the insulation can be recycled into a new product.