JP7319628B2 - Joint structure of concrete precast members - Google Patents

Description

TECHNICAL FIELD The present invention relates to a joint structure for joining concrete precast members used for floor slabs of bridges and the like.

Conventionally, concrete precast floor slabs manufactured in factories or on-site yards have been used in order to shorten the construction period in floor slab replacement work for bridges and the like. As a joint structure for connecting the precast concrete floor slabs, various structures have been proposed and put into practical use.

The joint construction that has been most commonly used is the so-called loop joint. As shown in FIG. 22, this loop joint is constructed by arranging loop-shaped joint reinforcing bars 51 and 52 protruding in the direction of the bridge axis at appropriate intervals. This joint structure 50 connects adjacent precast floor slabs by inserting reinforcing bars 53 from the joint structure 50 and placing cast-in-place concrete 54 in the interstitial space between precast floor slab bodies.

In addition, application of the loop joint structure requires that the floor slab thickness is 240 mm or more. A joint structure called is used. As shown in FIG. 23, the "streamlining joint" does not use a loop reinforcing bar and forms a fixing head 62 having a diameter larger than that of the connecting reinforcing bar at the tip of a straight connecting reinforcing bar 61. , a large number of these protrude from each joint side surface of the precast floor slab main body at predetermined intervals in the horizontal direction on the upper edge side and the lower edge side thereof, respectively, and connect the two precast floor slab bodies within the joint interval. The joint structure 60 has reinforcing bars 61, 61, .

Further, various mechanical joints have been conventionally proposed, which are intended to save labor by eliminating the installation of reinforcing bars in the interfilling portion, and to shorten the construction period by reducing the interfilling material. For example, in addition to the simplest mechanical joint in which a male joint is fitted to a female joint fitting having a grooved cross section (see, for example, Patent Document 2 below), Patent Document 3 below discloses precast concrete floor slabs, etc. A joint structure for joining plate-shaped concrete structures in a state of being aligned in the plane direction, at least an upper opening upward and a peripheral opening communicating with the upper opening at a part of the periphery is formed, and a cylindrical first joint fitting having a substantially U-shaped cross section, which has a fitting hole inside, is attached to both joint ends of the concrete structures to be joined to each other, the axis line along the thickness direction of the concrete structure or arranged diagonally with respect to the thickness direction, and the upper opening faces the upper surface and the peripheral opening faces the joint end surface, respectively, and the fitting from each opening The holes are embedded so as to communicate with the outside, and the peripheral openings of the first joint fittings are opposed to each other. are integrally formed at both ends of the first joint fitting, and have fitting portions that are housed inside the first fitting fitting and cannot be detached from the peripheral opening; Each concrete structure to be joined is connected by inserting it into the fitting hole of the joint fitting from the upper opening, and the inside of the fitting hole is filled with a solidifying material to form the fitting part of the first fitting fitting and the second fitting fitting. A joint structure for a concrete structure is disclosed, which is characterized in that it is formed by fixing

In addition, in Patent Document 4 below, a cotter type in which C-shaped joint fittings having grooves with lip grooves in cross section are opposed to each other and a cotter with an H-shaped cross section is inserted into the grooves that are united in an H-shape to fasten. In the joint device, bolt holes are drilled near the center of left and right flange portions of the cotter having an H-shaped cross section, and the C-shaped joint fitting is formed with a bottom portion having a predetermined thickness, A cotter-type joint device is disclosed in which a locking portion for a bolt to be inserted into the bolt hole is provided on the bottom portion.

JP 2015-1045 A Japanese Patent Application Publication No. 2017-190629 JP-A-7-71195 JP-A-2001-214694

The mechanical joint structure described above is superior to others in terms of minimizing the impact on surrounding traffic by minimizing restrictions due to lane restrictions and traffic restrictions by shortening the construction period. However, in the case of the so-called "cotter type joint" as in Patent Documents 3 and 4, an excessive precision is required for erecting the floor slabs in order to insert the H-shaped cotter, making it difficult to insert the cotter. If such a situation were to occur, there is concern that it would cause a significant delay in the process. In addition, the so-called "cotter type joint" such as those disclosed in Patent Documents 3 and 4 has a problem that the production cost is high and the construction cost is greatly affected.

In addition, as in Patent Document 2, in a joint structure in which a male joint provided with a circular fixing member at the tip of a reinforcing bar is fitted to a female joint having a groove-shaped cross section, the female joint and the male joint per location are separated from each other. Therefore, in order to ensure that the floor slabs have a constant connection strength as a whole, it is necessary to reduce the arrangement interval of the joints and install many joints on the joint end faces. For this reason, there is a problem that the precision control is difficult because the narrower the joint interval is, the more precision is required for positioning during installation.

Therefore, the main object of the present invention is to eliminate the installation of reinforcing bars in the filling part to save labor, reduce the amount of filling material, and stabilize the construction efficiency by facilitating positioning, etc. In addition to shortening the construction period, we have developed a mechanical joint structure for concrete precast members that facilitates precision control during erection by increasing the joint placement interval by increasing the engagement area per joint. to provide.

In order to solve the above problems, the present invention according to claim 1 is a joint structure for joining concrete precast members,
On the joint end surface of the concrete precast member on one side of the joint, the upper surface is opened at a predetermined interval in the horizontal direction, and the front end surface has a longitudinal groove along the vertical direction that communicates with the opened upper surface. The formed groove-shaped engaging portion having a groove-shaped cross section in plan view, and the female joint anchor extending rearward from the rear end surface of the groove-shaped engaging portion and formed in a flat plate shape along the vertical plane. A female joint consisting of a portion is embedded with the longitudinal groove facing the outside,
On the joint end face of the concrete precast member on the other side of the joint, at a predetermined interval in the horizontal direction, the male end protrudes from the joint end face of the concrete precast member, and the base end is embedded in the concrete. a male joint comprising a joint anchor portion and a fixing portion provided at the protruding tip of the male joint anchor portion and capable of being inserted into the groove-shaped engaging portion of the female joint is embedded;
The female joint of the concrete precast member on one side is engaged with the male joint of the concrete precast member on the other side, and the concrete precast members are connected to each other, and the inner space and the groove shape of the groove-shaped engaging portion are engaged. A grout material is filled in the gap between the upper space and/or the lower space of the engaging portion and the concrete precast member on one side and the concrete precast member on the other side,
The groove-shaped engaging portion is formed in a vertically elongated shape, the fixing portion is formed in a vertically elongated shape, and the male joint anchor portion is formed in a flat plate shape along a vertical plane. is formed of
The female joint is manufactured by die casting, and is formed with a ridge or recess extending in a predetermined direction on an arbitrary outer surface of the groove-type engaging portion. Inside, the front end face where the longitudinal groove is formed, the rear end face where the female joint anchor portion is connected, the ridges or grooves formed on the top and bottom faces extend in the horizontal direction, and the A joint structure for concrete precast members is provided, wherein the ridges or grooves extend in the vertical direction .

In the invention according to claim 1, the female joint provided with the groove-shaped engaging portion having a groove-shaped cross-section in a plan view in the concrete precast member on one side of the joint portion is in a state in which the vertical groove is exposed to the outside. A male joint is buried in the concrete precast member on the other side of the joint portion, and the female joint and the male joint are engaged to connect the concrete precast members to each other, and the groove type A grout material is filled in the gap between the internal space of the engaging portion, the upper space and/or the lower space of the groove-shaped engaging portion, and the concrete precast member on one side and the concrete precast member on the other side. The concrete precast members are thereby joined together.

Since it is a simple mechanical engagement structure in which the fixed portion of the male joint is engaged with the grooved engagement portion of the female joint, the allowable margin of error is large, and the manufacturing error and installation error are absorbed to facilitate alignment. Since it can be easily performed, the construction period can be greatly shortened. The grout material is filled in the inner space of the groove-shaped engaging portion, the upper space and/or the lower space of the groove-shaped engaging portion, and the concrete precast member on one side and the concrete precast member on the other side. Since it is a gap portion and the amount of grout material to be filled can be reduced, it is possible to shorten the work time and reduce the construction cost. Furthermore, since the space between the concrete precast members is small, the size of the concrete precast members can be increased to the limit of the transportation conditions, and the number of concrete precast members installed compared to the conventional loop joint can be reduced by 10 to 20%.

In addition, in the joint structure according to the present invention, the groove-shaped engaging portion of the female joint is formed in a vertically elongated shape, and the fixing portion of the male joint inserted into this groove-shaped engaging portion is vertically elongated. Since the male joint anchor part, which is formed in a vertically long shape that is long in the direction and extends to the rear of the fixing part, is formed in a flat plate shape along the vertical plane, it can be attached to the tip of the reinforcing bar like a conventional mechanical joint. Compared to a structure in which a male joint provided with a circular fixing member is fitted to a female joint, by having a vertically elongated engagement structure that is long in the vertical direction, the engagement area between the female joint and the male joint per location is reduced. increases, and the bonding strength increases. Therefore, even if the arrangement interval of the joints is increased, a certain degree of connection strength between the precast members can be secured, the number of joints can be reduced, and precision control during construction can be facilitated.

When a ridge or groove extending in a predetermined direction is formed on an arbitrary outer surface of the groove-type engaging portion, the direction in which the ridge or groove extends is arbitrary. Among them, it is preferable that the front end surface where the longitudinal groove is formed, the rear end surface where the female joint anchor part is connected, the upper surface and the bottom surface are formed so as to extend in the horizontal direction, and the both side surfaces are formed so as to extend in the vertical direction. . As a result, when manufacturing the female joint by a die casting method using a die that is divided into two in the width direction along the center line CL (Fig. 15(B)) passing through the center of the groove width of the longitudinal groove, It is possible to increase the fixing strength of the female joint against the tensile force acting in the bridge axis direction on both side surfaces and the bottom surface while ensuring ease of removal in the width direction of the mold that is divided into two parts on the bottom surface.

As a second aspect of the present invention, there is provided a joint structure for a concrete precast member according to claim 1, wherein a plurality of inwardly protruding protrusions are discretely formed on the inner surface of the groove-shaped engaging portion. be done.

By discretely providing a plurality of inwardly protruding protrusions on the inner surface of the groove-shaped engaging portion, fixability of the male joint in the groove-shaped engaging portion is improved.

As the present invention according to Claim 3 , the female joint anchor portion is formed with ridges perpendicular to each other in the vertical direction and the horizontal direction on both side surfaces along the vertical plane. There is provided a joint structure for concrete precast members according to the above .

By forming vertical and horizontal ridges perpendicular to the female joint anchor portion, the female joint can be moved in the width direction along the center line CL (Fig. 15(B)) passing through the center of the groove width of the longitudinal groove. When manufacturing by a mold casting method using a mold divided into two parts, the fixing strength of the female joint against the tensile force acting in the bridge axis direction while ensuring the ease of pulling out the mold divided into two parts in the width direction will be able to increase

As the present invention according to claim 4 , the concrete according to any one of claims 1 to 3, wherein the female joint anchor part and the male joint anchor part are arranged independently of the reinforcing bars arranged in the concrete precast member. A joint structure for precast members is provided.

In conventional mechanical joints, the male and female joints are directly connected to the distributing bars extending in the direction of the bridge axis, so the joint installation position may be restricted by the relationship with the distributing bars, resulting in freedom of design. I had a problem with low power. On the other hand, in the third aspect of the invention, the joint structure is independent of the force distributing bars, so that the strength of the joint can be improved and the degree of freedom in design can be improved.

According to a fifth aspect of the present invention, there is provided a joint structure for precast concrete members according to any one of the first to fourth aspects, wherein concrete is filled instead of the grout material.

In the invention according to claim 5, instead of the grout material, concrete is filled in order to reduce the construction cost.

As a sixth aspect of the present invention, there is provided a joint structure for a concrete precast member according to any one of the first to fifth aspects, wherein the concrete precast member is a floor slab.

In the sixth aspect of the invention, a floor slab used for a bridge or the like is used as the concrete precast member.

As described in detail above, according to the present invention, installation of reinforcing bars in the filling part is eliminated to save labor, and in addition to effects such as reduction of filling material, construction efficiency is improved by reducing the number of installed parts, facilitating positioning, etc. Concrete precast member that stabilizes the construction period, greatly shortens the construction period, increases the engagement area per joint, increases the joint spacing, and facilitates accuracy control during erection. It is possible to provide a mechanical joint structure of

FIG. 2 is a plan view showing concrete precast floor slabs 1A and 1B. It is the II-II sectional view. FIG. 2 is a sectional view taken along line III-III in FIG. 1; 3 is an enlarged plan view of a joint portion 2; FIG. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4; FIG. 2 is a sectional view taken along line VI-VI of FIG. 1; FIG. 2 is a cross-sectional view taken along line VII-VII of FIG. 1; 2 shows the female joint 3, (A) is a front view, (B) is a plan view, (C) is a left side view, (D) is a right side view, and (E) is a cross-sectional view along E-E of (B). 4 is a floor slab perspective view showing a male joint 4. FIG. 1 shows a male joint 4, (A) is a front view, (B) is a plan view, (C) is a left side view, and (D) is a right side view. 4A to 4C are diagrams (A) to (C) of procedures for joining precast floor slabs. It is a top view showing concrete precast floor slabs 1A and 1B concerning a modification. It is the XIII-XIII sectional view. 13 is a cross-sectional view taken along line XIV-XIV of FIG. 12; FIG. (A) is a front view, (B) is a top view, (C) is a left side view, (D) is a right side view, (E) is a bottom view, (E) is a bottom view, ( F) is a vertical cross-sectional view (cross-sectional view taken along line FF of (B)). FIG. 15 is an enlarged cross-sectional view of the main part of the outer surface of the female joint 3 (cross-sectional view taken along the line XVI-XVI in FIG. 15(C)); FIG. 15 is an enlarged cross-sectional view of the main part of the outer surface of the female joint 3 (cross-sectional view taken along line XVII-XVII in FIG. 15(D)); Fig. 8 shows a male joint 4 according to another embodiment, wherein (A) is a front view, (B) is a top view, (C) is a left side view, and (D) is a right side view. It is a front view of the vertical groove 5 which concerns on a modification. It is a sectional view of joint part 2 concerning a modification. 4 is a perspective view showing a buried state of the female joint 3. FIG. FIG. 3 is a longitudinal sectional view showing a conventional loop joint; It is a longitudinal cross-sectional view showing a conventional streamlined joint.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The present invention is a mechanical joint structure for joining concrete precast floor slabs (hereinafter simply referred to as precast floor slabs). In general, in the case of mechanical joints, compared to conventional loop joints and rationalized joints, labor can be saved by eliminating the installation of reinforcing bars in the filling part, and the construction period can be significantly shortened by reducing the filling materials. However, there are drawbacks such as the joint itself being expensive, the construction cost increasing, and high accuracy being required for alignment. Therefore, the present invention proposes a mechanical joint structure that has a simple structure, can absorb a predetermined amount of error, and is excellent in the workability of positioning.

Specifically, as shown in FIGS. 1 to 3, the joint structure is provided at a predetermined interval in the horizontal direction (perpendicular to the bridge axis) on the joint end surface of the precast floor slab 1A on one side of the joint portion 2. A female joint 3 composed of a groove-shaped engaging portion 6 having a groove-shaped cross section in a plan view and a female joint anchor portion 7 extending behind it is embedded with the vertical groove 5 facing the outside, and the joint portion 2, a male joint anchor portion 9, the tip of which protrudes outward at a predetermined interval in the horizontal direction, and the female joint 3 provided at the tip. A male joint 4 consisting of a fixing portion 8 that can be inserted into the groove-type engaging portion 6 is embedded,
As shown in FIGS. 4 to 7, the female joint 3 of the precast slab 1A on one side is engaged with the male joint 4 of the precast slab 1B on the other side. The fixing portion 8 of the male joint 4 is inserted into the portion 6 to connect both floor slabs, and the inner space IS of the groove-type engaging portion 6, the upper space US of the groove-type engaging portion 6, and the one side space It is a joint structure in which a grout material 18 is filled in a gap portion M between the precast floor slab 1A and the precast floor slab 1B on the other side.

More specific details will be given below.

First, the female joint 3 provided on the precast floor slab 1A on one side will be described in detail with reference to FIGS. 4 to 8. FIG.

As shown in detail in FIG. 8, the female joint 3 includes a groove-shaped engaging portion 6 having a groove-shaped cross-section in a plan view and having a vertical groove 5 formed in the front end face; It is a metal member composed of an end face of the portion 6 formed with the longitudinal groove 5 and a female joint anchor portion 7 extending rearward from the opposing end face.

The groove-shaped engaging portion 6 has an open top surface, and has a box-like shape in which the vertical groove 5 is formed on the front side surface to communicate with the open top surface. The groove-type engaging portion 6 may have an open bottom surface as well as an upper surface. However, as shown in FIG. is preferable. As a result, it is possible to prevent the groove-shaped engaging portion 6 from opening to both sides. In addition, an opening (not shown) for communicating with the filler may be provided in the central portion of the bottom surface of the groove-shaped engaging portion 6 .

The groove-type engaging portion 6 is formed in a vertically long shape that is long in the vertical direction. That is, the height H in front view shown in FIG. 8(A) is larger than the width B and depth C in plan view shown in FIG. 8(B). The height H of the groove-shaped engaging portion 6 is preferably 1.2 to 3 times, preferably 1.5 to 2 times the width B or depth C. Moreover, the height H of the groove-shaped engaging portion 6 is preferably about 50 to 90%, preferably about 60 to 80%, of the thickness of the precast floor slab 1A, and is substantially in the center of the thickness direction of the precast floor slab 1A. It is best to put it in place.

As shown in FIG. 8, the width dimension B of the groove-shaped engaging portion 6 is approximately 80 to 150 mm, preferably 100 to 130 mm, and the depth dimension C is equal to or less than the width dimension B. It is preferably approximately 60 to 120 mm, preferably 70 to 100 mm.

As shown in FIG. 8(D), the width S of the vertical groove 5 formed in the groove-shaped engaging portion 6 is 20 to 60 mm, preferably 30 to 50 mm, and constitutes the male joint 4 described later. The dimension is 110 to 220%, preferably 120 to 200%, of the thickness of the male joint anchor portion 8 . Since the ratio to the thickness of the male joint anchor portion 8 is closely related to the allowable range of manufacturing errors or installation errors, it is desirable to set the ratio to an appropriate numerical range. Also, if this ratio is too large, the contact between the male joint 4 and the fixing portion 8 will be reduced, and the joint strength will be reduced. In addition, when the upper end of the vertical groove 5 is formed to be wide as shown in FIG. 19 (when an inclined portion 5a described later is provided), the width S is the wide portion of the upper end (inclined portion 5a). It is the width dimension of the portion where both side edges are parallel.

The vertical groove 5 may be formed vertically through the groove-shaped engaging portion 6 from the upper edge to the lower edge, but as shown in FIG. A U-shaped longitudinal groove formed with a ridge is preferred. By connecting the lower ends as a U-shaped vertical groove, the vertical groove 5 can be prevented from opening to both sides. 8(D), the vertical groove 5 may be formed with a substantially uniform width over the entire length, or as shown in FIG. , an inclined portion 5a may be provided in which the groove width gradually increases toward the upper side. By providing the inclined portion 5a, the protruding male joint anchor portion 8 can be smoothly inserted into the vertical groove 5 when the precast floor slab 1B on the other side is dropped from above.

As shown in FIGS. 4 and 5, when the precast floor slab 1A on one side and the precast floor slab 1B on the other side are joined, a male joint protruding from the joint end face of the precast floor slab 1B on the other side is formed. The anchor portion 8 is inserted into the longitudinal groove 5 , and the fixing portion 8 provided at the tip of the male joint anchor portion 8 is inserted into the internal space of the groove-shaped engaging portion 6 .

As shown in FIG. 8, the female joint anchor portion 7 extending rearwardly of the groove-shaped engaging portion 6 is preferably formed in the shape of a flat plate along the vertical plane. The female joint anchor portion 7 extends rearward by a predetermined length from the central portion of the wall surface facing the wall surface on which the longitudinal groove 5 of the groove-shaped engaging portion 6 is formed. The rear end of the female joint anchor portion 7 is provided with a rear end fixing portion 7a projecting to both sides and having a flat plate shape along a plane parallel to the joint end face.

The height dimension of the female joint anchor portion 7 is preferably formed with a substantially uniform width over the entire length, and is 30 to 100%, preferably 40 to 60%, of the height H of the groove-shaped engaging portion 6. It is better to

The female joint anchor portion 7 is preferably arranged independently of the longitudinal reinforcing bars arranged on the precast floor slab 1A. That is, the stress in the bridge axis direction acting on the female joint 3 is substantially supported only by the female joint anchor portion 7 and does not act on the bridge axis direction reinforcing bars. In this way, by providing the female joint anchor part 7 independently of the longitudinal reinforcing bars, it is possible to improve the degree of freedom of design in terms of the arrangement of the longitudinal reinforcing bars. However, in the case of the female joint 3 according to the present invention, which is arranged independently from the reinforcing bars, it can be applied to the extent that the adjacent reinforcing bars are not hindered. It becomes possible.

In addition, the length of the female joint anchor portion 7 in the bridge axis direction is 1.2 to 3 times, preferably 1.5 to 2 times, the depth C of the groove-type engaging portion 6. It is not necessary to provide the precast floor slab 1A over the entire length in the bridge axis direction. As described above, the length of the female joint anchor portion 7 is short and it is not connected to the longitudinal reinforcing bars, so that the precast floor slab 1A can be easily handled when manufactured, and the handling performance is improved.

In order to arrange the female joint 3 on one side of the precast floor slab 1A, as shown in FIGS. The female joint anchor portion 7 is placed in a state of being completely embedded inside the skeleton of the precast floor slab 1A.

As for the method of manufacturing the female joint 3, it is desirable to use a mold casting method that allows a high degree of freedom in shape. As a result, the groove-type engaging portion 6 and the female joint anchor portion 7 can be integrally formed, and the structure is improved by integrating the joint portion body and the anchor portion without welding, pressure welding, or bolting. As well as being stabilized, there is no fear of fatigue damage, a high-strength joint structure can be obtained, and the precast floor slab 1A can be manufactured easily. In addition, by manufacturing by the die casting method, the adhesion strength to concrete is increased, and the fixability of the female joint 3 is improved.

Next, the male joint 4 provided on the precast floor slab 1B on the other side will be described with reference to FIGS. 4 to 6, 9 and 10. FIG.

As shown in detail in FIGS. 9 and 10, the male joint 4 includes a male joint anchor portion 9 whose distal end side protrudes from the joint end face of the precast floor slab 1B and whose proximal end side is embedded in concrete; It is provided at the protruding tip of the male joint anchor part 9 and is a metal member composed of a fixing part 8 that can be inserted into the groove-shaped engaging part 6 of the female joint 3 .

The fixing portion 8 is a wide portion protruding to both sides from the male joint anchor portion 9 in plan view shown in FIG. It is formed so that it can be inserted downward from the opening.

The fixing portion 8 is formed in a vertically long shape that is long in the vertical direction. That is, the height K of the fixing portion 8 in front view shown in FIG. 10(A) is larger than the width D of the fixing portion 8 in plan view shown in FIG. 10(B). The height K of the fixing portion 8 is preferably 60 to 90%, preferably 70 to 80%, of the height H of the groove-shaped engaging portion 6. As shown in FIG. It is preferable that the precast floor slabs 1A and 1B are arranged substantially in the center in the vertical direction of the grooved engaging portion 6 in a state where they are joined.

The fixing portion 8 has a substantially uniform width D over the entire length in the vertical direction, and is formed to have substantially the same projecting width from both sides of the male joint anchor portion 9 extending behind it. The width D of the fixing portion 8 is larger than the width S of the vertical groove 5 formed in the groove-shaped engaging portion 6. As shown in FIG. Both sides of the fixing portion 8 and both sides of the vertical groove 5 overlap each other in a direction (bridge axis direction) orthogonal to the joint end face when the fixing portion 8 is inserted into the joint end face. Since this overlap U is formed over the entire length of the fixing portion 8 in the height direction, the engagement area between the female joint 3 and the male joint 4 is increased, and the joint strength between the female joint 3 and the male joint 4 is increased. be able to raise it.

The male joint anchor portion 9 extending to the rear of the fixing portion 8 is formed in a flat plate shape along the vertical plane. One end of the male joint anchor portion 9 having such a flat plate shape protrudes from the joint end face of the precast floor slab 1B on the other side, is connected to the center portion in the width direction of the fixing portion 8 along the vertical direction, and the other end is the other end. It is arranged in a state of being embedded inside the frame of the precast floor slab 1B on the side. At the rear end of the male joint anchor portion 9, there is provided a rear end fixing portion 9a which protrudes to both sides in a plan view shown in FIG. there is

The male joint anchor portion 9 and the fixing portion 8 are formed so that the height of the male joint anchor portion 9 and the height of the fixing portion 8 are substantially equal at the connection portion thereof, and the upper and lower ends of both are substantially aligned. preferably formed. As a result, the entire male joint anchor portion 9 can bear the stress acting on the fixing portion 8 substantially evenly.

In the embodiment shown in FIG. 10(A), the height of the male joint anchor portion 9 is relatively small behind the intermediate portion. The ratio of the height of the rear portion formed with a relatively small height to the height of the front portion formed with a relatively large height is 40 to 80%, preferably 55 to 75%. Better to When changing the height, if a stepped portion where the height changes abruptly is provided, stress will be concentrated there and cause damage. It is preferable to provide The slope of the inclined portion 9b is preferably 30% or less, preferably 20% or less, with respect to the direction in which the male joint anchor portion 9 extends. Although the inclined portion 9b may be provided at either one of the upper and lower ends of the male joint anchor portion 9, it is preferable to form it in a tapered shape by providing it at both the upper and lower edges as in the illustrated example. The inclined portion 9b is preferably formed in the portion of the male joint anchor portion 9 embedded in the concrete of the precast floor slab 1B. It is preferable to form them with the same constant height. On the other hand, as shown in FIG. 20, the male joint anchor portion 9 may be formed to have a substantially uniform height over the entire length. Thereby, the fixing strength of the male joint anchor portion 9 can be further increased. At this time, the fixing portion 8 and the rear end fixing portion 9a connected to the front edge and the rear edge of the male joint anchor portion 9 are formed to have substantially the same height as the male joint anchor portion 9. is preferred.

The plate thickness T of the male joint anchor portion 9 may be substantially constant over the entire length, or may be varied. In any case, it is formed with a dimension smaller than the width S of the longitudinal groove 5 of the groove-shaped engaging portion 6 .

The male joint 4 may be manufactured by joining steel plates by welding or the like. The fixing portion 8 and the male joint anchor portion 9 can be integrally formed by manufacturing by the die casting method, and the joint portion main body and the anchor portion can be integrated without welding, pressure welding, bolting, or the like. Therefore, the structure is stabilized, the fear of fatigue damage is eliminated, a high-strength joint structure is obtained, and the precast floor slab 1B is easily manufactured. In addition, by manufacturing by the mold casting method, the adhesion strength to concrete is increased, and the fixability of the male joint 4 is improved.

(Combination procedure for precast floor slabs 1A and 1B)
As shown in FIG. 11(A), the male joint 4 of the following precast floor slab 1B is connected to the grooved engaging portion 6 of the female joint 3 of the precast floor slab 1A that has already been installed. The precast floor slab 1B is installed while the fixing portion 8 is dropped vertically from above, and both are aligned (FIG. 11(B)). The connection between the female joint 3 and the male joint 4 is achieved by inserting a male joint anchor portion 9 protruding from the joining end face of the male joint 4 into the longitudinal groove 5 of the groove-shaped engaging portion 6, as shown in FIG. 11(B). At the same time, the fixing portion 8 is inserted into the internal space of the groove-type engaging portion 6 of the female joint 3 to connect the two precast floor slabs 1A and 1B. In the present invention, since the simple fitting structure is provided by the female joint 3 provided with the groove-shaped engaging portion 6 and the male joint 4 provided with the fixing portion 8, the error tolerance is large, and the manufacturing error and installation error are reduced. Alignment can be easily performed by absorbing it.

Next, as shown in FIG. 11(C), the internal space IS of the groove-shaped engaging portion 6, the upper space US of the groove-shaped engaging portion 6, the precast floor slab on one side, and the precast floor on the other side A grout material 18 is filled in the gap portion M between the plate and the plate. Incidentally, instead of the grout material 18, concrete may be filled.

In the above embodiment, the female joint 3 is provided on the joint end surface of the precast floor slab 1A on one side, and the male joint 4 is provided on the joint end surface of the precast floor slab 1B on the other side. When three or more floor slabs are joined together, a female joint 3 is provided on one opposing surface of one rectangular precast floor slab, and a male joint 4 is provided on the other opposing surface of each precast floor slab. The precast floor slabs are installed by joining the floor slabs in order.

When joining three or more precast floor slabs, the female joint 3 is provided on the end face opposite to the end face provided with the male joint 4 of the succeeding precast floor slab 1B installed as described above. The following precast slabs are installed in the same way.

(Rebar 15 for opening prevention)
As shown in FIGS. 1 and 3, on both sides of the female joint 3, anti-opening openings extending in a direction parallel to the direction in which the female joint anchor portion 7 extends are provided at a predetermined distance from the female joint 3, respectively. A reinforcing bar 15 is preferably arranged. By arranging the opening-preventing reinforcing bars 15, the opening direction of the longitudinal grooves 5 (both sides of the female joint 3) is supported by the opening-preventing reinforcing bars 15 even when an excessive tensile force acts on the male joint 4. Therefore, it is possible to prevent the vertical grooves 5 from being deformed in the direction of opening to both sides. That is, if there is no anti-opening reinforcing bar 15, only concrete exists on both sides of the female joint 3, so that the vertical groove 5 is likely to open and deform. On the other hand, when the opening-preventing reinforcing bars 15 are arranged, the concrete on both sides of the female joint 3 is reinforced by the opening-preventing reinforcing bars 15, so that deformation of the longitudinal grooves 5 in the opening direction can be suppressed.

The opening-preventing rebar 15 may be a linear rod substantially parallel to the direction in which the female joint anchor portion 7 extends. It is preferable to use a substantially U-shaped or annular reinforcing bar having a loop portion 16 extending in the vertical direction at a position overlapping the joining portion 6 . Such a loop portion 16 can be formed by bending a rod material of a predetermined length into a semi-circular shape at approximately half position in the axial direction and processing it into a substantially U shape. As a result, the opening-preventing reinforcing bar 15 is formed with a loop portion 16 along the vertical direction on the side portion of the groove-shaped engaging portion 6 . As a result, the straight portions extending rearward are arranged in two stages, one above the other, so that the reinforcement strength of both sides of the female joint 3 is further increased. It is preferable that the height of the loop portion 16 is substantially the same as the height H of the groove-type engaging portion 6 .

Although the length of the opening-preventing reinforcing bar 15 in the direction of the bridge axis is arbitrary, it is preferable to form the length extending rearward from the female joint 3 . In the illustrated example, it is constituted by a portion of the joint end face side of the longitudinal reinforcing bar formed over substantially the entire longitudinal length of the precast floor slab 1A on one side.

As shown in FIG. 5, the loop portion 16 of the opening-preventing reinforcing bar 15 is arranged at a position overlapping the groove-shaped engaging portion 6 in the horizontal direction (perpendicular to the bridge axis). That is, in the cross-sectional view shown in FIG. 5 , the loop portion 16 of the opening-preventing reinforcing bar 15 is arranged so as to overlap the groove-shaped engaging portion 6 . As a result, the area where the opening-preventing reinforcing bar 15 and the groove-shaped engaging portion 6 overlap in the horizontal direction becomes larger than in the case of simply arranging the linear opening-preventing reinforcing bar, and the vertical opening formed in the groove-shaped engaging portion 6 increases. Deformation of the groove 5 in the opening direction can be reliably prevented. The top portion of the loop portion 16 (the top portion on the joint end surface side of the precast floor slab 1A with respect to the bridge axis direction of the opening prevention reinforcing bar 15) is the joint end surface (longitudinal groove 5 of the female joint 3) by the thickness of the concrete cover. is located on the rear side of the end face on which is formed).

As shown in FIG. 4 , the horizontal separation distance L between the groove-shaped engaging portion 6 and the opening-preventing reinforcing bar 15 is such that the vertical groove 5 of the groove-shaped engaging portion 6 is opened by the opening-preventing reinforcing bar 15 . 20 to 60 mm, preferably 30 to 50 mm, so as to reliably prevent this.

In the example shown in FIG. 1, two opening-preventing reinforcing bars 15 are arranged between the adjacent female joints 3, 3, and each of the reinforcing bars acts as opening-preventing reinforcing bars 15 for the adjacent groove-shaped engaging portion 6. However, when the horizontal arrangement intervals of the female joints 3, 3, . . . 3 may also be used for opening prevention reinforcing bars 15 (not shown).

The opening-preventing reinforcing bars 15 also function as bridge-axis direction reinforcing bars, and are arranged over substantially the entire length of the precast floor slab 1A on one side in the bridge axis direction. A plurality of similar longitudinal reinforcing bars 17 are also arranged on the side precast floor slab 1B at positions aligned with the longitudinal direction of the bridge.

As shown in FIG. 1, in the floor slab skeleton of the precast floor slab 1A on one side and the precast floor slab 1B on the other side, the opening prevention reinforcing bars 15 (bridge axis direction reinforcing bars) and the bridge axis direction reinforcing bars 17 are installed. In addition, reinforcing bars 19 perpendicular to the bridge axis, PC steel wires 20 perpendicular to the bridge axis, etc. may be arranged in a cross direction for firm reinforcement.

[Other form examples]
(1) In the above embodiment, the male joint 4 is fitted from above. An open space may be provided on the lower side, and the front longitudinal groove 5 may be formed so as to continuously extend upward from the lower edge. In this case, the space filled with the grout material 18 is the internal space IS of the female joint 3, the lower space of the female joint 3, and the gap portion M.

(2) In the above embodiment, the groove-shaped engaging portion 6 is formed in a box-like shape with an open top and a bottom. good too. In this case, both the upper surface and the lower surface of the groove-shaped engaging portion 6 are left open, and after the male joint 4 is coupled, both the upper space US and the lower space of the groove-shaped engaging portion 6 are filled with grout material. Fill 18.

(3) The bridge-axis-perpendicular reinforcing bars 19 and the bridge-perpendicular PC steel wires 20 arranged in the direction perpendicular to the bridge axis are arranged in various forms, as shown in FIGS. can be placed. In the illustrated example, a plurality of reinforcing bars 19 perpendicular to the bridge axis and PC steel wires 20 perpendicular to the bridge axis are arranged in two upper and lower stages as a set, which are arranged at predetermined intervals in the direction of the bridge axis. The longitudinal reinforcing bars 19 are connected to each other at a position perpendicular to the longitudinal reinforcing bars 15, and the longitudinal PC steel wires 20 are separated from the longitudinal reinforcing bars 15 toward the center in the vertical direction. are placed. For this reason, the vertical separation distance of the bridge axis-perpendicular reinforcing bars 19 is larger than the vertical separation distance of the bridge axis-perpendicular PC steel wires 20 .

In the form examples shown in FIGS. 1 to 3, in the region other than the vicinity of the joint end surface, the bridge axis perpendicular reinforcing bars 19 and the bridge axis perpendicular PC steel wires 20 are alternately arranged at substantially equal intervals in the bridge axis direction. On the other hand, in the region near the joint end surface where the female joint 3 or the male joint 4 is arranged, a bridge shaft having a relatively large vertical separation distance is placed at a position overlapping the female joint 3 or the male joint 4. A perpendicular reinforcing bar 19 is arranged continuously in the bridge axis direction, and a PC steel wire 20 perpendicular to the bridge axis is arranged continuously in the bridge axis direction at a position not overlapping the female joint 3 or the male joint 4 behind it. ing. The female joint anchor portion 7 of the female joint 3 and the male joint anchor portion 9 of the male joint 4 are arranged in the middle of the bridge axis perpendicular reinforcing bars 19, 19 which are vertically separated and do not cross the bridge axis perpendicular reinforcing bars 19. ing.

12 to 14, the reinforcing bars 19 perpendicular to the bridge axis and the PC steel wires 20 perpendicular to the bridge axis are alternately arranged at approximately equal intervals in the direction of the bridge axis. The bridge axis perpendicular reinforcing bars 19 and the bridge axis perpendicular PC steel wires 20 are also arranged at intersections with the female joint anchor portion 7 of the female joint 3 and the male joint anchor portion 9 of the male joint 4. The female joint anchor part 7 and the male joint anchor part 9 of the part are provided with an opening or a notch for inserting the bridge axis perpendicular reinforcing bar 19 or the bridge axis perpendicular PC steel wire 20, respectively.

(4) As shown in FIG. 15, the outer surface of the female joint 3 may be provided with uneven portions for fixing. Specifically, a plurality of ridges 24 or grooves 25 extending in a predetermined direction are formed on the outer surface of the female joint 3 at intervals in a direction orthogonal to the direction in which the ridges 24 or grooves 25 extend. there is As shown in FIG. 16, the ridge 24 is a portion having a substantially trapezoidal cross-section that protrudes relatively outward, and is formed in a line or band extending horizontally or vertically. Further, as shown in FIG. 17, the groove 25 is a portion having a relatively depressed substantially trapezoidal cross section, and is formed in a line or band extending horizontally or vertically.

The protruding line 24 and the recessed line 25 may be formed on any of the outer surfaces of the female joint 3. It is preferable to form the grooved line 25 on the front side end surface which will be the joint end surface of the floor slab 1A, and form the projected line 24 on the other surface. If a convex portion is formed on the front end face of the female joint 3, it will come into contact with the formwork during floor slab fabrication, and the gap between it and the precast floor slab 1B on the other side will be damaged during installation. It is preferable to form the recessed streak 25 that does not cause a crack.

The direction in which the ridges 24 or the grooves 25 extend with respect to each outer surface of the female joint 3 is arbitrary, but as shown in FIG. It is preferable that the formed front side end face, the rear side end face to which the female joint anchor portion 7 is connected, the upper surface and the bottom surface extend in the horizontal direction, and the both side surfaces extend in the vertical direction. In addition, it is preferable that the female joint anchor portion 7 is formed with ridges 24 perpendicular to each other along the vertical direction and the horizontal direction on both side surfaces along the vertical plane. As a result, when manufacturing the female joint 3 by a die casting method using a die divided into two parts in the width direction along the center line CL (FIG. 15(B)) passing through the center of the groove width of the longitudinal groove 5, the front and rear It is possible to increase the fixing strength of the female joint 3 against the tensile force acting in the bridge axis direction on both side surfaces and the bottom surface while ensuring ease of removal in the width direction of the mold that is divided into two parts at the end surface and the bottom surface. . In the example shown in FIG. 15(A), on both side surfaces of the groove-type engaging portion 6, a plurality of ridges 24 extending in the vertical direction are intermittently arranged at predetermined intervals. It is also possible to dispose ridges that are continuous in the vertical direction. Further, in the example shown in FIG. 15(A), on both side surfaces of the female joint anchor portion 7, orthogonal ridges 24 are arranged along the vertical and horizontal directions. You may arrange|position only the ridge 24 along. As shown in FIGS. 15A, 15B, and 15F, it is preferable to provide the ridges 24 on the upper surface of the groove-type engaging portion 6 as well, since the fixability of the female joint 3 is improved. In the illustrated example, a ridge 24 extending in a direction parallel to the joint end surface is formed on the rear portion of the upper surface of the groove-shaped engaging portion 6 formed in a substantially C shape, which is opposite to the longitudinal groove 5 . there is In the illustrated example, the ridge 24 is provided only in the intermediate portion that does not reach the edge of the rear portion, but it may be arranged so as to extend to the edge.

Moreover, it is preferable to form a plurality of protrusions 26, 26, . The protrusions 26 are discrete projections having a chevron cross section, and are provided on the inner surface facing both side surfaces of the female joint 3 . By providing the convex portions 26 . . . The convex portion 26 provided in the middle portion in the vertical direction is preferably formed in a chevron shape having a vertex in the center portion and gradually decreasing in height toward the outside. Further, it is preferable to provide a convex portion 26 at the upper end portion, and the convex portion 26 provided at the upper end portion is formed by a lower half portion obtained by vertically cutting the convex portion 26 provided at the intermediate portion at the top portion. It is preferable that the cut surface in the vertical direction is flush with the upper surface of the female joint 3, and that the height gradually decreases downward from this end surface. Concrete or grout material 17 filled in the groove-shaped engaging portion 6 is fixed by arranging a convex portion 26 having a top portion at the upper edge on the upper end portion of the inner surface of the groove-shaped engaging portion 6. In addition, the mortar filled in the column can be prevented from popping out due to vibration or the like.

When the male joint 4 is manufactured by die casting, as with the female joint 3, as shown in FIG. Specifically, of the male joint 4, the front end surface of the fixing portion 8, the both side surfaces along the vertical plane of the male joint anchor portion 9, and the rear end surface of the rear end fixing portion 9a of the male joint anchor portion 9 are each provided with the adhesive. , ridges 24 are formed. In addition, uneven portions can be provided on other surfaces. The direction in which the ridges 24 extend is arbitrary, but as shown in FIG. On both side surfaces of the anchor portion 9, it is preferable to form perpendicular protrusions 24 along the vertical direction and the horizontal direction. As a result, when the male joint 4 is manufactured by a mold casting method using a mold that is divided into two along the central portion of the plate thickness of the male joint anchor portion 9, the front surface of the fixing portion 8 and the rear end fixing portion 9a are It is possible to increase the fixation strength of the male joint 4 against the tensile force acting in the bridge axis direction on both side surfaces while ensuring ease of removal in the width direction of the two-part mold on the rear surface.

(5) The female joint 3 is placed on the concrete of the precast floor slab 1A on one side. 8 is optional as long as it can be inserted. In the above embodiment, as shown in FIG. 21(A), the concrete is arranged behind the rear end of the hollow portion of the groove-shaped engaging portion 6 above the upper surface of the groove-shaped engaging portion 6, Below the upper surface of the groove-shaped engaging portion 6, there is a stepped joining end surface in which concrete is arranged behind the front end surface of the groove-shaped engaging portion 6, as shown in FIG. 21(B). Alternatively, the concrete of the joint end face of the precast floor slab 1A on one side may be formed flat, and the front part may be formed so as to protrude from the joint end face of the concrete from the hollow portion of the groove-shaped engaging portion 6. As shown in FIG. 21(C), the female joint 3 is embedded in concrete, and only the hollow portions of the vertical groove 5 and the groove-shaped engaging portion 6 and the upper portions thereof are formed without concrete. good too.

(6) In the above embodiment, the precast concrete floor slab was explained as an example, but it can also be used for a joint structure for joining other precast concrete members.

1A, 1B... Concrete precast floor slab, 2... Joint part, 3... Female joint 4... Male joint, 5... Vertical groove, 6... Grooved engagement part, 7... Female joint anchor part, 8... Fixing part, 9 ... male joint anchor part, 15... reinforcing bar for opening prevention, 16... loop part, 17... bridge axis direction reinforcing bar, 18... grout material, 19... bridge axis perpendicular direction reinforcing bar, 20... bridge axis perpendicular direction PC steel wire, IS... Internal space of the groove-type engaging portion, US... Upper side space of the groove-type engaging portion, M... Gap portion

Claims (6)

A joint structure for joining concrete precast members,
On the joint end face of the concrete precast member on one side of the joint, the upper face is opened at a predetermined interval in the horizontal direction, and a vertical groove is formed on the front end face that communicates with the opened upper face and extends along the vertical direction. A box- shaped groove-shaped engaging portion having a groove-shaped cross section in a plan view , and a female extending rearward from the rear end surface of the groove-shaped engaging portion and formed in a flat plate shape along the vertical plane. A female joint composed of a joint anchor portion is embedded with the longitudinal groove facing the outside,
On the joint end face of the concrete precast member on the other side of the joint, at a predetermined interval in the horizontal direction, the male end protrudes from the joint end face of the concrete precast member, and the base end is embedded in the concrete. a male joint comprising a joint anchor portion and a fixing portion provided at the protruding tip of the male joint anchor portion and capable of being inserted into the groove-shaped engaging portion of the female joint is embedded;
The female joint of the concrete precast member on one side is engaged with the male joint of the concrete precast member on the other side, and the concrete precast members are connected to each other, and the inner space and the groove shape of the groove-shaped engaging portion are engaged. A grout material is filled in the gap between the upper space and/or the lower space of the engaging portion and the concrete precast member on one side and the concrete precast member on the other side,
The groove-shaped engaging portion is formed in a vertically elongated shape, the fixing portion is formed in a vertically elongated shape, and the male joint anchor portion is formed in a flat plate shape along a vertical plane. is formed of
The female joint is manufactured by die casting, and is formed with a ridge or recess extending in a predetermined direction on an arbitrary outer surface of the groove-type engaging portion. Inside, the front end face where the longitudinal groove is formed, the rear end face where the female joint anchor portion is connected, the ridges or grooves formed on the top and bottom faces extend in the horizontal direction, and the A joint structure for concrete precast members , wherein the ridges or grooves extend vertically . 2. The joint structure of precast concrete members according to claim 1, wherein a plurality of inwardly protruding protrusions are discretely formed on the inner surface of said groove-shaped engaging portion. The concrete precast member according to any one of claims 1 and 2, wherein the female joint anchor portion is formed with vertical and horizontal ridges perpendicular to each other on both side surfaces along the vertical plane. joint structure. The joint structure for concrete precast members according to any one of claims 1 to 3, wherein the female joint anchor portion and the male joint anchor portion are arranged independently of reinforcing bars arranged in the concrete precast member. The joint structure for concrete precast members according to any one of claims 1 to 4, wherein concrete is filled instead of the grout material. A joint structure for a concrete precast member according to any one of claims 1 to 5 , wherein the concrete precast member is a floor slab.

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