1.    Introduction

The Building Center at SRC-N is committed to the charter of the SRC-N, which states that: “The SRC-N shall promote alternative development models and strategies for the development of appropriate technologies and promotion of products, processes and services in programs relating to environmental management; livelihoods generation through asset-based and market-creation approaches; renewable energy technologies; shelter technologies; information and communications technologies.”

Shelter and habitat creation is a fundamental need for village-based communities. Hassan Fathy, an Egyptian architect, argues that housing (in developing economies) should be based on traditional forms of architecture, not those forms imported from the West. The people themselves should be intimately involved with the design, building and ownership of their own housing. When the government or private contractors step in and build for the people, the result is often housing and planning which is vastly out of touch with local social, cultural, economic and environmental conditions.

The Building Center at SRC-N is therefore involved in developing asset-based models that showcase sustainable and appropriate shelter technologies, which can be disseminated using the ‘market creation approach’ (MCA).

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2.    What is a ‘Building Center’?

A ‘Building Center’ is a grass-root level technology transfer mechanism for propagating cost effective and environment friendly building technologies. The main objectives are:

§     Function as a technology transfer center in the field of housing, building & development that disseminates information on cost effective and environment friendly shelter technology, especially in rural areas;

§     ‘Skill Upgradation & Training Center’ for masons, artisans, carpenters and other building work force trades in various cost effective and environment friendly building materials & technologies

§     ‘Manufacturing & Distribution Outlet’ that makes available building components to end user, including public agencies and individual home builders;

§     Provide ‘Design Consultancy & Services’ for matching technology to local situations;

§     Undertake field studies for development of appropriate, cost-effective and environment friendly building materials and construction techniques adapted to local situations.

The ‘Building Center’ at Nadia covers the following ‘Shelter Technologies’

§     Compressed Earth Blocks (CEB) Technology

§     Micro-concrete Roofing (MCR) Tiles Technology

§     Concrete Block Technology (CBT)

§     Ferro-cement Roofing Channels Technology (FCRT)

§     Ferroconcrete Doors and Windows (FCDW)

§     Eco Kiln (otherwise known as the ‘Vertical Shaft Brick Kiln’ (VSBK)

These technologies on ‘Shelter Products’ have been developed in close collaboration with Development Alternatives and Auroville for the following reasons:

§     They provide a means of employment and income generating opportunities, utilizing locally available materials, skills, manpower and management methods;

§     They provide building materials for making 'pucca' structures, that will improve the standard of living, by enhancing the self-assurance and confidence of the rural dwellers, who otherwise live in tattered and thatched, wobbly huts, at present, and

§     They provide an opportunity for enterprise development, inherently low in monetary cost;

§     They utilize renewable energy sources;

§     They are self-sustaining and promote self-reliance.

A comprehensive collection of knowledge resources on shelter technologies is contained in [housing_and_construction.pdf] (~180 kb), which is adapted from Village Earth’s AT Library.

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3.    Manual Press for Production of Compressed Soil Blocks

The Compressed Earth Block (CEB) Technology offers a cost effective, environmentally sound masonry system, suitable for a variety of applications in walls and roofs to make strong and durable buildings. The inputs needed are human and sunlight energy and ordinary soil as the raw material.

The TARA Balram machine (see image) produces standard chamfered blocks in two sizes: 23 x 10.9 x 7.6 cms and 23 x 23 x 7.6 cms. The manual machine costs about Rs. 35,000. The performance specifications for the manually operated unit are:

No. of blocks per cycle: 2 for Type A and 1 for Type B units

No. of cycles per hour: 160

No. of blocks per 8-hour day: 1000 -1500 for Type A units, and 500 - 750 for Type B units, including the time for soil preparation, block stacking and curing.

Six to ten persons are required to operate a manual machine. One skilled worker is required, the rest unskilled. Typically, the workers can be trained to operate any machine within 10 to 12 days.

An alternative machine made at Auroville is called the ‘Auroram’. CEBs made from a locally procured press have been used to make habitats and storage rooms at SRC-Nadia, as shown above.

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4.    Micro-concrete Roofing (MCR) Tiles

The TARA Tile Maker (see figure below) is used to produce micro-concrete roofing tiles (MCR). Roofs with MCR Tiles will resist cyclonic, high wind velocities. The MCR mix consists of 1 part cement, 2 parts of graded sand, and 1 part of stone grit, smaller than 6 mm in size. The mix requires a water-cement ratio between 0.45 and 0.5.

With this mix and a labor force of 4 persons, a production rate of upto 200 tiles a day per vibrator is easily achieved. Detailed project reports and costing estimates will be made available on request.

An MCR Tile Calculator has been developed to assist in developing the materials mix. MCR Tiles that have been made at SRC-Nadia have been used to make the roofs of the engineering sheds and the VSBK, as shown above.

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5.    Concrete Block Technology (CBT)

Concrete Block Technology (CBT) offers a speedier alternative to conventional materials, since it is typically equivalent to 4.5 bricks. They are compatible with other materials like fired bricks, CEBs and dressed stone for composite wall construction (see images below).

The most common sizes are 30 x 20 x 15 cm; its weight about 18-19 kg. The basic raw material is cement. Very little water is used. CBTs are produced using a semi-mechanized stationary type machine. The other production systems are:

§     Manual Moulds, which require hand tamping

§     Mobile Semi-Mechanized 'egg-laying' machine

§     Fully Mechanized system which combines compression and vibration.

High quality machines provide optimum vibration in the mix, so that the ratio of cement used can be reduced substantially, without compromising on the strength of the blocks.

The blocks are cured for a minimum period of 14 days, before they are ready to use. On an average, one skilled and 6-8 semi-skilled workers can make 600 - 800 blocks in 8 hours.

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6.    Ferrocement Roofing Channels Technology

FRCs have a uniform segmental profile of 2.5 cm thick and 83 cm wide. Maximum length of mechanically produced channels can be 6 meters. Longer spans of roofs can be built with intermediate support. FRCs can be safely transported after a curing period of 14 days. FRCs are prefabricated elements. The mechanized system of production uses a vibrating table and profiled steel shell moulds. The production yard (see Fig 8b) consists of a vibrating table positioned under a gantry system 6.5 meters in width.

A production team consisting of 2 masons, 6 semi-skilled workers and a supervisor can produce upto 5 channels of 4.6 meters length each, in 8 hours of operation.

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7.    Ferrocement Doors and Window shutters (FCDW)

Prefabricated Ferrocement Doors and Window shutters (FCDW) are (a) easy to manufacture, (b) they are strong and durable, (c) resistant against water and (d) requires little maintenance afterwards.

FCDW technologies have been very successfully demonstrated in the Technology Resource Centers at Vivekananda Kendra, Kanyakumari and the Auroville Building Centre, which has been using the prefabricated technique of casting doors since 1986.

The document entitled “Manufacturing Specifications of Prefabricated Ferrocement Doors”, produced by ‘Auroville Building Centre’, gives a detailed description of the manufacturing process for prefabrication of ferrocement products on a small scale. The main features and advantages of FCDWs are:

§     The materials required are commonly available;

§     Manufacturing techniques can be taught to semi -skilled men and women, after a short training period;

§     Only manual labor is involved in manufacturing the basic ferrocement door panels and window shutters;

§     FCDWs are strong, durable, fireproof, waterproof and termite resistant;

§     FCDWs can be made on any flat surface with ordinary mason tools and are easy to transport and install;

§     FCDWs can be made in various designs and shapes, and painted attractively to match the surrounding decor

§     A damaged ferrocement door can be repaired;

Since manual labor is the main activity in manufacturing FCDWs, it is ideal for providing employment opportunities in rural environments and a rural enterprise can be started with a low investment.

Detailed project reports and costing estimates will be made available on request.

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8.    DST-funded Eco Kiln (VSBK) Project

Reference: DST No.: SP/RD/060/2003 dated July 3rd 2006, (July 2006 to June 2008)

An Eco Kiln (or Vertical Shaft Brick Kiln--VSBK) has been built by Sankalpa Trust (with Dr. Subhrankar Mukherjee as the Co-Principal Investigator), in technical collaboration with Development Alternatives, New Delhi (with Dr. Soumen Maity as the Principal Investigator) at Village Baidyapur, District Nadia, West Bengal—as a model for demonstrating the effectiveness of the continuous process technology for firing bricks. The Eco Kiln has run on trial basis for about two months in February and March 2008, and intermittently again since December 2008, as sufficient funds were not available to make full-scale operational trials of the Eco Kiln since project completion in June 2008.

We have therefore developed a 'Concept Note'/proposal ([proposal_sttc.pdf] ~ 471 kb) under the Livelihoods Training & Education Center (LTEC) at SRC-N for submission to funding agencies entitled: “Training and Technology Transfer Workshops for disseminating Eco Kiln and Sustainable Shelter Technologies in West Bengal and North East India”, in which we propose to build a Shelter Technologies Training Center (STTC) that will generate in the village-based community (a) livelihood options for fired brick manufacture and distribution in particular, and shelter products and services in general; (b) the financial and management structures needed to run the public funded Eco Kiln, as a hands-on training center facility.

The features of the Eco Kiln are:

§     High energy efficiency: Energy savings of 30-50% over conventional BTK methods for firing the bricks;

§     Environment friendly: Requires less land, reduces deforestation and has ‘Green House Gas’ (GHG) emissions reduction and energy savings of 508.5 MTCO2/Year and 1.634 GWhth/Year, respectively;

§     Economically viable: High profitability with low initial investment and working capital; reduces drudgery through enhanced operator skills;

§     Uniform & consistent quality: Efficient heat management techniques result in VSBK bricks deep red in color, a metallic ring and compressive strength of 200 kg/cm2—with less than 2% breakages;

§     Round-the-year-production: Can be operated during monsoons subject to availability of dried green bricks, as the kiln has a roof to support continued firing operations, regardless of weather conditions; the only constraint is green-brick production, for which a covered shed is needed.

8.1   VSBK Technology

The VSBK has a vertical shaft of rectangular or square cross-section, as shown in the schematic figure above. The kiln works as a counter-current heat exchanger, with heat transfer taking place between the air moving up (continuous flow) and bricks moving down (intermittent movement).

Green bricks are loaded in batches at the top of the kiln and move down the shaft through brick pre-heating, firing and cooling zones and unloaded from bottom.

The combustion of coal (added along with bricks at the top) takes place in the middle of the shaft. Unloading of bricks is done from bottom of the shaft using a trolley. This ‘round-the-clock-operation’ requires special skills and supervision. The ‘firing’ operator needs to maintain a correct balance between: (a) Energy—controlled by amount of coal used; (b) Air-flow—controlled by stacking density and damper position; (c) Unloading speed—operator controlled.

8.2   Commercial benefits of the Eco Kiln (VSBK)

The VSBK kiln with two shafts can be set up in only 2000 sq.m. of land, excluding the brick-molding area. It will produce about 10,000 bricks per day. Any regular shaped, rectangular product having a minimum thickness of around 40mm can be fired in a VSBK.

If good firing practices are followed in the VSBK, energy savings of upto 50% compared to conventional kilns can be achieved, with high quality of bricks with a fine, deep red color and a good, metallic ring can be produced, depending upon the soil composition and particle size distribution.

With an initial investment of between Rs 25 Lakhs and 35 Lakhs as the project cost (these figures need to be vetted in view of the steep price of labor and material costs), sales exceeding well over one Crore rupees can be achieved, with handsome profit margins. From the second year investment is limited only to working capital requirements.

A VSBK gives substantial saving in energy costs. The owner can plan a precise production schedule. One batch of bricks is loaded and unloaded every two hours, remaining inside the kiln for approximately 24 to 30 hours instead of the 20 to 30 days required with a conventional BTK, reducing working capital requirements.

8.3   Process controls

The Sankalpa Eco Kiln at Village Baidyapur is perhaps the only VSBK in India that has permanently installed three thermocouple readouts for robust kiln temperature control. Temperature controllers are also installed in the hoist control equipment.

The VSBK at Nadia was run by Sankalpa Trust continuously for a test period of 70 days, during which time about 176,660 bricks were made and the VSBK process was stabilized.

Chart 1 shown below indicates that:

§     Breakages were less than 2% and

§     The production of Class 1 bricks steadily increased past 80%.

The second chart, Chart 2, shows the process control on the temperature for the first 30 days.

A comprehensive collection and analysis of VSBK production data for the first sixty days can be downloaded under [VSBK_Analysis.pdf] ~ 35 kb.

8.4   Socioeconomic benefits to the local community

The VSBK Project (see images 01 to 04 in the Appendix)—implemented by Sankalpa Trust in tandem with renewable energy projects—has brought a great deal of socioeconomic and environmental benefits to the local community at Village Baidyapur (for more details, please visit the official website of Sankalpa Research Center—Nadia at: [http://www.sankalpacmfs.org/src/index.html]).

Details of the ‘Sociological Survey’ that has been commissioned by Sankalpa Trust are available in our archives under [Sankalpa-Social-Survey.pdf]; it contains studies on the following subjects:

§     General characteristics of the respondent and the family

§     Ranked scores for expectations for improvements in ‘Quality of Life’

§     Household expenditure pattern

§     Crop Analysis

§     Willingness-to-pay (WTP) Contingent Valuations

§     Comparison between women and men members.

Sankalpa Trust/ARTS has promoted the use of VSBK bricks by local customers and householders and obtained their feedback and suggestions. The following images show use of ‘Sankalpa’ bricks by a satisfied local buyer—Mr. Sunil:

The SRC-Nadia projects have also served to provide inputs for improving the quality of life in the community, which include, amongst others:

a) Economic Benefits

Social surveys conducted in December 2006 (see chart on the right) indicates that the average monthly income for men and women in Village Baidyapur stood at Rs.1,692 and Rs.546, respectively – i.e. before commencement of the VSBK Project.

However, at the time of the VSBK pilot production run in April 2008, the average daily wages of men and women SHG members were Rs.100—150 and Rs.80—90, respectively—over an average of 20 days work involvement in a month. This represents an average monthly income for men and women SHG members of about Rs.2,500 and Rs.1,700 —which is 48% and 211% higher than the corresponding figures for December 2006—respectively, for men and women. The VSBK project therefore represents an enormous economic benefit for the entire village community, especially for the women.

b) Community involvement and participatory development:

Local community groups have been formed under the leadership of local community elders and active ‘Social Workers’.

Several meetings with local and area community members have been conducted to propagate the principles ‘Participatory Practices for Sustainable Development’. Video recordings of these proceedings have been archived for reference.

The local village-based community has accepted the VSBK project with enthusiasm and support, as can be seen in the proceedings of the village meetings and their commitments to the project.

During the VSBK pilot production run, four groups were formed as listed below: (see images 05 to 10 in Appendix 3 for involvement of SHG community members in VSBK operations).

The SHG Groups have decided to start savings for their future planning. More images of community involvement in the VSBK Project can be seen in the images presented at "Community participation in the VSBK Project" [community_involvement.pdf] ~ 672kb.

c) Women and Children:

The women and children of the village community are the principal beneficiaries of the social programs of SRC-Nadia. The first two images below show the impact of the Livelihoods Center for women:

In addition to livelihoods development for the women for their economic security, the children have been encouraged to participate in cultural programs, as shown in the images on the second row.

d) Safety First:

The awareness campaign for the use of safety equipment in the brick industry has been an important issue in the VSBK Project. Representative samples of safety equipments that have been issued to workers at the VSBK, Nadia are shown on the right.

A review of the special projects that have been designed for the benefit of the village-based community members of Village Baidyapur can be seen by clicking here [http://www.sankalpacmfs.org/src/index.html].

8.5   Cost of VSBK Bricks

About 176,660 bricks were produced in a pilot production batch in March/April 2008. A comprehensive collection and analysis of VSBK production data for the first sixty days can be downloaded by clicking here [VSBK_Analysis.pdf] ~ 35 kb. Please also download/see the images related to the pilot production by clicking here [Appendix_VSBK_images.pdf] ~ 701 kb.

The average cost estimates of VSBK bricks in this production lot are shown below:

8.6   Awareness programs

We have started to dismantle the barriers and prejudices that may stand in the way of wide-spread and large-scale use of bricks produced with VSBK technology, by conducting seminars and meetings with brickfield owners on the one hand, and the local people in the vicinity of Village Baidyapur, on the other.

An example is a ‘Workshop on Modern Brick-Making Technologies’, held on 28th August 2008 and organized by Sankalpa Trust (as a representative of Development Alternatives) to promote the VSBK technology to a group of fifteen brickfield owners in the Barasat area, hosted by the Narayantala Mass Communication Society (NMCS), Barasat and funded by GOAL India. A Powerpoint presentation on this seminar may be downloaded by clicking here [ecokiln_workshop.pdf] ~ 1,230 kb.

More such meetings are planned in the future with the office bearers and members of:

    (a) All-India Brick & Tile Manufacturers Federation (New Delhi); and

    (b) Bengal Brick Field Owners Association.

In addition to regional awareness programs, the Sankalpa Research Center—Nadia has hosted international training and awareness programs for spreading the benefits of adopting VSBK technologies.

Teams from Afghanistan and Bangladesh have visited Sankalpa Research Center, Nadia to study the construction and operational details, shown below:

Please see the Appendix for images related to the VSBK Project at Village Baidyapur, Nadia District, West Bengal.

8.7   Conclusions

The Eco Kiln (or Vertical Shaft Brick Kiln—VSBK) is a viable and alternate technology solution to the conventional ‘fixed chimney’ firing technologies for the manufacture of bricks.

Detailed project reports and cost estimates will be made available on request.

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9.    Contact details

Contact Person: Dr. Subhrankar Mukherjee, PhD,MBA

Designation: Managing Trustee—Sankalpa Trust; Director—SRC-N

Address: P6: Cluster 2, Purbachal, Salt Lake, Calcutta 700097, India.

Mobile: + 91 94330 19821 ; 93392 59812

eMail: [subra@engr.colostate.edu] ; [subra@sankalpacmfs.org] ; [subhrankar@gmail.com]

Website: [www.sankalpacmfs.org]

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