KES Aquatic Centre

Steelwork Erection Cranes utilized: - 25ton Mobile crane for offloading steelwork, stacking and infill work - 160ton Mobile crane to lift Fully assembled Plate girder portal frames - Assembled portal frame weight: 5.5 ton - Plate girder erection on 16th and 17th January 2020 - Bulk of remaining roof steelwork erected up to Covid lockdown in March 2020. - Last sections completed in May & June 2020 to main roof. Due to program constraints the swimming pool construction commenced at the same time as the steel fabrication and corrosion protection. Scaffold platforms were constructed inside the swimming pool below each portal frame assembly to support the steelwork ahead of being lifted. Each portal frame is unique and hence great care had to be taken to ensure each assembly have been assembled and placed accurately. Due to space constraints on site, the erection crane had to be set up in the road. Concrete columns had to be cast extremely accurate with Peikko COPRA Couplers in place. The Cladding Journey - Early-stage engagement with GRS Roofing to define sheeting constraints for double curvature. - Several workshops and proposal on tapered sheets, step requirements at critical junctions and purlin requirements - GRS Zip-Tek 420 sheet proposed from Chromadek Z200 sheet. - Detailed sheeting drawings and details done by GRS in agreement with Architect and Structural Engineer - Full scale worst bay mock-up done at GRS to confirm concealed fixing of Zip-Tek 420 sheet adequate to twist - Over purlin integrated Lambdaboard acoustic and thermal insulation panels proposed by Architect reviewed and approved by GRS Roofing - Insulation, sheeting and flashings installed by Lowveld Roofing Solutions

Design challenges - Creating a sleek slender structural solution within a long-span irregular architectural space = portalized plate girder solution to optimize structural depth High moment portal connections at end of plate girders to RC supports that are visible and needed robust yet elegant solution = Peikko cast-in COPRA coupler solution Corrosion protection within aquatic environment = specify aggressive coating system to plate girders and 85-micron min coating thickness to galvanized cold rolled sections Fabrication challenges - CFLC material had to be SAE1008 with min 200MPa material grade. Since SAE1008 CQ material do not come with a material certificate, material samples from two coils were sent to Metlab to be tested. QC passed coils were allocated, quarantined and used specifically for KES. The minimum galvanized coating thickness requirement for the CFLC material were 85 microns. Due to the influence the material composition of thin gauge material has on the galvanized coating thickness, the code minimum acceptable thickness is 70 microns. Similar samples to the above were hot dip galvanized prior to rolling and manufacturing of the purlins to ensure the engineer’s minimum thickness of 85 microns could be guaranteed. Detail modelling had to be done carefully due to the twist on purlins. High levels of quality control were required to ensure all steelwork have been fabricated accurately.