Post-tensioned reinforced concrete takes advantage of the excellent tensile behavior of high strength steel combined with concretes high compressive strength.
Thus, by tensioning up the steel tendons, compression forces and internal forces resulting from the profile of the strands are introduced in the structural elements.
As so, post tensioned structural elements final forces will be subject to a combination of external loads and forces of the prestressing action, resulting in an extremely favorable deformation and state of tension.
Advantages on the use of post-tensioning:
- Longer spans of the structures
- Greater slenderness of the structural elements
- Decreased self-weight
- Service and long-term behavior improvement
- Smaller deformations
- Rational use of concrete and high-strength steel
Post-tensioning systems and techniques:
- Steel is tensioned after the concrete achieves the necessary resistance (post-tension);
- The post-tensioning strengths transfer is made at the extremities, by the use of mechanical components (anchorages) and along the length of the strands.
Schematic principle of the post-tensioning action:
Action of the post-tensioning cable on the concrete
Fercanorte supplies its technical services to support and follow up of the project, designing, ultimate and serviceability limit state verification and economic analysis of the reinforced concrete or post-tensioned reinforced concrete slabs.
The analysis considers the following:
- Finite element structural modeling;
- Concrete cross-section optimization;
- Service state deformation verification
- Evolution of material properties over time (fluence, retraction and relaxation);
- Effects of the internal and external imposed deformations;
- Cost analysis according to market.
- Post-tensioning application projects, loss calculation, verification and optimizations of rebar and PT strands (flexion, shear and punching shear);
Fercanorte uses in its projects the
Mekano4 post tensioning system.
Unbonded Post-Tensining:
MUNB 1/0,6” anchor
Bonded Post-Tensining:
ML4/0,6" flat anchor and MSA anchor
