STEEL STRUCTURE FABRICATION
The steel-framed building derives most of its competitive advantage from the virtues of prefabricated components, which can be assembled speedily at site.
Unlike concreting, which is usually a wet process conducted at site, steel is produced and subsequently fabricated within a controlled environment.
This ensures high quality, manufacture offsite with improved precision and enhanced speed of construction at site.
The efficiency of fabrication and erection in structural steelwork dictates the success of any project involving steel-intensive construction.
Current practices of fabrication and erection of steel structures are generally antiquated and inefficient. Perhaps, this inadequate infrastructure for fabrication is unable to support a large growth of steel construction. In some countries and locations, the fabrication and erection of structural steelwork has been out of the purview of the structural designer.
Nevertheless, in the future emerging situation, the entire steel chain, i.e., the producer, client, designer, fabricator, and contractor should be able to interact with each other and improve their efficiency and productivity for the success of the project involving structural steelwork.
Hence it becomes imperative that structural designers also must acquaint themselves with all the aspects of the structural steel work including the “fabrication and erection,” to produce good fabrication and erection practices.
FABRICATION OF STEEL STRUCTURE
Structural steel fabrication can be carried out in shop or at the construction site.
Fabrication of steelwork carried out in shops is precise and of assured quality, whereas field fabrication is comparatively of inferior in quality.
In some countries and locations, construction site fabrication is most common even in large projects due to inexpensive field labour, high cost of transportation, difficulty in the transportation of large members, higher excise duty on products from shop. In some countries beneficial taxation for site work is a major financial incentive for site fabrication. The methods followed in site fabrication are similar but the level of sophistication of equipment at site and environmental control would be usually less. The skill of personnel at site also tends to be inferior and hence the quality of finished product tends to be relatively inferior.
However, shop fabrication is efficient in terms of cost, time, and quality. Structural steel passes through various operations during its fabrication.
Generally, the sequence of activities in fabricating shops is as shown in the following table:
The sequence and importance of shop operations will vary depending on the type of fabrication required.