Pioneered in the 1930s by French, structural engineer, Eugene Freyssinet, post-tensioning is a system for reinforcing concrete, structural elements. It consists of pre-installed steel tendons that run the length of the beam or deck span, are anchored at both ends, and then are stressed when installed.
By applying a pre-stress load, post-tensioning pre-emptively counteracts tensile stresses and is therefore an active reinforcing system, whereas rebar is passive. By keeping the concrete in compression, post-tensioning strengthens the concrete and foundation and helps reduce cracking. While the buildings can stand on their own, the post-tensioning carries the load.
Post-tensioning is typically used in parking decks, garages, bridges, and nuclear reactors built since the 1970s and 1980s. With age comes wear and deterioration. What original designers didn’t foresee, however, was the extensive use of salts and de-icing chemicals on these structures in cold weather. This contributed to faster wear and a greater degree of damage, including rust, which must be identified and repaired to keep the structures safe.
Many engineers evaluating the condition of these older structures were not even born when these structures were built. New engineers must assess buildings and make determinations when there is quite possibly no engineering information available from the original design. In addition, today’s engineers may not be as familiar with older systems which can be very different from the modern systems they install today. For example, parking decks built today are waterproofed; 50 years ago, they were paper wrapped. Most owners don’t know what materials were used in their structures, and most engineers don’t know how to deal with button head or rod systems from the early 1970s.
That’s where Colorado’s experts in post-tension repair come in. HEXA’s team has the in-depth know-how to repair and restore these structures safely and efficiently. We can help you understand what cracking, joint/slab misalignment, or chemical leaks from walls means for the future of your structure – and what it takes to repair it. Reach out today, and let’s chat about how we can help you add many useful and safe years to the life to your structures. Check out our Post-Tension Repair brochure here.