embodied energy in building materials

1. Embodied Energy in Buildings
Prof. B. V. Venkatarama Reddy
Department of Civil Engineering
Indian Institute of Science
Bangalore – 560 012

2. Need for
examining energy in buildings?

3. Indian construction Industry
• Employment generation
• Volume of materials produced
• Annual expenditure

4. Type of Material Period
Mud, stones, wood/thatch Prior 8000 BC
Sun dried bricks 6000 BC
Pottery products 4000 – 8000 BC
Burnt Bricks 4000 BC
Lime 3000 BC
Glass 1300 BC
Iron products 1350 BC
Lime-pozzolana cement 300 BC – 476 AD
Aluminium 1808 AD
Portland Cement 1824 AD
Plastics 1862
Historical developments in building materials

5. Common building materials
Burnt clay Bricks
Stones, Concrete
blocks
Cement, Steel,
Concrete
Aluminum, Zinc, SS
Glass
Tiles (ceramic/burnt)
Plastics/PVC
Paints, Timber

6. Common building materials
Burnt clay Bricks
Stones, Concrete
blocks
Cement, Steel,
Concrete
Aluminum, Zinc, SS
Glass
Tiles (ceramic/burnt)
Plastics/PVC
Paints, Timber
Mud
Unburnt bricks,
Lime
Wood/bamboo/re
eds
Country tiles
Stone boulders
Thatch

7. Materials consumed in bulk quantities
Type of material Current annual
consumption
Annual
Consumption
by 2020
Burnt clay bricks 170 X 109 Nos. 260 X 109 Nos.
Cement 110 X 106 t 260 X 106 t
Structural Steel 12 X 106 t 25 X 106 t
Coarse aggregates 300 X 106 m3 750 X 106 m3
Sand 300 X 106 m3 750 X 106 m3

8. 0
20
40
60
80
100
120
140
160
180
200
1975 1980 1985 1990 1995 2000 2005
Year
In
Millions
Housing Shortage
Housing stock
No. of households
Housing demand and existing housing stock

9. Annual cement capacity and production in India

10. Energy consumed in manufacture of
building materials
--------------------------------------------------
Current annual Consumption by
Consumption 2020
--------------------------------------------------------------------
2500 X 106 GJ 5000 X 106 GJ
or
~ 150 X 106 t of coal equivalent

11. Currently Building industry contributes:
---- 22% of CO2 emissions

12. Ex. Material resource consumption
Brick making: Fertile soil is used
Arable land: 1.62 X 106 sq. km.
Top soil consumption for bricks
1000 sq.km. (300mm depth)/year
@2.5% compound growth
Brick making can consume 300mm top
soil in ~75 years

13. Environment/resources conservation / protection
---- GHG emission reduction
---- Energy conservation
---- conservation of resources
How to achieve this?

14. 1) Use energy efficient alternatives
2) Adopt energy efficient processes in manufacture
3) Switchover to renewable energy sources
4) Reduce transportation
5) Recycling of solid wastes into building products
6) Maximum use of local resources & skills

15. Energy in buildings
Energy for maintenance
/servicing
Capital Energy
(Embodied energy)
• Material production
• Transportation
• Assembling into a
building

16. Low energy building materials
& technologies

17. Soil-cement blocks / Stabilised Mud Blocks
Definition/Concept/process
Mixture of
1) soil or and fines,
2) sand,
3) stabiliser (cement/lime) and
4) water
compacted into a high density block & cured

18. SMB production

19. Blocks of different shapes & sizes

21. 3 storeyed load bearing

25. SMB vaults

26. Intersecting vaults

27. SMB Filler slab roof

28. Ferrocement channel roof

29. Composite beam and panel roof

30. Composite jack-arch panel roof

31. Energy in basic building materials
Type of material Energy
(MJ per kg)
Cement
Lime
Lime-pozzolana
Steel
Aluminum
Glass
Mangalore tile
4.5
5.63
2.33
42.0
236.8
25.8
6 - 15 per tile

32. Energy in masonry materials
Type of unit Size (mm) Energy in 1 block
or brick (MJ)
Energy per brick
equiv. (MJ)
Size stone 180 X 180 x 180 0 0
Burnt clay
brick
230 X 105 X 70 4.25 4.25 (100%)
Soil-cement
block
230 X 190 X 100
230 X 190 X 100
2.60 (6% C)
3.50 (8% C)
1.00 (23.5%)
1.35 (31.7%)
Hollow
concrete block
400 X 200 X 200
400 X 200 X 200
12.30 (7% C)
15.00 (10% C)
1.32 (31.2%)
1.62 (38.1%)
Steam cured
block
230 X 190 x 100 6.70 (10% L) 2.58 (60.6%)

33. Energy in Transportation
Energy in (MJ)
Transportation
Production
50km 100km
175
175
200
100
100
87.5
87.5
100
50
1. Sand m3 0.0
2. Crushed aggregate m3 20.5
3. Burnt clay brick m3 2550
4. Cement tonne 5850
5. Steel tonne 42,000 50
Type of Material Unit

34. Energy in masonry unit
Energy in masonry
Energy in mortar

35. Energy in mortars
Proportion (by vol.)
Mortar type
Cement Soil Sand
0 6
8
6
6
3
0
0
2
0
Energy per
m3 (MJ)
Cement mortar 1 1405
Cement mortar 1 1091
Cement-pozz. mortar 0.8:0.2 941
Cement-soil mortar 1 865
LP mortar 1 (1:2) 756

36. Energy in masonry
Type of masonry Energy per m3 (MJ)
1. Burnt brick masonry 2141 (100%)
819 (38.3%)
(7% C blocks)
2. Hollow concrete
block masonry
971 (45.4%)
(10% C blocks)
646 (30.2%)
(6% C blocks)
3. Soil-cement block
masonry
810 (37.8%)
(8% C blocks)

37. Burnt bricks: Clay is destroyed
Soil-cement block:
Clay intact, aggregation of silt
& sand particles

38. Energy in different roofing systems
(span: 3.6m)
Type of roof
Energy/m2
of roof
(plan) (MJ)
Equiv.
energy of
R. C. roof
1. Composite beam-panel roof 500 0.59
2. R.C. ribbed slab roof 556 0.66
3. Brick masonry vault roof 601 0.71
4. Soil-cement block masonry vault 469 0.55
5. Ferrocement panel roof 111 0.13
6. SMB filler slab roof 686 0.81
7. Mangalore tile roof 221 0.26
8. R. C. roof 847 1.00

39. Total embodied energy in a building
Type of building No. of
storeyes &
built-up area
Embodied
energy per
100m2 (GJ)
Equivalent
amount of
coal (tonnes)
R. C. frame with
brick in-filled
walls
8
5120 m2 421 21
Load bearing
brickwork, R.C.
slab, Mosaic floor
2
149.5 m2 292 15
Soil-cement block
masonry, filler
slab, terracotta
tile floor
2
160.5 m2 161 8

40. Recycling of solid wastes

41. Type of solid wastes
• Fly ash (105 mil. tons/annum)
• Coal mine wastes (50 mil. tons/annum)
• Lime stone waste (18 mil. tons/annum)
• Blast furnace slag (11 mil. tons/annum)
• Iron ore tailings (10.5 mil. tons/annum)
• Copper mine tailings (4 mil. tons/annum)
• Marble dust (6 mil. tons/annum)
• Red mud, lime sludge, phospho-gypsum, zinc
tailings, kiln dust, gold mine tailings etc
Source: Morchhale, et al J. of Rural Tech. 2 (2) 2005

42. Examples
of
solid waste products

43. Gold mine tailings
from
Kolar Gold Fields

44. 130 year old mine dump

45. Top of the mine dump

46. Stabilized compacted
blocks from
KGF mine tailings

47. Some facts about KGF mine tailings
• 130 year old mine (now abandoned)
• 32 X 106 tons of tailings in 13 dumps
• Fortunately no serious environmental
problems
• Tailings can be converted bricks or blocks
• Can meet Bangalore’s demand for bricks for
another 50 years