Axel’s take on using Cellular Beams to future-proof buildings

What is a Cellular Beam?

A Cellular Beam is a modern version of the traditional castellated beam, but with a far wider range of applications. A universal beam, or column is profiled using a patented double cut profiling process, then assembled and welded into a section size, which is approximately 40-60% deeper than its parent section. The exact finished depth, cell diameter and cell spacing are all flexible dimensions. A Cellular Beam is up to two and a half times stronger than its parent section.

Cellular Beams can be used in floor, roof and column applications. Enabling one or all of the following to be achieved: Long clear spans; service integration and/or shallow overall floor depths. Cellular Beams are the perfect solution for curved roof applications, combining a considerable weight saving with a low-cost curving process. Cellular Beams used as rafters in roof applications offer an alternative to lattice truss girder solutions. Other Cellular Beam applications include Tapered, Asymmetrical and ultra-shallow floor beams.

At Macsteel, we can manufacture Cellular Beams of up to 22m in length.

Why Cellular Beams make sense

Cellular Beams ensure section flexibility through height, diameter and spacing of the cellular holes. When it comes to the design application, there is no, limiting set dimension like with a castellated beam.

Due to the increased height, Cellular Beams are able to span longer distances while keeping the weight of the beam the same, which is a highly useful design tool for structural engineers.

Curved Cellular Beams are much more economical to produce than curved, solid I-beams, which require much more energy to curve. To illustrate, it costs roughly R11 000 per ton just to curve a solid steel profile. When it comes to Cellular Beams the cost amounts to only R300 per ton. When the beam is split, it is very weak and it bends naturally due to the release of inherent stresses from the introduction of heat. Therefore it doesn’t take much energy to curve. It is then put it back together, achieving a stronger curved element.

Aesthetically cell beams look better. Architects like the uniformity of the cellular holes and the curved element that visually allows much more flexibility with the desired structure. The curved beam may be used in different orientations to create a sinusoidal curve, which is very pleasing to the eye. Cellular Beams are primarily used in floor applications in the UK. In South Africa, the construction market is very concrete heavy with our high rise buildings mostly consisting of concrete. Cellular Beams are therefore primarily used in roof applications.

However Cellular Beams may certainly be used in floor applications. Such applications are presented in either composite or non-composite floors. Non-composite floors will consist of the cell beam with a precast hollow core slab, whilst composite floors consist of the cell beam, Voidcon or Bond-Dek (metal sheeting profile) with sheer studs on top of the sheeting. The pouring of concrete follows, to create a composite profile for the floor that is made of steel and concrete working in unison. Ultra shallow floor beams are asymmetrical Cellular Beams utilizing a universal column for the top tee and universal beam for the bottom tee. This allows for very shallow floors to be constructed where the concrete slab can sit inside the beam supported by the bottom flange. These applications all aid in creating clear span solutions whilst reducing foundations required and thus reducing cost.