An improved method and apparatus for evaluating post-tensioning tendons, where the apparatus uses a positioning head placed directly into the pocket and against the anchor without making contact with the wedges as the apparatus seats on the tendon. From this position the apparatus evaluates the tendon by marking, measuring the tendon, and/or determining its location with increased reliability and precision.

In some embodiments, the disclosure is directed to a cable tensioning unit. In some embodiments, the cable tensioning unit includes a hydraulic jack mounting on a unit housing. In some embodiments, the unit housing includes a control panel with one or more actuators configured to control one or more pulling functions. In some embodiments, the cable tensioning unit includes a controller and a controller interface that enables a user to set interlocks and/or enter pull information. In some embodiments, pull information includes one or more of bed number, bed length, strand size, strand number, target initial tension, target final tension, target final elongation, date, time, actual initial tension, and/or actual final tension. In some embodiments, the controller is configured to automatically save data during one or more transient operations. In some embodiments, the controller is configured to display if pull information is within a tolerance during a pull operation.

An encapsulated splice chuck may include a splice chuck body and a body encapsulation positioned about an exterior surface of the splice chuck body. The encapsulated splice chuck may also include a first forcing cone threadedly coupled to the splice chuck body, the first forcing cone including a tapered inner surface. In addition, the encapsulated splice chuck may include a first forcing cone encapsulation positioned about an exterior surface of the first forcing cone and a first set of wedges positioned within the first forcing cone. The encapsulated splice chuck may include a second forcing cone mechanically coupled to the splice chuck body, the second forcing cone including a tapered inner surface, and a second forcing cone encapsulation positioned about an exterior surface of the second forcing cone. The encapsulated splice chuck may also include a second set of wedges positioned within the second forcing cone.

A system for monitoring tension forces of tendons disposed inside a concrete structure in post-tensioning includes a hydraulic jack coupled to one tendon at one end of the concrete structure to apply the tension force to the tendon by means of the forward movement of a piston; a hydraulic pump connected to the hydraulic jack by means of a hydraulic pressure supply pipe to supply a hydraulic pressure to the hydraulic jack; a digital elongation length measurement sensor disposed on the hydraulic jack to measure the elongation length of the piston; a measurement unit having a data logger adapted to receive and store the elongation length data measured by the digital elongation length measurement sensor and to send the elongation length data to a main server; a digital pressure measurement sensor disposed on the hydraulic pressure supply pipe of the hydraulic pump; and a control module adapted to receive the elongation length data from the data logger or the main server, calculate the tension force, compensate for the coefficient of elasticity of the tendon according to the ratio of the real-time elongation length data to the pressure data, and compensate for the tension force calculated.

A method for producing a three-dimensional construction material component preferably having at least one curved surface. A plurality of spacers are arranged in a formwork. A textile reinforcement is supported on the spacers, such that the textile reinforcement has a defined position within a formwork interior of the formwork. A tensile force is applied via a tensioning device to the textile reinforcement in at least one tension direction. Construction material is introduced into the formwork interior and surrounds the textile reinforcement. The construction material is then hardened, wherein the tensile force is maintained during the hardening. During this process, the spacers are integrated into the construction material component. The tensioning device has at least one clamping unit for clamping an end portion of the textile reinforcement between two clamping surfaces. The clamping surfaces are provided on clamping insert bodies, which are of a plastic material of a defined hardness.

A system for monitoring tension forces of tendons in post-tensioning includes a hydraulic jack to apply the tension force to the tendon, a hydraulic pump to supply a hydraulic pressure to the hydraulic jack, a digital elongation length measurement sensor to measure the elongation length of the piston, a measurement unit having a data logger adapted to receive and store the elongation length data measured by the digital elongation length measurement sensor and to send the elongation length data to a main server, a digital pressure measurement sensor, and a control module adapted to receive the elongation length data from the data logger or the main server, calculate the tension force, compensate for the coefficient of elasticity of the tendon according to the ratio of the real-time elongation length data to the pressure data, and compensate for the tension force calculated.

It is described an assembly for lifting pre-stressing cables for a pre-stressed concrete structure having ducts for pre-stressing cables, to be arranged on top of the concrete structure, comprising: (a) a rail 22 on which a hoist or pulley 30 is arranged, which has wheels, which allow hoist 30 to move along the rail 22; (b) a supporting structure 12, attached to rail 22; (c) a plurality of columns 14, which supports the supporting structure 12 of the rail 22, arranged at a certain distance from the rail; and (d) an hoists 30 having a chain 34 which is inserted into the vertical ducts 52 for the pre-stressing cables of the concrete structure, and uploads the wires to the top of the structure.

A lightweight jack includes a pressure cylinder, where the pressure cylinder has a pressure cylinder passage and a pressure cylinder body, the pressure cylinder body being a block through which a cylinder body passage is formed. The pressure cylinder is mechanically coupled to the pressure cylinder. The lightweight jack further includes a hydraulic actuator, where the hydraulic actuator is coupled to the pressure cylinder body. The hydraulic actuator includes an inner hydraulic cylinder, the inner hydraulic cylinder mechanically coupled to an inner cylinder head, and an outer cylinder, the outer cylinder mechanically coupled to an outer cylinder head. The lightweight jack also includes an extending body, the extending body coupled to the hydraulic actuator. The extending body is a block through which an extending body passage is formed, wherein the pressure cylinder passage, the cylinder body passage, and the extending body passage are aligned to form a tension member channel. The lightweight jack also includes a strand grabber, the strand grabber mechanically coupled to the extending body. The pressure cylinder, outer cylinder, and strand grabber are made of aluminum, titanium, fiber reinforced plastic, polymers, or carbon fiber.

An encapsulated splice chuck may include a splice chuck body and a body encapsulation positioned about an exterior surface of the splice chuck body. The encapsulated splice chuck may also include a first forcing cone threadedly coupled to the splice chuck body, the first forcing cone including a tapered inner surface. In addition, the encapsulated splice chuck may include a first forcing cone encapsulation positioned about an exterior surface of the first forcing cone and a first set of wedges positioned within the first forcing cone. The encapsulated splice chuck may include a second forcing cone mechanically coupled to the splice chuck body, the second forcing cone including a tapered inner surface, and a second forcing cone encapsulation positioned about an exterior surface of the second forcing cone. The encapsulated splice chuck may also include a second set of wedges positioned within the second forcing cone.

It is described an assembly for lifting pre-stressing cables for a pre-stressed concrete structure having ducts for pre-stressing cables, to be arranged on top of the concrete structure, comprising: (a) a rail 22 on which a hoist or pulley 30 is arranged, which has wheels, which allow hoist 30 to move along the rail 22; (b) a supporting structure 12, attached to rail 22; (c) a plurality of columns 14, which supports the supporting structure 12 of the rail 22, arranged at a certain distance from the rail; and (d) an hoists 30 having a chain 34 which is inserted into the vertical ducts 52 for the pre-stressing cables of the concrete structure, and uploads the wires to the top of the structure.