A STRATEGY FOR SUSTAINABLE HOUSING CONSTRUCTION IN THE SEMI-URBAN TOWNSHIPS OF NORTH INDIA

Transcription

1 A STRATEGY FOR SUSTAINABLE HOUSING CONSTRUCTION IN THE SEMI-URBAN TOWNSHIPS OF NORTH INDIA P.S. Chani [1], Shailja Singh [2] and S.Y. Kulkarni [3] [1] Assistant Professor [2] Postgraduate Scholar [3] Professor and Head Department of Architecture & Planning, IIT Roorkee THE PROBLEM CONSTRUCTION SECTOR A MAJOR CONSUMER OF ENERGY INCREASING CONSTRUCTION ACTIVITY INCREASING REQUIREMENT OF BUILDING MATERIALS INCREASING ENERGY REQUIREMENT 1

2 THE PROBLEM ENERGY ( x 10^6 GJ) CURRENT 2020 AD ENERGY CONSUMED IN MANUFACTURING BUILDING MATERIALS # # Reddy, B.V.V., Embodied Energy in Buildings, Dept. of Civil Engg., IISc, Bangalore THE PROBLEM Additional problem - topsoil consumption to manufacture traditional burnt clay bricks Brick manufacturing currently consumes top soil (upto 300 mm deep) from about 1000 sq. km. of the available arable land annually 2

3 THE PROBLEM BUILDING MATERIALS NEEDED FOR HOUSING CONSTRUCTION OTHER CONSTRUCTIONS 60% AROUND 3.9 MILLION HOUSES NEEDED PER ANNUM FROM AD THIS PRESSING NEED CANNOT BE MET BY EXISTING SUPPLY OF BUILDING MATERIALS IMPERATIVES TO CHECK ENERGY CONSUMPTION OF CONSTRUCTION SECTOR AND SIMULTANEOUSLY PROVIDE LARGER QUANTITIES OF BUILDING MATERIALS TO MEET INCREASING DEMAND 3

4 IMPERATIVES TO BE ACHIEVED BY PROVIDING ENERGY EFFICIENT SUBSTITUTES FOR CONVENTIONAL BUILDING MATERIALS POSSIBLE TO MANUFACTURE LARGER QUANTITIES OF ENERGY EFFICIENT MATERIALS WITHIN EXISTING LEVELS OF ENERGY CONSUMPTION BY CONSTRUCTION SECTOR THEREFORE, ESSENTIAL TO ESTIMATE ENERGY REQUIRED FOR CONSTRUCTION ENERGY ESTIMATION IN HOUSING TWO MAJOR CATEGORIES 1. OPERATING ENERGY COST (OEC) ENERGY NEEDED FOR HEATING, COOLING, LIGHTING AND OPERATING EQUIPMENT ETC 2. CONSTRUCTION ENERGY COST (CEC) ENERGY REQUIRED FOR CONSTRUCTION 4

5 ENERGY ESTIMATION IN HOUSING CONSTRUCTION ENERGY COST(CEC) EMBODIED ENERGY COST (EEC) Energy embedded in all building materials in a constructed structure SECONDRY ENERGY COST (SEC) Energy needed for: On site construction work Installation of electrical and sanitary fixtures Providing infrastructure Workers engaged in the construction work EEC 80% OF THE CEC EEC MAJOR COMPONENT OF CEC EEC SEC EEC W.R.T. SEC Studies undertaken by various researchers highlight: Significance of energy needed for housing construction Methods of estimating this energy 5

6 ENERGY ESTIMATION IN HOUSING EEC EEC T Sum of Embodied Energy Values (EEV) of all building materials: EEV consists of the energy needed to: Quarry raw material Transport to manufacturing unit Manufacture material Transport finished material to distribution outlet TEC T Sum of Transport Energy Values (TEV) of all materials required TEV - energy needed to TOTAL TEC TOTAL EEC transport building material from TOTAL distribution TEC VS TOTAL outlet to EEC construction site EEV - Embodied energy per unit quantity of material TEV - Transport energy per kg of material EEV obtained by DA/BMTPC - most comprehensive energy values for building materials in India EEC estimation using building elements has limited application EEC could also be estimated by breakup of materials required in construction, but this also cannot be directly adopted for preparing EEC estimates Most suitable format for estimating EEC - the detailed cost estimate Database of basic energy values/energy rates of materials essential to estimate the EEC, i.e., Schedule of Embodied Energy Rates Identification of the major contributor to the EEC what needs to be targeted for maximum energy saving use of alternative building materials 6

7 BOQ OR DETAILED COST ESTIMATE MATERIALS REQUIRED FOR CONSTRUCTION EER EEV EECT METHODOLOGY ESTIMATION OF EEC T Using the format of the detailed building estimate A detailed estimate requires: 1. Drawings of the Building/Project 2. Specifications of the Items of Work 3. Schedule of Rates SCHEDULE OF RATES ~ SCHEDULE OF ENERGY RATES 7

8 Embodied Energy Values (EEV) S.No. Building Material Size (Dim. in cm) Unit EEV (MJ/Unit) 1. Traditional brick 22.9x11.4x7.6 nos Cement - kg Fine sand - cum 0.00 Embodied Energy Rate (EER) Item Code No. # Description of Item of Work Materials Unit Qty. Energy Value (MJ/Unit) Energy Value (MJ) EER (MJ/Unit) Mortar Work Cement mortar 1:6 (1cement: 6 coarse sand) (Details for 1 cum) Masonry Work 1 st class brick work in foundations & plinth in cement mortar 1:6 (1 cement : 6 coarse sand) (Details for 1 cum) Cement Fine sand 1 st class bricks Cement mortar 1:6 kg cum nos cum MJ/cum MJ/cum METHODOLOGY Computation of EEC T using Embodied Energy Rates (EER) EEC T = EEC 1 + EEC 2 + EEC 3 + EEC 4 + EEC 5 where EEC 1 = EEC for masonry work EEC 2 = EEC for concrete work EEC 3 = EEC for RCC work EEC 4 = EEC for Flooring EEC 5 = EEC for Finishing 8

9 Project No LIST OF PROJECTS Description Dwelling - One Room and a Front Verandah Dwelling Unit with One Room, a Bathroom and a Front Verandah Dwelling Unit with Two Rooms and a Front Verandah Staff Residence, Navodaya Vidyalaya a Block of Two Units Principal s Residence, Navodaya Vidyalaya Dwelling Unit with Three Rooms Residence of O.N.Vidyarathi at II Phase Development, BHEL Yojna, Ranipur, Hardwar Residence for Shri R.K. Bansal at Plot No. K-112, II Phase Development, BHEL Yojna, Ranipur, Hardwar Single Storeyed Residence Residence of Y.P. Sharma at Plot No. J-25, II Phase Development, BHEL Yojna, Ranipur, Hardwar FA (sqm) % 90% INFERENCES PERCENTAGE BREAKUP OF EEC 80% 70% 60% 50% 40% 30% 20% 10% 0% PROJECT NO. EEC - MASONRY WORK EEC - CONCRETE WORK EEC - RCC WORK EEC - FLOORING EEC - FINISHING BREAKUP OF THE EEC 9

10 INFERENCES 100% BRICKS AND STEEL REMAINING MATERIALS 80% ENERGY SHARE OF BRICKS AND STEEL IN THE EEC 60% 40% 20% 0% BRICKS REMAINING MATERIALS ENERGY SHARE OF BRICKS IN MASONRY WORK REMAINING CIVIL WORK MASONRY AND RCC WORK CONTRIBUTION OF MASONRY & RCC WORK IN EEC T ALTERNATIVES Masonry Units 1. Traditional bricks (22.9cm x 11.4cm x 7.6cm) 2. Modular bricks (20cm x 10cm x 10cm) 3. Clay flyash bricks (20cm x 10cm x 10cm) 4. Sand lime bricks (20cm x 10cm x 10cm) 5. Hollow concrete blocks (40cm x 20cm x 10cm) 6. Hollow concrete blocks (40cm x 20cm x 20cm) 7. Aerated concrete blocks (40cm x 20cm x 20cm) 8. Solid concrete blocks (30cm x 20cm x 15cm) 9. Fal-G blocks (30cm x 20cm x 15cm) Mortar Mixes a. Lime mortar 1:1:1 (1 lime putty: 1 flyash: 1 fine sand) b. Cement mortar 1:3 (1 cement: 3 fine sand) c. Cement mortar 1:4 (1 cement: 4 fine sand) d. Cement mortar 1:5 (1 cement: 5 fine sand) e. Cement mortar 1:6 (1 cement: 6 fine sand) f. Composite mortar 1:1:6 (1 cement: 1 lime putty: 6 fine sand) g. Composite mortar 1:1:7 (1 cement: 1 lime putty: 7 fine sand) h. Composite mortar 1:1:8 (1 cement: 1 lime putty: 8 fine sand) i. Composite mortar 1:2:9 (1 cement: 2 lime putty: 9 fine sand) 10

11 ALTERNATIVES DROP IN EEC USING ALTERNATIVES EEC IN % MASONRY IN TRADITIONAL BRICKS MASONRY USING FAL-G BLOCKS,CLAY FLYASH BRICKS MASONRY USING HOLLOW AND AERATED BLOCKS ALTERNATIVES Energy savings achieved in masonry work by using hollow blocks and aerated blocks vis-à-vis traditional bricks because: Size of blocks: Blocks larger in size only 63 nos. of each type of block required per cum of masonry work As against 494 nos. of traditional bricks their contribution to the EER of masonry work is substantially less. Saving in mortar volume: Larger size of the blocks reduction in number of mortar joints required per cum of masonry work further reduction in the EER of masonry work 11

12 IN CONCLUSION Clear shift towards concrete based products for walling in some parts of India Significant shift of about 11%, over the last decades; this figure expected to grow very rapidly, particularly in the large cities Especially true in areas where suitable clay for manufacturing traditional bricks are not available; in many of these areas concrete block are already replacing bricks. Manufacture of concrete blocks can be ideally combined with stone crushers utilisation stone dust and chips (> 10 mm), which is otherwise a waste. Integrating concrete block production utilising stone dust is one way of immediately mitigating the effects of air pollution that this waste is creating IN CONCLUSION Clay flyash bricks and Fal-G blocks immensely useful as they utilise flyash - an ecological hazard. Flyash replaces clay by upto 40% in clay flyash bricks reducing the consumption of clay Saving precious top soil greater quantity of brick production (by upto 40%) from the same quantity of soil. Flyash also has a small calorific content due to the unburnt carbon left behind as a residue This carbon aids the firing of clay flyash bricks in the kiln reduced energy requirement in their firing saving coal upto 3-5 tonnes per 100,000 bricks. Amongst mortars, 1:6 cement mortar (1 cement: 6 fine sand) has the least EER 12

13 SATELLITE IMAGE OF ROORKEE SEMI URBAN TOWNSHIP DEVELOPMENT 13

14 DRYIN BEDS OF RIVER SOLANI DRYING BEDS OF RIVER SOLANI RECOMMENDATIONS Another major advantage - saving in top soil used in manufacturing traditional bricks Concrete blocks a suitable replacement, particularly in areas where stone or stone aggregates are available in abundance 14

15 RECOMMENDATIONS Traditional brick masonry work must be replaced by suitable alternatives to achieve a substantial reduction in the EEC of housing construction This will help in producing larger quantities of masonry units within the existing energy levels Moreover, the use of materials like clay flyash bricks and Fal-G blocks will help in dealing with the ecological problem of flyash END OF PRESENTATION THANK YOU 15