1
Construction Industry
and its Impact to Built
Environment
2
Construction Industry account for one-sixth
of the world's fresh water withdrawals, onequarter of its wood harvest.
The cement sector alone accounts for 5 % of
global man made CO2 emissions
3
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
4
Environmental
impacts





Resource depletion
Physical disruption
Chemical pollution
Other effects;
Social disruption,
undesirable visual
impact.
Social impacts
Economic impacts
 Loss of open space &
biodiversity
 Social Isolation
 Increased car
dependency
 Decreased air quality
 Unhealthy indoor
environment




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
7
GREEN Building
‘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;
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Green Buildings Materials
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;
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Choosing Building Materials
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.
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Characteristics of Sustainable
Managed Alternatives
1. CEMENT CONCRETE



Energy Intensive industry
Depletion of natural resources
Green house gas emissions
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Recommended Alternatives:
1. Blast furnace Slag Concrete
Using Ground Granulated Blast Furnace slag with
Cement (from steel plants) in mixes
12
Recommended Alternatives:
2. Using Recycled Aggregates
Crushed Concrete, Bricks and other masonry waste
13
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)
15
Looking back to think ahead……………..
Our predecessors knew it
better…….
We were much less resource dependent in the past
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RAMMED EARTH AND MUD BLOCKS
CONSTRUCTION IN BHUTAN
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Earthen Construction Technology
A brief History
Tabo Monastery , HP –
India , 996 AD
Our Very Own
Auroville-Earth Institute
Shey Monastery, Ladakh
17th Century
Aman, Gangtey
Ramasseum, Egypt
Around 1300BC
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
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Technical /Engineering Aspects
Block Production
Material 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
Granularity
(Grain size distribution test)
-Compressibility
(Ease of the soil to be
compressed)
Humus
(presence of organic materials0
Plasticity ( Capacity to withstand
deformation)
Cohesion(Property of the soil
grains to remain together)
• 15%gravel, 50%sand, 15% silt, 20%clay
• Compress a moist soil by hand
• Difficult to compress – gravely soil
• Very easy to compress – Clayey soil
• Smells Rotten – lot of humus
• Musty – humus
• Agreeable smell – no humus - suitable for construction
• Difficult to break – clayey soil
• Breaks easily – gravely soil
• Wash the hand on which the soil paste was made
• Soils grains does not stick on the palm – Gravely soil
• Thin film of soil stick on the palm – clayey 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
Dry Compressive Strength @28days
Wet compressive strength @28days (3days
immersion)
Dry bending Strength @28days
Dry Shear Strength @28days
Values
3 – 6Mpa (N/sqmm) ( +10% after 1 year,
20% after 2years)
2 – 3 Mpa
0.5 – 1 Mps
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 blocks
Properties
CSEB (HI - 245)
Ordinary class III
brick
Concrete 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 machines
Two Machines in the market
1) HI – CSEB Block machine – Habitech centre, Thailand
Designer/ manufacturer
Cost of Press
Habitat centre , Bangkok
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
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)
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
SQCA – Pilot Project
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Hollow Interlocking –Compressed
Stabilized Earth Block (HI-CSEB)
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Pilot house using HI-CSEB
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Some other buildings using HI-CSEB
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Advantages
1.
2.
3.
4.
Use of cheap & locally available materials
Job opportunity for local people
Biodegradable materials
Energy efficiency and eco friendliness 5 – 15 times
less energy consumed than fired brick and around 3
– 8 times less emission
5. Transferable technology
6. Import Reduction
Advantages
7. Cost effectiveness
8. Minimum mortar required
9. Keys that interlock with each other provides better
integrity
10. Hollow provisions for laying vertical and horizontal
reinforcements to improve the lateral load resisting
capacity
11. Ease and Fastness in construction
12. 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 you
and
Tashi Delek
www. sqca.gov.bt