JP7254289B2 - Joint structure of concrete precast floor slabs and joint structure of concrete precast members - Google Patents

Description

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

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. 19, 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. 20, 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, Patent Document 2 below discloses the simplest mechanical joint 70 in which a male joint 72 is fitted to a female joint 71 having a groove-shaped cross section, as shown in FIG.

JP 2015-1045 A Japanese Patent Application Publication No. 2017-190629

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 a mechanical joint in which a male joint is fitted to a female joint having a grooved cross section, as shown in FIG. Since the longitudinal groove 73 of 71 is not supported on the opening side, there is a problem that it is easily deformed in the opening direction.

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide a mechanical joint structure for a concrete precast floor slab and a mechanical joint structure for a concrete precast member, which are intended to prevent deformation of the vertical grooves in a female joint having a groove-shaped cross section. .

In order to solve the above problems, the present invention according to claim 1 is a joint structure for joining concrete precast floor slabs,
A female joint with a groove-shaped cross-sectional groove-shaped engagement part in a plan view faces the vertical groove to the outside at a predetermined interval in the horizontal direction on the joint end face of the concrete precast floor slab on one side of the joint part. It is buried with the
On the joint end surface of the precast concrete floor slab on the other side of the joint, the tips of the longitudinal reinforcing bars are projected outward at predetermined intervals in the horizontal direction, and the tips of these longitudinal reinforcing bars are opposite to each other. A male joint in which a large-diameter fixing member is installed is buried,
The male joint of the precast concrete floor slab on one side is engaged with the male joint of the precast concrete floor slab on the other side, so that the precast concrete floor slabs are connected to each other, and the internal space of the female joint and the female joint are connected. The space around and the gap between the precast concrete floor slab on one side and the precast concrete floor slab on the other side is filled with grout material,
Concrete precast floor slabs characterized in that opening prevention reinforcing bars extending in a direction parallel to the bridge axis direction reinforcing bars are arranged on both sides of the female joint at a predetermined distance from the female joint. A joint structure is provided.

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 on the precast concrete floor slab on one side of the joint portion is in a state in which the longitudinal groove is exposed to the outside. A male joint is buried in the concrete precast floor slab on the other side of the joint, and the female joint and the male joint are engaged to connect the concrete precast floor slabs to each other. A grout material is filled in the space between the internal space of the female joint, the space around the female joint, and the gap between the precast concrete floor slab on one side and the precast concrete floor slab on the other side. Further, in the joint structure according to the present invention, on both sides of the female joint, opening-preventing reinforcing bars extending in a direction parallel to the longitudinal reinforcing bars are arranged at a predetermined distance from the female joint. As a result, even when an excessive tensile force acts on the male joint, the open side of the vertical groove of the female joint is supported by the opening-preventing reinforcing bars, so that the vertical groove can be prevented from opening.

As a second aspect of the present invention, the joint for a concrete precast floor slab according to claim 1, wherein the opening-preventing reinforcing bar is formed in a loop shape along the vertical direction at a position overlapping the female joint in the horizontal direction. A structure is provided.

In the invention according to claim 2, the opening-preventing reinforcing bar is formed in a loop shape along the vertical direction at the position overlapping the female joint in the horizontal direction, so that the opening-preventing reinforcing bar is supported by the loop portion. As a result, deformation of the longitudinal groove of the female joint in the opening direction can be prevented more reliably.

As a third aspect of the present invention, there is provided a joint structure for a concrete precast floor slab according to any one of the first and second aspects, wherein the separation distance between the female joint and the opening-preventing reinforcing bar is 5 to 40 mm. be.

In the invention according to claim 3, by specifically defining the separation distance between the female joint and the opening-preventing reinforcing bar, the opening of the longitudinal groove of the female joint due to the opening-preventing reinforcing bar can be prevented more reliably. become.

As a fourth aspect of the present invention, there is provided a joint structure for a concrete precast floor slab according to any one of the first to third aspects, wherein the opening-preventing reinforcing bars are embedded in the concrete.

In the invention according to claim 4, the opening-preventing reinforcing bars are arranged in a state of being embedded in concrete. That is, both sides of the female joint are covered with concrete, and a reinforcing bar for preventing opening is buried inside. As a result, the space between the precast floor slabs on the other side becomes smaller, and the amount of filler used can be reduced.

As the present invention according to claim 5, the opening-preventing reinforcing bar protrudes from the joint end surface of the concrete precast floor slab on one side, and the reinforcing bar protruding from the joint end surface of the concrete precast floor slab on the other side is adjacent. There is provided the joint structure of the concrete precast floor slabs according to any one of claims 1 to 3, wherein the grout material is filled in the arranged state.

In the fifth aspect of the invention, the space is formed on both sides of the female joint, and the opening-preventing reinforcing bars are arranged in the space so as to protrude from the joint end surface of the concrete precast floor slab on one side. . Adjacent to this protruding opening prevention reinforcing bar, a reinforcing bar protruding from the joint end face of the precast concrete floor slab on the other side is arranged, and then filled with grout material. As a result, the rebar for preventing the opening of the precast concrete floor slab on one side and the rebar of the precast concrete floor slab on the other side transmit stress like a lap joint, so the longitudinal groove of the female joint opens. Transformation in the direction can be suppressed more reliably.

As the present invention according to claim 6, the female joint has a rear groove-type engaging portion in a groove-type cross-section in a plan view in a portion of the groove-type engaging portion buried in the concrete opposite to the vertical groove. and a male type fixing portion in which a relatively large diameter fixing member is arranged at the tip of the bridge axis direction reinforcing bar is engaged with the rear side groove type engaging portion. A joint structure for a concrete precast floor slab according to 1 is provided.

The sixth aspect of the invention defines a structure for connecting the female joint to the longitudinal reinforcing bars arranged on one side of the precast concrete floor slab. Specifically, a rear groove-type engaging portion having a groove-shaped cross-section in a plan view is formed in a portion of the groove-type engaging portion embedded in the concrete on the opposite side of the vertical groove, and this rear groove-type engaging portion is formed. The joining portion is connected by engaging a male fixing portion provided at the tip of the longitudinal reinforcing bar. As described above, since welding is not used to connect the female joints and the longitudinal reinforcing bars, the manufacturability of the concrete precast floor slab is improved, and there is no fear of fatigue damage.

As a seventh aspect of the present invention, there is provided a joint structure for a concrete precast floor slab according to any one of the first to sixth aspects, wherein the male joints are arranged vertically in two stages.

In the seventh aspect of the invention, the male joints are arranged horizontally at predetermined intervals, but it is desirable to arrange them vertically in two stages at each position. This is for coping with compressive force and tensile force due to bending.

As an eighth aspect of the present invention, there is provided a joint structure for a concrete precast floor slab according to any one of the first to seventh aspects, wherein the female joint is manufactured by a die casting method.

In the eighth aspect of the invention, the material of the female joint is specified. The female joint is desirably manufactured by a die casting method, which has a high degree of freedom in shape.

As a ninth aspect of the present invention, there is provided a joint structure for a concrete precast floor slab according to any one of the first to eighth aspects, wherein concrete is filled instead of the grout material.

According to the ninth aspect of the invention, concrete is filled in place of the grout material in order to reduce construction costs.

According to a tenth aspect of the present invention, a plurality of ridges or grooves extending in a predetermined direction are formed on the outer surface of the female joint at intervals in a direction orthogonal to the direction in which the ridges or grooves extend. A concrete precast floor slab joint structure according to any one of claims 1 to 9 is provided.

In the tenth aspect of the invention, the fixability of the female joint is enhanced by forming the fixing portion in an uneven shape on the outer surface of the female joint.

As the present invention according to claim 11, a joint structure for joining concrete precast members,
A female joint provided with a groove-shaped engaging portion with a groove-shaped cross section in a plan view faces the vertical groove to the outside at a predetermined interval in the horizontal direction on the joint end face of the concrete precast member on one side of the joint. buried in
On the joint end face of the concrete precast member on the other side of the joint, the tips of reinforcing bars extending in a direction orthogonal to the joint end face are formed to protrude outward at predetermined intervals in the horizontal direction. A male joint having a fixing member having a relatively large diameter 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 of the female joint and the surrounding of the female joint The grout material is filled in the space and the gap between the concrete precast member on one side and the concrete precast member on the other side,
Provided is a joint structure for concrete precast members, characterized in that opening prevention reinforcing bars extending in a direction parallel to the reinforcing bars are arranged on both sides of the female joint at a predetermined distance from the female joint. be done.

The invention defined in claim 11 defines that it can be used not only for precast concrete floor slabs but also for other precast concrete members.

As described in detail above, the present invention provides a mechanical joint structure for a concrete precast floor slab and a mechanical joint structure for a concrete precast member that is intended to prevent deformation of the vertical groove in a female joint having a groove-shaped cross section. becomes possible.

Fig. 2 is a plan view showing joint portions 2 of concrete precast floor slabs 1A and 1B; FIG. 2 is a vertical cross-sectional view of the joint portion 2 (cross-sectional view taken along the line II-II in FIG. 1). FIG. 3 is a lateral cross-sectional view of the joint portion 2 (a cross-sectional view taken along the line III-III in FIG. 2); FIG. 2 is a vertical cross-sectional view of the joint portion 2 (cross-sectional view taken along line IV-IV in FIG. 1). 3 is an enlarged plan view of a main part showing the female joint 3; FIG. FIG. 6 is an enlarged vertical cross-sectional view of the main part showing the female joint 3 (cross-sectional view taken along line VI-VI in FIG. 5); 1 shows a female joint 3, (A) is a longitudinal sectional view, (B) is a top view, (C) is a left side view, and (D) is a right side view. 4 is a floor slab perspective view showing a male joint 4. FIG. 4 is an enlarged plan view of a main part showing the male joint 4; FIG. Fig. 4(A) and (B) are connection procedure diagrams of concrete precast floor slabs. 4A to 4C are diagrams (A) to (C) of procedures for joining precast floor slabs. Fig. 10 is a plan view showing joint portions 2 of concrete precast floor slabs 1A and 1B according to a second embodiment; (A) is one side and (B) is an enlarged view of a principal part showing a joint end face of a concrete precast floor slab on the other side. (A) is a cross-sectional view along XIVa-XIVa in FIG. 13(A), and (B) is a cross-sectional view along XIVb-XIVb in FIG. 13(B). Fig. 3 is a cross-sectional view showing a state in which the opening-preventing reinforcing bars 15 of the precast floor slab 1A on one side overlap with the reinforcing bars 20 of the precast floor slab 1B on the other side. Shows the female joint 3 according to the third embodiment, (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, ( F) is a vertical cross-sectional view (cross-sectional view taken along line FF of (B)). FIG. 16 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. 16(C)); FIG. 16 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 XVIII-XVIII in FIG. 16(D)); FIG. 5 is a vertical cross-sectional view showing a conventional loop joint 50; FIG. 6 is a vertical cross-sectional view showing a conventional streamlined joint 60; 1 is a perspective view showing a conventional mechanical joint 70; FIG.

[Example 1]
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 FIG. 1, the joint structure is formed on the joint end surface of the precast floor slab 1A on one side of the joint portion 2 at predetermined intervals in the horizontal direction (perpendicular to the bridge axis). A female joint 3 having a front groove-shaped engaging portion 6 with a groove-shaped cross section is embedded with the front longitudinal groove 5 facing the outside, and the precast floor slab 1B on the other side of the joint portion 2 is joined. On the end face, the ends of the longitudinal reinforcing bars 8 are formed to protrude outward in at least two stages in the vertical direction at predetermined intervals in the horizontal direction. The male joint 4 is buried,
As shown in FIGS. 2 to 4, the male joint 4 of the precast floor slab 1B on the other side is inserted into the female joint 3 of the precast floor slab 1A on one side to connect the two floor slabs. The joint structure is such that grout material 17 is filled in the internal space IS of the joint 3, the upper space US of the female joint 3, and the gap M between the precast floor slab 1A on one side 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. 5 to 7. FIG.

As shown in detail in FIG. 7, the female joint 3 includes a front groove-type engaging portion 6 having a groove-shaped cross section in plan view, which has a front longitudinal groove 5 formed on one end surface, and a groove-type engaging portion 6 on the opposite side. A rear groove-shaped engaging portion 11 having a groove-shaped cross section in a plan view and having a rear longitudinal groove 10 formed on the other end surface of the partition wall 3a is arranged back-to-back on the left and right sides of the partition wall 3a. It is a substantially rectangular parallelepiped metal box-shaped member. As shown in FIGS. 2 and 3, in the front groove-shaped engaging portion 6, a bridge axial reinforcing bar 8 projecting from the joint end face of the precast floor slab 1B on the other side is inserted into the front longitudinal groove 5. In this state, the male joint 4 provided at the tip thereof is engaged. In addition, in the rear groove-type engaging portion 11, a bridge axis direction reinforcing bar 12 embedded in the concrete of the frame of the precast floor slab 1A on one side is inserted into the rear longitudinal groove 10, and at the tip thereof A male fuser 14 having a fuser member 13 of relatively large diameter is engaged.

As shown in FIGS. 5 and 6, the female joint 3 is embedded with the front groove-type engaging portion 6 facing the opening of the upper surface and the front longitudinal groove 5 to the outside. The rear groove-type engaging portion 11 is arranged on the joint end surface of the precast floor slab 1A in a state of being completely embedded in the concrete of the frame 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 shown in FIG. 7, the width dimension B and the depth dimension C of the front groove-type engaging portion 6 of the female joint 3 are approximately 80 to 150 mm, preferably 100 to 130 mm, respectively. Further, it is preferable that the width dimension B of the rear groove-type engaging portion 11 is the same as the width dimension B of the front groove-type engaging portion 6, and the depth dimension D is equal to the width dimension B of the front groove-type engaging portion 6. It is formed with a dimension smaller than the depth dimension C of , specifically approximately 50 to 100 mm, preferably 60 to 80 mm. Since the male joint 4 protruding from the joint end surface of the precast floor slab 1B on the other side engages the front groove-type engaging portion 6, it is designed to sufficiently absorb installation errors when installing the precast floor slab 1B on the other side. It is preferably formed with relatively large dimensions. On the other hand, the rear groove engaging portion 11 is a portion to which the male fixing portion 14 is engaged when the precast floor slab 1A on one side is manufactured at the factory. Dimensions can be formed. The height dimension H of the female joint 3 is preferably 60 to 90%, preferably 70 to 85% of the thickness of the floor slab.

As shown in FIG. 7(D), the width S1 of the front longitudinal groove 5 formed in the front groove-type engaging portion 6 is 15 to 45 mm, preferably 18 to 40 mm. The dimension is 110 to 220%, preferably 120 to 200%, of the diameter of the bridge axial reinforcing bars 8 constituting the bridge. Further, as shown in FIG. 7(C), the width S2 of the rear longitudinal groove 10 formed in the rear groove-type engaging portion 11 is smaller than the width S1 of the front longitudinal groove 5, Specifically, it is 10 to 40 mm, preferably 13 to 35 mm, and is 105 to 170%, preferably 110 to 150%, of the diameter of the longitudinal reinforcing bars 12 arranged on the precast floor slab 1A on one side. is assumed to be the dimension of The ratio to the diameter of the longitudinal reinforcing bars 8, 12 is closely related to the allowable range of manufacturing errors or construction errors, so it is desirable to set the ratio within an appropriate numerical range. Also, if this ratio is too large, the contact between the fixing member 9 of the male joint 4 and the fixing member 13 of the male fixing portion 14 becomes small, and the force transmission efficiency deteriorates. .

The front vertical groove 5 formed in the front groove-type engaging portion 6 and the rear vertical groove 10 formed in the rear groove-type engaging portion 11 are formed vertically through from the upper end edge to the lower end edge. However, as shown in FIG. 7, it is preferable to form a U-shaped vertical groove extending from the upper edge to the middle of the downward direction. By connecting the lower ends as a U-shaped flute, the front flute 5 and the rear flute 10 can be prevented from opening. Further, as shown in FIG. 7(D), it is preferable to form an inclined portion 5a at the upper end portion of the front vertical groove 5 so that the groove width gradually increases upward. As a result, when the precast floor slab 1B on the other side is dropped from above, the protruding reinforcing bars 8 in the bridge axial direction can be smoothly inserted into the front longitudinal grooves 5.例文帳に追加

In the precast floor slab 1A on one side, a male fixing portion 14 having a fixing member 13 having a relatively large diameter is formed at the tip of the longitudinal reinforcing bar 12 connected to the female joint 3. . When the precast floor slab 1A on one side is manufactured, the male fixing portion 14 is engaged with the rear groove engaging portion 11 of the female joint 3, and the female joint 3 is connected to the tip of the longitudinal reinforcing bar 12. The internal space of the rear groove-type engaging portion 11 and the space around the rear groove-type engaging portion 11 are filled with concrete, whereby the female joint 3 is fixed to the precast floor slab 1A on one side. . The fixing member 13 is fixed to the tip of the longitudinal reinforcing bar 12 by a fixing method such as friction welding or screwing without welding. Since no welding is used, there is no fear of fatigue damage. In particular, the fixing method by friction welding is preferable because the fixing work is simple.

The front groove-type engaging portion 6 and the rear groove-type engaging portion 11 may have their bottom surfaces opened in the same manner as the top surface opening, but the bottom portions are closed as shown in FIG. 7(A). By providing a bottom plate, it is preferable to form a grooved cross section with a bottom. This makes it possible to more reliably prevent the front groove-type engaging portion 6 and the rear groove-type engaging portion 11 from opening. In addition, an opening (not shown) for communicating with a filler may be provided in the central portion of the bottom surface of the front groove-type engaging portion 6 and the rear groove-type engaging portion 11 .

As shown in FIGS. 1 and 3, on both sides of the female joint 3, a predetermined distance from the female joint 3, and a bridge axial direction reinforcing bar 12 arranged on one side of the precast floor slab 1A. Opening prevention reinforcing bars 15 extending in parallel directions are arranged. By arranging the opening-preventing reinforcing bars 15, the opening direction of the front longitudinal groove 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, deformation in the opening direction of the front vertical grooves 5 can be prevented. That is, when there is no anti-opening reinforcing bar 15, only concrete exists on both sides of the female joint 3, so that the front longitudinal 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 front longitudinal grooves 5 in the opening direction can be suppressed.

The opening-preventing rebar 15 may be a straight bar substantially parallel to the longitudinal rebar 12. However, as shown in FIGS. It is preferable to use a substantially U-shaped reinforcing bar in which a loop portion 16 extending in the vertical direction is formed. 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 female joint 3, and extends rearward from the upper end and the lower end of the loop portion 16 in parallel with the longitudinal reinforcing bar 12, respectively. The linear portions extending vertically are arranged in two stages, and the reinforcing 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 female joint 3 .

The length of the opening-preventing reinforcing bar 15 in the bridge axis direction is arbitrary, but it is preferable to form it with a length that extends rearward from the female joint 3 . It is preferable to set it to about twice to five times.

As shown in FIG. 2, the loop portion 16 of the opening-preventing reinforcing bar 15 is arranged at a position overlapping the female joint 3 in the horizontal direction (perpendicular to the bridge axis). That is, in the cross-sectional view shown in FIG. 2, the loop portion 16 of the opening-preventing reinforcing bar 15 is arranged so as to overlap the female joint 3 . In particular, as shown in FIG. 2, it is more preferable to arrange the loop portion 16 at a position that overlaps the front groove-type engaging portion 6 in the horizontal direction. The area where the joining portion 6 overlaps in the horizontal direction increases, and the deformation of the front longitudinal groove 5 formed in the front groove-type engaging portion 6 in the opening direction can be reliably prevented. The front groove-type engaging portion 6 is formed with a larger depth dimension and a groove width of the front longitudinal groove 5 than the rear-side groove-type engaging portion 11 in consideration of the construction error of the precast floor slab 1B on the other side. When an excessive tensile force acts on the male joint 4, the front longitudinal groove 5 is more likely to be deformed in the opening direction than the rear longitudinal groove 10. The presence of 16 on both sides prevents such opening. 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 (the front longitudinal groove of the female joint 3) by the thickness of the concrete cover. 5 is located on the rear side of the end surface where 5 is formed.

As shown in FIG. 3, the horizontal separation distance L between the female joint 3 and the opening-preventing reinforcing bar 15 ensures that the opening-preventing reinforcing bar 15 prevents the front longitudinal groove 5 of the female joint 3 from opening. 5 to 40 mm, preferably 8 to 25 mm.

In the example shown in FIG. 1, only one of the opening-preventing reinforcing bars 15 is arranged between the adjacent female joints 3, 3, and is arranged on the side of each of the female joints 3 arranged on both sides thereof. The opening preventing reinforcing bar 15 is also used. On the other hand, although not shown, when the arrangement interval of the female joints 3, 3 . . . Two opening-preventing rebars 15, 15 may be arranged between the female joints 3, 3.

As shown in FIG. 1, in the floor slab frame near the embedded portion of the female joint 3, in addition to the bridge axis direction reinforcing bars 12 and the opening prevention reinforcing bars 15 connected to the rear side of the female joint 3, Axial reinforcing bars, perpendicular reinforcing bars, PC steel wires perpendicular to the bridge axis, etc. may be arranged in a cross direction for firm reinforcement.

Next, the male joint 4 provided on the precast floor slab 1B on the other side will be described in detail with reference to FIGS. 8 and 9. FIG.

The male joint 4 has ends of longitudinal reinforcing bars 8 protruding outside from the joint surface, and fixing members 9 are installed at the tips of the longitudinal reinforcing bars 8 . In the illustrated example, the fixing member 9 is configured by a nut having a diameter larger than that of the longitudinal reinforcing bar 8, a circular fixing plate, or the like. The fixing member 9 is fixed to the tip of the longitudinal reinforcing bar 8 by, for example, friction welding or screwing, without welding. Since no welding is used, there is no fear of fatigue damage.

As shown in FIG. 8, the male joints 4 are arranged in at least two stages in the vertical direction at predetermined intervals in the horizontal direction, and are spaced apart in the vertical direction from the front side groove-type engaging portion 6 of the same female joint 3 . It is designed to be arranged as follows (see Fig. 2). The diameter of the bridge axis direction reinforcing bar 8 is about D16 to D22, and is smaller than the width of the front longitudinal groove 5 of the female joint 3 . As shown in FIG. 10, the precast floor slabs 1A and 1B are connected by inserting the male joint 4 into the front groove-type engaging portion 6 of the female joint 3 from above and below.

As shown in FIG. 1, in the floor slab near the embedded portion of the bridge axis direction reinforcing bars 8, in addition to the bridge axis direction reinforcing bars 8, the bridge axis direction reinforcing bars, the bridge axis direction reinforcing bars, and the bridge axis A perpendicular PC steel wire or the like may be arranged in a cross direction for firm reinforcement.

(Coupling procedure for floor slab 1)
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 connecting three or more floor slabs, as shown in FIG. 10, one rectangular precast floor slab 1 is provided with a female joint 3 on one side facing each other, and a female joint 3 is provided on the other side facing each other. A male joint 4 is provided at the joint 4, and the precast floor slabs 1, 1, . . .

Specifically, as shown in FIGS. 10 and 11(A), the male joint 4 of the following precast floor slab 1 is attached to the female joint 3 of the preceding precast floor slab 1 that has already been installed. The precast floor slabs 1 are installed while dropping vertically from the upper side, and the positions of both are aligned (Fig. 11(B)). The connection between the female joint 3 and the male joint 4 is achieved by engaging the fixing member 9 of the male joint 4 with the front longitudinal groove 5 of the female joint 3, as shown in FIG. 9 is positioned inside the front groove-type engaging portion 6 of the female joint 3, and the longitudinal reinforcing bars 8 are inserted into the front longitudinal grooves 5 to connect the two precast floor slabs 1, 1 together. The invention of the present application has a simple fitting structure with the female joint 3 having the front groove-type engaging portion 6 and the bridge axis direction reinforcing bar 8 having the male joint 4. Therefore, the tolerance for error is large, and manufacturing errors and Alignment can be easily performed by absorbing construction errors.

Next, as shown in FIG. 11(C), the inner space IS of the front groove-type engaging portion 6, the upper space US of the front groove-type engaging portion 6, the precast floor slab on one side, and the A grout material 17 is filled in the gap portion M between the precast floor slab. Incidentally, instead of the grout material 17, concrete may be filled.

The female joint 3 is provided on the end face opposite to the end face on which the male joint 4 of the trailing precast floor slab 1 installed in this way is provided. A precast floor slab 1 is installed. When three or more precast floor slabs are joined together, axial reinforcing bars that are continuous over almost the entire length of one precast floor slab in the bridge axial direction are arranged. 1 protruding from the joint end face and having a male joint 4 at its tip, the other is provided with the male fixing part 14 at its tip, and the rear side groove-type engaging part of the female joint 3 11 constitutes the bridge axial reinforcing bar 12 engaged with.

[Second form example]
In the first embodiment, the opening-preventing reinforcing bars 15 are embedded in concrete, but as shown in FIGS. The grout material 17 is filled with the tip of the reinforcing bar 20 protruding from the end face and protruding from the joint end face of the precast floor slab 1B on the other side adjacent to the opening preventing reinforcing bar 15. good too.

On the joint end face of the precast floor slab 1A on one side, a concave portion 21 is formed in which the front groove-type engaging portion 6 of the female joint 3 and the ends of the opening-preventing reinforcing bars 15, 15 arranged on both sides thereof protrude. It is As shown in FIGS. 13(A) and 14(A), this recessed portion 21 is an area where no concrete exists, which penetrates the upper and lower surfaces of the precast floor slab 1A and constitutes the floor slab skeleton. In this concave portion 21, the front groove-shaped engaging portion 6 of the female joint 3 and the tip of the opening-preventing reinforcing bar 15 projecting from the bottom surface (joint end surface) of the concave portion are arranged.

In the precast floor slab 1A on one side, among the axial direction reinforcing bars 12, 12 . The female joint 3 is connected, and only the male fixing portion 14 is provided at the tip of the longitudinal reinforcing bar 12 therebetween, and the female joint 3 is not connected. The longitudinal reinforcing bars 12 not provided with the female joints 3 are arranged so as to extend toward the joint end face side from the longitudinal reinforcing bars 12 provided with the female joints 3, and the tips of the longitudinal reinforcing bars 12 are adjacent to each other in the direction perpendicular to the bridge axis. It is arranged so as to extend in a convex portion 22 that relatively protrudes toward the joint end surface between the concave portions 21 , 21 .

The protruding end of the opening-preventing reinforcing bar 15 (the top of the loop portion 16) extends to a position substantially equal to the end of the female joint 3 on the protruding side. Further, the protruding side end portions of the opening-preventing reinforcing bars 15 and the female joint 3 are arranged at positions substantially coinciding with the joint end surfaces of the convex portions 22 .

Similarly, in the precast floor slab 1B on the other side, the precast floor slab 1A on the one side of the precast floor slab 1A on the one side of the longitudinal reinforcing bars 8, 8, . . . The tip of every other bridge axial reinforcing bar 8 corresponding to the reinforcing bar on which the female joint 3 is arranged is formed to protrude outside and the male joint 4 is provided, while the tip of the bridge axial reinforcing bar 8 therebetween is on the other side. is embedded in concrete without protruding from the precast floor slab 1B. A fixing member 9 having a relatively large diameter is installed at the tip of the axial rebar 8 that does not protrude to the outside, similarly to the axial rebar 8 that protrudes to the outside and forms the male joint 4 .

On both sides of the bridge axis direction reinforcing bars 8 projecting to the outside, opening prevention reinforcing bars 15 project from the end face of the precast floor slab 1A on one side while the male joint 4 is connected to the female joint 3. A reinforcing bar 20 arranged adjacent to is formed to protrude. As the reinforcing bar 20, a substantially U-shaped reinforcing bar provided with a loop portion 23 having a protruding end formed in a loop shape extending in the vertical direction is used in the same manner as the opening-preventing reinforcing bar 15. As shown in FIG. As shown in FIG. 15, the loop portion 23 of the reinforcing bar 20 is arranged so as to cross the loop portion 16 of the opening-preventing reinforcing bar 15 while the male joint 4 is connected to the female joint 3. , is positioned so as to overlap the female joint 3 in the horizontal direction. As a result, the side portions of the front vertical groove 5 in the opening direction are reinforced by the opening-preventing reinforcing bars 15 and the reinforcing bars 20, and the opening of the front vertical groove 5 can be prevented more reliably. It is preferable that the ends of the reinforcing bars 20 on the protruding side are arranged so as to be substantially equal to or protrude outwardly from the tips of the longitudinal reinforcing bars 8 having the male joints 4 at their tips.

Said rebar 20 is arranged adjacent to the side of a given side of each anti-opening rebar 15 . As a result, when dropping the trailing floor slab, interference between the opening prevention reinforcing bars 15 and the reinforcing bars 20 is less likely to occur, and the male joint 4 and the female joint 3 are easily engaged.

In the second embodiment, in connecting the precast floor slabs 1A and 1B, the male joint 4 of the following precast floor slab 1B is engaged with the female joint 3 of the preceding precast floor slab 1A to prevent opening. After placing the reinforcing bar 20 adjacent to the reinforcing bar 15, the inner space IS of the front groove-type engaging portion 6 and the space around the front groove-type engaging portion 6, that is, the upper portion of the front groove-type engaging portion 6 The grout material 17 is filled in the space US, the side space, the lower space, and the gap portion M between the precast floor slabs.

As described above, the recess 21 provided on the joint end face of the precast floor slab 1A on one side may be configured so that the concrete of the building frame portion is not placed through it in the vertical direction, or it is located below the female joint 3. A concrete bottom portion may be arranged extending from the frame portion of the floor slab.

[Third form example]
In the third embodiment, as shown in FIG. 16, the outer surface of the female joint 3 is 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. 17, 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. 18, 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 ridges 24 and the grooves 25 may be formed on any of the outer surfaces of the female joint 3, but they are the joint end surfaces of the precast floor slab 1A on which the front longitudinal grooves 5 are formed. It is preferable to form grooves 25 on the surface and to form projections 24 on the surfaces other than the upper surface. Moreover, it is preferable that neither the convex line nor the concave line be formed on the upper surface. If a convex portion is formed on the front end face of the female joint 3, it hits against the formwork during floor slab fabrication, and the gap between it and the precast floor slab 1B on the other side is damaged during installation. It is preferable to form the grooves 25 that do not cause problems.

The direction in which the ridges 24 or the grooves 25 extend relative to each outer surface of the female joint 3 is arbitrary, but as shown in FIG. It is preferable to extend horizontally on both end surfaces and the bottom surface, and to extend vertically on both side surfaces. As a result, the female joint 3 is divided into two parts in the width direction along the center line CL (FIG. 16(B)) passing through the center of the groove width of the front longitudinal groove 5 and the rear longitudinal groove 10. When manufacturing by the method, while ensuring ease of removal in the width direction of the mold divided into two at both end surfaces and the bottom surface where the front longitudinal groove 5 and the rear longitudinal groove 10 are formed, bridges are formed on both side surfaces and the bottom surface. The fixing strength of the female joint 3 against tensile force acting in the axial direction can be increased.

Further, as shown in FIG. 16(F), a plurality of inwardly protruding protrusions 26, 26, . . . is preferred. 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 fixability of the male joint 4 in the front grooved engagement portion 6 and the male fixing portion 14 in the rear grooved engagement portion 11 is improved. The convex portion 26 provided in the middle portion in the vertical direction is preferably formed in a mountain shape having an apex at 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. By arranging a convex portion 26 having a top portion on the upper edge at the upper end of the inner surface of the front groove-type engaging portion 6 and the rear groove-type engaging portion 11, the front groove-type engaging portion 6 and the rear groove-type engaging portion 11 are arranged. The fixability of the concrete or grout material 17 filled in the rear groove type engaging portion 11 is further improved.

[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 17 is the internal space IS of the female joint 3, the lower side space of the female joint 3, and the gap portion M.

(2) In the above embodiment, the front groove-type engaging portion 6 is formed in a box shape with an open top and a bottom, but it is formed with a groove-shaped cross section that is open on both the top and bottom surfaces and penetrates in the vertical direction. may In this case, both the upper and lower surfaces of the front groove-type 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 front groove-type engaging portion 6 are opened. Fill with grout material 17 .

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

1, 1A, 1B... Concrete precast floor slab, 2... Joint part, 3... Female joint 4... Male joint, 5... Front longitudinal groove, 6... Front groove-type engagement part, 8... Bridge axis direction reinforcing bar, 9... Fixing member 10 Rear longitudinal groove 11 Rear groove engaging portion 12 Bridge axis direction reinforcing bar 13 Fixing member 14 Male fixing portion 15 Opening prevention reinforcing bar 16 Loop portion 17... grout material, 20... reinforcing bar, 21... concave part, 22... convex part, 23... loop part, 24... convex line, 25... concave line, IS... internal space of groove-shaped cross section, US... groove-shaped cross section Upper space, M... Gap part

Claims (11)

A joint structure for joining concrete precast floor slabs,
A female joint with a groove-shaped cross-sectional groove-shaped engagement part in a plan view faces the vertical groove to the outside at a predetermined interval in the horizontal direction on the joint end face of the concrete precast floor slab on one side of the joint part. It is buried with the
On the joint end surface of the precast concrete floor slab on the other side of the joint, the tips of the longitudinal reinforcing bars are projected outward at predetermined intervals in the horizontal direction, and the tips of these longitudinal reinforcing bars are opposite to each other. A male joint in which a large-diameter fixing member is installed is buried,
The male joint of the precast concrete floor slab on one side is engaged with the male joint of the precast concrete floor slab on the other side, so that the precast concrete floor slabs are connected to each other, and the internal space of the female joint and the female joint are connected. The space around and the gap between the precast concrete floor slab on one side and the precast concrete floor slab on the other side is filled with grout material,
Concrete precast floor slabs characterized in that opening prevention reinforcing bars extending in a direction parallel to the bridge axis direction reinforcing bars are arranged on both sides of the female joint at a predetermined distance from the female joint. joint structure. 2. The joint structure of a concrete precast floor slab according to claim 1, wherein said opening-preventing reinforcing bar is formed in a loop shape along the vertical direction at a position overlapping said female joint in the horizontal direction. 3. The joint structure for a concrete precast floor slab according to claim 1, wherein a separation distance between the female joint and the opening-preventing reinforcing bar is 5 to 40 mm. The joint structure of a concrete precast floor slab according to any one of claims 1 to 3, wherein the opening-preventing reinforcing bars are embedded in the concrete. The opening-preventing rebar protrudes from the joint end surface of the precast concrete floor slab on one side, and the rebar protruding from the joint end surface of the precast concrete floor slab on the other side is arranged adjacent to the grout material. The joint structure of a concrete precast floor slab according to any one of claims 1 to 3, wherein the joint structure is filled with In the female joint, a rear groove-type engaging portion having a groove-shaped cross-section in a plan view is formed in a portion of the groove-type engaging portion embedded in the concrete on the opposite side of the longitudinal groove, and the rear groove-type engaging portion is The precast concrete floor slab according to any one of claims 1 to 5, wherein the engaging portion is engaged with a male fixing portion in which a fixing member having a relatively large diameter is arranged at the tip of the longitudinal reinforcing bar. joint structure. The joint structure for a concrete precast floor slab according to any one of claims 1 to 6, wherein the male joints are arranged vertically in two stages. The joint structure of a concrete precast floor slab according to any one of claims 1 to 7, wherein the female joint is manufactured by a die casting method. The joint structure of a concrete precast floor slab according to any one of claims 1 to 8, wherein concrete is filled instead of the grout material. 10. Any one of claims 1 to 9, wherein a plurality of ridges or grooves extending in a predetermined direction are formed on the outer surface of the female joint at intervals in a direction perpendicular to the extending direction of the ridges or grooves. The joint structure of the concrete precast floor slab described. A joint structure for joining concrete precast members,
A female joint provided with a groove-shaped engaging portion with a groove-shaped cross section in a plan view faces the vertical groove to the outside at a predetermined interval in the horizontal direction on the joint end face of the concrete precast member on one side of the joint. buried in
On the joint end face of the concrete precast member on the other side of the joint, the tips of reinforcing bars extending in a direction orthogonal to the joint end face are formed to protrude outward at predetermined intervals in the horizontal direction. A male joint having a fixing member having a relatively large diameter 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 of the female joint and the surrounding of the female joint The grout material is filled in the space and the gap between the concrete precast member on one side and the concrete precast member on the other side,
A joint structure for a concrete precast member, wherein opening-preventing reinforcing bars extending in a direction parallel to the reinforcing bars are arranged on both sides of the female joint at a predetermined distance from the female joint.

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