cseb blocks
TRANSCRIPT
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Construction Industry Construction Industry and its Impact to Built and its Impact to Built
EnvironmentEnvironment
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Construction Industry account for one-sixth of the world's fresh water withdrawals, one-quarter of its wood harvest.
The cement sector alone accounts for 5 % of global man made CO2 emissions
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Construction & Demolition (C&D) generate between 10% and 40% of the solid waste stream in most countries (Kibert et al, 2000). C&D wastes can generally be used for low-priority works like footpaths, drains, pavements etc.
Most bonding & drying agents in carpets, veneers, particle board, plywood and paint emit volatile organic compounds (VOC’s) which contribute to greenhouse gases and global warming.
Pollution and Waste
Environmental
impacts
Resource
depletion Physical
disruption Chemical
pollution Other effects; Social
disruption,
undesirable
visual impact.
Social impacts
Loss of open space & biodiversity Social Isolation Increased car dependency Decreased air quality Unhealthy indoor environment
Economic impacts
To Builders: Increased compliance costs & waste disposal costs
To Owners: Increased utility & maintenance costs
To Occupiers: Loss of well being & productivity
To Society: Decreased environmental quality
• According to the World Watch Institute about 40% of the world's total energy usage is dedicated to the construction and operation of buildings.
• The building industry consumes 3 billion tons of raw materials annually, 40% of the total material flow in the global economy.
• Only about 0.003 % of earth's water is readily available as fresh water for human use (Miller, 1992). Building materials manufacturing, construction and operations consumes 16% of available fresh water annually
• In 1990 the building industry consumed 31% of Global energy and emitted 1900 Megaton's of Carbon.
Towards an innovative & eco-friendly
Construction Industry
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‘Continued ability of a society, an ecosystem, or any such interactive system to function without exhausting key resources and without adversely
affecting the Environment’
Principles:
1.Maximizing the use of renewable and natural resources;
2.Minimizing the use of energy and water;
GREEN BuildingGREEN Building
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Green building materials offer specific benefits to the building owner and building occupants:
Reduced maintenance/replacement costs over the life of the building;
Energy conservation and reduce harmful emissions;
Improved occupant health and productivity;
Lower costs associated with changing space configurations;
Do not exhaust the existing supplies of finite materials;
Green Buildings MaterialsGreen Buildings Materials
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Underlining Principle:
Assuming that all stages in the life of a material right from extraction, manufacture, transportation to the installation, operation, maintenance and the recycling and waste management cause some degree of Environmental impact which needs to be evaluated.- This is called Life Cycle Analysis (LCA) for any material/product.
Choosing Building MaterialsChoosing Building Materials
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1. CEMENT CONCRETE
Energy Intensive industry Depletion of natural resources Green house gas emissions
Characteristics of Sustainable Characteristics of Sustainable Managed AlternativesManaged Alternatives
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Recommended Alternatives:
1.Blast furnace Slag Concrete
Using Ground Granulated Blast Furnace slag with Cement (from steel plants) in mixes
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Recommended Alternatives:
2.Using Recycled Aggregates
Crushed Concrete, Bricks and other masonry waste
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3. Mortars and Plasters:
Basic Mortar used: 1 : 6 (Cement : Sand)
1.Cement : Lime : Sand (1 : 1 : 6)
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2. Lime : rha : Sand (1 : 1 : 1)rha: Rice husk ash - hard protecting coverings of grains of rice (burnt)
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Our predecessors knew it better…….
We were much less resource dependent in the past
Looking back to think ahead……………..
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RAMMED EARTH AND MUD BLOCKS RAMMED EARTH AND MUD BLOCKS
CONSTRUCTION IN BHUTANCONSTRUCTION IN BHUTAN
Earthen Construction TechnologyA brief History
Tabo Monastery , HP – India , 996 AD Shey Monastery, Ladakh
17th Century
Ramasseum, EgyptAround 1300BCOur Very Own
Auroville-Earth Institute
Aman, Gangtey
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Innovative Building Technologies:
Hollow Interlocking-Compressed Stabilized Earth Block(HI-CSEB)
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Innovative Building Technologies:
Machine that produces HI-CSEB, developed by Auroville Earth Institute, Tamil Nadu, India
Aurum Press 3000
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HI-CSEB
Economical/affordable, environmentally friendly, easily available, stronger, energy saving and simple to
manufacture
Better Thermal Insulation
Warm in winter and cool in summer
Technical /Engineering Aspects
Block ProductionMaterial selection
Soil Identification – Top soil and soil with organic matter should not be used. Grain size distribution - more of sandy is preferred.
Gravel (mm) Sand(mm) Silt(mm) Clay(mm)
20 to 2mm 2 – 0.02 0.02 – 0.002 0.002 - 0
Some basic test for identifying the suitability of soil
Proportions
• Cement : Soil (1 : 6)• Water content = 25 liters for one bag of
cement• Varying the ratio esp. the cement has the
proportionate cost involved • The ratio can go up to 1 cement to 10 soil
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Same basic data on CSEB
Properties Values
Dry Compressive Strength @28days3 – 6Mpa (N/sqmm) ( +10% after 1 year,
20% after 2years)
Wet compressive strength @28days (3days immersion)
2 – 3 Mpa
Dry bending Strength @28days 0.5 – 1 Mps
Dry Shear Strength @28days 0.4 – 0.6Mpa
Density 1700 to 2000kg/cum
Water absorption @ 28days after 3 days immersion 8 to 12 % by weight
Energy Consumption 110MJ ( Kiln fired bricks = 539MJ)
Comparison with other building blocksProperties CSEB (HI - 245) Ordinary class III
brickConcrete hollow
blocks
Size 245x 245 x 95 195 x 95 x 75 390 x 190 x 190
Weight 8kg 3kg 16kg
Compressive strength (28days)
30 – 60kg/cmsq 35kg/cmsq 45kg/cmsq(approx)
Cost (Nu.) 13 per block ( 1:6 mix ratio)
11 per brick @ Thimphu
38.00 per block @ Thimphu
For a 250mm thick 1msq wall in a load bearing building @ Thimphu
Block Numbers Cost(Nu)
HI - CSEB 40(Approx) 520
Ordinary second class brick 166(approx) 1496.00
Hollow concrete Block 19.5(approx) 741
Block production machinesTwo Machines in the market
1)HI – CSEB Block machine – Habitech centre, Thailand
2) AURUM PRESS 3000 – Auroville,India Designer/ manufacturer Auroville Earth institute/ Aureka,
Cost of Press Rs 69,800.00
Cost of Mould ( 1 set) Rs 41,500.00
Max Blocks size 245 x 245 x 95
Compression force 150KN( 15 tones)
Production capacity per day with 7 workers
500 Blocks (average)
Designer/ manufacturer Habitat centre , Bangkok
Cost of Press 73,500.00 (Nu) 2008 rate
Cost of Mould ( 1 set) -
Max Blocks size 300 x 150 x 95
Production capacity per day ( 6- 7 workers)
500 average
Pilot House Construction – SQCA using HI – CSEB 245
• Two storied load bearing structures - serve as model for the earthquake resistant design features
• Sample Blocks test results
Soil sample source Average Compressive Strength Proposed construction site (1:8 mix
ratio
22 kg/cmsq
Buddha Dodema site ( 1: 8) 33 kg/cmsq
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SQCA – Pilot Project
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Hollow Interlocking –Compressed Stabilized Earth Block (HI-CSEB)
Pilot house using HI-CSEB
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Some other buildings using HI-CSEB
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Advantages
1. Use of cheap & locally available materials2. Job opportunity for local people3. Biodegradable materials4. Energy efficiency and eco friendliness 5 – 15 times
less energy consumed than fired brick and around 3 – 8 times less emission
5. Transferable technology6. Import Reduction
Advantages
7. Cost effectiveness8. Minimum mortar required9. Keys that interlock with each other provides better
integrity10. Hollow provisions for laying vertical and horizontal
reinforcements to improve the lateral load resisting capacity
11. Ease and Fastness in construction12. Fire resistant
Limitations• Only for low rise structures: maximum 2 storey
• Strength very much dependant on the properties of soil
• Too much stabilization(cement) will make no economic sense
• Interlocking features do not provide air tightness. Minimum gap is formed due to which termite/air current can pass.
Limitations
• Requires minimum mortar between the blocks to maintain horizontal construction level
• Too much mortar between the blocks jeopardizes the interlocking feature
• For frame structures, HI-CSEB can be used as filler materials but the structural members sizes increases due to increase in the block weight
HI-CSEB in Bhutan
• No of private individuals who procured the machine-2
• Commercial basis- Established in Jemina by 2 firms
Way forward
1. Conference on GREEN Construction – Awareness and exchange of knowledge;
2. Sensitization w/shops & trainings in Green building practices;
3. Standards and regulations;
R & D required
Formulation of standards and guidelines
Conclusion• Sustainable /economical/eco friendly building
material • Easy and simple technology• Creates employment opportunities • Reduce dependency on import of bricks• Making housing affordable
Therefore, production and construction with HCSEB is relevant and it is to be adopted where ever possible.
Thank youand
Tashi Delek
www. sqca.gov.bt