Clear Span is a term to describe the distance between the two inside surfaces of the span supports – the distance that is unsupported (i.e. a wide space clear of pillars or columns). For any width over 21 metres void of beams or posts, a pre-engineered steel structure is the way to go.
A clear span building offers the most usable space and is ideally suited to factories and warehouses where vehicles such as fork lift trucks are used within the building. Other applications include aircraft hangers and indoor sports complexes.
As with all pre-engineered steel buildings, there are advantages in terms of self-weight, high strength-to-weight ratio, seismic resistance, green building characteristics, precise design and prefabricated in the factory, and efficient construction.
However, with large clear-span steel buildings, these values become augmented:
1. Maximises the high strength characteristics of steel, thereby reducing the structural steel material per m2. On average, the weight per m2 could be 25kg to 60kg in clear span buildings.
2. Increases energy-savings in construction process as the building gets bigger, enabled by modular assembly, fully bolted building and prefabrication to exact dimensions. Compared with traditional concrete construction, this savings could be more than 30%.
3. Magnifies Green Building characteristics
- Dust pollution reduction of more than 80% at the construction site.
- Precise engineering and prefabrication to exact dimensions at the factory enable reduction of scrap to a larger extent (volume) both in the factory and at site.
- When a pre-engineered steel building reaches the end of its service life, more than 90% of the discarded steel components can be recycled and reused.
4. Stronger seismic resistance as large-span steel structure buildings have good ductility. When damaged under dynamic impact load, it can absorb a lot of energy, thereby reducing the risk of brittle damage of buildings.
