Abstract

The use of aluminium as material of choice in the manufacture of window and door openings in Mauritius has escalated significantly in recent years. This has given rise to a considerable number of small-and medium-sized companies operating in the aluminium fabrication sector. The main aim of this study was to identify and investigate the common problems reported with aluminium openings and to assess the structural resistance, water-tightness and safety of the openings. A survey was carried out among local aluminium importers and fabrication companies to gather information about the different profiles and grades of aluminium commonly used for exterior window and door applications in the residential sector. A questionnaire was designed and circulated to clients of aluminium fenestration products. This helped to identify the most common problems encountered with aluminium openings. Site visits were also conducted which enabled the investigation of some common problems identified such as water ingress and rigidity of moving parts. The structural loading of openings was assessed using finite element analysis using SolidWorks. Models of openings of different sizes and corresponding to typical opening designs used locally were created and a uniform pressure was applied on the frames. This uniform pressure was derived from a wind speed of 280 km/h – the maximum wind speed used for design calculations for buildings in Mauritius. The resulting deflections were analysed and compared to the maximum permissible deflections – which were calculated using the guidelines of North American Fenestration Standard (NAFS-11). Results showed that the maximum deflections for frames sizes exceeding a span of 1.5 m, exceeded the maximum allowable values, and necessitated the use of more rigid profiles. Deflections observed in the triple frame design were also higher than those in the double frame. These observations point out to the need of selecting the right profiles for different sized applications to ensure that openings do not incur significant deflections when subjected to wind loads, which would be encountered during severe cyclonic conditions in the island.