JPH01105807A - Connection structure of precast concrete floor panel - Google Patents

Abstract

PURPOSE: To reduce the connection gap by projecting a threaded reinforcing bar from a connection end face of a precast concrete slab, and fixing each threaded reinforcing bar to an anchor plate provided between the slabs to be connected using a nut in a non-overlapped manner. CONSTITUTION: A large number of threaded reinforcing bars 5 are projected on a connection end surface of a precast concrete slab (PC slab). In connecting the PC slabs 2 to each other, the threaded reinforcing bar 5 is arranged on the PC slab 2 so that the threaded reinforcing bars 5 on the connection end face are not intersected with each other. The threaded reinforcing bar 5 of the slab 2 to be connected is inserted in an anchor plate 6 piercing the threaded reinforcing bar 5, and then, tightened by a nut 7. A concrete is placed in a connection part of both slabs 2 to complete the connection of the PC slab 2. Connection of the PC slabs 2 with small intervals between the slabs can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a connection structure between precast concrete slabs, which is used for forming road surfaces such as commercial bridges.

(Prior art) Conventionally, as shown in Fig. 10.11.12, the connection structure between precast concrete slabs is the reinforcing bars of the precast concrete slabs 2.2 installed on the top 72 inches of the main girder 1. The ends 3a and 3a of 3.3 were lapped together to form a lap joint, and concrete 4 was poured between the floor slabs 2.2 to integrally connect the floor slabs 2.2. structure is known.

When connecting the floor slabs 2.2 to each other with this lap joint, the deck slabs 2. The overlapping length 1 of the two is approximately 30 of the diameter d of the reinforcing bar 3.
It is required that the setting be approximately twice that.

(Problem to be solved by the invention) Recently, however, due to the demand to shorten the period of time required for transportation as much as possible, the strength of the concrete 4, which is poured at an irregularly stacked length, is exerted in a short period of time. So-called super-rapid hardening concrete has come into use. This ultra-quick hardening concrete is about 20 times more expensive than conventional concrete, and when used for this large ball length 1, the construction period can be shortened, but it has the disadvantage of resulting in a very expensive floor slab.

As a connection structure to shorten this overlap length,
There is one disclosed in No.-22083.

As shown in Fig. 13, the precast concrete slab 2.2 is placed so that the joint ends of the reinforcing bars 3 are arranged in a staggered manner, and 7 rattupers 9 are placed on the top surface of the reinforcing bars 3 arranged in a staggered manner. After that, a washer 12 with a protrusion 11 welded to the upper side to prevent removal is inserted, and this is screwed and fixed with a nut 10, and concrete 4 is poured between both deck slabs.

In this connection structure, the flat bar 9 is installed after the precast concrete slab 2 is placed, so on-site construction is easy. (This has the disadvantage of increasing the cracks in the concrete.

To deal with this, it is disclosed that 7 rat bars are installed above and below the reinforcing bars 3, but this requires a lot of on-site work, such as the need to hold the 7 rat bars during installation and the precision of the dimensions of the flat bar. The disadvantage is that it is complicated.

In addition, Japanese Utility Model Application No. 60-70616 discloses a relay member 1 as shown in FIG. 14 as a member to replace the flat bar.
It is disclosed to use 3.

This relay member 13 is composed of a pair of (III@ portions 14 and a connecting plate 15 that connects the side plate portions, and the side plate portions 14 are provided with notch holes 16 into which the joint ends of the reinforcing bars fit respectively. There is.

In this structure, the notch hole 16 is the place where the maximum bending moment occurs due to the tensile force of the reinforcing bars, and if the notch hole 16 is provided in this part of the side plate part 14, it is necessary to increase the thickness of the side plate part 14, This is a structural defect. *Side plate part 14
A large amount of welding is required between the connecting plate 15 and the connecting plate 15, which increases the manufacturing cost.

The present invention provides a connection structure for precast concrete slabs that can shorten the distance between both slabs without these drawbacks.

(Means for Solving the Problems) The present invention has the end surfaces of precast concrete slabs to be connected to each other facing each other at intervals, and the respective joint ends of the reinforcing bars of both slabs are connected to each other. In the connection structure of precast concrete slabs that are connected by pouring concrete between the slabs, reinforcing bars with threads are used in the joint layer of the slab, and an opening is provided through which the joint ends of the reinforcing bars of both slabs pass through. The feature is that the reinforcing bar joint ends of both deck slabs are passed through the anchor plate so that they do not cross each other, nuts are fitted into the reinforcing bar joint ends of both deck slabs, and concrete is poured between the subsequent slabs that are connected via the anchor plate. This is a precast concrete slab connection structure.

(Function) The method of fastening both slabs through anchor plates with openings through which the joint ends of the reinforcing bars penetrate improves strength without shifting the direction of the axial force line of the reinforcing bars, and allows both slabs to be connected at a short distance. This is to connect with. In addition, during construction, the anchor plate can be easily handled by penetrating the reinforcing bar joint end of one floor slab in advance, and the connection can be made simple and reliable.

(Example) 1 and 2 show examples of the connection structure of the present invention.

The reinforcing bars 5 of both precast concrete slabs 2 are arranged so that their respective joint ends do not cross each other, and the anchor plates 6
Pass the reinforcing bar joint ends of both sandals through each opening of the nut 7.
and then concrete 4 was poured. The opening distance m of the connection portion may be smaller than the overlapping length 1 in the connection structure shown in FIGS.

FIG. 3 shows an example of the shape of the anchor plate 6 used in the connection structure of the present invention. The anchor plate 6 is made of a steel plate, and the opening part 8 through which the reinforcing bars 5 pass through the center part thereof is provided in accordance with the pitch of the reinforcing bars arranged in a staggered manner between the precast concrete floor slabs. Then, as shown in FIG. 4, the reinforcing bar 5 is passed through the opening 8 and fastened with a nut 7.

In this way, by making the opening part instead of the notch part, the nine-strength pongee rope can be combined, the strength can be improved, and the thickness of the anchor plate can be reduced.

Figure 5 shows the connection of the present invention! An example of the construction procedure for Ft construction is shown below.

First, as shown in FIG. 3A, a precast concrete floor slab 2 having reinforcing bars 5 with screws is installed, for example, on the upper 7 rungs of the girder. Next, as shown in FIG. 6(b), another precast concrete floor slab 2 is installed in which the anchor plate 6 is inserted into the reinforcing bars to a position where it does not hit the opposing reinforcing bars. At this time, it is convenient to set nuts 7 at the ends of the threaded reinforcing bars of other precast concrete slabs.

The reinforcing bars for both opposing slabs should be fabricated in a staggered manner.

The reinforcing bar 5 is optimally a threaded reinforcing bar with a thread formed by rolling, but it may also be a threaded round bar.

Once both precast concrete slabs have been installed, move the anchor plate 6 to the bottom as shown in Figure (c), and tighten the nuts from both sides using a torque wrench etc. as shown in Figure (d). Tighten with torque and then complete the connection by pouring concrete between both slabs.

Further, as shown in FIG. 6(a), after inserting the anchor plate 6 into the reinforcing bars 5 of the precast concrete slab 2 previously installed, as shown in FIG. 6(b), e)
It is also possible to install and fasten other precast concrete slabs as shown in .

In this case as well, it is convenient to set the nut 7 at the end of the reinforcing bar into which the anchor plate 6 is inserted.

If only tensile force acts on the joint, the single nut method shown above is sufficient, but if both tensile force and compressive force act, the double nut method as shown in Figure 7 is used, and the anchor Fi
6 is preferably tightened with nuts 7 from both sides of each reinforcing bar.

In this way, the anchor plate is easy to handle and can be easily worked on site.

FIGS. 8 and 9 show an example in which precast concrete slabs are connected in succession using the connection structure of the present invention.

(Effects of the Invention) According to the connection structure of the present invention, precast concrete slabs can be connected at short intervals without shifting the load line direction of the reinforcing bars. In addition, the anchor plates are easy to handle, and precast concrete slabs can be connected easily and reliably.

[Brief Description of the Drawings] Figures 1 and 2 are diagrams showing examples of the connection structure of the present invention, Figures 3 and 4 are diagrams showing examples of the shape of the anchor plate used in the connection structure of the present invention, PPJs diagrams, Figures 6 and 7 are diagrams showing examples of construction procedures for connection a″i of the present invention, and Figures 8 and 9 are diagrams showing examples of construction procedures for connection a″i of the present invention. Figures 10-14 are diagrams showing the connection structure of conventional precast concrete slabs. 1... Main girder, 2... Precast concrete slab, 3... Reinforcing bars. , 4... Concrete top, 5... Rebar, 6... Anchor plate, 7... Nut, 8... Opening part, 9... 7. Rat par, 10... Nut, 11
... protrusion, 12 ... washer, 13 ... relay member, 1
4... Side plate portion, 15... Connecting plate, 16... Notch hole.

Claims (1)

[Claims] (1) Face the end faces of the precast concrete slabs that are to be connected to each other at intervals, connect the joint ends of the reinforcing bars of both slabs, and connect by pouring concrete between both slabs. In the connection structure of precast concrete slabs, reinforcing bars with screws at the joint ends are used in the slab, and the joint ends of the reinforcing bars of both slabs are connected to an anchor plate with an opening through which the joint ends of the reinforcing bars pass through. This connection structure of precast concrete slabs is characterized in that the reinforcing bars are passed through so as not to intersect with each other, nuts are fitted into the reinforcing joint ends of both slabs, the joints are fastened via anchor plates, and then concrete is poured between both slabs.