HEMP CONCRETE OR “HEMPCRETE”
Hemp concrete is composed of hemp hurd (the woody core of the industrial hemp) selected for construction and a mixture of lime and additions such as clays or pozzolans. The product is manufactured on site of construction using a mixer. Subsequently it is shaped into formwork in order to be cured naturally outdoors.
Using a horizontal drum mixer, the mixing process is faster and more effective allowing for greater cost savings.
Natura Matéria has a mixer capable of producing more than 250 L per mixture.
Field of Application
Low density hemp concrete is thermal and acoustic insulator, fire resistant, and guarantees the comfort and amortization of indoor and outdoor noise. It can be used in new construction or rehabilitation. Due to its light characteristics allows to lighten the loads on the foundations, very beneficial in rehabilitations.
For the construction process hemp concrete requires an integrated structure of wood, steel or reinforced concrete.
Depending on the building element the dosages of the constituents may be different. Typically, the densities of dry mixtures per element are as follows:
Walls – medium density (250-350 kg/m3);
Roofs – low density (150-250 kg/m3);
Floors – medium and high density (350 – 700 kg/m3).
Hemp concrete with a dry density of about 320 kg/m3 has a compressive strength of more than 150 KPa and a thermal conductivity of about 0.07 W/m.ºC.
For the durability of hemp concrete constructions this product requires a knowledge of the raw materials and their properties, the ideal amount of water, curing conditions and times, type of support substructure, protections, etc.