Steel bars are used in construction to create the skeletons of buildings, providing strength to concrete. However, they have corrosion problems and are a major source of CO2 emissions. We present the material that could replace them: hemp.
Hemp: the vegetable that can replace steel
Rensselaer Polytechnic Institute, a private university located in Troy, New York, USA, has developed a methodology that replaces reinforcing steel bars in cement construction, to give rigidity and resistance that this material alone lacks.
This replacement would be for bars whose main component is the vegetable known as hemp. According to this research, the bars would prolong the life of the buildings, since they would not be affected by corrosion due to moisture filtration, in addition to being sustainable and ecological.
The process that transforms hemp into bars stronger than steel
These bars are composed of a combination of a bioplastic resin, fused when heated at high temperature, with fibers that come from the hemp stem. This, using a method called “decortication technology.”
In which the plant fibers are separated from their woody inner core without harming the mechanical resistance properties of the material. It is based on a degumming procedure that is sustainable, ecological, environmentally friendly and free of CO2 gas emissions.
So it is a combination of several innovative ways of processing the biocompounds of this plant. To create these special reinforcing bars, a CNC machine available in the university’s construction materials laboratories was used.
One of the properties that makes this vegetable an ideal material for producing structural reinforcing bars is its growth speed. A hemp tree grows twice as fast as a tree of other species and does not need special conditions.
In addition, its carbon absorption is also double, which makes it possible to have quality and sufficiently mature raw material in a very short time. However, the variety of plant needed must be taken into account, since what is known as “industrial hemp” is used.
A drawback for production is that there is no supply chain. reliable supply of industrial hempa variety of this vegetable that has unique properties of resistance and strength, making it very suitable for the manufacture of these reinforcing elements.
The benefits and costs of rebar made from hemp
One of the main construction disadvantages of steel is the corrosion that occurs within the structure due to water infiltration. The worst thing is that this damage is invisible and weakens the element made of concrete or cement, requiring special studies to detect it.
Another way to estimate the damage is by taking into account factors such as climate and average humidity in the environment. Likewise, steel is responsible for a large percentage of greenhouse gas emissions due to its production and use.
On the other hand, reinforcing bars made with this vegetable are as strong or stronger than steel and do not suffer from corrosion, so the useful life of houses and buildings would be prolonged. In addition, their cost is very low and the process to produce them is very ecological and sustainable.
As you have seen, structural reinforcements made of hemp are as robust as those made of steel, but without their disadvantages and are environmentally friendly. So it is not unreasonable to assume that the next houses will be built without this mineral.
