New Pre-Tensioning Method "NAPP Method" (Hollow PC Steel Rod)

The tensioning has already been introduced at our factory. This is a PC steel bar that does not require tension management or grouting work at the construction site.

The NAPP method involves placing pre-tensioned hollow PC steel rods, called "NAPP units (R)," within a formwork, and after pouring and curing the concrete, releasing the tension to introduce prestress into the concrete. The tension is introduced at our factory, which is strictly managed, and delivered to the site. At the construction site, prestress can be introduced without using reaction abutments or hydraulic jacks, eliminating the need for complex tension management, sheath placement, and grouting. This method is particularly efficient in challenging work environments, such as high altitudes, where introducing prestress is difficult. ■ Examples of NAPP method implementation Reinforcement of external cable anchorage, reinforcement of misalignment sections, reinforcement of PC steel anchorage, shear reinforcement, and lateral tightening. ■ Examples of NAPP anchor method implementation Widening of existing bridge abutment edges, reinforcement of external cable anchorage, and reinforcement of bridge substructures (widening of low slabs).

Renovation and repair methods