Post-tensioned (PT) slabs

Post-tensioned (PT) slabs are typically flat slabs, band beam and slabs or ribbed slabs. PT slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. Longer spans can be achieved due to prestress, which can also be used to counteract deflections.

Post-tensioned slabs use high-strength tensioned steel strands to compress the slabs, keeping the majority of the concrete in compression. This gives a very efficient structure which minimises material usages and decreases the economic span range when compared to reinforced concrete.


Download 'High tension: An introduction to specifying post-tensioned slabs', an article extracted from Concrete Quarterly, spring 2020. 

More information on post-tensioning, including example case studies, can be found at the Post-tensioning Association (PTA) website at

Post-tensioned Concrete Floors