INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) CONCRETE + GREEN = FOAM CONCRETE. K.Krishna Bhavani Siram 1, K.

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1 INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) International Journal of Civil Engineering and Technology (IJCIET), ISSN ISSN (Print) ISSN (Online) Volume 4, Issue 4, July-August (2013), pp IAEME: Journal Impact Factor (2013): (Calculated by GISI) IJCIET IAEME CONCRETE + GREEN = FOAM CONCRETE K.Krishna Bhavani Siram 1, K.Arjun Raj 2 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 (CO 2 ) 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 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 CO 2 to the atmosphere in the last 200 years. Half of this amount was added in the last 30 years alone. CO 2, the most heat-trapping gas in the atmosphere, is the important gas causing climate change on 179

2 the whole. Others include methane (CH4), nitrous dioxide (NO 2 ), 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. 180

3 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 effective starting from the construction stage till the operating and maintenance s. 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 points, Gold between and Platinum between 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 181

4 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 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 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 of 1 Block = 2080/83 = Rs /- 1 CLC block equals to 7 clay bricks in terms of size 4.2 Clay Brick Basic Pricing (for bricks) Sand (30 Rs.750/-per each) = Rs. 22,500 Boiled ash( /TON)) = Rs. 2,970 Boiled rice husk ash ( /Ton) (for the purpose of mixing with sand) = Rs. 4,500 Water (3.5 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 Rs.6000/-) = Rs. 22,500 Husk (for burning 4 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 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 /- Though the production 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. 182

5 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 COST PARTICULARS No. of units CLC BLOCK Unit Total TRADITIONAL CLAY BRICK No. of units Unit Total Bricks for 1 cubic metre Cement for mortar joints Sand for mortar joints Cement for plastering Sand for plastering Total 4,388/- 5,966/- 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 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 effective. Due to its relatively low consumption of readily available raw materials, excellent durability, energy efficiency, innovative technology and relative effectiveness, Foam Concrete deserves to be said as GREEN CONCRETE 183

6 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: 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 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 , ISSN Print: , ISSN Online: 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 , ISSN Print: , ISSN Online: 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 , ISSN Print: , ISSN Online: