Multi story buildings in steel have been used extensively in Europe and surrounding areas since the 1940’s. With today’s advanced technology and latest innovations, the use of structural steel and concrete composite deign is being applied in the construction of multi-story buildings. In addition to a faster construction speed, an increased economy is achieved when applying such design techniques.
STRUCTURAL STEELWORK SPECIFICATIONS
The applicable British Standard specifications shall apply appropriate to materials and workmanship.
All steelwork has to be manually cleaned with wire and painted with one coat of red oxide zinc paint before dispatch
All bolts have to be mild steel and to have a tensile strength of not more than 432N/mm2 (28tons/inch2) and a minimum elongation of 17%. All steel washers have to be mild steel.
Where applicable all high tensile nuts and washers are to have a minimum tensile strength of 570N/mm2 (37tons/inch2)
Decking sheets are fixed to the top flange of I-Beams with self-drilling screws. The decking sheets are designed to free span between the beams, therefore eliminating the need for props and shuttering during the casting of the concrete slab. This makes the construction method very quick and efficient since the contractor does not wait for the curing time of the slab before moving to other upper floor levels.
An Alu-Zinc coated angular trough profile is used with thickness varying from 0.5mm to 1.2mm depending upon the design load.
The decking sheets act as permanent shutter supporting both the construction and final design loads and therefore the bottom of the shutter acts as the slab soffit finish.
The composite steel beam and concrete deck system can be designed to accommodate loads of 2.5KN/m2 for light weight office blocks and 10.0KN/m2 for heavy industrial load and car park systems.
As the design load increases additional reinforcement can be added to the slab to resist high shear loads and longitudinal loading stress.