Arbolite concrete blocks or wood concrete is a unique building material that combines the characteristics of both stone and wood. Arbolit has high thermal insulation qualities and is not a combustible material, it is not subject to drying and rotting. Arbolit refers to lightweight concrete on mineral binder with organic aggregates from wood processing waste and agricultural production, and additives. The mixture includes standard and quickly hardening Portland cement, gypsum and gypsum-cement-puzzolanic binder. Crushed wood is added as an organic aggregate; it is obtained by grinding up waste from the processing of various types of wood. These wastes are initially chopped up on a special device, then crushed with a crusher. Shredded material has a particular grain composition. Various impurities in it should be in an amount not exceeding 5 percent. When preparing the concrete mixture, mineralizers – calcium chloride or liquid sodium glass – are added to the composition, they eliminate the effects of harmful water-soluble substances of wood, and make the concrete hardening process faster.
Arbolite in construction
Production of arbolite slabs in their modern form refers to the 2nd half of the last century. Soviet scientists together with foreign scientists, have developed the optimal composition of concrete and prepared a powerful material basis for its manufacture. Arbolite blocks are mainly used for the construction of buildings with a small number of floors of different purposes. Construction is based on the use of wall blocks of permanent formwork standard type. When building blocks are stacked on top of each other without using a binder in the horizontal joints. Not so often arbolite boards are used to replace polystyrene and mineral wool permanent formwork. Arbolite walls regulate humidity and are very similar to wooden walls in their characteristics. Arbolite blocks have a structure with a coarse porosity. This creates a perfect exchange of air indoors. Arbolite walls can also be monolithic, using removable and sliding formwork.
Technological process of making arbolite blocks
In order to get the durable blocks of the correct shape the following dimensions are required: length 3 – 15 cm and width 0.5 – 2 cm. The first step will require the necessary volume of wood shavings, the technology of obtaining sawdust is different. The next step is to season the wood shavings outdoors to clean them from sugar, which negatively affects the composition, seasoning is carried out about one to two months, at the same time requires periodic turning of sawdust to penetrate air into the lower layers. After that, it is required to pass the workpieces through a coarse sieve to remove from their composition residual soil and other organic impurities. The next step will be soaking the sawdust with water and adding liquid glass to the composition, the resulting mixture should be mixed in a special device, which mixes concrete, with a mechanically rotating drum. However, please note that when the mixture is bored, the proportions are determined by the strength to have arbolite blocks, usually used the proportion – 1:2:6 (one bag of cement requires two bags of sand and six bags of sawdust). Then comes the process of mixing the mixture in a special rotating drum, which mixes the concrete. Then, once the mortar is obtained, the final step is to make a special form, which will have arbolite blocks. The form is made with the help of a special template, which has a rectangular shape.
Advantages of arbolite blocks
- Arbolite slabs – environmentally safe building material. Arbolite is not dangerous for people and the environment.
- Arbolite blocks are resistant to rotting. They have good air permeability. Arbolite slabs are very easy to absorb moisture from the air.
- They have low thermal conductivity.
- Arbolite blocks are one of the warmest building materials.
- Arbolite slabs have good sound insulation.
- According to the subgroup of combustibility, Arbolit is classified as slow-burning, by inflammability – slow-burning, by smoke formation – low smoke-forming.
- Arbolite blocks do not crack.
- When limit loads appear, the slabs of arbolite do not break, but deform reversibly.
- They have a low specific weight.
- Uncomplicated in processing. It is possible to hammer nails and screw into arbolite. It can be easily drilled, chopped and sawed.
Disadvantages of Arbolite blocks
No matter how perfect arbolite, it still has disadvantages. The abundance of “homemade” quality blocks in the market. Their received characteristics are unknown and the manufacturer itself. To make high-quality products in artisanal conditions is simply unreal.
- Disadvantages in the accuracy of geometry.
- The need for protection from the direct action of humidity.
- Expensive price of arbolite blocks.
- Limitations in the selection of materials for finishing.
Another disadvantage that should be considered – for proper operation it is necessary to combine with arbolite masonry only “breathable” methods of finishing.
Typically, the dimensions of the block of arbolite for fixed formwork – 400 x 200×200 millimeters with 2 through holes 120 x 120 millimeters, which are symmetrically located relative to the center of the block. When using the modern generation of hollow arbolite blocks as permanent formwork, it is possible to construct buildings with a higher number of stories. Such formwork is similar in its characteristics to, for example, polystyrene concrete formwork.