On July 31, 2015, Beijing successfully won the 24th winter Olympic Games 2022. Following, Beijing 2022 Olympics programs' construction attracted many attentions. Being article 3 in Asia, and the domestic first snowmobiles sled track with the function of Olympic events, Beijing yanqing division of the national center for snowmobiles sled track has the most difficult design and the most difficult and complicated construction among them.
The construction materials used for such a racetrack with so many “the most” are also extremely demanding. According to the research, the concrete reinforced with industrial hemp fibre was used to build the downhill course. Designed and manufactured by Greenfield Technologies, a Canadian manufacturer, the material helps prevent cracks in freshly poured concrete when it dries, while meeting other high standards such as increasing track strength and impact resistance.
More impressively, the construction of the National Bobsled Center positively echoes the design ideas of green ecology. A large amount of air trapped in industrial hemp concrete and the material itself make the track good thermal insulation performance, and the combination of refrigeration unit achieving long-term low-temperature refrigeration effect and reducing energy consumption. The project combines high technology and practicality with environmental protection and sustainable development.
Industrial hemp can be used for building?
As we all know, concrete is the most widely used engineering material in engineering construction. We usually use concrete construction with low tensile strength, small limit elongation, brittle and a series of shortcomings, resulting in the building easy to crack and so on. Therefore, adding fibers with high tensile strength, high ultimate elongation and good alkali resistance to concrete can overcome these shortcomings, and this has became a composite technology developed rapidly in recent years.
Common composite materials include asbestos cement, steel fibre concrete, polypropylene fibre concrete and so on. The new building material we are talking today is Hempcrete, which is described as "the material of the future full of possibilities".
What's your impression about hemp?
Although industrial hemp and hemp are the same species, they belong to different types and have different characteristics. Industrial hemp, which is mostly used for seeds, fibers and stems, contains only about 0.3 percent THC, is harmless to humans.
The industrial hemp variety chosen as a building material is the same variety commonly as hemp rope, clothing and textiles, which are increasingly used in construction because of its lightness and insulation, at a cost similar to that of traditional materials.
What is industrial Hempcrete?
Hempcrete (industrial hemp concrete) was first discovered in 6th century France. It is a composite material made from the wooden parts of the interior of an industrial hemp plant that combine with water and lime.
The industrial hemp plant "Woody" contains large amounts of silica inside, which is unique to the industrial hemp plant compared to other natural fibers. This silica keeps everything tightly together to create industrial hemp concrete (Hempcrete).
Lime's unique chemical and physical properties make it an ideal material for combining with hemp. It maintains a high permeability throughout the lime curing process, allowing steam to pass through the composite, thus drying the flax completely. This, coupled with the alkaline nature of lime, acts as a natural fungicide, ensuring that the hemp fibers are protected from mold and bacteria.
Application
Hempcrete is a lightweight cement-like material, one-eighth the weight of concrete, but ten times as strong, so it is quite strong. This kind of hemp concrete are very ideal in thermal performance, structure and moisture treatment performance, that can be described as a high quality building insulation material. Most importantly, according to the amount of mixed material, the concrete can be widely used for roof, wall or slab insulation.
Industrial hemp is very easy to maintain and does not require pesticides, fungicides or fertilizers. Most of the factories used to make industrial hemp concrete are surplus materials from other cannabis-using industries.
At here, have you ever wondered why hempcrete can quickly hit the construction market as internet star?
Choosing industrial hemp fiber as building concrete has many potential benefits. Compared to other natural fibers, the overall cost of finished industrial hemp construction products is lower, effectively increasing the profitability of the entire value chain. Its good fiber toughness, high strength, higher strength support, increased the durability of the building. At the same time, the unique fire resistance of industrial hemp makes it a building material of choice in arid areas.
Zero carbon emission
Industrial hemp plants absorb large amounts of carbon dioxide from the atmosphere as they grow. In addition, both the processes of production and use of industrial hemp concrete are very low-impact, even taking into account the transport and energy consumption of industrial hemp structures, which exceed all of them in terms of the amount of carbon they absorb over their lifetime.
Sound and heat insulation, energy conservation
The sound and heat insulation degree of 200mm deep limestone walls are more above the prescribed standards. Hempcrete has good thermal performance. Regardless of the weather, buildings made of hemp remain the same in temperature. Because of its excellent insulation and air tightness, the building has little heat or cooling loss. As a result, the hemp concrete house is very comfortable. It’s warm in winter and cool in summer, greatly reducing energy consumption.
Moisture absorption, ventilate
Hempcrete is super breathable and can regulate humidity. The reason is when humidity is high, hemp concrete and plaster absorb moisture from the air into the walls. They are then released into the air when humidity drops. This stops mold from growing and keeps humidity that stops bacteria from growing, and no ventilation system required to achieve this effect.
Good seismic performance, not easy to crack
Unlike ordinary concrete, the mechanical flexibility of Hempcrete allows it to move without cracking. This flexibility makes it earthquake-resistant, no gaps between Hempcrete structures, even in the event of strong vibrations or the house being moved. The way the lime works can also heal itself if cracks occur. Any moisture entering will reactivate the lime around the crack, filling the void and re-sealing the material.
Non-toxic materials
Grows without pesticides or fungicides, industrial hemp is much less damaging to the environment. Conventional construction was made with a lot of synthetic and potentially toxic materials. These can cause dampness, mildew and release toxic chemicals. Once placed on a wall, industrial hemp concrete does not release toxins or gases into the interior space. The lime binder mixture is also anti-fungal and prevents bacterial growth.
Fireproofing
Industrial hemp concrete blocks have a slight coking when burned, but they are more fire-resistant than ordinary homes. Up to the size and thickness of the blocks, they can stay off fire for up to two hours.
