An exemplary method of indicating a condition of grout within a post-tensioned tendon involves positioning a magnet and a metallic sensing plate in close proximity to an outer surface of the post-tensioned tendon; rotating the magnet and the metallic sensing plate around the outer surface of the post-tensioned tendon; measuring an amount of magnetic forces applied to the magnet during rotation of the magnet around the post-tensioned tendon; measuring an impedance between the metallic sensing plate and metallic strands within the post-tensioned tendon during rotation of the metallic sensing plate around the post-tensioned tendon; and generating an image of a cross-section of the post-tensioned tendon indicating one or more grout conditions in spatial proximity to the metallic strands within the post-tensioned tendon based on measurement data using the magnet and the metallic sensing plate.

A closure assembly includes a section of duct, a duct coupler assembly, a closure load plug, and an end cap. The duct coupler assembly is fit against the section of duct. The closure load plug is mechanically connected to the duct coupler assembly. The end cap is mechanically connected to the closure load plug.

A closure assembly includes a section of duct, a duct coupler assembly, a closure load plug, and an end cap. The duct coupler assembly is fit against the section of duct. The closure load plug is mechanically connected to the duct coupler assembly. The end cap is mechanically connected to the closure load plug.

A pre-compression system for pre-compressing a concrete structure, the system comprising a first tubular element (31) that is expandable in a longitudinal direction and interposed between the first and the second head (21, 22). The first tubular element (31) is movable between a longitudinally elongated configuration, in which a pressurized fluid is placed inside the first tubular element (31), and a contracted configuration, in which said fluid is at least partly removed, the passage from the elongated configuration to the contracted configuration bringing about a compression on the concrete which at least partly envelops the first tubular element (31).

A pre-compression system for pre-compressing a concrete structure, the system comprising a first tubular element (31) that is expandable in a longitudinal direction and interposed between the first and the second head (21, 22). The first tubular element (31) is movable between a longitudinally elongated configuration, in which a pressurized fluid is placed inside the first tubular element (31), and a contracted configuration, in which said fluid is at least partly removed, the passage from the elongated configuration to the contracted configuration bringing about a compression on the concrete which at least partly envelops the first tubular element (31).

An assembly and method for repairing sheathing on a tension member of a post-tensioning tendon may include an outer tube having first and second end portions, a tubular long seal positioned inside the outer tube, the tubular long seal being shorter than the outer tube, first and second seals positioned in the first and second end portions of the outer tube, respectively, and first and second nuts retaining the first and second seals in the first and second end portions of the outer tube, respectively. The assembly may define a longitudinal passage adapted to receive the tension member and the presence of the assembly on the tension member seals the portion of the tension member that is within the assembly. An inner tube may be positioned between the outer tube and the tubular long seal and may radially compress the tubular long seal.

An assembly and method for repairing sheathing on a tension member of a post-tensioning tendon may include an outer tube having first and second end portions, a tubular long seal positioned inside the outer tube, the tubular long seal being shorter than the outer tube, first and second seals positioned in the first and second end portions of the outer tube, respectively, and first and second nuts retaining the first and second seals in the first and second end portions of the outer tube, respectively. The assembly may define a longitudinal passage adapted to receive the tension member and the presence of the assembly on the tension member seals the portion of the tension member that is within the assembly. An inner tube may be positioned between the outer tube and the tubular long seal and may radially compress the tubular long seal.

An anchor assembly for use on a tension member in a post-tensioning concrete application, the anchor assembly may comprise an encapsulated anchor body, the encapsulation defining front and rear encapsulation extensions, a rear nut engaging the rear encapsulation extension, a cap engaging the front encapsulation extension and having a cap extension, a front nut engaging the cap extension, wherein placement of a tension member in the anchor assembly results in definition of front and rear annular spaces, and front and rear seal positioned in the front and rear annular spaces, respectively. The seals may be split seals. A method includes positioning a tension member in the bore, decoupling the cap from the front encapsulation extension, positioning at least one wedge in the frustoconical inner chamber, recoupling the cap, decoupling the front and rear nuts; positioning a seal in each annular space, and recoupling the front and rear nuts.

An assembly for use with a post-tensioning tension member may comprise an anchor body; an anchor encapsulation including rear and front encapsulation extensions; a rear nut coupled to the rear encapsulation extension; a cap coupled to the front encapsulation extension and including a cap extension; a cover extending around a portion of the tension member, the cover being tubular and having proximal and remote end portions; a coupler coupled to both the cap extension and the proximal end portion; and a remote nut coupled to the remote end portion. The assembly may further include a rear seal positioned between the rear encapsulation extension and the tension member; a front seal positioned between the cap extension and the tension member; a proximal seal positioned between the proximal end portion and the tension member; and a remote seal positioned between the remote end portion and the tension member.

There is provided a method of prestressing a beam-column joint with an appropriate ratio among the magnitudes of compression in the directions of X, Y, and Z axes. The method introduces prestress in a beam-column joint with a tensile introducing force generated by tensionally anchoring prestressing tendons that are arranged in PC beams extending along two horizontal directions (or X axis and Y axis) and PC columns extending along the vertical direction (or Z axis) and passed through the beam-column joint to bring the beam-column joint in triaxial compression, the prestress being introduced such that a diagonal tensile force T generated by an input shear force due to a seismic load of an extremely great earthquake that may occur very rarely will be cancelled completely or partially so as not to allow diagonal cracks to occur. The ratio of the prestresses introduced in the directions of the respective axes satisfies the following equation (1):
σx:σy:σz=1:1:0.3−0.9   (1)
where σx, σy, and σz are prestresses introduced in the directions of the X axis, the Y axis, and the Z axis respectively.