An introduction to Structural Steelwork
• The beginning of steel construction • Frames in Buildings
• Structural Elements

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The beginnings of the modern day structural frame
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Joseph Paxton’s Crystal Palace of 1851 was a watershed in building design.
Its geometry was based around the size of the panes of glass. These were the largest available at the time, measuring 10 inches (254mm) wide by 49 inches
(1245mm) long.
The whole outer surface was glazed using millions of identical panes, thereby drastically reducing both their production cost and the time needed to install them.
Each module was identical, fully prefabricated, selfsupporting, and fast and easy to erect. All of the parts were mass-produced in large numbers, and many parts served multiple functions, further reducing both the number of parts needed and their overall cost.
Total building cost was £85,000

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Most of the building had a flat-profile roof, except for the central transept, which was covered by a
22m wide barrel-vaulted roof that stood 51m high at the top of the arch.
Unfortunately, when completed, rain was found to be leaking into the huge building in over a thousand places. The leaks were sealed with putty, but the relatively poor quality of the sealant materials available at the time meant that the problem was never totally overcome.
The modules could be erected as quickly as the parts could reach the site - indeed, some sections were standing within eighteen hours of leaving the factory. More than 5000 navvies worked on the building during its construction, with up to 2000 on site at one time during the peak building phase. More than
1,000 iron columns supported 2,224 trellis girders and 30 miles of guttering – a total of 4,000 tonnes of iron.

Industrial Revolution
• During the 19th Century, iron and then steel became more widely available • This permitted construction of lightweight, long spanning structures that could be constructed at greater height • Mathematical equations were also developed at this time to allow prediction of structural behaviour and material science was much better understood than previously. 27/10/2014

Structural Steelwork
• After 1900 steel largely replaced iron – its great advantage being the ability to create long rolled beams and columns from the molten state
• Since the beginning of the 20th century steel quality & fabrication methods have been continuously improved 27/10/2014

Steel Fabrication

Steelwork fabrication yards are highly computerised nowadays to allow accurate placing of bolt holes, connection plates etc etc
Steelwork connections are nowadays efficiently designed for both performance in use as well as ease of construction
Steel can be curved, chamfered and tailored to suit a multitude of design configurations

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Modern Connections
Historically rivets were used as connections.
Steelwork connections today tend to be either bolted or welded as these are both efficient design and construction methods for structural performance (ie strength, durability and deformation) as well as ease of construction

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Frames in buildings

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Common steel cross-sections

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Structural Elements
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Beams
Columns
Struts
Ties
Bracing
Members

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We defined a Structural Frame at the last lecture as:
• The beams & columns which support the floors
& roof structure and bracing which provides lateral stability
I re-iterate
• It includes only elements which are essential to the integrity/stability of