The floor arrangement at the Paris Office project is an excellent example of a steel framed building using modern long-span construction techniques.

London Office 1 is a typical composite steel framed building using long-span construction. In order to provide uninterrupted areas of office space, the structural solution adopted cellular beams.

London Office 2 is a typical composite steel framed building using cellular beams. On plan, the floor construction uses long-span secondary beams, which span between the central core area and the building façade, with their spacing dictated by the spanning capabilities of the composite slab.

London Office 3 is another excellent example of a composite steel framed building using long-span construction techniques. In order to minimise the floor zone, the structural solution adopted very shallow cellular beams.

London Office 4 is a recently constructed composite steel framed building using cellular beams.

Planning and architectural restrictions have always resulted in structural and service Engineers competing with each other for the available space.

Structural zones are squeezed up resulting in heavier inefficient structural solutions. Whilst at the same time the service Engineer is forced to use inefficient high aspect ratio rectangular ducting.

Cellular beams solve both problems with consequential environmental advantages.

A presentation illustrating how cellular beams solve both planning and architectural restriction problems with consequential environmental advantages.

Rolling tolerances for beams

Concern has been raised that the temperature of the web-post in a cellular beam with intumescent coating increases at a faster rate compared to a similar size web in a solid beam. If the temperature of the web-post increases faster than expected premature failure of the cellular beam could occur due to instability of the web-post.

To investigate whether the web-post temperatures increase, at a faster rate than expected, a series of tests were derived on unloaded, protected and unprotected, indicative beams. This report presents the results from the first of the series of tests on an unloaded, unprotected, cellular beam and an identical solid web beam. Both the cellular and solid beams were placed in the same furnace and thus subjected to the same temperature environment.

Researches sponsored by ECSC have just demonstrated that, in case of fire in car parks or in high buildings, it is generally not necessary to insulate the steel section (beam and/or columns) to obtain a satisfactory safety level. These researches are based on some specific simple fire tests and on numerical simulations.