7

8

Stabilized Compressed Earth Block Technology

 

The Stabilized Compressed Earth Block (SCEB) Technology offers a cost effective, environmentally sound masonry system. The product, a stabilized Compressed Earth Block has a wide application in construction for walling, roofing, arched openings, corbels etc. Stabilized Earth Blocks are manufactured by compacting raw material earth mixed with a stabilizer such as cement or lime under a pressure of 20 - 40 kg/cm2 using manual soil press such as Balram. A number of manual and hydraulic machines are available in India. The basic principal of all the machines is the compaction of raw earth to attain dense, even sized masonry. Some of the hydraulic machines can even manufacture interlocking blocks. These interlocking blocks are highly suitable for speedy and mortar less construction. Stabilized Compressed Earth Block (SCEB) Technology helps in offsetting the use of fuel wood that is getting expensive every day. On the other hand, Compressed earth blocks are sundried and use cement as stabilization for gaining the required strength.

Product
The Stabilised Compressed Earth Block is a masonry unit of cuboidal shape. This may be solid or hollow or interlocking. The shape and size of a block is defined by the equipment used in its manufacture. SCEBs can be used for load bearing construction upto 3 storeys. The cost of a block depends upon a variety of factors including quality and price of available soil, amount of stabilisation, labour productivity equipment and overhead costs. The degree of stabilization has the maximum influence on the cost of the product.

Raw Material and Manpower
The primary raw material for the production of SCEB is raw earth or soil. OPC cement in small quantities and water are other constituents. Coarse sand or stone dust may be added depending on soil quality. Soil is made up of grains of various sizes. The grain size distribution of a soil determines its suitability for the manufacture of SCEB.

6-10 persons are required to operate a manual machine. For hydraulic machines the manpower required is 6-8 persons. In both the systems 1 skilled worker is required while the rest are semiskilled. The workers can be trained to operate any machine in 10-12 days.

Areas of Application

Fired bricks has potential of 460 billion bricks every year, which has been proven by NCAER and leading brick association and is increasing steadily by 3-5% growth rate every year. Even 5% market share will lead to 23 million bricks per year. Compressed earth blocks can be used for almost all the applications of burnt clay bricks. SCEBs can be used for load bearing construction upto 3 storeys.
The basic design principles of a good SCEB building are :
-

Strong foundation with sufficient plinth height.
Sufficient roof overhang and a strong wall finish.
Careful detailing of joints and use of concrete elements where tensile stresses are active

In India more than 5 million Stabilised Compressed Eatlh Blocks have been used to build residential and community buildings in both urban and rural areas.

Brief production process
Production process

The production of SCEB is based on the principle of densification of raw earth mixed with stabiliser (cement or lime) in small quantities ranging from 5-10% by weight of the mix. The production process incorporates 3 main stages

Mix Preparation Compaction Post Production
Sieving Filling the mould Humid and wet curing
Batching Moulding Final storage
Mixing Block ejection and stacking Transportation


Advantage of CEB

Cost effective
Environmental friendly - conserves agricultural soil and non-renewable fuel
Provides better thermal insulation
Uses local resources
Appealing aesthetics - elegant profile and uniform size



Development Status

Commercialized 
 

Technical Data
The performance specifications of SCEB are based on B.I.S code IS 1725, 1982 and tested in accordance with IS 3495-1992.

Techno-economic characteristics Specifications
Dimensional Variation +/-2 mm
Wet compressive strength 20-30 kg/cm2
Water absorption <15% by weight
Erosion <5% by weight
Expansion on Saturation Expansion on Saturation
Surface characteristics No pitting on the surface


 

Economic Data

Infrastructure cost for office and workshop includes: Working shed, office space, cement godown, facilities-electricity and water)  Rs 100,000
Equipment  TARA Balram model (manual machine) Rs 30,000
Hydraform with pan mixer (with hydraulic machine) Rs 475,000
Transportation and insurance (in India) Rs 12,000
Installation and know how transfer Rs 25,000
Total (package with hydraulic machine) Rs 7,42,000/-   (US$ 14,84
These cost do not include cost of land, as it varies considerably from place to place)

 
 

Business
This technology package with manual machine TARA Balram is ideally suited for small entrepreneurs manufacturing cement Jali’s, Chajja’s or other similar products used in building construction. Owners of local clamp brick kilns can diversify into production of CEB. Group housing societies making individual houses can benefit from the use of available local material at the site of construction. Contractors can take the advantage of the mobility of the equipment and save on the transportation cost by producing bricks at site of construction.

HYDRAFORM Interlocking Hydraulic machine is capable of producing 1000 of blocks per day by eight workers. Total project cost is Rs 7.5 Lac for setting up one machine unit. The project cost does not include price of land and building. Adding more machines can increase the capacity based on the demand.

The equipment is supplied by TARA (Technology and action for Rural Advancement), a leading sustainable technology marketing organisation.

Transfer forms
Product, process on turnkey basis


For further information, please contact:

Mr. Subroto Roy
Senior Business Development Executive
Development Alternatives
B-32, TARA Crescent
Qutab Institutional Area
New Delhi – 110016

Tel :     91+ 11+ 696-7938, 685-1158
Fax :    91+ 11+ 6866031
Email : tara@
devalt.org
             
sroy@devalt.org
URL:     www.devalt.org
 

7

8