For a long time, large spans in buildings have posed a design challenge to consultants who have to strike a balance between longer clear spans and increased dimensions of structural members. Architectural designs favor larger spans for design simplicity and aesthetics, while structural design leans towards shorter spans with closely spaced supports for a more efficient structural design
Post-tensioning technology allows designers to have longer spans with significantly thinner structural members without compromising on structural design principles. This is attributed to the higher tensile strength of post-tension reinforcement which is four times the strength of standard steel reinforcement bars and the application of external force that compresses the structural members to balance deflection under loading.
Over the years prestressed concrete technology has been widely used in roads and bridge infrastructure due to the large spans and loads requirement. This principle applies also to building construction where the system has been used as a value engineering alternative where cost savings is realized in spans greater than 7m. Therefore, its application in a building could be limited to the critical areas with large spans posing a challenge with conventional design or it could be applied to the whole building where the support columns spans are widely spaced from the initial design process.
The adoption of prestressed concrete technology, therefore, offers designers flexibility to design spaces of varying spans while maintaining the structural integrity of elements with the most economical design. It addresses the need for clear open spaces by architects while giving confidence to structural engineers. Professionals in the building industry are advised to opt for this system to develop more cost-efficient and structurally sound buildings.