Cement-bonded particle boards TAMAK in wooden house building
L. M. Kovalchuk, Doctor of Technical Sciences, TsNIISK named after Kucherenko; V. P. Likhodiyevsky, Production Director; A. V. Kofanov, Deputy Director for Technical Operations of TAMAK CJSC
As wooden house construction is developing, different design and technology solutions are being used. One of the effective trends is application of cement-bonded particle boards (CBPB).
|CBPB can be one of the most important elements of light and durable structures in many building industry branches. High density (1100-1400 kg/m3), hardness (45-65 MPa), water resistance (water absorption of not more than 16%), fire resistance (G1 class) allow CBPB to be used for making walls, floors, and ceilings in any kind of rooms including bathrooms.|
The plates are suitable for construction and reconstruction of public, industrial, and farm buildings, residential houses, additional storeys, hospitals, shops, garages, kiosks, fuel and repair stations. These advantages distinguish CBPB from other plate materials.
The density of cement-bonded particle boards is quite high, the ultimate bending strength being not more than 9-12 MPa according to GOST 26816-86 “Cement-bonded particle boards”.
High durability of cement-bonded particle boards is provided by their four-layer structure: the two exterior layers contain small-sized wood chips providing hardness, durability, moisture resistance and creating smooth surface while the interior ones are made of longer chip fractions increasing the bending strength of the plates.
CBPB is an ecologically sound material emitting no harmful substances since it is produced from low-toxicity materials, and therefore, this parameter does not create any restrictions for using the boards in any kind of construction. CBPB does not contain any phenol and formaldehyde substances and other poisonous staff as it is produced without glues. The main binding agent is cement. The mixture becomes hard and durable thanks to pressing, the natural process of hardening, and drying under plant conditions.
The plates are highly biostable. Even being exposed to moisture for a long time the material does not show any signs of biological damage. TAMAK delivered and constructed houses with CBPB trimming of walls and floor slabs to regions with high humidity, such as Krasnodar Krai (boarding houses Don-2, Dolphin), India, and Iran. CBPB resistance to insect damage including termites is also worth mentioning.
Iran. Photos of TAMAK’s panel timber frame house with CBPB trimming during construction and after finishing
Frost resistance is one of the most important advantages of CBPB widening the geography of its usage. For example, bending strength reduction after 50 cycles must not exceed 10% according to GOST 8747-88 “Asbestos cement plate products. Testing methods”. The actual rate is even lower.
Long-lasting experience of application of CBPB structures in construction of different purpose buildings in Yakutiya, Khanty-Mansiysk proved high performance properties of this material. This turned out to be especially important for construction and maintenance of fast-erected panel timber frame houses during a long period of time.
Fire resistance of cement-bonded particle boards is quite high (G1 class according to GOST 30244-94 “Building materials. Combustibility testing methods”). For example, panel timber frame houses with CBPB trimming (one layer) are referred to fire resistance class IV. If an additional layer of gypsum plasterboard (12 mm) is used in constructions and special design measures are taken, then building fire resistance class III is achieved with REI 60 fire endurance which allows building panel timber frame houses up to three storeys. These design solutions have been tested in the laboratory of building structure fire protection of TsNIISK named after Kucherenko and approved of by a positive expert report of FGU VNIIPO MCHS of Russia.
Cement-bonded particle boards used for trimming are referred to the group of materials which are difficult to ignite and do not spread fire. Thanks to its properties, cement-bonded particle boards are widely used in fire partitions. According to SNiP 21-01-97  CBPB is referred to G1 combustibility category with low ability of smoke formation. Exposed to fire in buildings, cement-bonded particle boards do not emit toxic gases and vapour.
One more property should be mentioned, and that is the possibility to use structures with CBPB trimming for constructing houses in districts of high seismic hazard and for multi-storey buildings. After the earthquake in Spitak (Armenia) in December 1988 TsNIISK named after Kucherenko worked a lot studying the experience of panel timber frame house construction in districts of high seismic hazard. In January 1989 several residential houses for builders were constructed. The following 8.0 magnitude earthquakes in February 1989 showed that the buildings managed to go through this natural test successfully: even the wall paper in the corners of the houses was not torn.
The approach to light panel house construction in regions of high seismic hazard was changed by order of the Government. TsNIISK named after Kucherenko worked out the structure of the strengthened load-bearing timber frame panel and methods of its joint with the foundation. The concept of the structure has been used up to now.
During construction of apartment buildings in Sochi, such structures went through successful unofficial expertise and the one carried out by TsNIISK named after Kucherenko.
The boards are most widely used in panel timber frame trimming in low-rise construction (picture 4). Thanks to their durability the boards render additional rigidity to the wooden frame and offer protection from atmospheric actions.
Load-bearing and enclosing house structures with CBPB trimming do not require additional treatment thanks to their smooth surface.
Therefore, for external finishing of the house the walls just need to be painted.
Usage of CBPB TAMAK in building, assembly, and finishing works is actually cost-effective. That can be explained by the fact, that the boards are not expensive and, at the same time, do not require much effort for assembly and finishing.
|8, 10, 12, and 16 mm boards are used in construction of moisture resistant partitions. This is explained by their physical-mechanical properties.|
Ecologically sound boards TAMAK create smooth surfaces of walls and partitions. TAMAK’s boards are used for internal wall trimming in residential, public, and industrial buildings with dry, normal or moist conditions. Cement-bonded particle boards can be used in bathroom partitions in different purpose buildings. In this case the boards need to be precoated and painted with treatments suitable for service in high humidity conditions.
Cement-bonded particle boards having thickness of 12, 16, 20, 24 and 36 mm can be used as the following flooring elements: base for different coverage, underlayer, leveling plate, finished floor with surface coverage.
Cement-bonded particle boards having thickness of 12, 16, and 24mm can be used as elements of retained formwork for building foundations of low-rise buildings.
Simple structure of the formwork helps to make foundation works less effort-taking and much more cost-effective.
Moreover, CBPB can be used for building internal “sandwich” partitions filled in with mineral plates, polystyrene foam, and so on; ventilation channels, garden paths.
The company makes window sill boards with thickness of 24 and 36 mm according to GOST 8242-88 “Wood and wooden material details for construction” which have the following advantages: geometric size stability, absence of joints and seams, and reasonable price. CBPB window sills are suitable for any modern interior design.
CBPB building structures are widely used in different regions of the Russian Federation for providing affordable accommodation for citizens of Russia, and are successfully supplied to Western Europe and other countries of the world.