Hemp Lime Concrete (HLC)A carbon-negative construction material
Didier Lesueur – Materials R&D ManagerGRD meeting – Limelette – April 6th 2011
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Outline
• Hemp Lime Concrete
• Regulation and Application
• Practical Examples
• Conclusions
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Outline
• Hemp Lime Concrete
• Regulation and Application
• Practical Examples
• Conclusions
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What is Hemp Lime Concrete?
Hemp Lime Concrete
Additives& Admixtures
Water
HempShiv
Aggregate
HydratedLime
Hydraulic Binder
Dry Mix
Binder
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Why lime?
• Hemp shiv has a huge water demand
• Lime imparts good water retention
• Hence a balanced competition for water• Otherwise,
flouring risk with purely hydraulic binders
source: Y. Hustache, Synthèse des Connaissances sur les mortiers et bétons de chanvre, Lhoist/CenC, 2008
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Roof Wall Screed Render
110 220 280 600kg binder / m³
Different types of Hemp Lime Concrete
With different binder concentration:
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Hemp Lime ConcreteRelative Properties
• Low Compressive Strength Need load bearing structure
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
HLC
AAC
Clay Bricks
SLB
Concrete
Compressive strength (MPa)
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Hemp Lime ConcreteRelative Properties
• Good thermal insulation performance¬ 2-3 times thicker HLC layer than traditional insulation¬ 10 times better than traditional cement concrete
0.1-0.2 AAC
0.04 Exp. PolyStyrene / Mineral Wool
1 Concrete
0 Perfect insulation
0.026 Air
λ thermal conductivity
(W/m/K)
0.3-0.5 Clay brick
0.07-0.11: HLC
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Hemp Lime ConcreteRelative Properties
• Thermal dampening better than expected from static thermal conductivity
0
5
10
15
20
3 7 11 15 19 23 27 31 35 39 43 47
Outside temperature
Hemp Lime Concrete
Aerated concrete
Wood + insulation
Inside wall temperature vs outside daily 0-20°C temperature cycle
Hours
Insulatedbrick
0
5
10
15
20
3 7 11 15 19 23 27 31 35 39 43 47
Outside temperature
Hemp Lime Concrete
Aerated concrete
Wood + insulation
Inside wall temperature vs outside daily 0-20°C temperature cycle
Hours
Insulatedbrick
source: A. Evrard, Ph. D. Thesis, UCL, 2008
U = 0.44 W/m2/K
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Hemp Lime ConcreteRelative Properties
• Unique hygrothermal behaviour
• Allows humidity regulation and good thermal dampening¬ Shiv / binder porosity
stores and releases humidity
¬ Water sorption / evaporation improves thermal dampening (Phase Change Material)
• Yields superior comfort perception
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Tradical® Hemcrete® (2007) Cavity Wall (1970’s)
Hemp Lime ConcreteThermal Performance
Thermographic Images
source: I. Mawditt, Living Space Sciences, 2008
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Hemp Lime ConcreteRelative Characteristics
• Negative carbon-footprint
-0,4-0,2
00,20,40,60,8
11,21,41,6
kg eq CO2 /m²/year
clay brick (monomur)
Aerated Concrete
Concrete + insulation
HLC
source: M.-P. Boutin et al., INRA, 2005
over 100 years
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Outline
• Hemp Lime Concrete
• Regulation and Application
• Practical Examples
• Conclusions
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Hemp Lime ConcreteRegulation
• France¬ Règles
professionnelles
• UK• BBA / LABC approved
• Wallonia• Entering the list of
accepted insulation materials
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Placed between shutters...
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... or sprayed
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Shutters can be removed after 24 hours
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Final render applied after ~ a month
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Outline
• Hemp Lime Concrete
• Regulation and Application
• Practical Examples
• Conclusions
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Industrial
Renovation
Hemp Lime ConcreteUsed in all construction categories
New
Multiple housing
Commercial
Single housing
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• Maison Diocésaine Odette Prévost (2004)¬ Chalons-en-Champagne (F)¬ Architect: Atelier Méandre ¬ Observ’ER Award 2006 ¬ « Insulation » of the stones walls
with an hemp plaster (5 to 7 cm)
Renovation work
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New industrial building
• Adnams Distribution Center (2006)¬ Southwold (UK)¬ Architect:
Aukett Fitzroy Robinson
¬ David Alsop Sustainability Award 2007
¬ No air cooling system (400 000 £ saved)
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New industrial building
• Wine Society (2009)¬ Stevenage (UK)¬ Architect: Vincent &
Gorbing¬ 400,000 kWh of gas +
electricity saved each year (compared to project)
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New industrial building
• Marks & Spencer (due 2011)¬ Cheshire Oaks (UK)¬ Architect: Aukett Fitzroy
Robinson ¬ M&S biggest store outside
London (14 000 m2)
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New private or social housing
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Outline
• Hemp Lime Concrete
• Regulation and Application
• Practical Examples
• Conclusions
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Hemp Lime ConcreteConclusion and Perspectives
• Carbon-negative construction material¬ Wall, floor and roof insulation¬ Phase Change Material with dynamic thermal properties
better than predicted from static thermal conductivity
• Growing number of projects• 20 years of experience in France (> 10 000 references)• 5 years of experience in the UK (> 250 references)• Emerging in Belgium• Project size is increasing (UK first, now France)
• Technical challenges ahead• How to take into account the PCM effect in buildings
thermal design?• Reach industrial application rates (faster drying...)