A stackable rebar chair includes a one-piece body of molded plastic that includes four vertical support legs and four vertical leg receiving sockets. The one-piece body also includes first and second concave rebar cradles that are oriented perpendicular to each other. Each of the support legs has a cross section that defines a first polygon, and each of the leg receiving sockets defines a partial second polygon that is both larger, and differently shaped, that the first polygon. When the rebar chairs are stacked, the four supporting legs of the upper chair are received in the leg receiving sockets of the lower chair in such a manner that a plurality of vertices of the first polygon are positioned, shaped and oriented to simultaneously match respective vertices of the partial second polygon.

A tool device is for positioning a reinforcement mesh for concrete. The tool device may include a lever arm having a first end, a second end opposite the first end, and a pivot point between the first end and the second end. The tool device may include a pivoting vertical support coupled to the lever arm at the pivot point and cooperating with the pivot point to rotate about the pivot point, and a toe coupled to the first end of the lever arm and to engage the reinforcement mesh.

A combined structure of the combined bundle of columns in the column includes a plurality of main steel bars, a one-drawing consecutive stirrup, and a plurality of tie bars. The plural main steel bars are arrayed to form an inner confined region and an outer confined region surrounding the inner confined region. Further, the one-drawing consecutive stirrup proceeds with a one-drawing consecutive turning and surrounding along the inner confined region and the outer confined region, and surrounds a region in the one-drawing consecutive stirrup of the inner confined region so as to form a column core. As such, a complete confinement can be provided for the main steel bars, so as to effectively prevent the main steel bars from buckling, such that the performance of seismic resistance for the columns can be enhanced.

The disclosure herein discloses a rebar tying tool that ties plural rebars using a wire. The rebar tying tool includes a housing and a twisting motor, and may include a twisting mechanism that twists the wire around the plural rebars by the twisting motor. The twisting mechanism may include a screw shaft, a gripping member that grips the wire in cooperation with rotation of the screw shaft, a first reduction mechanism that reduces and transmits rotation of the twisting motor to a relay shaft, and a second reduction mechanism that reduces and transmits rotation of the relay shaft to the screw shaft. The first reduction mechanism may be a coaxial reduction mechanism, and the second reduction mechanism may be a parallel-axis reduction mechanism.

A composite rebar includes a cylindrical body having a cylindrical opening formed therethrough from a first end to an opposing second of the cylindrical body. The composite rebar is formed from a fiber reinforced polymer. The opening is cylindrical in shape and is arranged concentric with an outer circumferential surface of the cylindrical body.

The disclosure herein discloses a rebar tying tool that ties plural rebars using a wire. The rebar tying tool includes a housing and a twisting motor, and may include a twisting mechanism that twists the wire around the plural rebars by the twisting motor. The twisting mechanism may include a screw shaft, a gripping member that grips the wire in cooperation with rotation of the screw shaft, a first reduction mechanism that reduces and transmits rotation of the twisting motor to a relay shaft, and a second reduction mechanism that reduces and transmits rotation of the relay shaft to the screw shaft. The first reduction mechanism may be a coaxial reduction mechanism, and the second reduction mechanism may be a parallel-axis reduction mechanism.

The present invention relates to a novel form of self-locking mechanical rebar coupler which is able to easily couple neighboring rebars by way of an inserting plug welded to one side of the rebar, which penetrates a receiving socket which is welded to another piece of rebar. It is then locked into place by a spring-loaded dowel which penetrates the inserting plug when the inserting plug pushes down a cap at the bottom of the receiving socket which had been holding the spring-loaded dowel in place. The purpose of this coupler is to transfer a load against tensile force and compression force in a stable manner by coupling two separate pieces of rebar and locking them into place. Various diameters of rebar can be used in this self-locking mechanical rebar coupler. The assembly by providing a self-locking rebar coupling, is aimed to reduce the size of rebar components which can be combined together on a construction site and improve construction speed.

The present invention relates to a sleeve for connecting a steel bar, wherein a body prevents generation of tolerance at the circumferential surface of at least one of an upper steel bar and a lower steel bar through a tolerance generation preventing unit, the body allowing the upper steel bar to be inserted from one side thereof in an axial direction and the lower steel bar to be inserted from the other side thereof in the axial direction.

The present invention relates to a sleeve for connecting a steel bar, wherein a body prevents generation of tolerance at the circumferential surface of at least one of an upper steel bar and a lower steel bar through a tolerance generation preventing unit, the body allowing the upper steel bar to be inserted from one side thereof in an axial direction and the lower steel bar to be inserted from the other side thereof in the axial direction.

The present invention provides a fixture with which a plurality of grids can be definitely constructed in a short period of time even by an inexperienced worker without causing the worker to do heavy work. In substantially center positions in the lengthwise direction of bottom portions of first frame members, a pair of third frame members included in connecting means are provided. In the third frame member, a base portion is caused to stand on a bottom portion of the first frame member. One of arms of a U-shape of the base portion works as a holding portion included in the connecting means, and the end of the holding portion is bent inward of the base portion to form a connection bent portion having a function to engage with a circumferential surface of a vertical wire material or a lateral wire material of a second welded wire mesh, and a function to prevent the vertical wire material or the lateral wire material of the second welded wire mesh from coming off from the connecting means.