Hempcrete; Sustainable Choice for Development in the Mountains
The cement industry is one of the most polluting, accounting close to 5% of man-made CO2 emissions per year. Rocks, bricks and other material needs to be transported beside cement. This cause 7% of concrete’s CO2 with the trucks pumping CO2 at the rate of 0.147 kg per tonne –mile (Source: The Economist). Steel reinforced construction, which is the most popular worldwide, has also concerns with respect to durability and longevity. The unprotected steel corrodes while shielding only slows the inevitable decay. Timber is becoming scarcer, and costlier. The human aspiration has also deteriorated the natural dense quality of several hundred-year-old trees by cutting them down at a young age (leading to deforestation).
In the mountains, one has to pay a hefty price for transport of the material. Primary research in Kumaon, Uttarakhand suggests that one has to pay c. INR 4 lakh just for the transport of material to the site. The cement-brick or timber structures have failed time and again in eco-sensitive zones pertaining to weather conditions or calamities (forest fires, flood, etc.). The current choice of construction material isn’t sustainable, but perhaps is the only option. The Problem clearly is the lack of sustainable construction material alternative and ecologically deteriorating construction in the mountain terrain.
Hempcrete is a sustainable choice, and a proven construction material – shielding Ellora caves from decay for 1500 years now. It is imperative to suggest adopting local resource hemp as solution to develop social infrastructure in the mountains. It can be done on experimental basis with certain projects in the beginning. In the mountain country, Nepal, hemp structures are thriving. Several projects have been completed by Shah Hemp Inno-Ventures (SHIV) in Nepal, a Company with a vision to make Nepal and its people sustainable with optimal utilization of locally available resources.
Several benefits of hempcrete includes being 1) Fireproof, 2) Waterproof, 3) Carbon-capturing, and 4) Pest resistant. The processing of green material can be done using simple technology using decortication to extract fibre, then using mixer to bind hemp shives with lime binder. A mould can be used for particular shape of the hempcrete which can then be used along with a wood or bamboo frame to build structures.
Hempcrete can help farmers and processors in the value chain in Uttarakhand. The product can reap economic sustainability for local community with integration of them in the supply-chain. The social infrastructure development in the state would provide livelihood and welfare for the people of the state. Hempcrete is perhaps a sustainable choice for infrastructural development in the mountains!