JP2018204204A - Precast floor slab joint structure - Google Patents

Abstract

To provide a precast floor slab joint structure which can reduce man-hours at a construction site and prevents a floor slab thickness from being unnecessarily increased.SOLUTION: A precast floor slab joint structure comprises: an upper joint reinforcement 22 and a lower joint reinforcement 23 which are arranged with a distance from each other in a vertical direction and extended from an edge face of a floor slab body 21 in a bridge axial direction; and a joint member 24 with an upper side and a lower side thereof fixed to the upper joint reinforcement 22 and the lower joint reinforcement 23 respectively. Because the joint member 24 enables bearing force of a filling material 20a to be utilized and can be made of a material different from the upper and lower joint reinforcement 22 and 23, a vertical distance between the upper and lower joint reinforcement 22 and 23 is not subject to the joint member 24 and thereby preventing a floor slab thickness from being unnecessarily increased unlike in a case of a conventional loop joint where a loop section causes the floor slab thickness to be increased.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a joint structure of precast slabs used for erection of viaducts such as ordinary roads and highways.

  Conventionally, in this type of viaduct construction, a plurality of concrete precast floor slabs manufactured at factories or the like are arranged on the main girder in the bridge axis direction, and the precast floor slabs are joined together to form the entire floor slab. (For example, refer patent document 1).

  The precast floor slab is provided with a plurality of joint rebars extending in the bridge axis direction so that the end side extends from the joint end surface of the floor slab body, and the end side of each joint rebar is in the padding between the floor slab bodies The precast floor slabs are arranged so as to be positioned, and a plurality of reinforcing reinforcing bars extending in the direction perpendicular to the bridge axis are bound to each joint reinforcing bar in the filling portion, and then the filling portion is filled with concrete.

  In addition, as the joint reinforcing bar, a reinforcing bar arranged on the upper side of the floor slab body and a reinforcing bar arranged on the lower side extend from the end face of the floor slab body and are continuous in a loop shape (for example, Patent Document 1). In this conventional example, among the precast slabs adjacent to each other, the joint bars on one precast floor slab side and the joint reinforcing bars on the other precast floor slab side are alternately positioned in the direction perpendicular to the bridge axis. The reinforcing reinforcing bars extending in the direction perpendicular to the bridge axis are arranged inside each loop-shaped portion.

JP 2009-264040 A Japanese Patent No. 5337122

  However, in the case of the former conventional example, since it is necessary to bind a large number of reinforcing bars extending in a direction perpendicular to the bridge axis to each joint reinforcing bar, the work man-hour at the construction site increases and the construction time becomes longer. There was a problem. On the other hand, in the latter case, since the supporting pressure from the interstitial concrete is obtained by the loop-shaped portion, the number of reinforcing reinforcing bars can be reduced. However, since the loop-shaped part is formed by bending the reinforcing bar, the distance between the upper and lower reinforcing bars is equal to the diameter of the loop-shaped part. There is a limit on bending strength. For this reason, even when the space between the upper and lower reinforcing bars is smaller than the diameter of the loop-shaped part under the floor slab design conditions, it must match the diameter of the loop-shaped part, and the floor slab thickness is required. More than that. As a result, there is a problem that the load on the main girder due to the weight of the floor slab and the amount of concrete used in the floor slab body are unnecessarily increased.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to reduce the number of work steps at the construction site and to reduce the thickness of the floor slab unnecessarily. It is to provide a joint structure.

  In order to achieve the above object, the present invention provides a plurality of joint reinforcing bars arranged at intervals in a direction perpendicular to the longitudinal direction so as to extend from the end face of the precast floor slab, and the end face of the precast floor slab In the joint structure of precast floor slabs in which a plurality of precast floor slabs are joined together by filling in between them, one end side and the other end side of one joint reinforcing bar and the other joint reinforcing bar adjacent to each other The joint member is provided with at least one hole penetrating in a direction perpendicular to the longitudinal direction of the joint reinforcing bar.

  Thereby, since the bearing pressure from the padding material is obtained by the joint member, the number of reinforcing bars extending in the direction orthogonal to the longitudinal direction of the joint reinforcing bar can be reduced. At this time, since the joint member is provided with a hole penetrating in a direction orthogonal to the longitudinal direction of the joint reinforcing bar, the bearing pressure can be obtained also by the inner peripheral surface of the hole. Moreover, since a joint member can be formed from components different from a joint reinforcement, the space | interval of the joint reinforcement adjacent to each other is not restricted by the joint member.

  According to the present invention, since the number of reinforcing bars can be reduced, the field work required for binding reinforcing bars can be reduced, which is extremely advantageous for rapid construction using a precast floor slab. In this case, since the bearing pressure can be obtained also by the inner peripheral surface of the hole provided in the joint member, the joining strength (tensile strength) between the precast slabs can be further increased. Further, since the interval between the joint reinforcing bars adjacent to each other is not restricted by the joint member, the floor slab thickness is not increased more than necessary due to the loop portion as in the case of using a conventional loop joint. Can be made to dimensions as designed. Thereby, there exists an advantage that the load to the main girder by the weight of a precast floor slab and the concrete usage-amount of a floor slab body do not increase unnecessarily.

Front sectional drawing of the precast slab which shows the 1st Embodiment of this invention Plan view showing the joint part of the precast slab Side sectional view showing the joint part of the precast slab Side view of joint member Perspective view of joint rebar and joint member Schematic side view showing the floor slab erection process Side sectional view showing joining process of precast slab Side sectional view showing joining process of precast slab Perspective view showing joining process of precast floor slab Perspective view showing joining process of precast floor slab The side view of the coupling member which shows the 2nd Embodiment of this invention The side view of the coupling member which shows the 3rd Embodiment of this invention

  FIG. 1 to FIG. 10 show a first embodiment of the present invention, which shows a precast floor slab joining structure used for laying a viaduct used in, for example, general roads and highways.

  In the present embodiment, the precast floor slabs 20 are arranged on the main girder 10 side by side in the bridge axis direction, and the precast floor slabs 20 are joined to each other by the following joining structure.

  The main girder 10 is made of a steel girder having an upper flange 12 and a lower flange 13 at the upper end and lower end of the web 11, respectively, and is arranged in a plurality of rows at intervals in the direction perpendicular to the bridge axis.

  The precast floor slab 20 is manufactured, for example, in a factory or a manufacturing yard, is transported to a construction site, and is installed on the main girder 10. The precast slab 20 has a plurality of upper joint reinforcing bars 22 and lower joint reinforcing bars 23 extending in the bridge axis direction from the end face of the concrete slab body 21 in the bridge axis direction. They are arranged in the direction and the direction perpendicular to the bridge axis, and are arranged at intervals in the direction perpendicular to the longitudinal direction. Each joint reinforcing bar 22 and 23 consists of a deformed steel bar, and another reinforcing bar (not shown) extending in the direction perpendicular to the bridge axis is provided in the floor slab body 21.

  A joint member 24 is provided on the end side of each joint rebar 22, 23. The joint member 24 is formed of a rectangular steel plate whose thickness direction is perpendicular to the bridge axis, and the upper end and the lower end thereof are welded to the upper joint rebar 22 and the lower joint rebar 23. In this case, the joint member 24 is formed so that the dimension in the vertical direction is equal to the interval between the joint reinforcing bars 22 and 23, and the center in the thickness direction is arranged to coincide with the center position of the joint reinforcing bars 22 and 23. Has been. Further, the joint member 24 is provided with a hole 24a penetrating in the thickness direction, and the hole 24a is disposed at the center of the joint member 24 in the vertical direction and the front-rear direction.

  When the precast floor slab 20 is installed, the precast floor slab 20 is transported to the construction site, and is lifted by the crane car A and placed on the main beam 10 as shown in FIG. At that time, the adjacent precast floor slabs 20 are arranged so as to have a gap between the end faces in the bridge axis direction, and the joint reinforcing bars 22 and 23 extending from each precast floor slab 20 are provided between the end faces in the bridge axis direction. And each joint member 24 is arrange | positioned. At that time, the joint reinforcing bars 22 and 23 on the one precast floor slab 20 side and the joint reinforcing bars 22 and 23 on the other precast floor slab 20 side are alternately arranged in the direction perpendicular to the bridge axis. In this case, the joint member 24 on the one precast floor slab 20 side is arranged closer to the other precast floor slab 20 than the joint member 24 on the other precast floor slab 20 side, and the joint member 24 on the other precast floor slab 20 side. Is arranged closer to one precast floor slab 20 than the joint member 24 on one precast floor slab 20 side.

  Further, a plurality of reinforcing bars 25 extending in the direction perpendicular to the bridge axis are provided between the bridge axis direction end faces of the precast slab 20, and each reinforcing bar 25 is provided above the upper joint reinforcing bar 22 and below the lower joint reinforcing bar 23. A plurality of them are arranged at intervals in the bridge axis direction. In this case, the reinforcing reinforcing bar 25 arranged on the lower joint reinforcing bar 23 side is previously bound to the connecting reinforcing bar 23 by a steel wire or a wire at a factory or the like, and the reinforcing reinforcing bar 25 arranged on the upper joint reinforcing bar 22 side is precast floor slab. After 20 is placed on the main girder 10, it is bound to the joint rebar 22 on site.

  Next, as shown in FIG. 3, a filling material 20 a made of fast-hardening concrete or mortar is filled between the end surfaces in the bridge axis direction of the precast slab 20. Thus, the tensile strength in the bridge axis direction is obtained by the adhesive force generated between the joint reinforcing bars 22 and 23 and the padding 20a and the support pressure generated between the joint member 24 and the padding material 20a. The precast floor slabs 20 are joined together. At that time, as shown by the white arrow in FIG. 4, the supporting pressure F is generated on one end face in the bridge axis direction of the joint member 24 and half of the inner peripheral face of the hole 21 a. The bridge axis direction end faces of the floor slab body 21 that face each other at the padding portion 20a may be tapered inclined faces, or formed so that the lower end side of the end faces protrudes into a jaw shape. It may be.

  As described above, the plurality of precast floor slabs 20 arranged in the bridge axis direction are joined by the padding material 20a, the joint reinforcing bars 22, 23, and the joint members 24 to form the entire floor slab. And the wall height column 20b is provided in the width direction both sides of a floor board, and a road surface is formed in the floor slab upper surface by the asphalt 20c.

  Further, the reinforcing reinforcing bars 25 may be disposed in the holes 24 a of the joint members 24. In this case, since the reinforcing reinforcing bars 25 must be inserted into the holes 24a of the joint members 24 from the direction perpendicular to the bridge axis, a space corresponding to the length of the reinforcing reinforcing bars 25 is required on the side of the precast floor slab 20, Since the reinforcing reinforcing bars 25 in the holes 24a of the joint members 24 do not need to be bundled, the field work can be reduced correspondingly.

  Thus, according to the present embodiment, the upper joint rebar 22 and the lower joint rebar 23 that are spaced apart from each other in the vertical direction are provided so as to extend from the end surface in the bridge axis direction of the floor slab body 21. At the same time, each joint rebar 22, 23 is provided with a joint member 24 whose upper end side and lower end side are fixed to the upper joint rebar 22 and the lower joint rebar 23, respectively. The pressure can be obtained, and the number of reinforcing bars 25 can be reduced accordingly. Thereby, the field work required for binding the reinforcing reinforcing bars 25 can be reduced, which is extremely advantageous for rapid construction using the precast floor slab 20.

  In this case, since the joint member 24 is provided with a hole 24a penetrating in a direction perpendicular to the bridge axis, a bearing pressure can be obtained also by the inner peripheral surface of the hole 24a, and the joint strength (tensile strength) between the precast floor slabs 20 can be obtained. Strength) can be further increased.

  Further, since the joint member 24 can be formed from a separate part from the joint rebars 22 and 23, the vertical distance between the upper joint rebar 22 and the lower joint rebar 23 is not restricted by the joint member 24. . As a result, the floor slab thickness does not become unnecessarily large due to the loop portion as in the case of using a conventional loop joint, and the floor slab thickness can be set to dimensions as designed. Thereby, there exists an advantage that the load to the main girder 10 by the weight of the precast floor slab 20 and the concrete usage-amount of the floor slab main body 21 are not increased unnecessarily.

  Furthermore, since the joint member 24 is formed by a plate-like member whose thickness direction is perpendicular to the bridge axis, the joint members 24 interfere with each other even if the gap between the joint reinforcing bars 22 and 23 in the direction perpendicular to the bridge axis is reduced. The joint rebars 22 and 23 can be arranged with high density.

  Further, of the precast slabs 20 adjacent to each other in the bridge axis direction, the joint reinforcing bars 22 and 23 on one precast floor slab 20 side and the joint reinforcing bars 22 and 23 on the other precast floor slab 20 side are mutually perpendicular to the bridge axis direction. Since it arrange | positions so that it may be located alternately, the distance between the bridge-axis direction end surfaces of the precast slab 20 can be shortened, and the usage-amount of the padding material 20a can be decreased.

  In the above embodiment, the joint member 24 is formed of a steel plate. However, if the joint member 24 is fixed to the upper joint rebar 22 and the lower joint rebar 23, the joint member such as a hardened plastic may be replaced with another member. You may make it form with the member which consists of material.

  Furthermore, FIG.11 and FIG.12 shows other embodiment of a coupling member. That is, the joint member 26 shown in the second embodiment in FIG. 11 is provided with a plurality of holes 26a arranged in the bridge axis direction, and the bearing pressure can be increased by the number of the holes 26a. Further, the joint member 27 shown in the third embodiment in FIG. 12 is provided with a plurality of holes 27a arranged in the vertical direction, and the length of the joint member 27 in the bridge axis direction when the floor slab thickness is large. The supporting pressure can be increased without increasing the pressure.

  In each of the above embodiments, the precast floor slabs 20 arranged side by side in the bridge axis direction are joined in the direction perpendicular to the bridge axis. However, for example, when an existing floor slab is replaced half by width, etc. It can also be applied to a joining structure in which precast floor slabs are joined in a direction perpendicular to the bridge axis. In this case, by providing the joint reinforcing bar so as to extend in the direction perpendicular to the bridge axis from the end surface in the width direction of the precast floor slab, the joint member fixed to the joint reinforcing bar can be used as in the above embodiment.

  Moreover, in each said embodiment, although the thing which fixed the upper end side and lower end side of the joint member arrange | positioned vertically to the upper joint reinforcement 22 and the lower joint reinforcement 23 was shown, the joint member arrange | positioned sideways You may make it fix both ends of two to the two upper joint reinforcement 22 (or lower joint reinforcement 23) adjacent to each other in the horizontal direction.

  DESCRIPTION OF SYMBOLS 1 ... Composite girder, 10 ... Main girder, 20 ... Precast floor slab, 20a ... Filling material, 21 ... Floor slab body, 22 ... Upper joint reinforcement, 23 ... Lower joint reinforcement, 24 ... Joint member, 24a ... Hole, 25 ... Reinforcing bars, 26 ... Joint members, 26a ... Holes, 27 ... Joint members, 27a ... Holes.

Claims (5)

By providing a plurality of joint reinforcing bars arranged at intervals in a direction perpendicular to the longitudinal direction so as to extend from the end face of the precast floor slab, and by filling a space between the end faces of the precast floor slab, In the joint structure of precast floor slabs that joins multiple precast floor slabs,
A joint member in which one end side and the other end side are respectively fixed to one joint rebar and the other joint rebar adjacent to each other;
The joint structure of precast slabs, wherein the joint member is provided with at least one hole penetrating in a direction perpendicular to the longitudinal direction of the joint reinforcing bar. The joint structure for a precast floor slab according to claim 1, wherein the joint member is formed of a plate-like member. Among the precast slabs adjacent to each other, the joint reinforcing bars on one precast floor slab side and the joint reinforcing bars on the other precast floor slab side are alternately arranged in the direction perpendicular to the longitudinal direction of the joint reinforcing bars. The joint structure of precast slabs according to claim 1 or 2, wherein The joint structure for precast slabs according to claim 1, 2 or 3, wherein a plurality of holes in the joint member are provided at intervals in the longitudinal direction of the joint rebar. 5. The precast slab joining structure according to claim 1, wherein a plurality of holes of the joint member are provided at intervals in a direction perpendicular to the longitudinal direction of the joint reinforcing bar.

Images