Fabrication - Multi-Storey Building Form.

The choice of structural form and method of connection detailing have a significant impact on the cost and speed of fabrication and erection. Simple braced frameworks with bolted connections are considered the most economic and the fastest to build for low- to medium-rise buildings.

Economy is generally linked to the use of standard rolled sections but, with the advent of automated cutting and welding equipment, special fabricated sections are becoming economic if there is sufficient repetition.

The development of efficient, automated, cold-sawing techniques and punching and drilling machines has led to the fabrication of building frameworks with bolted assemblies.Welded connections involve a greater amount of handling in the fabrication shop, with consequent increases in labour and cost.

Site-welded connections require special access, weather protection, inspection and temporary erection supports. By comparison, on-site bolted connections enable the components to be erected rapidly and simply into the frame  and require no further handling.

The total weight of steel used in continuous frames is less than in semicontinuous or simple frames, but the connections for continuous  frames are more complex and costly to fabricate and erect.On balance, the cost of a continuous frame structure is greater, but there may be other considerations which offset this cost  differential. For example, in general the overall structural depth of continuous frames is less.This may reduce the height of the building or improve the distribution of building services, both of which could reduce the overall cost of the building.

Corrosion protection to internal building elements is an expensive and time- consuming activity. Experience has shown that it is unnecessary  for most internal locations and consequently only steelwork in risk areas should require any protection. Factory-applied coatings of intumescent fire protection can be cost-effective and time-saving by removing the operation from the critical path.

0 comentarios:

Post a Comment