12 Sep What’s behind the rise of elevated post-tensioned slabs?
Post-tensioned concrete in-situ (i.e. formed on site) was first developed in the 1960s. This form of construction has become prevalent throughout the UK, Singapore, Philippines, Australia and the United States.
Until recently, pre-cast concrete construction was the default construction method in this country. However, there are three developments in the past decade or so that have led to post-tensioned slabs becoming much more popular in multi-storey developments.
Firstly, we’ve seen the emergence of material supply chain pressures that have extended construction programmes.
Secondly, seismic events have revealed fundamental structural deficiencies in older construction techniques, leading to a re-appraisal of the place of pre-cast concrete.
Finally, we have imported overseas labour who are unfamiliar with pre-cast construction. As a result, many local buildings that would have been earmarked for precast construction at the feasibility stage are no longer stacking up as commercially viable.
Why not use steel instead?
Of course, concrete isn’t the only material suitable for high-rise structures. But steel-based construction brings its own issues.
Steel is subject to a volatile pricing index, leading to unpredictable material costs. It also requires expensive coatings for fire and corrosion protection that in turn necessitate ongoing maintenance.
Both steel and pre-cast construction also require significant crane time on site, and need larger cranes due to the size of the components being transported and lifted into place. With elevated post-tensioned slab construction, it is possible for the entire structure to be poured on site, significantly reducing crane dependency.
We look forward to showcasing a number of premier construction projects, from luxury apartments and hotels though to student accommodation, carparks and shopping malls – all of which take advantage of the flexibility and security of elevated post-tensioned slab-based construction.