Saturday, May 6, 2017
WHAT IS PREFABRICATION ?
- The concept of precast structures also known as prefabricated/ modular structures.
- The prefabrication is the oldest and most successful construction techniques.
- Prefabrication is a practice of assembling components of a structure in a factory or other manufacturing site and transporting complete assemblies to the construction site where the structure is located.
- On industrial basis it is accepted in Civil Engineering ,car, aircraft , manufacturing without question
HISTORICAL DEVELOPMENT: PREFABRICATION
- Prefabrication has been used since ancient times. For example, it is claimed that the world's oldest known engineered roadway, the Sweet Track constructed in England around 3800 BC, employed prefabricated timber sections brought to the site rather than assembled on-site
- Sinhalese kings of ancient Sri Lanka have used prefabricated buildings technology to erect giant structures, which dates back as far as 2000 years, where some sections were prepared separately and then fitted together, specially in the Kingdom of Anuradhapura and Kingdom of Polonnaruwa
- In 19th century Australia a large number of prefabricated houses were imported from the United Kingdom.
- The method was widely used in the construction of prefabricated housing in the 20th century, such as in the United Kingdom to replace houses bombed during World War II.
- The Crystal Palace, erected in London in 1851, was a highly visible example of iron and glass prefabricated construction; it was followed on a smaller scale by Oxford Rewley Road railway station.
- The Victorian Engineers took their lead from the earlier pioneers of the Industrial Revolution and tackled many projects in ways which were then innovative, to produce structure which could not be made without prefabrication
- Stephenson in 1845 moved the main box girders for the Britannia Bridge across the Menai Straits on barges to be then jacked up on their final abutments.
- Concrete structures have also been similarly constructed and moved in a variety of ways.
How is the scope of precast
construction in India?
•Employment for about
33 million people in India.
•Rapid development in
its technology,
•In this line, Indian
construction industry now marches towards high rise constructions in housing
and industrial buildings, underground tunnelling, roads, etc.
•The present economic
growth demands faster construction without losing quality aspects and without
project delay, project cost outfit involved in labour shortage or similar
related construction uncertainties. This further justifies the use of precast
technology.
•In India, European
technology is being used widely in precast factories for concrete batching,
handling and placing purposes at the moment. Among those, WECKENMANN Anlagentechnik GmbH & Co. KG,
Germany, having its own office in Delhi NCR, is one of the notable and
established players in supplying both automatic/semi-automatic machineries for
typical precast factory installations.
•In Delhi NCR -
Ghaziabad, BCC Infrastructures is developing a huge township where precast
concrete elements of wall panels, lattice girder half slabs, staircases and
balconies will be produced at site factory to erect high rise residential
towers. The precast on-site factory will be operational in the first quarter of
2014.
The future of precast construction in
India: a forecast
•The number of
existing precast facilities in India which produce both floor and wall panels
and also possess the requisite knowledge is clearly concentrated mainly around
the major cities of the country.
•But this will
certainly change in the near future. In the coming years, especially in the
middle and lower residential construction segments, there will continue to be a
very strong demand. These demands, in conjunction with increasing customer
requirements in the areas of quality and delivery time, can only be met with a
successful introduction of new production methods such as precast technology.
