JP2015025330A - Lightweight floor slab, lightweight floor slab construction method, and lightweight floor slab connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor slab which is more lightweight than a conventional floor slab and construction using the lightweight floor slab, to improve work efficiency, and to solve problems of conventional floor slab construction.SOLUTION: A lightweight floor slab has a plurality of pipes arranged in concrete of the floor slab in a connection direction of floor slabs, and the pipes are arranged at intervals in a direction crossing the connection direction of the floor slabs, and united with the concrete in the presence of a design load. A pipe has, at its axial end, a connection part which can be connected to a pipe of another floor slab which is arrayed in the connection direction. In a lightweight floor slab construction method, two or more lightweight floor slabs are arranged side by side in the connection direction of the lightweight floor slab such that pipes of the lightweight floor slabs communicate with each other, pipes of adjacent lightweight floor slabs are connected to each other so as to connect the two or more lightweight floor slabs to each other. Here, two or more floor slab units which have two or more lightweight floor slabs connected together in the connection direction can be arranged and connected to each other.

Description

  The present invention relates to a precast concrete floor slab (PC floor slab) that can be used as a floor slab of various structures such as bridges and highways, a construction method of the PC floor slab, and a connecting structure.

  Conventionally, concrete floor slabs, steel floor slabs, composite floor slabs obtained by synthesizing concrete and steel members, and the like are known as floor slabs used for bridges, highways and the like.

Both floor slabs have been desired to be lightweight for the following reasons.
(1) Since the width of bridges, highways, and the like is narrow, there are cases where rescue work and restoration work are delayed in the event of a disaster such as heavy snow, and the expansion of the width has been required. However, since the conventional floor slab is heavy, it becomes heavier when the width is increased, and the load applied to the bridge girder and the bridge pier supporting it increases, and an unreasonable burden is imposed on the bridge pier and the bridge girder.
(2) Large earthquakes such as the Great Hanshin-Awaji Earthquake and the Great East Japan Earthquake have a greater seismic force than previously anticipated, so that the risk of damage such as falling bridges can be avoided even during a major earthquake. It is desirable to reduce the load on the bridge girder as much as possible.

  In order to reduce the weight of the floor slab, a rib is provided on the bottom steel plate of the floor slab, a steel pipe is fixed on the rib, a reinforcing bar is placed on the steel pipe, and concrete is placed on the reinforcing bar. A hollow composite floor slab has been proposed (Patent Document 1). In addition, there was a construction method as shown in FIG.

  9 (a) to 9 (d), a large number of floor slabs A are arranged on a bridge girder (not shown), and a PC steel material (usually stranded wire) is placed on the two or more floor slabs A arranged. ) B is inserted, mortar (filler) C is filled between the floor slabs A, the mortar C is cured to develop the required strength, and then the bearing plate D is attached to the PC steel B, and the stranded wire This is a construction method in which B is tensioned and prestressed to the floor slab A for connection.

Japanese Patent Laid-Open No. 2004-212367

  The hollow composite floor slab described in Patent Document 1 has a steel pipe and a rib attached to a bottom steel plate at a factory (prepared and manufactured), and this structure is transported to the site. It took time and there was a problem that work efficiency was bad. Even in the construction method shown in FIGS. 9A to 9D, there is a problem that the PC is tensioned after confirming the appearance of the material strength to be filled in the floor slab joint.

  The problem to be solved by the present invention is a floor slab that is lighter than a conventional floor slab and a construction that uses the lightweight floor slab, and has improved work efficiency and can solve the above-mentioned problems of conventional floor slab construction. It is in providing a plate construction method and a floor slab connection structure.

[Lightweight floor slab]
The lightweight floor slab of the present invention is a concrete precast floor slab that is used with a plurality of pieces arranged and connected.In the concrete of the floor slab, a plurality of long and rigid pipes are arranged in the connecting direction of the floor slab, The pipes are arranged at intervals in a direction crossing the connecting direction of the floor slabs, and are integrated with the concrete under the design load. By using rigid pipes (for example, steel pipes, aluminum pipes, FRP pipes, etc.), conventional steel bars can be substituted, leading to labor-saving construction. Moreover, a lightweight aggregate may be used as the concrete material, or fiber reinforced concrete may be used.

  The lightweight floor slab may include a connecting portion that can be connected to a pipe of another floor slab arranged in the connecting direction of the floor slab at an end portion in the axial direction of the pipe. In order for the pipe and concrete to be integrated under the design load, the surface of the pipe contacting the concrete is roughened or an adhesive is applied to increase the adhesion.

[Lightweight slab construction method]
The lightweight floor slab construction method of the present invention is a floor slab construction method in which two or more floor slabs are arranged and connected in the connecting direction, and the two or more lightweight floor slabs are arranged in the connecting direction of the lightweight floor slabs. The two or more lightweight pieces are connected by connecting the connecting portions at the axial ends of the adjacent lightweight floor slab pipes directly or via a connecting jig. It is a construction method that connects floor slabs.

  The lightweight floor slab construction method is a construction method in which two or more floor slab units in which two or more lightweight floor slabs are connected by pre-processing are arranged in the connecting direction, and the two or more floor slab units are connected. It may be.

  The lightweight floor slab construction method includes providing a floor slab unit by connecting two or more lightweight floor slabs in the connection direction by one construction, and providing two or more floor slab units by repeating the connection. It can also be set as the construction method which connects the above floor slab unit in the connection direction.

  The lightweight floor slab construction method is such that PC steel is inserted into the pipes of two or more lightweight floor slabs in which the tubes are arranged in a line, and the PC steel is tensioned to give a prestress to the lightweight floor slab. You can also

  In the lightweight floor slab construction method, the adjacent lightweight floor slabs are tension-connected, and an adhesive is applied to the joint surface of the lightweight floor slabs, and the durability of the connection portion can be increased by bonding with the adhesive. . In addition, the application of an adhesive prevents moisture and the like from entering the joint and contributes to improved durability.

[Lightweight slab connection structure]
The lightweight floor slab connection structure of the present invention is a floor slab connection structure in which two or more floor slabs are arranged and connected, and the two or more lightweight floor slabs are arranged side by side. Are arranged in such a way that a tube row is formed in communication with the connection direction of the lightweight floor slabs, and among the arranged lightweight floor slabs, the connecting portions at the axial ends of the adjacent lightweight floor slab tubes are directly or connected to each other It is the connection structure connected via the jig | tool.

  In the lightweight floor slab connection structure of the present invention, two or more floor slab units in which the lightweight floor slabs are arranged and connected in the connecting direction are arranged side by side in the connecting direction, and the floor slab unit is a lightweight floor slab. The pipes are arranged to communicate with each other in the connecting direction of the lightweight floor slab so as to form a tube row, and among the arranged floor slab units, the connecting portions at the axial ends of the adjacent floor slab units are directly connected to each other. Or it may be connected via a connecting jig.

  In the lightweight floor slab connection structure, PC steel is inserted into one or more of a plurality of tube rows of two or more lightweight floor slabs, and the PC steel is tensioned to prestress the two or more lightweight floor slabs. It may be a connecting structure in which is connected. Moreover, you may insert PC steel materials inside the pipe | tube of a connection structure.

The lightweight floor slab of the present invention has the following effects.
(1) Since there is a hollow tube inside the slab, it is lighter than conventional solid concrete slabs. For this reason, even if the width of a bridge, an expressway, or the like is increased, the load applied to the bridge girder can be equal to or less than the conventional one, and the load on the bridge pier or the bridge girder is reduced.
(2) Since the pipe disposed inside the floor slab also functions as a reinforcing material, at least the same strength as that of a conventional concrete floor slab can be secured.
(3) Since the pipe for weight reduction has the same function as a reinforcing steel bar, the strength is improved as compared with the case of concrete alone. For this reason, the number of reinforcing bars that have been used in the past can be reduced, and even if pipes are used, the cost increase can be suppressed, and labor saving of the bar arrangement work can be realized.
(4) Since there is an inner space in the floor slab, it also has a heat insulating function and becomes a road surface that is difficult to freeze.
(5) Since the pipe is disposed along the connecting direction of the floor slabs and the connecting part is provided at the axial end of the pipe, adjacent floor slabs can be easily connected to each other by the connecting part.

The lightweight floor slab construction method of the present invention has the following effects.
(1) Since the connecting portions of the adjacent lightweight floor slab pipes are connected directly or via a connecting jig, the connecting work is facilitated, and the filler (mortar, etc.) filled between the floor slabs is cured. There is no waiting time and quick construction is possible.
(2) When adhering the joint surfaces of adjacent lightweight floor slabs with an adhesive, it is not necessary to fill the concrete filler between the joint surfaces, reducing costs, and waiting for curing concrete for strength development. Therefore, quick construction is possible.
(3) When the floor slab unit is constructed, the construction work efficiency is improved as compared with the case where the lightweight floor slabs are constructed one by one.

The lightweight floor slab connection structure of the present invention has the following effects.
(1) Since the adjacent lightweight floor slabs are connected by the connecting portion of the pipe, the floor slab structure is surely connected. By connecting the joints between floor slabs, shear force can be transmitted reliably. Moreover, the bending moment of a joint part can also be transmitted with a connection structure.
(2) Since the space is secured with pipes in the floor slab, it becomes a heat-insulating bridge and a highway that is difficult to freeze.

(A) is a perspective view which shows an example of the lightweight floor slab of this invention, (b) is a perspective view which shows the other example of the lightweight floor slab of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It shows an example of the lightweight floor slab connection structure of this invention, Comprising: (a) is sectional drawing at the time of welding and fixing a member different from the said steel pipe to a steel pipe as a fitting protrusion, (b) is a steel pipe Sectional drawing at the time of using one part as a fitting protrusion. An example of the lightweight floor slab connection structure of this invention is shown, Comprising: (a) is sectional drawing at the time of using the connection jig provided with the external screw for connection of a steel pipe, (b) is for connection of a steel pipe Sectional drawing at the time of using the connecting jig of the thickness which can be press-fitted in a steel pipe. (A)-(e) is work procedure explanatory drawing which shows an example of the lightweight floor slab construction method and lightweight floor slab connection structure of this invention. The X section enlarged view of Fig.2 (a). (A)-(e) is work procedure explanatory drawing which shows the other example of the lightweight floor slab construction method and lightweight floor slab connection structure of this invention. It is explanatory drawing of the connection location of the lightweight floor slab of this invention, Comprising: (a) is plane explanatory drawing of the lightweight floor slab connection structure shown in FIG.4 (e), (b) is the lightweight floor shown in FIG.6 (e). Plane explanatory drawing of plate connection structure. It is explanatory drawing of the lightweight floor slab connection structure shown in FIG.4 (e), Comprising: (a) is a top view, (b) is ss sectional drawing of (a), (c) is t- of (a). t sectional drawing. (A)-(d) is work procedure explanatory drawing which shows an example of the conventional floor slab construction method.

(Embodiment 1 of lightweight floor slab)
An example of the lightweight floor slab 1 of the present invention will be described with reference to the drawings. The lightweight floor slab 1 of the present invention is a precast concrete slab (PC floor slab) and is used as a bridge slab or a road slab.

  As an example, a lightweight floor slab 1 shown in FIG. 1 (a) is a concrete floor slab having a length of about 1000 mm × width of 1000 mm × thickness of about 200 mm, and a plurality of (seven in the example of FIG. 1) steel pipes 2 are contained therein. Has been placed. Each steel pipe 2 is arranged along the connecting direction of the lightweight floor slab 1 (connecting direction when two or more sheets are connected), and a plurality of steel pipes 2 are arranged in parallel in the width direction of the lightweight floor slab 1 at a predetermined interval. Has been.

In the example shown in FIG. 1A, the distance between the steel pipes 2 (the distance L between the symbols C ₁ and C ₂ in FIG. 1A) is about 142.8 mm. The porosity φ of the lightweight floor slab 1 shown in FIG. 1 (the total volume of the seven steel pipes 2 relative to the floor slab volume) is (7 × 90 × 90 × 1000) / (1000 × 1000 × 200) = 0.283 (about 28%). The number and arrangement interval of the steel pipes 2 can be changed according to the size of the lightweight floor slab 1. Moreover, the dimension (size) and shape of the steel pipe 2 can also be changed according to the shape and size of the lightweight floor slab 1.

  The steel pipe 2 shown in FIG. 1 (a) is a square steel pipe having an inner diameter of 90 mm square and a wall thickness of 3.2 mm, and its weight is 8.51 kg / m. The steel pipe 2 may be other than a square, and for example, a round pipe or a deformed pipe may be used. As the steel pipe 2, a steel pipe having a roughened surface can be used. By using the deformed pipe or the steel pipe 2 subjected to roughening, the contact area with the concrete is widened, and the integrity between the steel pipe 2 and the concrete is strengthened. Alternatively, an adhesive may be applied to the outer periphery of the steel pipe 2 so as to be integrated with the concrete.

  The connection part 3 is provided in the axial direction edge part of the steel pipe 2, and the steel pipes 2 of the lightweight floor slab 1 arrange | positioned adjacently can be connected now. For example, as shown in FIGS. 2 (a) and 5, a fitting protrusion 5 that protrudes outward from an end face (joint surface) 4 of the lightweight floor slab 1 on one end side in the axial direction of the steel pipe 2 of the lightweight floor slab 1. And a fitting recess 6 protruding outward from the other end surface (joint surface) 4 of the lightweight floor slab 1 is formed on the other axial end of the steel pipe 2, and one adjacent lightweight floor slab is formed. By fitting one fitting protrusion 5 into the fitting recess 6 of the other adjacent lightweight floor slab 1, both the steel pipes 2 can be connected and adjacent lightweight floor slabs 1 can be connected. The fitting protrusion 5 and the fitting recess 6 can be provided by welding a pipe having a diameter smaller than that of the steel pipe 2 to the inner peripheral surface of the steel pipe 2 as shown in FIG. In order to achieve smoothness, the step portion of the connecting portion of the adjacent lightweight floor slabs 1 can be filled with a filler 15 such as mortar.

  As shown in FIG. 2 (b), the fitting projection 5 and the fitting recess 6 project one end of the steel pipe 2 of one lightweight floor slab 1 to the outside of the joint surface 4 of the lightweight floor slab 1, The protruding portion may be the fitting protrusion 5, and the one end side of the steel pipe 2 of the other lightweight floor slab 1 may be thin to form the fitting recess 6. In this case, both the steel pipes 2 can be connected and the lightweight floor slab 1 can be connected by press-fitting the fitting protrusion 5 of one steel pipe 2 into the fitting recess 6 of the steel pipe 2 of the other lightweight floor slab 1. it can.

  In the above embodiment, the steel pipe 2 disposed on the lightweight floor slab 1 is a square steel pipe. However, when the steel pipe 2 is a round steel pipe, a connecting jig 7 as shown in FIG. It is also possible to connect the steel pipes 2 together. The connecting jig 7 is a round pipe provided with a flange 8 at the center, and external screws 9 are formed on the outer peripheral surfaces on both outer sides of the flange 8. The external screw 9 can be screwed into an internal screw 10 formed at the end of the steel pipe 2, and by rotating the connecting jig 7, the external screw 9 of the connecting jig 7 can be connected to the two lightweight floor slabs 1. The steel pipes 2 are connected to each other by being screwed into the steel pipe 2.

  The steel pipe 2 can be connected using a connecting jig 7 as shown in FIG. 3B instead of the connecting jig 7 as shown in FIG. The connecting jig 7 shown in FIG. 3B is a pipe material having an outer diameter that is the same as the inner diameter of the steel pipe 2. One half of the connecting jig 7 is press-fitted into the steel pipe 2 of one lightweight floor slab 1 and the other half is press-fitted into the steel pipe 2 of the other lightweight floor slab 1 so Can be connected.

  The connection means of the steel pipe 2 described above is an example, and it can be connected by means other than these. If possible, an adhesive can be applied to the end face of the steel pipe 2 for connection.

(Embodiment 2 of lightweight floor slab)
Another example of the lightweight floor slab 1 of the present invention is shown in FIG. The basic structure of the lightweight floor slab 1 is the same as that of the lightweight floor slab 1 of the above embodiment. The difference is that a recessed housing space 11 is provided at one end of the lightweight floor slab 1 in the connecting direction. The accommodation space 11 is for accommodating and arranging a bearing plate (support plate) 12 and a coupler 13 (both of which are shown in FIG. 7B).

  In the example shown in FIG. 1B, the accommodation space 11 is provided on the axial extension line of the steel pipe 2. The accommodation space 11 can be provided on the extension line of all the steel pipes 2, but it is only necessary to provide it in a portion through which the tensioning PC steel material 14 is inserted. One PC steel material 14 is provided as shown in FIG. In the example of inserting every other, the accommodation space 11 is also formed every other steel pipe 2. The number of the accommodation spaces 11 can be appropriately changed according to the number of PC steel materials 14 for tension.

  Both the above embodiments are merely examples, and the number and shape of the steel pipes 2 and the shape and dimensions of the lightweight floor slab 1 can be appropriately designed within a range in which the intended purpose of the present invention can be achieved. Moreover, instead of the steel pipe 2, a pipe such as an aluminum pipe or an FRP pipe can be used for the lightweight floor slab 1 of the present invention.

(Embodiment 1 of lightweight floor slab construction method)
An example of the lightweight floor slab construction method of this invention is demonstrated with reference to Fig.4 (a)-(e). This embodiment is an example in which the lightweight floor slab 1 of FIG. 1A is used as a bridge floor slab, and the construction procedure will be described next.
(1) As shown in FIG. 4A, a plurality of lightweight floor slabs 1a, 1b, 1c, 1d are laid side by side on a main beam (not shown). These lightweight floor slabs 1 are arranged so that steel pipes 2 communicate with each other to form a steel pipe row. Since the illustrated lightweight floor slab 1 is provided with seven steel pipes 2, in this case, seven steel pipe rows are formed. The lightweight floor slab 1 can be laid by hanging it with a heavy machine such as a crane.
(2) As shown in FIG.4 (b), among the lightweight floor slabs 1 laid on the main girder, adjacent lightweight floor slabs 1 (for example, lightweight floor slabs 1a and 1b, 1b and 1c, 1c and 1d) Steel pipes 2 (for example, steel pipes 2a and 2b, 2b and 2c, 2c and 2d) are connected. The steel pipe 2 can be connected by a method as shown in FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b), for example. It is desirable to apply an adhesive to the joint surface 4 of the adjacent lightweight floor slab 1 (or the end surface of the steel pipe 2).
(3) As shown in FIG.4 (c), PC steel material 14 is penetrated in the steel pipes 2a-2d of the lightweight floor slab 1 (lightweight floor slab 1a-1d) laid continuously. For the PC steel material 14, a wire or a PC steel bar can be used from the existing PC steel. The PC steel material 14 can be inserted into all the steel pipe rows (seven steel pipe rows in the illustrated example), but in this embodiment, the PC steel material 14 is inserted into every other steel pipe row. By inserting every other PC steel material 14, it is possible to reduce the weight of the bridge slab after being connected by the PC steel material 14 and to reduce the cost by reducing the number of PC steel materials 14.
(4) As shown in FIG. 4 (d), among the lightweight floor slabs 1 arranged in large numbers, bearing plates at both ends of the PC steel material 14 projecting outward from the end surfaces of the lightweight floor slabs 1a and 1d at both ends in the arrangement direction. 12 is attached, the PC steel material 14 inserted through the steel pipe row is tensioned, and the lightweight floor slab 1 is prestressed and connected. Tensioning can be done with conventional tensioning methods using conventional tensioning devices.
(5) As shown in FIG. 4 (e), the stepped portion of the connecting portion of the adjacent lightweight floor slabs 1 is filled with a filler 15 such as mortar for smoothness, and the filler 15 is cured. After the required strength is developed, the construction work is finished. When the lightweight floor slab 1 is temporarily assembled and the smoothness is confirmed in advance, the notch structure shown in FIG. 5 can be eliminated and the filling work of the filler 15 can be omitted.

(Embodiment 2 of lightweight floor slab construction method)
Another example of the lightweight floor slab construction method of the present invention will be described with reference to FIGS. This embodiment is an example in which the lightweight floor slab 1 of FIG. 1A and the lightweight floor slab 1 of FIG. 1B are used as a bridge floor slab. This embodiment is an example in which, for example, when three sheets are laid for overnight construction and three new sheets are laid on the next day, tension is applied to each lightweight floor slab 1 constructed overnight. For convenience of explanation, in the following explanation, a floor slab constructed overnight is referred to as a “floor slab unit”.
(1) As shown in FIG. 6A, a plurality of lightweight floor slabs 1a, 1b, 1c constituting a bridge floor slab are laid side by side on a main girder (not shown). The plurality of lightweight floor slabs 1a to 1c are arranged side by side along the axial direction of the steel pipes 2a to 2c so that the steel pipes 2a to 2c communicate with each other to form a plurality of steel pipe rows. Of the adjacent lightweight floor slabs 1, the portions where the steel pipes 2 face each other are connected by means shown in FIGS. 2A and 2B and FIGS. 3A and 3B. The PC steel material 14x is inserted into the steel pipe rows of the layed floor slabs 1a to 1c, and the supporting plate 12 is attached to both ends of the PC steel material 14x protruding outward from the end surfaces of the light weight slabs 1a and 1c at both ends. 14x is tensioned and prestressed and connected to the lightweight floor slabs 1a to 1c. Tensioning can be done with conventional tensioning methods using conventional tensioning devices.
(2) As shown in FIG. 6B, new lightweight floor slabs 1d, 1e, and 1f are disposed outside the floor slab unit laid and tensioned on the previous day, and these three newly laid lightweight The PC steel material 14y is inserted into the steel pipe row in which the steel pipes 2d, 2e, and 2f of the floor slabs 1d to 1f communicate.
(3) As shown in FIG. 6 (c), the PC steel material 14x projecting outward from the end face of the lightweight floor slab 1a laid in the step (1), and the lightweight floor laid in the step (2). A PC steel material 14 y protruding outward from the end face of the plate 1 d is connected by a coupler 13. Moreover, the steel pipe which does not let PC steel material 14 pass is connected by the means shown to Fig.2 (a) (b) and Fig.3 (a) (b).
(4) As shown in FIG. 6 (d), the support plate 12 is attached to the end of the PC steel material 14y inserted into the steel pipe row of the lightweight floor slabs 1d to 1f in the step (3), and the PC steel material 14y is tensioned and connected to these lightweight floor slabs 1d to 1f by applying prestress.
(5) As shown in FIG. 6 (e), the stepped portions of the connecting portions of the respective lightweight floor slabs 1a to 1f are filled with a filler 15 such as mortar, and the filler 15 is cured to obtain a required strength. After the expression, the construction is finished.

  In any of the above-described embodiments, since the filling amount of the filler 15 is smaller than that of the conventional construction method, the curing does not take time and rapid (rapid) construction can be realized.

(Embodiment 1 of lightweight floor slab connection structure)
An example of the lightweight floor slab connection structure of the present invention (hereinafter simply referred to as “connection structure”) will be described with reference to the drawings. This connection structure is an example when the lightweight floor slab 1 shown in FIG. 1A is used as a bridge floor slab.

  The example shown to Fig.7 (a) is an example when the four lightweight floor slabs 1a, 1b, 1c, and 1d shown to Fig.1 (a) are arrange | positioned along the bridge-axis direction. The plurality of lightweight floor slabs 1a to 1d are arranged side by side in the axial direction of the steel pipes 2a to 2d so that the steel pipes 2a to 2d communicate with each other to form a plurality of steel pipe rows. The steel pipes 2 (for example, steel pipes 2a and 2b, 2b and 2c, 2c and 2d) of adjacent lightweight floor slabs 1 (for example, lightweight floor slabs 1a and 1b, 1b and 1c, 1c and 1d) are shown in FIG. ) (B) and the means as shown in FIGS. 3 (a) and 3 (b). When a level difference occurs in the connecting portion between the steel pipes 2, it is preferable to fill the level difference portion with a filler 15 such as mortar so that the surface of the lightweight floor slab 1 is smooth.

  In the example of FIG. 7A, the PC steel material 14 is inserted into the even-numbered steel pipe rows from the top (second, fourth, sixth from the top in the figure). The supporting plate 12 is attached to the axial direction end of each PC steel material 14 and protrudes outward from the joint end surface of the lightweight floor slabs 1a and 1d, and the PC steel material 14 is tensioned. Thus, the lightweight floor slabs 1a to 1d are connected by applying prestress.

  Although not shown in FIG. 7A, reinforcing members 16 such as reinforcing bars and PC steel are provided above and below the steel pipe 2 as shown in FIGS. 8A to 8C. Specifically, the reinforcing material 16 is disposed above and below the steel pipe 2 in a direction intersecting the bridge axis direction (a direction orthogonal or substantially orthogonal). In the example shown in FIGS. 8 (a) and 8 (b), five reinforcing bars are arranged on each of the upper side and the lower side of the steel pipe 2, but even if the number of reinforcing members 16 is more than this, It may be the following.

(Embodiment 2 of lightweight floor slab connection structure)
Another example of the connection structure of the present invention will be described with reference to the drawings. This connection structure is an example in which a lightweight floor slab 1 shown in FIG. 1A and a lightweight floor slab 1 shown in FIG. 1B are used as a bridge floor slab.

  As an example, the connection structure shown in FIG. 7 (b) is an example in which the lightweight floor slabs 1a and 1c shown in FIG. 1 (b) are arranged on both outer sides of the lightweight floor slab 1b shown in FIG. 1 (a). . At the actual construction site, for example, these three lightweight floor slabs 1a to 1c are constructed overnight to complete the floor slab unit, and the next day the three lightweight floor slabs 1d to 1f are newly constructed. Complete the plate unit. The lightweight floor slab 1 is connected to the nightly construction one by one, and the floor slab unit is connected using a coupler 13 for the next day and after.

  In the example shown in FIG. 7B, a plurality of lightweight floor slabs 1a to 1c are arranged, and the steel pipes 2a to 2c communicate with each other to form a plurality of steel pipe rows in the longitudinal direction of the steel pipes 2a to 2c. Among the light-weight floor slabs 1a to 1c, the odd-numbered ones of the steel pipes 2 (for example, the steel pipes 2a and 2b, 2b and 2c) of the adjacent light-weight floor slabs 1 (for example, the light-weight floor slabs 1a and 1b, 1b and 1c) The steel pipes 2 (first, third, fifth, seventh from the top in the figure) are connected by means such as FIGS. 2 (a) (b) and 3 (a) (b). The PC steel material 14x is inserted through the even-numbered steel pipe rows (the second, fourth, and sixth steel pipe rows from the top in the figure). The three lightweight floor slabs 1a to 1c (floor slab units) constructed overnight are given prestress on that day. Specifically, the bearing plates 12 are attached to both ends in the longitudinal direction of the PC steel material 14x inserted through the steel pipe rows of the three lightweight floor slabs 1a to 1c, and the PC steel material 14x is tensioned and connected.

  As shown in FIG. 7 (b), on the right side of the bridge axis direction of the pre-stressed floor slab unit (right side of FIG. 7 (b)), the same as the floor slab unit constructed the day before, New lightweight floor slabs 1d to 1f (floor slab units) are being constructed. The newly constructed lightweight floor slabs 1d to 1f are odd-numbered steel pipes 2 (first, third, fifth and seventh from the top in the figure), similarly to the lightweight floor slabs 1a to 1c constructed on the previous day. While being connected to each other, they are connected by being strained by the PC steel material 14y inserted into the even-numbered steel pipe rows (the second, fourth and sixth steel pipe rows from the top in the figure).

  The PC steel material 14y inserted into the steel pipe row of the newly installed floor slab unit is connected to the PC steel material 14x via the coupler 13. The coupler 13 is adapted to be accommodated in the accommodating space 11 provided in the lightweight floor slabs 1c and 1d.

  Since there is a step in the accommodating space 11 in which the bearing plate 12 and the coupler 13 are arranged, the step portion is filled with a filler 15 such as mortar so that the surface of the bridge deck is uniform. In the case where there is a step in the other connecting portion of the lightweight floor slab 1 (for example, between the lightweight floor slabs 1a and 1b, between the lightweight floor slabs 1b and 1c, etc.) It is preferable to fill the filler 15 so that the surface of the lightweight floor slab 1 becomes smooth. The filling of the filler 15 can be performed collectively after the construction of all the floor slabs is completed.

  Although not shown in FIGS. 7 (a) and 7 (b), reinforcing members 16 are disposed above and below the steel pipe 2 as in FIGS. 8 (a) and 8 (b).

  When constructing the floor slab unit as described above, several lightweight floor slabs 1 can be pre-tensioned with PC steel 14y to form a unit, and the floor slab unit can be constructed. After the 13 connections, the newly adjacent floor slab units can be tensioned together.

[Weight comparison example]
The weight per 1 m ² of the slab thickness lightweight slab 1 at 200mm of the present invention, when compared to the weight per 1 m ² of conventional concrete slab (hereinafter referred to as "conventional slab"), is as follows. In addition, the lightweight floor slab 1 of the present invention, which is the object, has seven steel pipes with a weight of 8.51 kg / m arranged per m and seven PC pipes 14 with a weight of 1.101 kg / m per m. Ten of them are arranged.

[Conventional RC floor slab]
W = 2.5 × 1 × 1 × 0.2 = 0.5ton = 500kg ... (X)
Here, 2.5 (ton / m ³ ) is a unit volume weight of reinforced concrete.
[Lightweight slab of the present invention]
(1) If the weight of one steel pipe is 8.51 kg / m and the number of steel pipes per meter is seven, the total weight W _P of the steel pipe 2 is
W _P = 7 × 8.51kg = 59.57kg
(2) If the weight of one PC steel (15.22mm) is 1.101kg / m, ten per m, the total weight W _PC of PC steel 14 is
W _PC = 10 x 1.101 = 11.10 kg
(3) the weight W _C of concrete,
W _C = 2300 × 0.2 × 1 × 1 × 0.717 = 330kg
Here, 2300 (kg / m ³ ) is a unit volume weight of concrete.
(4) The weight IW of the lightweight floor slab of the present invention is:
IW = W _P + W _PC + W _C ≒ 400kg ・ ・ ・ ・ (Y)
(5) weight IW _L in the case of using a lightweight concrete weight W _L lightweight floor plate of the present invention,
W _L = 2000 × 0.2 × 1 × 1 × 0.717 = 287kg
IW _L = W _P + W _PC + W _C ≈ 358 kg ··· (Z)
Here, 2000 (kg / m ³ ) is a unit volume weight of the lightweight concrete.

  As described above, the lightweight floor slab of the present invention has a weight of about 400 kg (Y) when using ordinary concrete and a weight of 358 kg (Z) when using light concrete, and is a conventional RC floor slab. The weight (500 kg (X)) is 80% when ordinary concrete is used, and 70% when lightweight concrete is used, and a weight reduction of 20% to 30% can be realized.

  The lightweight floor slab 1 of the present invention can be used not only as a bridge floor slab but also as a road floor slab for an expressway.

DESCRIPTION OF SYMBOLS 1, 1a-f Light weight floor slab 2, 2a-f Steel pipe 3 Connection part 4 Joining surface 5 Fitting protrusion 6 Fitting recessed part 7 Connection jig 8 ９ 9 Outer screw 10 Inner screw 11 Housing space 12 Supporting pressure plate 13 Coupler 14 , 14x, 14y PC steel 15 Filler 16 Reinforcement material A Floor slab B PC steel (twisted wire)
C mortar D bearing plate

Claims (10)

In concrete precast floor slabs that are used with multiple pieces arranged and connected,
Several long and rigid pipes are arranged in the floor slab concrete in the floor slab concrete,
The pipes are spaced apart in the direction intersecting the connecting direction of the floor slabs, and integrated with the concrete under the design load action,
A lightweight floor slab characterized by that. In the lightweight floor slab of Claim 1,
At the axial end of the tube, provided with a connecting portion that can be connected to other floor slab tubes arranged in the connecting direction of the floor slab,
A lightweight floor slab characterized by that. In the floor slab construction method in which two or more floor slabs are arranged and connected in the connecting direction,
The lightweight floor slabs according to claim 1 or claim 2 are arranged side by side in the connecting direction of the lightweight floor slabs by communicating the pipes of the lightweight floor slabs,
Of the lightweight floor slabs arranged as described above, two or more sheets arranged by connecting the connecting portions of the axial ends of the adjacent lightweight floor slabs directly or via a connecting jig. Articulating lightweight floor slabs,
A lightweight floor slab construction method characterized by that. In the lightweight floor slab construction method according to claim 3,
Two or more floor slab units in which two or more lightweight floor slabs are connected by pre-processing are arranged in the connecting direction, and two or more arranged floor slab units are connected,
A lightweight floor slab construction method characterized by that. In the lightweight floor slab construction method according to claim 3,
By one construction, two or more lightweight floor slabs are connected in the connecting direction to provide a floor slab unit,
Two or more floor slab units are provided by repeating the connection,
Connecting the two or more floor slab units in the connecting direction;
A lightweight floor slab construction method characterized by that. In the lightweight floor slab construction method according to any one of claims 3 to 5,
PC steel is inserted into the pipes of two or more lightweight floor slabs with the pipes arranged in a row,
Prestressing and connecting to the lightweight floor slab by tensioning the PC steel material,
A lightweight floor slab construction method characterized by that. In the lightweight floor slab construction method according to any one of claims 3 to 6,
Increase the durability of the connecting part by bonding the joint surface of the adjacent lightweight floor slab with an adhesive.
A lightweight floor slab construction method characterized by that. In the floor slab connection structure where two or more floor slabs are arranged and connected,
Two or more lightweight floor slabs according to claim 1 or 2 are arranged side by side,
The lightweight floor slab is arranged such that the tubes communicate with each other in the connecting direction of the lightweight floor slab to form a tube row,
The connecting portions of the axial end portions of the adjacent lightweight floor slabs among the arranged lightweight floor slabs are connected directly or via a connecting jig,
A lightweight floor slab connection structure characterized by that. In the floor slab connection structure where two or more floor slabs are arranged and connected,
The floor slab unit in which two or more lightweight floor slabs according to claim 1 or 2 are arranged and connected in the connecting direction is arranged in two or more in the connecting direction,
The floor slab unit is arranged so that the pipes of the lightweight floor slabs communicate with each other in the connecting direction of the lightweight floor slabs,
The connecting portions of the end portions in the axial direction of the pipes of the adjacent floor slab units among the arranged floor slab units are connected directly or via a connecting jig,
A lightweight floor slab connection structure characterized by that. In the lightweight floor slab connection structure according to claim 8 or 9,
PC steel material is inserted into any one or more of a plurality of tube rows of two or more lightweight floor slabs,
The PC steel was tensioned and connected to two or more lightweight floor slabs by applying prestress,
A lightweight floor slab connection structure characterized by that.

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