JPH01158151A - Joint structure of reticulate reinforcement - Google Patents

Abstract

PURPOSE: To smoothly transmit the stress in a joint part, prevent concrete fracture in the joint part, and improve the proof stress and deformation performance by arranging lateral joint reinforcing bars laid across respective horizontal reinforcements of a net reinforcement to be connected. CONSTITUTION: Net reinforcements A', A formed by arranging double inside/ outside paired net reinforcement materials having respective vertical/horizontal reinforcements 1, 2, 1', 2' welded together and set the reinforcement interval of a joint part set to two times as long as the bar arrangement interval of the general part are stacked and connected together so that the vertical reinforcement 1 of the joint part of one net reinforcement A is positioned in the intermediate part of the adjoining joint part vertical reinforcements 1' of the other net reinforcement A'. A lateral joint reinforcing bar 3 laid across the respective horizontal reinforcements 2, 2' of the respective net reinforcements A, A' is arranged in the outside end of the joint part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a joint structure of reticular reinforcing bars, which is formed by enclosing vertical and horizontal reinforcing bars.

(Prior art) In Japanese Patent Application No. 62-122560, the present inventors attached vertical and horizontal reinforcing bars to the bag, and made the bar spacing at the joint part twice that of the remaining general part. A joint of mesh reinforcing bars made by overlapping and welding a pair of mesh reinforcing bars such that the joint reinforcement of one mesh reinforcing bar is located between the adjacent joint reinforcing bars of the other mesh reinforcing bar is also patented. In No. 62-140052, a pair of reticulated reinforcing bars were installed with vertical and horizontal reinforcing bars, and the spacing at the joint part was twice that of the remaining general part.
Connecting reinforcing bars are arranged oppositely so as to be located on the same plane, and then connecting reinforcing bars to which longitudinal and lateral reinforcing bars are attached, and which have the same reinforcement spacing as the joint parts of the mesh reinforcing bars, are placed across the joint parts of the sketch-shaped reinforcing bars. At the same time, the joints of the connected reticulated reinforcing bars are arranged so that the reinforcing bars of the connecting reinforcing bars are located in the middle of the reinforcing bars of each joint, increasing the bearing pressure area of the concrete at the joints of the reticulated reinforcing bars. This made it possible to effectively prevent bearing pressure cracking of the same concrete.

(Problem to be solved by the invention) However, vertical and horizontal reinforcing bars (a) (b), (a') (b
At the joint of adjacent mesh reinforcing bars (A) (A'), which are made by double reinforcing inner and outer mesh reinforcing bars (A) (A'), the transverse reinforcing bars ( b) When a tensile force T acts on (b'), both reinforcing bars (bl(b')) are positioned eccentrically, so an eccentric moment M of Txe (e: eccentric distance of the horizontal reinforcing bars) is generated.

(See Figure 14) This is not a problem if it is a small-diameter mesh reinforcing bar with a diameter of 10 or less, but it becomes a problem when it occurs in a welded mesh reinforcing bar that uses large-diameter reinforcing bars. It also creates stress in the concrete, causing it to break before the reinforcing steel yields.

(Means for Solving the Problems) The present invention has been proposed in order to solve the above problems, and is a reticular reinforcing bar in which internal and external reticular reinforcing bars are double reinforced by welding vertical and horizontal reinforcing bars. This invention relates to a joint structure for reticular reinforcing bars characterized in that, in the joint portion, a lateral joint reinforcing bar is disposed to span between the lateral reinforcing bars of the reticulated reinforcing bars that overlap with each other.

(Function) Since the present invention is configured as described above, when a tensile force is applied to the horizontal reinforcing bars at the joint portion of the mesh reinforcing bars,
The force generated by the bending moment caused by the misalignment of the horizontal reinforcing bars is restrained by the horizontal joint reinforcement reinforcing bars that straddle each horizontal reinforcing bar of the two adjacent sets of reinforcing bars that overlap each other at the joint, and the mesh reinforcing bars at the joint Ensure smooth stress transmission between the two.

(Example) The present invention will be described below with reference to the illustrated embodiments.

Figures 1 to 3A and 3B show vertical and horizontal reinforcing bars (1) (
2) (1') (2') and the reinforcement spacing of the joint part is twice (=21) the reinforcement spacing l of the general part. Reticulated rebar (A)
(A') so that the vertical reinforcing bars (1) at the joint of one mesh reinforcing bar (^) are located between the adjacent longitudinal reinforcing bars (1') of the other mesh reinforcing bar (A'). An example is shown in which the present invention is applied to a joint of reticulated reinforcing bars shown in the above-mentioned Japanese Patent Application No. 62-122560, which are polymerized and connected.
Each horizontal reinforcing bar (2) (2') of each of the above-mentioned mesh reinforcing bars (A) (A')
) lateral joint reinforcing bars (3) are arranged.

Since the illustrated embodiment is configured as described above, the tensile force T acts on the horizontal reinforcing bars (2) (2'), and the horizontal reinforcing bars (
2) The force generated by the bending moment M generated based on the eccentricity IJe in (2') is applied to the lateral joint reinforcement (3).
) to ensure smooth transmission of stress between the reticulated reinforcing bars (A) and (A') at the lap joint of the reticular reinforcing bars (A) and (A'), thereby causing stress in the concrete part. prevent its destruction.

In addition, if the cross section of the concrete surrounded by the adjacent longitudinal reinforcing bars (]) and (1') is small and there is a high possibility that the concrete will cause a bearing pressure splitting failure, the horizontal joint reinforcing bars (3) should be This prevents bearing pressure cracking.

In the above example, the lateral joint reinforcing bars (3) are concentrated at the outermost ends of the joints of the reticulated reinforcing bars (A) (A'), and are designed to improve the strength and deformation performance of the joints. This is sufficient, but as shown in Fig. 4, the vertical and horizontal reinforcing bars (1) (
2) When placed between all joint intersections of (1') and (2'), the strength and deformation performance of the joint are further improved.

Figures 5 and 6 show the mesh reinforcing bars (^
) (A') are placed opposite each other so as to be located on the same plane, and the vertical and horizontal reinforcing bars (1') (2') are attached to the joints of the mesh reinforcing bars (A) and (A'). (A'
) in the above-mentioned patent application No. 62-140052, which is polymerized across the joints of the joints and located in the middle of the joints.
An embodiment of the present invention is shown in which the present invention is applied to the joint part of the reticulated reinforcing bars shown in No. 1, and each of the reticulated reinforcing bars (A) (A') is attached to both outer ends of the joint part of the reticulated reinforcing bars (A) (8'). Lateral joint reinforcing bars (3) spanning across (2') are arranged between the horizontal reinforcing bars (2) (2') and the horizontal reinforcing bars (B).

Note that the effects of this embodiment are substantially the same as those of the previous embodiment, so the description thereof will be omitted.

Furthermore, the seventh example shows an example in which the lateral joint reinforcing bars (3) are arranged between the intersections of the vertical and horizontal reinforcing bars (1') (2'') of the reinforcing bars (B) at the joint.

Although the above-mentioned embodiment shows the case where the mesh reinforcing bars are joined facing each other at the joint part, the present invention is also applicable to the case where the mesh reinforcing bars are joined back to back. 1 shows an example thereof, and parts in the figure that are equivalent to the above-mentioned example are given the same reference numerals.

Note that the present invention is also applied to a joint of rope-like reinforcing bars in which double-reinforced mesh reinforcing bars having normal spacing between reinforcing bars are arranged.

Next, as shown in FIGS. 12 and 13, which show examples of the present invention, in order to investigate the properties of a joint using a D38 large-diameter welded wire mesh, an experiment was conducted in which the reinforcing bars at both ends of the test piece were pulled in both directions.

The test specimens were one in which horizontal joint reinforcement was concentrated at the outermost end of the joint as shown in Figure 12, and one in which horizontal joint reinforcement was placed at the intersection of the outermost end and each welding point as shown in Figure 13. Three specimens were compared: one with reinforcement and one without lateral joint reinforcement. The yield strength and deformation performance of the joint are shown in Figure 12, and even with horizontal joint reinforcing bars placed only at the outermost end, the strength and deformation are sufficient for the joint performance. Those with directional joint reinforcing bars have excellent strength and deformation performance. However, those without lateral joint reinforcing bars broke before the load to which the reinforcing bars yielded, and exhibited inferior properties compared to those with lateral joint reinforcing bars arranged.

The specifications of the test specimens shown in Figures 12 and 13 are shown in Table 1 below.
As shown in Table 1-2.

Table 1 Table 2 (Effects of the Invention) According to the present invention, in the joint part of the mesh reinforcing bars in which the mesh reinforcing bars made of vertical and horizontal reinforcing bars are double reinforced, the mesh reinforcing bars to be connected can be By arranging lateral joint reinforcing bars that span each lateral reinforcing bar, even if an eccentric bending moment is applied due to misalignment of the lateral reinforcing bars of the mesh reinforcing bars, the force generated in the joint due to the bending moment can be restrained. , Smooth transmission of stress between flocculent reinforcing bars at the joint, prevents the concrete at the joint from breaking, and greatly improves the strength and deformation performance of the joint.

Further, the lateral joint reinforcing bars can prevent the concrete from cracking under the bearing pressure at the joint.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view showing an embodiment of a joint structure for mesh reinforcing bars according to the present invention, FIG. 2 is a cross-sectional plan view thereof, and FIGS. 4 is a cross-sectional plan view showing another embodiment of the present invention, and FIGS. 5 and 6 are a partial slope view and a cross-sectional plan view showing other embodiments of the present invention, respectively. , 7th
The figure is a cross-sectional plan view showing still another embodiment of the present invention, FIG. 8 is a cross-sectional plan view showing still another embodiment of the present invention, the ninth figure is a front view thereof, and FIG. View XX, No. 11
Figure 12 is a chart showing test results of joint performance of the present invention.
Figure A, Figure 12B, and Figure 12C are a side view, a plan view, a longitudinal sectional view, and a vertical sectional view of the test specimen used in the test, respectively.
Figures 3A, 13B, and 13C are side views, plan views, and longitudinal cross-sectional views of other test specimens, and Figure 14 is an explanatory diagram showing the state of action of bending moment on a joint of conventional mesh reinforcing bars. be. (A) (A') - Reticulated reinforcing bars (B) - Reinforcing bars (1) (1') (1') - Vertical reinforcing bars (2) (
2") (2') ---One horizontal reinforcing bar (31-m- Lateral joint reinforcement agent Patent attorney Shige Okamoto 2 people outside of the text Figure 3A Figure 3B ¥4 Figure

Claims (3)

[Claims] (1) At the joints of mesh reinforcing bars that are double-arranged with inner and outer mesh reinforcing bars made by welding vertical and horizontal reinforcing bars, horizontal joint reinforcing bars are provided that span between the horizontal reinforcing bars of the mesh reinforcing bars that overlap each other. A joint structure of reticular reinforcing bars characterized by: (2) The joint structure of reticular reinforcing bars according to claim 1, wherein the lateral joint reinforcing bars are disposed at the outer end of the joint part. (3) The reticulated reinforcing bar joint structure according to claim 1, wherein the lateral joint reinforcing bars are arranged between all joint intersections of the longitudinal and lateral reinforcing bars in the joint part.