Part 1 of a presentation into the feasibility of Hempcrete as a masonry substitute.

1. Hempcrete –Feasibility as
an alternative to current
masonry applications focusing on
structural adequacy with an
investigation into a
strenghtening additive

2. 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

3. Methods of hempcrete application
IN FILL CAST

4. Methods of hempcrete application
SPRAY ON

5. Methods of hempcrete application
PRECAST BLOCKS

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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