NZ220507A

NZ220507A - Seal and sleeve assembly for grouted reinforcement bar splice

Info

Publication number: NZ220507A
Application number: NZ220507A
Authority: NZ
Inventors: Tadashi Kadota
Original assignee: Tadashi Kadota
Priority date: 1986-06-26
Filing date: 1987-06-02
Publication date: 1990-04-26
Also published as: AU7363387A; CN1011426B; CN87104226A; GB8713774D0; JPH0791883B2; JPS637453A; GB2192210A

Description

<_/ Lj/\ i—>J \ i . t Reg'.19(0 Tee: _ 150 T~ , ,?£ (■ -r/jL' Prior.ty Dy.e%: ''''["'i'i'ii Specification F; co: Ci3": - • fe*• „ 220507 Insert number of Provisional Specification(s) (i f any) and date(s) of filing; otherwise leave blank.

PATENTS ACT 195 3 Number: Date: COMPLETE SPECIFICATION Insert Title of Invention. insert fulI name, full street address and nationality of (each) applicant.

SPLICE SLEEVE FOR REINFORCING BARS I/WE TADASHI KADOTA, a Japanese citizen of 3-35, Nishimachi 1-chome, Kokubunji-shi, Tokyo, Japan hereby declare the invention for which I/we pray that a patent may be granted to me/us and the method by which it is to be performed, to be particularly described in and by the following statement:- The following page is numbered "la" Indicate if following page is numbered '1(a)' 220507 -la- BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a mortar grout sleeve splice for reinforcing bars utilized in concrete 5 wall structures, and more particularly to a splice sleeve having a cylindrical shell of which the interior surface is provided with annular ridges, the annular space between the interior of the sleeve and the exterior of the reinforcing bars being filled with 10 grouting for fixedly connecting and generally aligning the opposite ends of the reinforcing bars. 2. Background of the prior art As disclosed by N.Z. Pat. Spec. 217027, the splice sleeve has a cylindrical shell of which the 15 internal surface is formed with annular ridges progressively increasing in their inward radial dimension from the innermost ridges toward the opposite end surfaces with an opening receiving the reinforcing bars. The shell is formed with a pair of ver\t and 20 grout-injection ports projected from the external ' cylindrical surface. The upper reinforcing bar passes through the hollow portions defined by the annular ridges, its end situating in the innermost hollow portion. The hollow portions progressively increase 25 their inner diameter from the opening toward the innermost ridges. The relatively large innermost hollow portion allows the end portion of the upper reinforcing bar to deviate from the axis of the splice sleeve and, sometimes, come too near to or too distant from the vent port.

The known sleeve has its upper end surface covered by a rubber cap prior to being set in a mold r form. The upper reinforcing bar is endwise inserted into r /T£n?\. the upper opening of the shell through the bore A 0 14 MAR 1990 " m.

El' 4&J 22050 the cap covering the end surface of the sleeve and then disposed in the mold form, which is fi lied up with concrete except the inside space of the splice sleeve to * fabricate a concrete wall structure. The cap is formed with a side bore to be fitted on the vent port in addition to the top bore. The concrete in the mold form is compacted by a concrete vibrator prior to hardening. The vibration compacting would cause the cap to remove ij from the shell without the side bore fitted on the vent port projected from the cylindrical surface of the shell. However, it is not easy to stretch the cap to the extent that the side bore is fitted on the vent port. The boss portion around the top bore of the cap is bound to the reinforcing bar with wires while the bottom 15 peripheral portion of the cap is taped to the external surface of the shell with adhesives to allow no gap between the top bore and the reinforcing bar nor clearance between the cap and the external surface of the shell. It is expensive to prepare the same kinds of 20 caps as the sleeve size. Besides, the rubber cap is not so fit to the ribs of the reinforcing bar to form no gap therebetween, thereby sometimes permitting the concrete to penetrate into the inside of the shell and reduce the splicing strength of the sleeve. Another disadvantage is 25 that the rubber cap prevents the exterior surface of the sleeve from being fully concreted to reduce the sectional area of the concrete wall structure or make a weak point in the concrete wall structure like a cavity. A further disadvantage is that the end of the 30 reinforcing bar in the splice sleeve is easy to deviate from the center of the splice sleeve during the vibration compacting, resulting in that the precast concrete wall structure sometimes ends in failure due to the intolerable deviation between the axes of the 35 reinforcing bar and the splice sleeve. The end portion of the reinforcing bar, if inclined too near to the vent • / 220507 port, will cause air to remain within the sleeve and prevent the injection of mortar grout into the shell. If it is inclined too distant from the vent port, the grout will flows out of the vent port without filling up the inside of the shell. When upper and lower precast concrete walls are joined with each other, a washer is always attached to the end of the reinforcing bar projected from the lower wall to protect the inside space of the sleeve against the joint mortar between the both walls. However, it is troublesome to attach the washer to the upper end of each reinforcing bar projecting from the upper surface of the lower reinforced concrete wall structure.

SUMMARY OF THE INVENTION An object of the invention is to solve the problems due to the conventional rubber cap as described above and provide an improved splice sleeve for connecting the ends of reinforcing bars, the splice sleeve being capable of shutting the inside space against concreting without an outside rubber cap when reinforced concrete wall structures or the like are precast.

Another object of the invention is to provide an improved splice sleeve in accordance with the preceding object in which the exterior surface of the sleeve is fully concreted without producing a weak point like a cavity nor reducing the cross-sectional area in the precast concrete wall structure or the like.

A still another object of the invention is to provide an improved splice sleeve capable of protecting the inside space against joint mortar without a washer attached to the end of the reinforcing bar projected from the precast wall.

A further object of the invention is to provide an improved splice sleeve in which the end of the reinforcing bar always aligned with the axis of splice 220507 sleeve when the concrete wall structure is precast.

A still further object of the invention is to provide an improved splice sleeve in which a sealing member is preliminarily built and closely fit to the 5 exterior, inclusive of the ribs, of the reinforcing bar.

The present invention consists in a splice sleeve for connecting upper and lower reinforcing bars in reinforced concrete wall structures or columns comprising an elongated shell of one-piece construction, 10 the shell including internal and external cylindrical surfaces and upper and lower end surfaces provided with upper and lower openings, respectively receiving the end portions of upper and lower reinforcing bars to be connected, the internal surface having a plurality of 15 longitudinally spaced, inwardly extending annular ridges spaced from the exterior of the reinforcing bars inserted into the shell, the upper end surface having an annular projection extending longitudinally therefrom to define an upper recess for receiving a sealing member 20 outside the upper end surface, the annular projection being formed with radially inwardly projecting edges to prevent the sealing member from removing out of the recess, the sealing member having .a central hole to be closely fitted on the exterior of the reinforcing bar, 25 the innermost ridge defining the innermost hollow portion to axially align the endmost portion of the upper reinforcing bar with the shell.

In preference, the sealing member is made from a foam resin material, such as a foam styrol board and the 30 like, and shaped in the form of a hollow disk. The sealing member protects the inside of the shell against the penetration of the concrete during the vibration compacting when the reinforced concrete wall structure is precast. The sealing member built in the shell 35 produces no weak point like a cavity in the precast concrete wall structure, because the external surface of 220507 the shell is fully concreted irrespective of the sealing member. The innermost ridge prevents the end of the upper reinforcing bar from intolerably deviating out of the center of the shell with the result that the axes of 5 the shell and the reinforcing bar are always aligned. The lower end portion is also preferable to have an annular projection for protection of the inside space of the shell against the penetration of the joint mortar when the lower reinforcing bar is inserted into the 10 lower opening to join the lower precast wall structure with the upper one.

The advantages offered by the invention are mainly that the sealing member is preliminarily built in the sleeve to protect the inside of the sleeve against 15 the penetration of the concrete when the reinforced concrete wall structure is molded. The sealing member is made from a flexible material, such as a foam plastic board and the like, and shaped in the form of a hollow disk, thereby being easy to be mounted within the 20 annular recess in the shell. The sealing member is formed with a central hole closely fitted on the ribs of the reinforcing bar. The sealing member produces no reduction in the cross-sectional area of the reinforced concrete wall structure. The effective length of the 25 sleeve is lengthened to receive the sealing member and increase the strength of the precast concrete wall structure. The innermost ridge ensures that the precast concrete wall structure is molded to have the reinforcing bars axially aligned with the sleeves. All 30 in all, the splice sleeve of the invention is free from the known rubber cap that is expensive and troublesome.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully 35 hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof. 220507 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal, sectional view of the splice sleeve of the invention, illustrating the structure and association of the splice sleeve with the upper and lower reinforcing bars and grouting; FIG. 2 is a perspective view, on an enlarged scale, of the upper end portion of the splice sleeve and the sealing member to be mounted in the recess in the end portion; FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1, illustrating the innermost or central ridge of the splice sleeve; FIG. 4 is a view similar to FIG. 3, of another embodiment illustrating the splice sleeve with the upper reinforcing bar; FIG. 5 is a longitudinal, sectional view of a further embodiment of the invention in which the recesses are formed in the both end portions of the sleeve; FIG. 6 is a sectional view of the relevant portion of the reinforced concrete wall structure which is precast in the mold form; and FIG. 7 is a sectional view of the upper and lower precast concrete wall structures which are to be joined with each other.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, the splice sleeve of the invention has a one-piece shell 10 constructed of metal, such as ductile cast iron or the like. The shell 10 has a somewhat spindle-like configuration of which the upper half is frustoconical, the lower half being cylindrical. The upper and lower end surfaces 25 and 26 of shell 10 are each provided with upper and lower openings 11 and 12, the upper opening 11 being less in diameter than the lower. The upper opening 11 receives the end portion of the upper reinforcing bar 20 when the 22050 reinforced concrete wall structure is precast. The lower opening 12 receives the end portion of the lower reinforcing bar 29 projecting from a non-illustrated lower concrete wall structure when the upper and lower 5 concrete wall structures are joined with each other. The external surface 18 of the upper half of the shell 10 is provided with a vent port 13 which is less in diameter than the other grouting port 14 in the external surface 18 of the lower half so that grout 34 entering the 10 larger port will completely fill the cavity due to the restricted discharge. The shell 10 has an annular projection 21 extending longitudinally from the upper end surfaces 25 to form an upper recess 2 3 outside the upper opening 11. The upper annular projection 21 has 15 parts projecting radially inwardly to form a pair of arcuate edges 22. A sealing member 30 is preliminarily mounted in the upper recess 23 to tightly fit on the upper reinforcing bar 20.

Referring to FIG. 2, the arcuate edges 22 are 20 diametrically disposed on the endmost of the annular projection 21 of the shell 10. The sealing member 30 is shaped in the form of a hollow disk to have an outer diameter similar to or slightly less than the inner diameter of the recess 23. The sealing member 30 has a 25 central hole 31 of which the inner diameter is similar to or slightly less than the outer diameter of the reinforcing bar 20, exclusive of the ribs 19. The sealing member 30 is made from such a material that is flexible and resistible against concreting. For example, 30 it may be made from a light, inexpensive plastic board, such as a foam styrol resin board and the like. The sealing member 30 is resiliently bent to pass by the edges 22 and then put in the recess 23. Once the sealing member 3 0 is set in the recess 23, the edges 22 prevent 35 it from removing out of the recess 23. The sealing member 30 made of a foam styrol resin board is easily 22050 built in the recess 23 and well fit to the reinforcing bar 20, thereby no gap remaining between the inner surface of the central hole 31 and the external surface, inclusive of the ribs 19, of the reinforcing bar 20.

As seen in FIG. 1, the internal surface 17 of the shell 10 includes a central or innermost ridge 15 with a higher radial dimension from the internal surface 17 than other ridges 16. The central ridge 15 in the shell 10 is shaped in the form of a hollow circle with 10 or without radial slits 3 6 as seen in FIGS. 3 and 4. The ridges 15 and 16 together with ribs 19 on the reinforcing bar 20 provide a very secure and rigid bond and interaction between the grout 34, the reinforcing bar 20 and the shell 10 of the splice sleeve. The 15 innermost ridge 15 defines a hollow portion the inner diameter of which is similar to or slightly larger than the inner diameter of the upper opening 11 so that the end portion of the upper reinforcing bar 20 is prevented to come too near to and too distant from the vent port 20 13. If the upper reinforcing bar 20 were too near to the vent port 13, the air within the shell 10 could not get out of the vent port but resist the grouting when the mortar grout is injected into the sleeve. On the other hand, if the reinforcing bar 20 were too distant from 25 the vent port 13, the grout would flow out of the vent port without filling up the space diametrically opposite to the vent port 13.

Referring to FIG. 5 in which is shown another embodiment of the splice sleeve of the invention, the 30 cylindrical shell 10 has upper and lower annular projections 21 and 27 extending longitudinally from the upper and lower end surfaces 25 and 26 to form upper and lower recesses 23 and 24. The internal surface 17 of the shell 10 includes an innermost ridge 15 and a plurality 35 of ridges 16 which are substantially equally spaced between the upper and lower openings 11 and 12. The 2 2050 innermost ridge 15 defines a hollow portion slightly larger in diameter than the reinforcing bar 20 so that the shell 10 and the reinforcing bar 20 are axially aligned with each other. The ridges 16 have at least two 5 sorts of radial dimensions from the internal surface 17 of the shell 10 and define hollow portions of which the inner diameters are different from each other but larger than that of the innermost hollow portion defined by the central ridge 15. The ridges 15 and 16 together with the 10 ribs 19 on the reinforcing bar 20 provide a very secure and rigid bond and interaction between the grout, and reinforcing bar and the shell of the splice sleeve. The sealing member 30 is mounted in the upper recess 23 and prevented from removing therefrom by the edges 22 before 15 the reinforcing bar 20 is inserted into the upper opening 11. The shell 10 is provided with the vent port 13 and the grouting port 14.

Referring to FIG. 6 in which a reinforced concrete wall structure is precast in a mold form, the 20 end portion of the reinforcing bar 20 is inserted into the sealing member 30 and the opening 11 of the shell 10 which is fixed to the mold form 38 by the use of a fixture 39. The sealing member 30 Has its inner diameter similar to the outer diameter of the reinforcing bar 20, 25 except the ribs 19, so that there is no clearance between the outer surface of the reinforcing bar 20 and the inner surface of the hole 31. The concrete fills the space in the mold form 38 to press the sealing member 30 on the end surface 25 of the shell 10 and seal the 30 opening 11 without penetrating into the inside of the shell 10 when it is compacted by vibration. The shell 10 has its external surface 18 fully concreted, so that there remains no space to reduce the cross-sectional area of the precast wall structure. The sealing member 35 30 inside the external surface 18 of the shell 10 does not reduce the cross-sectional area of the wall but 220 50 7 increase the effective length of the splice sleeve, thereby contributing to improve the strength of the precast wall structure.

Referring to FIG. 7 in which the upper and lower 5 precast concrete wall structures 41 and 42 are vertically joined with each other, the lower surface o£ the upper concrete wall structure 41 is pressed on the joint mortar 35 on the upper surface of the lower one 42. The joint mortar 35 is received in the lower recess 10 24 of the shell 10 in the upper concrete wall structure 41 without entering the inside of the shell 10 through the lower opening 12. This means that no washer is necessary to be attached to the end portion of the reinforcing bar 29 projecting from the upper surface of 15 the lower concrete wall structure 42 in order to protect the inside space of the sleeve against the penetration of the joint mortar 35 when the both concrete wall structures are joined with each other.

The foregoing is considered as illustrative only 20' of the principles of the invention. Further, since numerous, modifications and changes will readily occur to* those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable 25 modifications and equivalents may be resorted to, falling within the scope of the invention, as claimed.

Claims

2205C7 WHAT l/WE CLAIM IS: -11"

1 • ^ splice sleeve assembly far connecting upper and lower 2 reinforcing bars in reinforced concrete construction 3 comprising ah elongated shell of one-piece construction, 4 said shell including internal and external cylindrical 5 surfaces and upper and lower end surfaces provided with 6 upper and lower openings, respectively, for receiving the 7 end portions of upper and lower reinforcing bars to be 8 connected, said internal surface being formed with a 9 central ridge defining a central annular space to 10 receive the endmost portion of the upper reinforcing 11 bar, said shell having an upper annular projection 12 extending longitudinally from said upper surface and 13 defining an upper recess which receives a sealing member I 14 outside said upper end surface, said annular projection 15 being formed with radially inwardly projecting edges-to 16 prevent movement of said sealing member from said recess, said sealing iroriber having a central hole therein which can be closely fitted on the upper reinforcing bar.

2. The splice sleeve assembly of claim 1, wherein said she! 2^ is provided with a lower annular projection extending 3 longitudinally from said lower end surface and defining a 4 lower recess for receiving joint mortar.

3. The splice sleeve of claim 1, wherein said sealing mentoer is made frcm a foam plastic board. 2 3 4 5 6

4. The splice sleeve assembly of claim 1, wherein said internal surface is formed with a plurality of longitudinally spaced, inwardly extending annular ridges, inclusive of said central ridge, each defining an annular space for receiving the reinforcing bar to be inserted into the shell. MAR 1990 } -12- 220507

5. The splice sleeve assembly of claim 4, wherein, said central ridge forms an annulus and can include radial slits extending from the inner periphery thereof.

6. The splice sleeve assembly of claim 4, wherein said annular ridges, except the central one, are of at least two differing radial dimensions from the internal surface of the shell, each radial dimension being smaller than that dimension for the central ridge.

7. The splice sleeve assembly of claim 1, wh^xin said shell is composed of upper and lower half portions, said upper half portion tapering frustoconically upwardly frcm said lower cylindrical half portion.

8. The splice sleeve assenbly of claim 1, wherein the annular space defined by the central ridge has a diameter slightly larger than the outer diameter of the t upper reinforcing bar to be received therein. J. D. HARDIE & CO. Patent Attorneys for the Applicant(s).