Hempcrete –Feasibility as an alternative

to current masonry applications focusing on

structural adequacy with an investigation into a

strenghtening additive

What is Hempcrete?

In a traditional sense, Hempcrete or Hemp concrete is a term used to describe a hemo-lime bio-composite construction material

It is created by mixing water through a blend of Shiv (woody stem of the hemp plant) Lime based binder

The subsequent reaction creates a mouldable material that is traditionally used to form Walls Floor slabs Ceilings Roof insuation

Methods of hempcrete application

IN FILL CAST

Methods of hempcrete application

SPRAY ON

Methods of hempcrete application

PRECAST BLOCKS

Mechanical Properties - Strength

Traditionally very low compressive strength Largely put down to the high flexibility of the aggregates and the

arrangement of the particles On average achieves a compressive strength of 2 MPa Studies have shown that the compressive strength can be increased

through the form of an additive or increasing the density through extensive compaction

Have been known to achieve approximately 6 MPa through this method

Mechanical Properties - Weight

Exact weight will depend on individual mixture and method of application

Approximatley weighs a seventh of the weight of concrete A fully cured hempcrete block can float in a bucket of water

Mechanical Properties – Weight & Durability Exact weight will depend on individual mixture and method of

application Approximatley weighs a seventh of the weight of concrete A fully cured hempcrete block can float in a bucket of water

Evidence of hemp-lime composite are evident in French homes dating back to the 1980’s

No reports of the material deteriorating Studies have shown it can withstand exposure to salt, freeze-thaw

and biodeterioation

Mechanical Properties – Thermal performance Excellent insulator, U-value of approximately 0.15

W/m2K for a 300 mm wall

Contains a high amount of thermal mass, allowing buildings internal temperature to fluctuate less and allow occupants to be more comfortable

Hygroscopic material that absorbs moisture during high humidty periods and releases it when the humidity falls

Mechanical Properties – Thermal performance Excellent insulator, U-value of approximately 0.15

W/m2K for a 300 mm wall

Contains a high amount of thermal mass, allowing buildings internal temperature to fluctuate less and allow occupants to be more comfortable

Hygroscopic material that absorbs moisture during high humidity periods and releases it when the humidity falls

Highly breathable material

Other benefits

Sustainable and Eco friendly - Each tonne of lime-based Hempcrete is estimated to absorb and sequester 249 kg of CO2 over a 100 year lifecycle

Termite Resistant Fire Resistant Acoustically sound Recyclable Easy and non hazardous to work with