A stud-weldable rebar and a method for making the rebar are disclosed. The rebar has a steel body with a weld end and a diameter that is substantially uniform along a length of the body. A tip portion at the weld end includes a hardened zone and a base portion is formed of the remaining steel body. The hardened zone has a hardness that is about 1.5-3.0 times greater than a hardness of the base portion. Induction hardening is used to form the hardened zone.

A rebar anchoring system and method are provided. The system includes: a rebar, with an external thread formed on the periphery of at least one end; an anchoring head, with a first perforation and a second perforation disposed respectively at both ends extending axially into the anchoring head and communicating with each other, the inner sides of the first and second perforations being formed respectively with a first internal thread matching with the external thread of the rebar and a second internal thread, and the anchoring head being mounted on the end of the rebar through the first internal thread and the external thread of the rebar; and a bolt, having a screw rod matching with the second internal thread, the screw rod being locked into the second perforation of the anchoring head, and the end of the screw rod pressing against the end of the rebar.

Method and means of manufacturing ties, fasteners and rods (15) having a plurality of longitudinal threads by forcing a coil of roll-profiled feed-wire made of steel (11) through a twisting-die made of plastic (1). Also described is: a twisting-die made of plastic (1) that is suitable for twisting profiled feed-wire (11) made of steel; a method of forming a plastic twisting die (1) using an driven tap (31) in the form of a twisted rod (15); and a helically-shaped member (15) having lead measurements (X) along the length of the helical thread that vary less than pitch measurements (Y) along the lengths of the helical threads.

A rebar anchoring system and method are provided. The system includes: a rebar, with an external thread formed on the periphery of at least one end; an anchoring head, with a first perforation and a second perforation disposed respectively at both ends extending axially into the anchoring head and communicating with each other, the inner sides of the first and second perforations being formed respectively with a first internal thread matching with the external thread of the rebar and a second internal thread, and the anchoring head being mounted on the end of the rebar through the first internal thread and the external thread of the rebar; and a bolt, having a screw rod matching with the second internal thread, the screw rod being locked into the second perforation of the anchoring head, and the end of the screw rod pressing against the end of the rebar.

The joint has a prefabricated-reinforced-concrete column, a reinforced-concrete foundation, a column anchoring longitudinal bar, a grouting sleeve and a foundation anchoring steel bar. The foundation anchoring steel bar and the column anchoring longitudinal bar are connected by a seam filling material filling the grouting sleeve. A splicing seam between the reinforced-concrete foundation and the prefabricated-reinforced-concrete column is filled with the seam filling material. The foundation anchoring steel bar includes a vertical portion and a horizontal portion. The vertical portion includes an upper-portion anchoring section protruding out of an upper surface of the reinforced-concrete foundation, a middle-portion non-adhesive section buried within the foundation and a lower-portion anchoring section. An exterior of the middle-portion non-adhesive section is provided with an isolating sheath for isolating the middle-portion non-adhesive section and the concrete adhesion.

A threaded reinforcing bar coupling structure comprises a pair of reinforcing bars and a tubular coupler connecting the pair of reinforcing bars. Each of the reinforcing bars is a deformed reinforcing bar having spiral node portions on an outer periphery of a reinforcing bar main body having a round shaft shape. A cylindrical portion with node portions removed is formed on an end portion of the reinforcing bar, and a male threaded portion is formed on the cylindrical portion. The male threaded portion has hardness or tensile strength greater than that of a remaining portion of the reinforcing bar. The pair of reinforcing bars is connected by the screw tubular coupler that is screwed onto the male threaded portions.

A threaded reinforcing bar coupling structure comprises a pair of reinforcing bars and a tubular coupler connecting the pair of reinforcing bars. Each of the reinforcing bars is a deformed reinforcing bar having spiral node portions on an outer periphery of a reinforcing bar main body having a round shaft shape. A cylindrical portion with node portions removed is formed on an end portion of the reinforcing bar, and a male threaded portion is formed on the cylindrical portion. The male threaded portion has hardness or tensile strength greater than that of a remaining portion of the reinforcing bar. The pair of reinforcing bars is connected by the screw tubular coupler that is screwed onto the male threaded portions.

A composite structure includes a concrete matrix and a fiber embedded in the concrete matrix. The fiber includes steel. A surface of the fiber has a series of striations. The series of striations are arranged in a striation pattern.

A composite structure includes a concrete matrix and a fiber embedded in the concrete matrix. The fiber includes steel. A surface of the fiber has a series of striations. The series of striations are arranged in a striation pattern.

A stud-weldable rebar and a method for making the rebar are disclosed. The rebar has a steel body with a weld end and a diameter that is substantially uniform along a length of the body. A tip portion at the weld end includes a hardened zone and a base portion is formed of the remaining steel body. The hardened zone has a hardness that is about 1.5-3.0 times greater than a hardness of the base portion. Induction hardening is used to form the hardened zone.