Arbolite blocks
HempBuild Solutions co-founder Silviu Rachile told Logos Press. “Arbolite is a unique material that can be used both for the construction of external and internal walls of houses (using a frame made of wood, concrete or other materials) and for external and internal finishing of buildings,” the entrepreneur said.
Arbolite was invented by the Dutch in the 1930s. According to the technology, it is a lightweight concrete based on binding cement, organic aggregates (up to 80-90% of the volume) and chemical additives. It is also known as woodcrete.
The organic aggregate used is shredded wood (wood chips), flax or hemp bark (costrocrete), crushed rice straw or crushed cotton stalks.
For Moldova, the use of hemp was the most suitable option, as rice and cotton do not grow here and the wood processing industry is underdeveloped.
“We spent two and a half years researching the necessary proportions of the combination of hemp, clay and lime until we got a result we were satisfied with,” said Silviu Racilă.
As a demonstration sample, the company built a house in the village of Tudora, part of the La Tudora agro-pension complex (pictured), and is already using it as an example to explain the advantages of a new material for Moldova.
With a wall thickness of 40 cm, the heat loss is 0.05 W per square meter (watt/m2), which is much less than the maximum of 0.25 watt/m2 allowed by our SNIPs.
Arbolite provides excellent sound insulation. Well regulates the humidity in the room: when wet – draws water, when the air is dry – gives it away. By the way, these properties allow you to tighten cracks in the walls, if they appear.
The presence of industrial hemp in the composition does not allow the development of mold, and also repels mice, rats, other rodents and insects, which is very important for houses in rural areas.
“The material is very environmentally friendly,” continues Silviu Rachile. – It absorbs CO2 from the air and within 20-25 years it hardens and becomes like concrete. It is also non-combustible. We heated a 12.5 cm thick wall to 700-800 degrees on one side and 26 degrees on the other. The arbolite did not undergo any major changes.
Separately, the entrepreneur spoke about the benefits of growing industrial hemp.
It can be grown even on poorly fertile and contaminated land where other crops don’t take root. For example, on areas that have been heavily exposed to pesticides, on former landfill sites or on soils that have been depleted by intensive farming. Because of its ability to restore soil structure and enrich it with organic matter, hemp helps to restore the ecosystem and prepare the soil for other plants. It grows for only 120 days, allowing for up to two harvests per year. The plant is unpretentious to moisture, but with good irrigation it can reach a height of up to 4 meters, which significantly increases yields.
Hemp farmers are primarily interested in its seeds, leaves and fibers, which are used in the food, textile and cosmetics industries. However, the stalks, which are valuable raw materials for the production of environmentally friendly building materials, often go unclaimed. At best, they are sold to make pellets, and at worst, they are simply burned, resulting in the loss of a valuable bioresource.
On November 13, 2024, the Cabinet of Ministers of Moldova amended the Regulation on the regulation of the activity of cultivation of plants containing narcotic or psychotropic substances. The ban on the cultivation of industrial hemp (Cannabis sativa) was abolished and now agrarians can grow cannabis for seed and fiber production on the basis of a license to be issued by an authorized body.
HempBuild Solutions is going to develop in Moldova the production of arbolite as a promising and environmentally friendly building material. This technology was recognized and awarded at the Moldova Eco Energetică 2024 Gala by the Global Clean Technology Innovation Program in Moldova (GCIP Moldova).
