Hempcrete

Hempcrete is a bio-composite, which is breathable, self-insulating and carbon negative material. It has high silica content which allows it to bind well with lime. This property is unique to hemp among all natural fibers. The result is a lightweight cementitious insulating material weighing about a seventh or an eighth of the weight of concrete.

Raw Materials

 

  • Hemp stalks
  • Hydrated Lime

Hemp stalks were broken down into small shiv  30-10 mm for larger aggregates and 5-1 mm for smaller aggregates.

Hemp stalks, fiber and the final product.

Shives were mixed throughly and soaked in water for for 2 hours

Lime was added to the mixture (1:1:0.5; Water :Lime : Hemp)

Mixture was transferred to the mold in thin layers and compacted well.

The first prototype didn't turned up good. Shiv weren't dried before adding lime, so water content went to high and layers were compacted using a flat tool, this resulted in thin solid masses which started sliding over each other.

For the next prototype mixture ratio was reworked to (1:1:3; Water :Lime : Hemp). Hemp was dried before adding lime. For compacting a slender tool was employed, so as to prevent forming of internal layers.

For further prototypes 10% cement will be added as stabilizing agent.