JPH0784778B2 - Mortar filling type rebar joint sleeve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a mortar-filled type rebar joint sleeve used as a joint of a reinforcing bar for reinforcing concrete in a construction for constructing a structure made of reinforced concrete.

Mortar-filled rebar joint sleeves can be joined even if there is some displacement of the rebar, and there is no need to fill the joint part with concrete after joint work.Therefore, columns, beams or wall columns are designed separately. However, these members are widely used as joints for the precast reinforced concrete construction method in which these members are manufactured in advance in a factory and are assembled at the construction site to be assembled into a building.

(Prior Art) The mortar-filled type rebar joint sleeve is disclosed in Japanese Examined Patent Publication Sho 53-12732.
No. 61-57732, the body of the sleeve, as shown in FIG. 8, when concrete is placed in the production of precast reinforced concrete members.
It was not uncommon for mortar injection to become impossible at the joining site, because the reinforcing bars 20 inserted into the inside 10 contacted the inner surface of the sleeve and blocked the exhaust port 13 due to the weight and vibration of concrete. Further, the reinforcing bar was too close to the side opposite to the exhaust port, so that the mortar did not rotate there and the joint performance deteriorated.

(Problems to be Solved by the Invention) The present invention has been made in order to solve problems such as inability to inject mortar and deterioration of joint performance due to excessive eccentricity of reinforcing bars inserted in joint sleeves in precast reinforced concrete members. An object of the invention is to provide a mortar-filled rebar joint having a structure in which the rebar inserted in the joint sleeve is not excessively eccentric due to the weight and vibration of concrete.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the characteristic means of the present invention is:
As shown in the embodiment of FIG. 1, the reinforcing bar insertion ports 11 and 12 are provided at both ends.
The central projection 15 is formed on the inner center of the main body 10 of the joint sleeve slightly closer to one side, and the tip of the reinforcing bar 20 inserted from the reinforcing bar insertion port 11 by the central projection is excessively eccentric during the manufacturing of the precast reinforced concrete member. It is to prevent that.

To prevent eccentricity of this rebar, the inner diameter of the rebar insertion port 11 for inserting the rebar during precast is small, for example, about 1.3 times the nominal diameter of the rebar or less, but to facilitate the insertion of the rebar during construction, construction The inner diameter of the rebar insertion port 12 at the time is large,
For example, it should be about 1.5 times the nominal diameter of the rebar or more.

As shown in the embodiment of FIGS. 2 and 3, the central protrusion 15 is integrally formed with the main body 10 in the shape of a hollow hollow ring or the shape of a hollow hollow ring. The inner diameter of the hollow portion formed by the central protrusion 15 may be such that it prevents excessive eccentricity of the inserted reinforcing bar, so it should be the same as or slightly larger than the inner diameter of the reinforcing bar insertion port for inserting the reinforcing bar during precasting. .

In order to improve the adhesion between the mortar to be injected and filled into the joint sleeve and the sleeve, it is desirable to provide an internal projection having a continuous or continuous spiral or ring shape, as shown in FIG. In the case of a straight tube type sleeve, two or more types of internal protrusions, which are lower than the radial height of the central protrusion, are provided in order to make the adhesion to the same extent as the spindle type.

In order to facilitate the insertion of the reinforcing bar at the time of construction, the inner diameter from the center of the main body 10 to the reinforcing bar insertion port 12 into which the reinforcing bar is inserted at the time of construction is made larger than the inner diameter of the reinforcing bar insertion port 12 including internal protrusions.

(Operation) Since the sleeve of the present invention is provided with the central projection 15 which forms a hollow portion having an inner diameter slightly larger than the reinforcing rod inserted into one side of the inner center of the main body 10 at the shaft center, at the time of manufacturing the precast reinforced concrete member. Even if the reinforcing bar 20 inserted from the reinforcing bar insertion port 11 is eccentric due to the weight or vibration of concrete, the tip of the reinforcing bar 20 is held near the axial center by the central projection 15, so that the reinforcing bar 20 is eccentric so as to block the exhaust port 13. It does not come to the opposite side of the exhaust port 13 so that the mortar does not rotate.

Between the central protrusion 15 of the sleeve and the reinforcing bar insertion ports 11 and 12 at both ends, there is a spiral or ring-shaped internal protrusion having a lower radial height than the plurality of central protrusions 15.
Since 16 is formed, the adhesion between the mortar inserted and filled inside and the sleeve is good. In particular, when the main body is straight pipe-shaped to facilitate winding the auxiliary reinforcing bar on the outside of the sleeve, two or more types of internal protrusions 16 and 17 with different radial heights
Are provided, and the reinforcing bar insertion openings 11 and 12 at both ends, the internal projections 16 and 17,
When the envelope surface of the inner edge of the central protrusion 15 forms a large number of continuous spindles, the adhesion between the mortar and the sleeve is not inferior to that of the spindle-shaped sleeve.

(Example) The present invention will be described based on an example shown in the drawings, but the present invention is not limited to the example.

The main body 10 of the first embodiment shown in FIG. 1 is cast from ductile cast iron, and the outer shape is a spindle shape in which the upper half is slightly finer than the lower half. Reinforcing bar insertion ports 11 and 12 are provided on the upper and lower surfaces, but the inner diameter of the upper rebar insertion port 11 is about 1.3 times the nominal diameter of the rebar or less, and the inner diameter of the lower rebar insertion port 12 into which the reinforcing bar is inserted during construction. Is more than about 1.5 times the nominal diameter of the rebar. An exhaust port 13 is provided on the side surface of the upper end portion of the main body 10, and a mortar inlet port 14 is provided on the side surface of the lower end portion. A shallow groove spiral is provided in the hollow portion of the main body 10, and a central protrusion 15 is formed on the upper side of the central portion. As shown in FIG. 2, the central protrusion 15 has an unbroken ring shape, and the inner diameter of the hollow portion thereof is slightly larger than the outer diameter of the reinforcing bar 20. Central protrusion
As shown in FIG. 3, 15 may be formed in a ring shape with a cut.

The rebar 20 of the precast reinforced concrete member is inserted into the main body 10 through the rebar insertion port 11 on the upper surface, and its tip end fits in the central portion of the central protrusion 15. Therefore, even if the position of the reinforcing bar 20 is displaced by the weight of the concrete or the vibration that hits the concrete, the central projection 15 holds the tip end, so that the reinforcing bar 20 is excessively eccentric to block the exhaust port 13, or to the opposite side. The mortar doesn't get so close that it doesn't rotate.

The main body 10 of the second embodiment shown in FIG. 4 is a straight pipe type. The straight tube type sleeve makes it easy to wind the reinforcing bars,
As it is, the adhesion between the injected mortar and the sleeve is inferior to that of the spindle type. However, according to the present invention,
Two kinds of ring-shaped internal protrusions 16 and 17 which are either continuous or have a gap between the central protrusion 15 and the upper and lower rebar insertion openings 11 and 12.
Since the radial height of the internal projection 16 is lower than the radial height of the central projection 15 but higher than the other internal projection 17, the fracture surface of the injected mortar 30 has a sawtooth shape shown by a dashed line in the figure. And shows performance comparable to spindle-shaped sleeves.

The main body 10 of the third embodiment shown in FIGS. 5 and 6 is spindle-shaped and is provided with a central protrusion 15 for restricting the eccentricity of the reinforcing bar 20 as in the above-mentioned embodiment. Further, a concrete inflow prevention plate 40 is attached on the reinforcing bar insertion port 11. The upper peripheral wall 41 of the sleeve 10 extends upward, and a part of the upper peripheral wall 41 is further bent in the inner radial direction to form a mounting seat 42. Since the concrete inflow prevention plate 40 is formed of a flat plate-like material such as Styrofoam,
Compared to the conventional rubber cap, it can be fitted into the mounting seat 42 extremely easily. This concrete inflow prevention plate 40
Prevents the intrusion of concrete into the body 10 during the production of precast reinforced concrete members.

The main body 10 of the fourth embodiment shown in FIG. 7 is a straight pipe type, and has a central projection 15 and internal projections 16 and 17 as in the second embodiment. Also, the mounting seats 42 and 43 are provided above and below, unlike the third embodiment. The concrete inflow prevention plate 40 fitted to the upper mounting seat 42 blocks the inflow of the concrete sleeve into the main body 10 during the production of the precast reinforced concrete member as in the third embodiment, but the lower mounting seat 43 does not. The fitted concrete inflow prevention plate (40) prevents the joint mortar from entering the sleeve body (10) at the time of joining and assembling the precast reinforced concrete members.

(Effect of the invention) As described above, the main body 10 of the present invention prevents the excessive eccentricity of the reinforcing bar due to the concrete placing by holding the central projection 15 at the tip portion of the reinforcing bar inserted during the production of the precast reinforced concrete member, It has an excellent effect that an accident such as rebar excessively eccentric to block the exhaust port unlike the conventional sleeve and mortar does not sufficiently rotate around the rebar during assembly does not occur.

Further, the one having a plurality of internal projections 16 and 17 between the central projection 15 and the upper and lower reinforcing bar insertion openings 11 and 12 has a good airtightness with the mortar, so that the external shape is the work of winding the reinforcing bar. Even if it is a straight tube type that is easy to manufacture, it has performance comparable to that of a spindle type.

Further, the one in which the mounting seat 42 of the concrete inflow prevention plate 40 is provided on the outer side of one or both of the upper and lower rebar insertion openings 11 and 12, is a concrete inflow that can be easily mounted instead of a rubber cap which is troublesome to mount. The prevention plate 40 can be used.

Since the reinforcing bar insertion opening 12 into which the reinforcing bar is inserted at the time of construction is wide, and the inner diameter of the inside is larger than that of the reinforcing bar insertion opening 12, there is an extraordinary effect that the insertion of the reinforcing bar at the time of construction becomes extremely easy.

[Brief description of drawings]

1 is a longitudinal sectional view taken along the exhaust port and mortar inlet of the sleeve of the first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is another embodiment. Corresponding to FIG. 2, FIG. 4 is a longitudinal sectional view of the sleeve of the second embodiment, FIG. 5 is a longitudinal sectional view of the sleeve of the third embodiment, and FIG. 6 is an upper surface of the sleeve of FIG. 7 and 8 are longitudinal sectional views of the sleeve of the fourth embodiment, and FIG. 8 is a longitudinal sectional view of a conventional sleeve. In the figure, reference numeral 10 is a main body, 11 and 12 are reinforcing bar insertion openings, 15 is a central projection, 16 and 17 are internal projections, and 20 is a reinforcing bar.

Claims (4)

[Claims] 1. A tubular main body (10) having an outer diameter which is the same at both ends as the central part or which is smaller than the central part and into which a reinforcing bar (20) is inserted at the time of precasting, and a reinforcing bar provided on the end faces of the both ends. A sleeve having an insertion port (11, 12), wherein the reinforcing bar insertion port (11) on one side is formed to have an inner diameter smaller than that of the reinforcing bar insertion port (12) on the other side, and The one side rebar insertion port (1
A ring-shaped central protrusion (15) forming a hollow portion having an inner diameter equal to or slightly larger than the inner diameter of (1) is integrally provided with the main body, and the central portion of the main body (10) and the opposite side reinforcing bar. A mortar-filled rebar joint sleeve, wherein an inner diameter of a hollow portion between the insertion ports (12) is formed larger than an inner diameter of the rebar insertion port on the opposite side. 2. A plurality of spirals or a plurality of spirals forming a hollow portion having an inner diameter larger than the hollow portion formed by the central projection (15) inside the main body (10) and the reinforcing bar insertion opening (11). The mortar-filled rebar joint sleeve according to claim 1, wherein ring-shaped internal projections (16, 17) are integrally provided with the main body. 3. The internal projections (16, 17) are made of a plurality of types having different radial lengths, and connect the tips of the peaks of the internal projections between the central projection (15) and the reinforcing bar insertion port (11). The mortar-filled rebar joint sleeve according to claim 2, characterized in that the space portion that forms a plurality of valleys. 4. A recessed mounting seat (1) in which one or both peripheral walls (41) of both ends are extended in the longitudinal direction of the main body (10) and a disk-shaped concrete inflow prevention plate (40) is fitted to the end surface of the main body (10). Four
2) is formed, and then at least a part of the peripheral wall is bent in the inner radial direction so as to support the concrete inflow prevention plate from the outside.
The mortar-filled rebar diameter sleeve according to any one of items 1 to 3.