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Concrete block technology

 

In present construction scenario, concrete blocks are well-accepted masonry unit to build foundations, walls, arches and corbels, etc. A typical concrete block is equivalent to 4.5 bricks, thus construction is faster than with other masonry units. The mortar used is also less which results in cost saving. Concrete blocks have been extensively used in combination with conventional roofing systems like RCC, RBC, GI sheets, ACC sheets etc. They are also compatible with other materials like fired bricks, dressed stone and compressed earth blocks for composite wall construction.

Acceptability of concrete blocks is very high in urban areas for all types of buildings. It is a popular walling material for major qualities like low maintenance and investment for institutional and industrial buildings. The durability of a cement-based product is making concrete blocks a preferred choice in rural areas as well.

The Product
Specifications and the characterizations of concrete blocks depend upon design mix and the machine used to manufacture the block. The most common size of solid concrete blocks is 300x200x150mm. The SAKAR machine from Susanji Udyog Pvt Ltd. is a versatile equipment which produces solid, hollow, paving, tree guard and toilet interlocking concrete blocks of various sizes with the same equipment. It is possible to produce all these blocks with the single machine by just changing the mould. The basic raw material is cement, fine aggregate and coarse aggregate. The mechanised compaction and vibration, gives the block high quality, inspite of the lean mix, which uses very little cement. Weight of an average concrete block is about 18-20 kgs. Concrete blocks can be surface engineered by using pieces of stone or ceramic waste on their face.

The production process
This machine with high quality tabletop vibrator provides 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 design mix corresponding to required compressive strength is prepared using the mixer and then it is filled in the moulds, which are placed on the vibrator. The machine also compacts and consolidates the mix so that the blocks are uniform in size and attain desired physical properties. The blocks are cured for a minimum period of 14 days, before they are ready to use. On an average 600-800 blocks can be in 8 hours with 1 supervisor, 1 skilled and 6-8 unskilled workers.


 Advantages

Cost effective compared to other traditional walling systems
High quality high strength, uniform size and shape
Energy efficient - Does not require any non-renewable resources for production
Environmental friendly - Utilises wastes and local resources
Structural performance can be engineered as per application
Decentralised production allows both factory and on-site production
Machine production provides smooth finish which offers savings on further cement plaster etc
Semi mechanised process produces high quality material and provide adequate working opportunities

Areas of Application
Concrete blocks have various types like; solid, hollow, paving, treeguard blocks, and each of them are available in various shapes and sizes. This vast range of products offers a large market for application.

In load bearing structures - low rise residential and office buildings, bungalows, shelter units for rural housing, highway constructions, institutional buildings, godowns and warehouses etc
In frame structures High rise residential apartments, office buildings, market complexs, hospitals and hotels etc
As ground laying units interlocking paving blocks for roadside walkways, garden pathways, curb stones, exhibition grounds, fuel pumping stations, movement corridors, high traffic movement areas like : bus and train stations etc.
Specific usage areas: tree guard blocks for road side and garden tree plantations


Development Status

Commercialized 
 

Technical Data

Annual production for solid or hollow blocks 180,000 (with 600 blocks/day) for paving blocks 300,000 (with 1000 blocks/day)
Land requirement 180 m2 of covered working space and cement godown Total 2000m2 for casting, demoulding, curing,stacking and movement space
Electricity requirement 5 KVA
No.of jobs created 8 (1 supervisor, 1 skilled, 6 unskilled)


 

Economic Data

Infrastructure cost for office and workshop includes: Working shed, office space, cement godown, facilities-electricity and water)  Rs 100,000
Equipment  (With 25 No of moulds for solid, hollow and paving blocks and concrete mixer and accessories) Rs 122,000
Hydraform with pan mixer (with hydraulic machine) Rs 475,000
Transportation and insurance (in India) Rs 12,000
Installation and know how transfer Rs 15,000
Total (package with hydraulic machine) Rs 2,49,000/- (US$ 4,820)
These cost do not include cost of land, as it varies considerably from place to place)

  

Business
Concrete block technology is a highly profitable business for small scale building material producers or civil contractors and builders. A total investment of Rs. 2,49,000/- for a semi-mechanised production system assures a turnover of Rs 16,50,000/- per annum. Looking at the fast growing market for concrete blocks, it has a recovery potential of more than 50% percent of investment, within first year of operations. The equipment is marketed 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+ 2696-7938, 2685-1158
Fax :    91+ 11+ 26866031
Email : tara@
devalt.org
             
sroy@devalt.org
URL:     www.devalt.org
 

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