The document discusses foam concrete as a sustainable building material that can reduce carbon dioxide emissions from cement production. Some key points: 1) Cement production accounts for 5% of global CO2 emissions, so more sustainable building materials are needed. 2) Foam concrete is a lightweight, insulating material made with cement, water, and a foaming agent. It requires less cement and energy to produce and transport. 3) A cost analysis found that while foam concrete blocks cost slightly more to produce than clay bricks, walls made with foam blocks are cheaper overall due to using fewer materials.

1. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
179
CONCRETE + GREEN = FOAM CONCRETE
K.Krishna Bhavani Siram1
, K.Arjun Raj2
1
(Asst.Professor, Civil Engg. Dept., Mahatma Gandhi Institute of Technology, Hyderabad, Andhra
Pradesh, India)
2
(4/4 B.Tech, Civil Engg. Dept., Mahatma Gandhi Institute of Technology, Hyderabad, Andhra
Pradesh, India)
ABSTRACT
A green building is an environmentally sustainable building, designed, constructed and
operated to minimise the total environmental impacts. The Green Building Index (GBI) is recognised
green rating tool for constructions to promote sustainability in the built environment and raise
awareness among various groups in construction industry and the Public about environmental issues
and our responsibility to the future generations. Carbon dioxide (CO2) is the primary greenhouse gas
emitted through human activities. It is claimed that 5% of the world’s carbon dioxide emission is
attributed to cement industry, which is the vital constituent of concrete. Due to the significant
contribution to the environmental pollution, there is a need for finding an optimal solution along with
satisfying the civil construction needs. Apart from normal concrete bricks, Foam concrete is a new
innovative technology for sustainable building and civil construction which fulfils the criteria of
being a Green Material. This paper concludes that Foam Concrete can be an effective sustainable
material for construction and also focuses on the cost effectiveness in using Foam Concrete as a
building material in comparison with Clay Brick.
Key words: Carbon dioxide emission, Cost effectiveness of Foam Concrete, Foam Concrete, Green
Building Index, Sustainable Construction
1. INTRODUCTION
There are both natural and human sources of carbon dioxide emissions. Natural sources
include decomposition, ocean release and respiration. Human sources come from activities like
cement production, deforestation as well as the burning of fossil fuels like coal, oil and natural gas.
Data from the World Resources Institute (WRI) show that humans have added 2.3 trillion tonnes of
CO2 to the atmosphere in the last 200 years. Half of this amount was added in the last 30 years alone.
CO2, the most heat-trapping gas in the atmosphere, is the important gas causing climate change on
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND
TECHNOLOGY (IJCIET)
ISSN 0976 – 6308 (Print)
ISSN 0976 – 6316(Online)
Volume 4, Issue 4, July-August (2013), pp. 179-184
© IAEME: www.iaeme.com/ijciet.asp
Journal Impact Factor (2013): 5.3277 (Calculated by GISI)
www.jifactor.com
IJCIET
© IAEME

2. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
180
the whole. Others include methane (CH4), nitrous dioxide (NO2), and several artificial gases
(Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs); and Sulphur hexafluoride (SF6). These 6
groups are accounted for under the Kyoto Protocol. Further increases in carbon dioxide are likely to
have a profound effect on climate, leading to higher seas and greater coastal flooding, more intense
weather disasters like droughts and heat waves, and an extreme acidification of the ocean. Scientists
fear this carbon dioxide emission could double or triple before emissions are brought under control.
The most commonly used material in the building and civil engineering construction today is
concrete. Ordinary concrete contains approximately 12% of cement. It has to be born in mind that
cement industry alone contributes to 5% of the whole global emission of carbon dioxide for its yearly
production, concrete being a part if cement industry has a share in that 5%. Also Construction as well
as demolition debris constitute a considerable fraction of solid waste. As stated by Winfield and
Tailor (2005), “there will be an effect on habitat due to the extraction of aggregates from pits and
quarries”, which results in the destruction of the natural habitats of many organisms and in the
disturbance of the pre-existing stream flow and water resources. There is great impact of the natural
aggregate production on the quality of both groundwater and running surface water. Even then,
Concrete has its extreme importance in the construction field. Thus the importance of reducing
carbon dioxide emission has gained instantaneous importance and there by Sustainable Construction
has gained high priority in the recent construction era.
Foam concrete is one such building construction material which satisfies the principles of
Sustainable Construction along with securing its qualification of being a Green Building material.
Foamcrete is defined as a cementitious material having a minimum of 20 percent by volume
of mechanically entrained foam in the mortar slurry in which air-pores are entrapped in the matrix by
means of a suitable foaming agent. Its main advantages being
Very light in weight
Very low water absorption
Fire resistant
Highly thermal insulation
Energy efficient
Sound insulation
Offers excellent strength
2. SUSTAINABLE CONSTRUCTION WITH FOAM CONCRETE
Sustainable construction aims at reducing the environmental impact of a structure over its
entire lifetime, while optimizing its economic viability and the comfort and safety of its occupants.
The principles of Sustainable Construction apply to the entire life cycle of construction, from
planning to disposal.
a) Reduce resource consumption (Reduce) – Foam Concrete consumes a comparatively small
amount of raw material relative to the amount of finished product produced
b) Re-use Resources (Re-use) – Recent advancements in construction field are making use of
recycled foam concrete to replace sand in the insulation layers.
c) Use recyclable resources (Recycle) – In India total production of fly ash is nearly as much as
that of cement. But our utilisation of fly ash is only 5% of the production. Foam concrete
production consists of the recycled material fly ash (a by-product of thermal power plants)
d) Protect Nature (Nature) – The disposal of fly ash has become a problem and is a serious
environmental problem which can be brought down with the production of Foam concrete
blocks. Besides, the manufacturing of Foam concrete produces no pollution and thus protects
nature.

3. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
181
e) Eliminate Toxics (Toxics) - It does not emit toxic gases even when exposed to fire and also
its manufacture process is non-toxic.
f) Apply Life-cycle Costing (Economics) – Proves itself to be cost effective starting from the
construction stage till the operating and maintenance costs.
g) Focus on Quality (Quality) – Along with maintaining low density due to the usage of
foaming agent, Foam concrete satisfies the strength criteria. Lightweight concrete at its
lightest density is stable and strong.
Sustainability is the ability to achieve continuing economic prosperity while protecting the
natural systems of the planet and providing a high quality of life for its people. Green building befits
these concepts through its building practices and thus ‘Green’ buildings are a subset of sustainable
construction.
3. GREEN BUILDING AND GREEN BUILDING RATING SYSTEM
A green building is an environmentally sustainable building, designed, constructed and
operated to minimise the total environmental impacts. The US Green Building Council defines Green
Building Design “To significantly reduce or eliminate the negative impact of buildings on the
environment and on the building occupants.” In other words, Green Building is defined as "The one
which uses less water, optimises energy, conserves natural resources, generates less waste and
provides healthier spaces for occupants, as compared to a conventional building."
The Leadership in Energy and Environmental Design (LEED-INDIA) Green Building Rating
System is a nationally and internationally accepted benchmark for the design, construction and
operation of high performance green buildings. LEED is a credit-based system. 64 credit points are
divided among the first 5 environmental impact areas excluding 5 additional points for the last
category of Innovation and design process.
LEED Evaluation - Credit Points
Sustainable Sites - 13
Water Efficiency - 06
Energy and Atmosphere - 17
Materials and Resources - 13
Indoor Environmental Quality - 15
Innovation and Design Process - 05
In order to earn a LEED certification for a new construction, a minimum of 26 points must be
achieved (in addition to all the prerequisites). A Silver rating is achieved by earning between 33-38
points, Gold between 39-51 and Platinum between 52-69.
3.1 Rating Foam Concrete as per Green Building Rating System
1. Water Efficiency: - With surfactants as foaming agents, water resources can be conserved. If
the water in the mixture is not sufficient for the initial reaction of the chemical paste, the
cement withdraws water from the foam. But care must be taken that there shouldn’t be too
scarce water used for mixing the foam concrete which may lead to rapid degeneration of
foam with continuous absorbing and drawing out of water from foam. Also in the production
process of Foam Concrete, the amount of water required for the production is quite less
compared to the amount required in the production of traditional concrete.
2. Energy and Atmosphere:- Foam concrete has excellent insulating qualities resulting in
increased energy efficiency. Thermal Insulation, Sound Insulation, Fire Resistance are the
ones which lead to the energy saving in buildings of Foam Concrete.
3. Materials and Resources:- In India, the total production of fly ash is more than 100 million
tons, but our utilisation of fly ash is only about 5% of the production. Also the disposal of fly

4. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
182
ash has become a serious concern to the environmental protection. The utilisation of fly ash
as an ingredient satisfies the credits of resource re-use. And the fly ash can usually be under
the category of Local/Regional Material making it suitable under this credit category.
4. Indoor Environmental Quality:- An additional quality contributing to the sustainability of a
building product is its ability to reduce and absorb noise or to improve or maintain indoor air
quality
5. Innovation and Design Process:- The introduction of innovative raw materials like surfactants
and usage of fly ash, in the production process of Foam Concrete fits it to the title of Green
Concrete.
4. COST EFFECTIVENESS OF FOAM CONCRETE (CLC BLOCK) IN COMPARISON
WITH CLAY BRICK
4.1 CLC Blocks Basic Pricing
Cement (5 Bags @ Rs.300/-) = Rs. 1,500
Fly ash = Rs. 200
Foaming Agent (Rs.130/- per 1Cu.m) = Rs. 130
Water = Rs. 20
Labour = Rs. 100
Power = Rs. 30
1 Litre Oil = Rs. 50
Machine depreciation = Rs. 50
Total Cost = Rs. 2,080/-
For 1 Cubic Metre = 24 x 8 x 4 inch = 83 Blocks
Production cost of 1 Block = 2080/83 = Rs. 25.06/-
1 CLC block equals to 7 clay bricks in terms of size
4.2 Clay Brick Basic Pricing (for 38000-40000 bricks)
Sand (30 tractors @ Rs.750/-per each) = Rs. 22,500
Boiled ash(4.5 TONS @ 660/TON)) = Rs. 2,970
Boiled rice husk ash (1.5 Tons @ 3000/Ton)
(for the purpose of mixing with sand) = Rs. 4,500
Water (3.5 tankers @ Rs.200/- each) = Rs. 700
Labour (@ Rs.400/- for making 1000 bricks) = Rs. 16,000
Labour for arranging bricks (@300/- per 4000 Bricks) = Rs. 3,000
Coal (3.75 ton @ Rs.6000/-) = Rs. 22,500
Husk (for burning 4 ton @ Rs.3000/-) = Rs. 12,000
Sand for burning(1 tractor) = Rs. 750
Tractor for tamping = Rs. 1,500
Coal for breaking = Rs. 1,500
Total Cost (for 40,000 Bricks) = Rs. 87,920/-
Hence, Production cost of 1 Brick = 87920/40000 = Rs. 2.20/-
Since 1 CLC Block = 7 Clay Bricks in size
Cost of clay Bricks as per CLC Block size = 7x 2.20 = Rs. 15.40/-
Though the production cost of CLC blocks is more than that of Red Bricks, when it comes to wall
construction, the scenario changes completely as per real time example illustrated below.

5. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
183
4.3 Real time comparison between CLC Blocks & Clay Bricks
Market price of CLC Blocks of size 24 x 8 x 4 in India is Rs 3375/- per cubic meter. Market
price of Red bricks in India is Rs 2576/- per cubic meter. These market prices may vary from place
to place.
Then, why should I spend more money for CLC bricks?
The above question is investigated with an example of considering 1 unit wall brick construction
with both CLC block and Red Brick
It is evident that at the end of the one unit wall construction, the amount spent for Red
brick is more than the amount spent for CLC blocks. And thus CLC proves to be cost effective along
with being eco-friendly Green Material.
CONCLUSION
The greatest challenge of 21st century is pollution-free environment for which foam concrete
is one of the solutions in terms of construction industry. Substitution of recycled materials like fly
ash with cement in the production of foam concrete reduces the emission of carbon dioxide into the
environment without compromising the purpose, performance besides being cost effective. Due to its
relatively low consumption of readily available raw materials, excellent durability, energy efficiency,
innovative technology and relative cost effectiveness, Foam Concrete deserves to be said as GREEN
CONCRETE
COST
PARTICULARS
CLC BLOCK TRADITIONAL CLAY BRICK
No. of
units
Unit
cost
Total
cost
No. of
units
Unit
cost
Total
cost
Bricks for 1 cubic
metre
75 45 3375 560 4.6 2576
Cement for mortar
joints
1 300 300 2.5 300 750
Sand for mortar
joints
4 35 140 10 35 350
Cement for
plastering
1.5 300 450 6 300 1800
Sand for plastering 3.5 35 123 14 35 490
Total 4,388/- 5,966/-

6. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308
(Print), ISSN 0976 – 6316(Online) Volume 4, Issue 4, July-August (2013), © IAEME
184
REFERENCES
1. IGBC Green Homes Abridged Reference Guide
2. Kibert C.J. (2007), Sustainable Construction: green building design and delivery, 2nd edition,
John Wiley and Son, USA.
3. Mehta, P.K.2001, Reducing the environmental impact of concrete, Concrete International,
ACI, October issue, pp: 61 – 66.
4. M. S. Shetty, Concrete Technology Theory & Practice, Published by S. CHAND & Company
5. Neville, A.M. (1996). Properties of Concrete. Longman group Limited, Essex.
6. Kevin A.Baumert, Timothy Herzog, Jonathan Pershing., Navigating the numbers-Green
house Gas data and International Climate Policy, World Resource Institute
7. http://www.nanoliteinfratech.com/nanolite-technology.html
8. H.S.Sahasrabuddhe, Dr. A.G.Bhole and Dr. N.V.Deshpande, “Application of Green Building
Concept for an Integrated Township Project- A Case Study”, International Journal of Civil
Engineering & Technology (IJCIET), Volume 3, Issue 1, 2012, pp. 67 - 81, ISSN Print:
0976 – 6308, ISSN Online: 0976 – 6316.
9. Vinod P, Lalumangal and Jeenu G, “Durability Studies on High Strength High Performance
Concrete”, International Journal of Civil Engineering & Technology (IJCIET), Volume 4,
Issue 1, 2013, pp. 16 - 25, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316.
10. Syed Moazzam Ali and Dr.Balu Naik Banoth, “Low Energy Consumption Hvac Systems for
Green Buildings using Chilled Beam Technology”, International Journal of Advanced
Research in Engineering & Technology (IJARET), Volume 4, Issue 3, 2013, pp. 316 - 324,
ISSN Print: 0976-6480, ISSN Online: 0976-6499.