JP2020186583A - Precast concrete member and coupling structure of the same - Google Patents

Abstract

To provide a precast concrete member which restricts use of concrete while maintaining good workability of hanging down.SOLUTION: A precast concrete member 103b of the present invention forms a cutout 114 into which coupling units 1, 1 are inserted to have a wide W to be maximum at an insertion side opening 163 and decrease as it enters deeper from the insertion opening so that there is no interference between the coupling units 1, 1 and a distributing bar 167a during the insertion and workability of hanging down increases, and a distributing bar 167b is continuously arranged within a slit 114 so that it is not necessary to maintain a projecting length L by divided arrangement and the width W of the cutout 114 in a lower range can be narrowed, and thus, combined with an increased contact region area of a tensile strength transmission part provided at the cutout 114 and the precast concrete member 103b, a volume of the cutout 114 and the use of concrete can be lowered than a case of a rectangular cross section.SELECTED DRAWING: Figure 2

Description

The present invention mainly relates to a precast concrete member used as a floor slab, particularly a floor slab for a bridge, and a connecting structure thereof.

Social and economic infrastructures such as roads, railroads, rivers, and harbors are being constructed intensively in Japan during the period of high economic growth, and in relation to this, aging has been progressing all at once in recent years. There is an urgent need for maintenance or renewal, but in the superstructure of bridges where roads and railroads are laid, if the floor slab is significantly damaged, it will be necessary to replace it, and the superstructure will be a steel girder. In the case of a girder with an RC floor slab overlaid, measures to replace the RC floor slab with a precast concrete floor slab of RC structure or PC structure (hereinafter, simply referred to as precast floor slab) are widely adopted. There is.

When replacing the floor slabs using the precast floor slabs, after removing the existing floor slabs, arrange the precast floor slabs along the bridge axis direction, and then insert PC steel into these precast floor slabs. Then, a method of connecting the precast floor slabs to each other by introducing a tensile force is adopted (Patent Document 1).

On the other hand, instead of completely removing the existing floor slab, for example, if one of the two lanes is allowed to pass while the other is partially removed and the floor slab is replaced, the total road closure during the construction period can be avoided. (Patent Document 2).

JP-A-2017-82496 Japanese Unexamined Patent Publication No. 2016-98490

In the above partial removal, if the precast floor slabs are juxtaposed in the direction perpendicular to the bridge axis, the insertion holes for the PC steel material will open on both sides of the superstructure, and the PC steel material insertion work and the precast through the PC steel material will be opened. Since scaffolding must be constructed separately for stress introduction work and the length of the PC steel material becomes long, depending on the scale of the bridge, not only the workability of inserting into the prestressed slab deteriorates, but also the transportation cost and transportation cost There is a concern that storage costs will increase.

Therefore, the applicant has provided a notch in at least one of the two precast concrete members, and then the above-mentioned two precast concretes so that the PC steel material is positioned in the notch. The members and the PC steel material are juxtaposed at the construction site, and then concrete is placed in the notch to provide a tensile force transmission part in the notch and the PC steel material is embedded in the notch. We are developing a connecting structure in which two precast concrete members are attracted to each other by the tensile force of the PC steel material, and according to this connecting structure, it is necessary to insert a long PC steel material into the two precast concrete members at the construction site. This eliminates the need for a scaffold for the insertion work, and as for the tensile force of the PC steel material, the one introduced in advance at the factory or the like can be released at the construction site, so that the scaffold for introducing the tensile force is also unnecessary. It becomes.

Here, the above-mentioned tensile force transmitting portion is an important structural element for transmitting a load between the PC steel material or the fixing plate attached to the PC steel material and the precast concrete member, and therefore has excellent strength performance. It is desirable to use high-quality concrete, for example, room-temperature curable ultra-high-strength fiber-reinforced concrete, but in that case, from the viewpoint of economic efficiency, the amount of concrete used should be reduced as much as possible to reduce costs. Desired.

However, in the case where the connecting unit in which the PC steel material is incorporated is arranged in the notch provided in each of the precast concrete members in the state where the two precast concrete members are arranged in advance, the notch is provided. In the case where the precast concrete member is placed in advance and then the precast concrete member with a part of the connecting unit is placed in the trailing position, if the width of the notch is too narrow, the rest of the connecting unit is cut. Since it tends to interfere with the reinforcing bars protruding from the notched facing inner surface, it takes time to suspend the precast concrete member, and there is a concern that the suspending operation itself becomes difficult.

That is, if the notch width is reduced to reduce the amount of concrete used, it becomes difficult to carry out the hanging work at the construction site, and if the notch width is increased to improve the workability at the time of hanging, the amount of concrete used is increased. Has caused the problem of increasing costs and leading to high costs.

The present invention has been made in consideration of the above-mentioned circumstances, and provides a precast concrete member capable of reducing the amount of concrete used while maintaining good workability of the hanging work and a connecting structure thereof. The purpose.

In order to achieve the above object, as described in claim 1, the precast concrete member according to the present invention is opened as a joint side opening on the side of the joint side end face and is orthogonal to each other so as to be back to back from the joint side end face. Of the pair of non-joining surfaces extending to, a notch is provided on the side of one of the non-joining surfaces as an opening on the insertion side, and the notch is provided with a tensile force transmitting portion made of post-cast concrete. A precast concrete member that can be provided in a predetermined range including an end portion of a PC steel material or in a state where a fixing means attached to the end portion is embedded.
The facing inner surface distance of the notch along the direction parallel to the pair of non-joining surfaces and parallel to the joining side end surface is maximum at the insertion side opening, and is continuous or non-continuous as it becomes deeper from the insertion opening. The notch is formed so as to decrease continuously.

Further, in the precast concrete member according to the present invention, the facing inner surfaces of the notches are each stepped inner surfaces.

Further, in the precast concrete member according to the present invention, reinforcing bars parallel to the pair of non-joining surfaces and along the direction parallel to the joining side end faces are arranged in two stages at intervals, and the reinforcing bars on the side close to the insertion side opening are arranged. Is used as the first reinforcing bar, the reinforcing bar on the side far from the insertion side opening is used as the second reinforcing bar, and the reinforcing bars along the direction orthogonal to the joint side end face are arranged in two stages and inserted. The reinforcing bar on the side closer to the side opening is the first main reinforcing bar, the reinforcing bar on the side far from the insertion side opening is the second main reinforcing bar, and the portion extending from the opposite inner surface of the notch is the first force distribution bar. It is divided and arranged so as to be separated from each other as protruding ends, and the second force distribution bars are continuously arranged so as to extend from one of the opposing inner surfaces of the notch to the other.

Further, the precast concrete member according to the present invention is made of prestressed concrete.

Further, as described in claim 5, the connection structure of the precast concrete member according to the present invention is such that the first precast concrete member and the joint side end face and the joint side end face of the first precast concrete member face each other. The precast concrete member according to any one of claims 1 to 4 as the second precast concrete member juxtaposed, and the post-cast concrete in the notch so as to be continuously integrated with the second precast concrete member. The tensile force transmitting portion provided in the above and the fixing means including a predetermined range including one end or attached to the one end are embedded in the first precast concrete member, and the rest including the other end. The first precast concrete member and the second precast concrete member are provided with a PC steel material having a fixing means attached to the range of or the other end thereof embedded in the tensile force transmitting portion. It is attracted to each other by the tensile force of the PC steel material with the compressive force acting on each other on the end faces on the joint side as a reaction force.

Further, as described in claim 6, the connecting structure of the precast concrete member according to the present invention includes the precast concrete member according to any one of claims 1 to 4 as the third precast concrete member and the first. 3. The precast concrete member according to any one of claims 1 to 4, and the third precast concrete member as the fourth precast concrete member arranged side by side so that the joint side end faces and the joint side end faces of the precast concrete member 3 face each other. Two tensile force transmitting portions provided with post-cast concrete in each notch belonging to each precast concrete member so as to be continuously integrated with each of the precast concrete member and the fourth precast concrete member. Among the tensile force transmitting portions, a fixing means having a predetermined range including one end or being attached to the one end is embedded in the tensile force transmitting portion belonging to the third precast concrete member, and the fourth The third precast is provided with a PC steel material in which the remaining range including the other end is embedded in the tensile force transmitting portion belonging to the precast concrete member or the fixing means attached to the other end is embedded. The concrete member and the fourth precast concrete member are attracted to each other by the tensile force of the PC steel material having the compressive force acting on the end faces on the joint side as a reaction force.

In the precast concrete member according to the present invention, one of a pair of non-joining surfaces that opens as a joining-side opening on the side of the joining-side end face and extends in the orthogonal direction from the joining-side end face so as to be back to back with each other is non-joined. A notch that opens as an insertion-side opening is provided on the surface side, and the notch is along a direction parallel to the pair of non-joining surfaces and parallel to the joining-side end surface (hereinafter referred to as a width direction). The facing inner surface distance (hereinafter, referred to as width W) is formed so as to be maximum at the insertion side opening and continuously or discontinuously decrease as the depth from the insertion opening increases.

In this way, since the width of the notch is large at the opening on the insertion side, the insertion work of the connecting unit in which the PC steel material is incorporated becomes easy.

In addition, since the width of the notch decreases as it gets deeper from the insertion opening, the cross-sectional area of the notch becomes equivalent to the case where the width is constant with respect to the depth (in the case of a rectangular cross section). Since the contact area area between the tensile force transmitting portion provided in the notch and the precast concrete member is larger than that in the case of the rectangular cross section, the amount of concrete used can be reduced.

Typical examples of precast concrete members are those manufactured as floor slabs, especially those manufactured as floor slabs for bridges, but precast concrete members may be manufactured for other parts such as walls, columns, and beams, and harbors and other civil engineering structures. It can be applied to building structures as well as objects.

When the precast concrete member is a floor slab, the surface of the peripheral surface facing another precast concrete member to be connected, which is vertical in the connected state, is the end surface on the joint side, and is horizontally in the connected state. The extending surfaces (upper surface, lower surface) are a pair of non-joining surfaces, and in the case of a wall, the surface facing another precast concrete member to be connected, and the surface that is vertical or horizontal in the connected state, is the peripheral surface. It becomes the end surface on the joint side, and the vertically extending surface (side surface) becomes a pair of non-joint surfaces in the connected state, and in the case of a beam, the surface of the peripheral surface facing another precast concrete member to be connected, the connected state. In this case, the vertical surface is the end surface on the joint side, and the horizontally extending surfaces (upper surface and lower surface) are a pair of non-joint surfaces in the connected state.

The insertion side opening is formed on one of a pair of non-joining surfaces, but this does not exclude a configuration in which another opening, so to speak, a non-inserting side opening is formed on the other non-joining surface. However, according to the configuration in which the non-insertion side opening is formed, when the reinforcing bar is arranged, the covering area of the reinforcing bar becomes narrow and the coarse aggregate is clogged, and the solidified state of the concrete around the reinforcing bar becomes poor. Can be prevented.

The notch is arbitrary in cross-sectional shape and is paired, as long as the notch is formed so that its width is maximal at the insertion opening and decreases continuously or discontinuously as it gets deeper from the insertion opening. A configuration in which the facing inner surfaces are slanted with respect to the non-joining surfaces of the above, and a configuration in which one of the facing inner surfaces is slanted and the other is upright are included. If it is an inner surface, the contact area area between the tensile force transmission part and the precast concrete member can be further increased, and as a result, the total length of the notch is significantly shortened, and thus the amount of concrete used is further reduced. It becomes possible to do.

In addition, the tenon action (dowel action) of the stepped inner surface also improves the resistance to external forces in the direction orthogonal to the pair of non-joining surfaces.

When arranging the reinforcing bars on the precast concrete member, the arrangement configuration is arbitrary, but the reinforcing bars along the width direction of the notch are arranged in two steps and the reinforcing bar on the side close to the insertion side opening is the first force distribution bar. , The reinforcing bar on the side far from the insertion side opening is used as the second force distribution bar, and the reinforcing bars along the direction orthogonal to the joint side end face are arranged in two stages and the reinforcing bar on the side close to the insertion side opening is the first. The main rebar and the rebar on the side far from the insertion side opening are used as the second main rebar, and the first rebar is divided and arranged so that the portions extending from the opposite inner surfaces of the notches are separated from each other as protruding ends. A typical example is a configuration in which the second force distribution bars are continuously arranged so as to extend from one of the opposing inner surfaces of the notch to the other.

In the above typical example, the PC steel materials are also arranged in two stages, and are arranged in the space sandwiched between the protruding ends of the first force distribution bars on the side close to the insertion side opening, and on the side far from the insertion side opening. , Arranged so as to intersect the second force distribution muscle.

The precast concrete member can be made of reinforced concrete or fiber reinforced concrete, but when it is made of prestressed concrete, it is possible to improve the strength and durability.

Further, in the connecting structure of the precast concrete member according to the present invention, the PC steel material is not penetrated through the two precast concrete members, but is arranged in each of the two precast concrete members so that each end of the PC steel material is not exposed. It is a configuration.

That is, in the connecting structure of the precast concrete member according to the present invention, of the two precast concrete members, one is a first precast concrete member and the other is a second precast concrete member, and the first precast concrete member is used. One end of the PC steel material or a fixing means attached to the end is embedded, and a tensile force transmitting portion is provided in the notch of the second precast concrete member with post-cast concrete, and the PC is provided in the tensile force transmitting portion. The other end of the steel material or the fixing means attached to the end is embedded, or the tensile force transmission part is post-cast in each notch formed in the third precast concrete member and the fourth precast concrete member. It is provided with concrete, and each end of the PC steel material or the fixing means attached to each end is embedded in each tensile force transmitting portion, and two precast concrete members are formed by the tensile force of the PC steel material. It is a structure that attracts each other.

In this way, it is not necessary to insert a long PC steel material into two precast concrete members at the construction site, a scaffolding for the insertion work becomes unnecessary, and the tensile force of the PC steel material can be adjusted at a factory or the like. Since it is sufficient to release the pre-introduced material at the construction site, a scaffolding for releasing the tensile force is not required.

Incidentally, the release of the tensile force of the PC steel material in the present invention is similar to the conventional connection configuration of the PC steel material penetration type in the sense that it introduces a prestress of compressive force into the concrete, but in the present invention, there are two. The compressive force is generated only in the concrete area extending near the end face on the joint side of the precast concrete member, that is, only in the area required as a reaction force for attraction, and the compressive force is introduced into the entire precast concrete member. It is clearly different from the conventional connection structure in which the member has a prestressed concrete structure.

As described above, the configuration in which the end portion of the PC steel material is embedded in concrete differs between the case where a notch is formed in only one of the two precast concrete members and the case where a notch is formed in both. In the former, one end of the PC steel material is embedded in the precast concrete member on the side without the notch, and the other end or the like is continuously integrated with the precast concrete member on the side with the notch. It is configured to be embedded in the tensile force transmission part provided with cast concrete, and in the latter, each end of the PC steel material is provided in each tensile force transmission part provided with post-cast concrete so as to be continuously integrated with each precast concrete member. The structure is such that each part is buried.

Here, in the above-mentioned buried configuration, when the tensile force of the PC steel material is balanced with the compressive force of the surrounding concrete through adhesion on the peripheral surface of the PC steel material, a predetermined range including one end portion and the other end portion are used. When the tensile force of the PC steel material is balanced with the compressive force of the surrounding concrete via the bearing pressure in the fixing means attached near each end, the remaining range including the above is to be buried, and one end is used. The fixing means attached to the portion and the fixing means attached to the other end portion shall be embedded respectively.

The tensile force transmitting portion can be configured by any structure such as reinforced concrete and fiber reinforced concrete as long as it is provided so as to be continuously integrated with the precast concrete member, but these tensile force transmitting portions are made of PC steel or Since it is an important structural element for carrying out load transmission between the fixing plate attached to the PC steel material and the precast concrete member, the post-casting concrete constituting them is a high-quality concrete having excellent strength performance. In particular, it is desirable to use room temperature curing type ultra-high strength fiber reinforced concrete.

It is a figure which showed the appearance which the connection structure 104 of the precast concrete member which concerns on 1st Embodiment was applied to the floor slab 101 of a bridge, (a) is a plan view, (b) is an arrow seen from the CC line direction. View. It is a figure which showed the precast concrete member 103b used for the connection structure 104 of the precast concrete member, (a) is a plan sectional view, (b) is a vertical sectional view along the DD line, (c) is EE. Vertical cross section along the line. It is a figure which showed the connection structure 104 of the precast concrete member, (a) is a horizontal sectional view, (b) is a vertical sectional view along the FF line. It is a figure of the connection unit 1 used when constructing the connection structure 104 of a precast concrete member, (a) is a front view, (b) is an assembly view seen from the front. Assembly perspective view of the connecting unit 1. A partial cross-sectional view of the connecting unit 1 is an arrow view, (a) is an arrow view looking in the AA line direction, and (b) is an arrow view looking in the BB line direction. The figure which showed the procedure which introduced the tensile force to the PC steel rod 2 of the connecting unit 1. The figure which showed the construction procedure of the connection structure 104 of the precast concrete member as the procedure of replacing the floor slab of a bridge. It is a view showing the state of continuously replacing the floor slab of the bridge as the state before the post-casting concrete is placed, (a) is a horizontal sectional view, and (b) is a vertical sectional view along the GG line. A vertical cross-sectional view along the HH line showing the state of continuously replacing the floor slab of the bridge as the state before placing the post-casting concrete. A horizontal cross-sectional view showing how the floor slab of the bridge is continuously replaced as it is after the post-casting concrete is placed. It is the figure which showed the state of changing the floor slab of a bridge continuously, (a) is a plan view which showed the state that the tensile force of PC steel rod 2 is released, (b) is a released PC. FIG. 5 is a plan view showing how the precast concrete members 103a and 103b are connected to each other by the tensile force of the steel rod 2. The figure which showed the modification of the connection unit 1. A horizontal cross-sectional view showing another procedure for constructing a connecting structure 104 of precast concrete members. A vertical sectional view showing a precast concrete member according to a modified example. It is a figure which showed the appearance which the connection structure 144 of the precast concrete member which concerns on 2nd Embodiment was applied to the floor slab 141 of a bridge, (a) is a plan view, (b) is an arrow seen from the direction of line I-I. View. It is a figure which showed the connection structure 144 of the precast concrete member, (a) is a horizontal sectional view, (b) is a vertical sectional view along the JJ line. It is the figure which showed the construction procedure of the connection structure 144 of the precast concrete member as the state before the post-casting concrete is placed in the procedure of replacing the floor slab of a bridge, (a) is a horizontal sectional view, (b) is K -Vertical cross section along the K line. Similarly, a horizontal cross-sectional view showing the construction procedure of the connecting structure 144 of the precast concrete member as a state after the post-casting concrete is placed in the procedure of replacing the floor slab of the bridge.

Hereinafter, embodiments of the precast concrete member and its connecting structure according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is an overall view showing a state in which the connection structure of the precast concrete member according to the present invention is applied to the floor slab 101 of the bridge, (a) is a plan view, and (b) is a view from the CC line direction. It is a view of the arrow.

As shown in the figure, in the floor slab 101, rectangular precast concrete members 103a and 103b are bridged over the main girder 102 of the bridge in a form in which the rectangular precast concrete members 103a and 103b are juxtaposed with each other in the direction perpendicular to the bridge axis, and these are bridged in the bridge axis direction. Although it is laid in a row along the bridge, the connecting structure 104 of the precast concrete members is configured by connecting the precast concrete members 103a and 103b to each other in the direction orthogonal to the bridge axis.

By forming the precast concrete members 103a and 103b with prestressed concrete, it is possible to improve durability and strength.

Here, as shown in FIG. 2, the precast concrete members 103a and 103b are connected so that their joint side end faces 115a and 115b face each other, but the precast concrete member 103b is provided with a notch 114. The notch opens as a joint-side opening 161 on the side of the joint-side end surface 115b, and a pair of non-joint surfaces extending in the orthogonal direction from the joint-side end surface so as to be back to back with each other (left and right in the figure (b)). (Upper surface and lower surface), one of which is formed so as to open as an insertion side opening 163 on the side of the upper surface 162a as a non-joining surface and as a non-insertion side opening 164 on the lower surface 162b side. The connecting units 1 and 1, which will be described later, are inserted and arranged in two upper and lower stages through the side opening 163.

The notch 114 is in a direction parallel to the upper surface 162a and the lower surface 162b, which are a pair of non-joining surfaces, and parallel to the joining side end surface 115b (vertical direction in FIG. 3A, horizontal direction in FIG. The facing inner surface distance (hereinafter referred to as width W) along the insertion side opening becomes maximum (W _max ) at the insertion side opening 163, and decreases discontinuously as the depth from the insertion side opening increases, and the non-insertion side opening Although it is formed so as to be the minimum in 164, in the present embodiment, as shown in FIG. 6C, the facing inner surfaces 166 and 166 are respectively stepped inner surfaces.

In the precast concrete member 103b, reinforcing bars along the width direction of the notch 114 are arranged in two steps apart from each other, and the reinforcing bars on the side close to the insertion side opening 163 are the force distribution bars 167a as the first force distribution bars, and the insertion side. Reinforcing bars on the side far from the opening 163, that is, on the side closer to the non-insertion side opening 164 are used as the second reinforcing bars 167b, and the reinforcing bars along the direction orthogonal to the joint side end surface 115b are provided in two stages. The reinforcing bars on the side closer to the insertion side opening 163 are the main reinforcing bars 168a as the first main reinforcing bars, and the reinforcing bars on the side farther from the insertion side opening 163, that is, the side closer to the non-insertion side opening 164 are the second main reinforcing bars. The main reinforcing bar 168b is provided as a main reinforcing bar 168b, and the force distribution bar 167a is divided and arranged so that the portions extending from the opposite inner surfaces 166 and 166 of the notch 114 are separated from each other as protruding ends, and the force distribution bar 167b is cut. The notches 114 are continuously arranged so as to extend from one of the opposing inner surfaces 166,166 to the other.

Here, the protruding portion of the force distribution bar 167a is formed so that when the tensile force transmitting portion 113 described later is provided in the notch 114 with the post-cast concrete, the post-cast concrete is continuously integrated with the precast concrete member 103b. The protrusion length L of is appropriately set.

As shown in FIG. 3, the connecting structure 104 of the precast concrete member uses a disk-shaped fixing plate 3a as a fixing means attached to one end of the PC steel rod 2 as a PC steel material to the precast concrete member 103a. The disc-shaped fixing plate 3b as a fixing means attached to the other end is connected to the tensile force transmitting portion 113 made of post-cast concrete provided in the notch 114 so as to be continuously integrated with the precast concrete member 103b. In addition to being buried respectively, a joint portion 116 also made of post-cast concrete is provided between the joint side end faces 115a and 115b of the precast concrete members 103a and 103b, and PC steel is provided through bearing pressure in the fixing plates 3a and 3b. By balancing the tensile force of the rod 2 with the compressive force generated in the surrounding concrete and taking the compressive reaction force from the joint side end faces 115a and 115b of the precast concrete members 103a and 103b, the tensile force of the PC steel rod is used for precasting. The concrete members 103a and 103b are attracted to each other and connected to each other.

As can be clearly seen in FIG. 3B, the PC steel material 2 and the fixing plates 3a and 3b are arranged in two sets in two upper and lower stages along the thickness direction of the precast concrete members 103a and 103b.

The joint side end surface 115b of the precast concrete member 103b is formed with a ridge in the width direction of the notch 114 so that the adhesion strength between the precast concrete member and the joint portion 116 is increased, and the precast concrete member 103a is joined. Also on the side end surface 115a, ridges are formed in the width direction of the notch 114 so that the adhesion strength between the precast concrete member and the joint portion 116 is increased.

The PC steel rod 2 and the fixing plates 3a and 3b are a part of the elements constituting the connecting unit 1 described later, and other components belonging to the connecting unit are also connected to the tensile force transmission unit 113 and the joint portion 116. Although it is buried, such other components are omitted from FIG. 3 because they do not exert a special effect as a connecting structure.

4 to 6 are views showing a connecting unit 1 used in the connecting structure 104 of the precast concrete member. As shown in these figures, the connecting unit 1 includes a PC steel rod 2, fixing plates 3a and 3b, a pair of tubular reaction force members 4a and 4b as reaction force members, and a reaction force generation and release mechanism. It includes a pair of female screw members 5a and 5b.

The tubular reaction force members 4a and 4b are each composed of hollow cylindrical members, and a compressive force, which is a reaction force for introducing a tensile force into the PC steel rod 2, is transmitted to the vicinity of each end of the PC steel rod 2. As described above, the PC steel rod 2 is arranged coaxially with the PC steel rod so as to be inserted through the PC steel rod, and in the present embodiment, the fixing plates 3a and 3b are arranged via the end portions 7a and 7b opposite to each other. By applying the above-mentioned compressive force to the facing surfaces, a tensile force can be introduced into the PC steel rod 2.

The female screw members 5a and 5b are screwed into the male screws 9a and 9b, which are right-hand threads formed on the opposing ends 8a and 8b of the tubular reaction force members 4a and 4b, respectively. By turning each of them counterclockwise while being screwed into a screw, the opposing ends 8a of the tubular reaction force members 4a and 4b are taken from each other via the annular sliding member 10 described later. , 8b are expanded to separate them to generate the above-mentioned compressive force, and by turning them in the opposite direction (clockwise), the opposing ends 8a and 8b can be brought close to each other to release the compressive force. It has become like.

As can be clearly seen in FIG. 6, the connecting unit 1 has one end in the annular space between the inner peripheral surface of the facing end portion 8a and the outer peripheral surface of the PC steel rod 2, and the inner peripheral surface of the facing end portion 8b and the PC steel rod. A tubular material end guide member 6 is provided so that the other end can be inserted into the annular space between the two outer peripheral surfaces, and the opposite ends of the tubular reaction force members 4a and 4b are expanded and contracted. While allowing the relative movement of the portions 8a and 8b in the material axis direction, the relative movement of the opposing end portions 8a and 8b in the direction orthogonal to the respective material axes is restrained.

Further, in the connecting unit 1, an annular sliding member 10 is arranged between the female screw members so as to be sandwiched between the pair of female screw members 5a and 5b.

The annular sliding member 10 has a central plate 11 that is projected from the peripheral surface of the material end guide member 6 in a brim shape, and through holes 13a and 13b that are arranged on both sides of the central plate 11 and that allow the material end guide member 6 to pass through. It is composed of the formed side plates 12a and 12b.

Here, when the female screw members 5a and 5b are rotated counterclockwise, a frictional force is applied to the contact surface between the central plate 11 and the side plates 12a and 12b according to the magnitude of the compressive force acting between them. However, the central plate 11 is generated so that the rotational operation of the female screw members 5a and 5b is not hindered by the frictional force, in other words, the contact surface between the central plate 11 and the side plates 12a and 12b becomes a sliding surface. Is configured by coating both sides of an appropriate base material with PTFE (polytetrafluoroethylene), and the side plates 12a and 12b are each composed of stainless steel plates.

According to such a configuration, the female screw members 5a and 5b take reaction forces from each other in the material axial direction via the annular sliding member 10, and the tubular reaction force members 4a and 4b are operated by their rotation operations. It is possible to push and expand the opposing end portions 8a and 8b to separate them, and to introduce a tensile force to the PC steel rod 2 by the compressive force generated in the tubular reaction force members 4a and 4b.

It is desirable that the side plates 12a and 12b are configured so that the compressive force from the female screw members 5a and 5b is evenly transmitted to each surface of the central plate 11.

Next, a case where the construction procedure of the connecting structure 104 of the precast concrete member according to the present embodiment is applied to the replacement of the floor slab of the bridge will be described.

First, in order to introduce a tensile force into the PC steel rod 2 constituting the connecting unit 1, the female screw members 5a and 5b are operated so that the axial deformation of the tubular reaction force members 4a and 4b is restrained in the contracted state. To do.

To specifically explain the process of introducing the tensile force into the PC steel rod 2, first, the material end guide to which the tubular reaction force member 4a, the female screw member 5a, and the annular sliding member 10 are attached to the PC steel rod 2. It is sequentially inserted into the member 6, the female screw member 5b, and the tubular reaction force member 4b. At this time, one end of the material end guide member 6 is inserted into the opposing end portion 8a of the tubular reaction force member 4a, and the other end is inserted into the opposing end portion 8b of the tubular reaction force member 4b.

Next, the female screw members 5a and 5b are screwed into the male screws 9a and 9b of the tubular reaction force members 4a and 4b, and the female screw members 5a and 5b are turned clockwise respectively to rotate the female screw members to the facing ends. The fixing plates 3a and 3b are temporarily retracted from the portions 8a and 8b to the fixing plates 3a and 3b, and in this state, the fixing plates 3a and 3b are attached to each end of the PC steel rod 2 by, for example, screwing.

Next, as shown in FIG. 7A, the female screw members 5a and 5b are turned counterclockwise to bring their facing surfaces into contact with the side plates 12a and 12b of the annular sliding member 10, respectively, from this state. Further, the rotation operation is continued.

In this way, as shown in the figure, the female screw members 5a and 5b take reaction forces in the material axial direction from each other via the annular sliding member 10, and the opposite ends of the tubular reaction force members 4a and 4b. The portions 8a and 8b are expanded to separate the opposing ends, and a compressive force is generated in the tubular reaction force members 4a and 4b, and the compressive force becomes a reaction force and the PC steel rod 2 Tensile force is introduced into.

Here, when the female screw members 5a and 5b are rotated, as shown in FIG. 7B, the side plates 12a and 12b that rotate together with the female screw member are in contact with each surface of the central plate 11. Then, they all try to rotate clockwise when viewed from the female screw members 5a and 5b in opposite directions, but as described above, they are annular so that slip occurs between the central plate 11 and the side plates 12a and 12b. Since the sliding member 10 is formed and the frictional force generated on the contact surface is small, the side plates 12a and 12b slide on each surface of the central plate 11, and the female screw members 5a and 5b can be rotated. There is no risk of being hindered.

Since the material end guide member 6 allows the relative movement of the opposing end portions 8a and 8b in the material axial direction due to the expansion and contraction of the tubular reaction force members 4a and 4b, the tubular reaction force members 4a and 4a, The relative movement in the material axial direction at the opposing ends 8a and 8b due to the separation of 4b is not restricted by the material end guide member 6.

On the other hand, as the rotation operation of the female screw members 5a and 5b progresses, the compressive force generated in the tubular reaction force members 4a and 4b increases and buckling occurs, or the central plate 11 constituting the annular sliding member 10 is formed. The opposing ends 8a and 8b of the tubular reaction force members 4a and 4b are shown in the figure because the frictional force generated on each surface of the above surface becomes non-uniform in the circumferential direction or the balance of the frictional force acting on both surfaces is lost. As shown in 7 (c), lateral displacement may occur, but the relative movement of the tubular reaction force members 4a and 4b at the opposing ends 8a and 8b in the direction perpendicular to the material axis causes the material end guide member 6 to move. Therefore, even if a load that causes lateral displacement occurs, the lateral displacement load is applied to the inner peripheral surfaces of the opposing end portions 8a and 8b and the outer circumference of the material end guide member 6, as shown in the figure. It is supported by the material end guide member 6 via the load transmission with the surface, and there is no possibility that the opposing end portions 8a, 8b of the tubular reaction force members 4a, 4b cause lateral displacement.

When the introduction of the tensile force into the PC steel rod 2 constituting the connecting unit 1 is completed, the fixing plate 3a of the connecting unit is embedded in the precast concrete member 103a, and the connecting unit 1 is in two stages in the precast concrete member 103a. The precast concrete member is manufactured so as to be arranged.

On the other hand, in a process different from the introduction of the tensile force into the connecting unit 1, the precast concrete member is manufactured so that the notch 114 is formed in the precast concrete member 103b.

Next, the precast concrete member 103a to which the connecting units 1 and 1 are attached in advance so as to have two upper and lower stages and the precast concrete member 103b in which the notch 114 is formed are conveyed, and the slab of the bridge at the construction site. Bring it to the replacement site.

For example, in the case of two lanes on each side, if only one lane of the bridge is closed and the remaining one lane is allowed to pass, it is possible to avoid full road closure and avoid road congestion. Therefore, taking this as an example, first, as shown in FIG. 8 (a), of the existing floor slabs 121a and 121b to be replaced, only the existing floor slab 121b is first removed, and then the same figure (b). ), A precast concrete member 103b having a notch 114 formed at the removed portion is installed.

Next, after removing the existing floor slab 121a as shown in FIG. 3C, a precast concrete member 103a to which the connecting units 1 and 1 are attached is installed at the removed portion as shown in FIG. To do.

When installing the precast concrete member 103a, as shown in FIG. 9A, the connecting units 1 and 1 attached to the precast concrete member are positioned at the center of the width of the notch 114 formed in the precast concrete member 103b. At that time, as shown in FIG. 10, the lower connecting unit 1 of the connecting units 1 and 1 is arranged without hitting the force distribution muscle 167a protruding into the notch 114. It can smoothly pass through the arrangement space sandwiched between the protruding portions of the force muscles and can be stacked directly above the force distribution muscle 167b, and the upper connecting unit 1 collides with the force distribution muscle 167a protruding into the notch 114. Consideration is given to the protrusion length L of the power distribution bar 167a and whether or not postcast concrete can be filled around the protrusion of the force distribution bar so that the space can be smoothly positioned in the arrangement space sandwiched between the projecting parts of the force distribution bar. While doing so, the width W _{max of the} notch 114, the width Sw of the step portion, and the depth Sd of the step portion are appropriately set.

Next, as shown in FIG. 11, concrete is cast in the notch 114, and the joint side of the precast concrete members 103a and 103b is excluded except for the operation work area 131 for operating the female screw members 5a and 5b. Concrete is poured into the space extending over the end faces 115a and 115b.

The above-mentioned concrete to be cast as post-casting concrete is preferably a room temperature hardening type ultra-high strength fiber reinforced concrete.

In this way, the notch 114 is provided with the tensile force transmitting portion 113 in a form of being continuously integrated with the precast concrete member 103b, and the fixing plate 3b is embedded in the tensile force transmitting portion.

Further, in the space extending to the joint side end faces 115a and 115b of the precast concrete members 103a and 103b, the joint portion 116 is provided in a form of being continuously integrated with the precast concrete members 103a and 103b.

Next, after the concrete strength of the tensile force transmitting portion 113 and the joint portion 116 is developed, the female screw members 5a and 5b are operated so that the contracted state of the tubular reaction force members 4a and 4b is released.

Specifically, as shown in FIG. 12A, the female screw members 5a and 5b are rotated clockwise to bring the tubular reaction force members 4a and 4b closer to each other.

As described above, since the annular sliding member is configured so that slip occurs between the side plates 12a and 12b constituting the annular sliding member 10 and the central plate 11, the female screw members 5a and 5b Can be loosened smoothly.

When the female screw members 5a and 5b are operated in this way, the compressive force generated in the tubular reaction force members 4a and 4b and the tensile force of the PC steel rod 2 using the compressive force as a reaction force are released and released. As shown in FIG. 3B, the tensile force of the PC steel material 2 is balanced with the compressive force of the surrounding concrete through the bearing pressure of the fixing plates 3b and 3a, and the compressive force of the concrete is the precast concrete member. The compressive reaction forces received from the joint side end faces 115a and 115b of 103a and 103b balance each other, and thus the two precast concrete members 103a and 103b interact with each other on the joint side end faces 115a and 115b via the joint portion 116. The PC steel materials 2 are attracted to each other and connected by the tensile force of the PC steel material 2 having a compressive force as a reaction force.

The unboxed operation work area 131 may be appropriately filled with concrete or mortar after the tensile force is released.

As described above, according to the precast concrete member 103b according to the present embodiment, the joint side opening 161 and the insertion side opening 163 and the non-insertion side opening 164 are opened on the joint side end surface 115b, the upper surface 162a, and the lower surface 162b, respectively. The notch 114 is provided, and the width W of the notch is maximized at the insertion side opening 163 (W _max ) and decreases discontinuously as the depth from the insertion opening is increased to the non-insertion side opening 164. The width W of the notch 114 is widened at the insertion side opening 163 into which the connecting units 1 and 1 are inserted because the notch 114 is formed so as to be the minimum.

Therefore, when the precast concrete member 103b is suspended, the connecting units 1 and 1 attached to the precast concrete member interfere with the force distribution bars 167a protruding from the facing inner surfaces 166 and 166 of the notch 114, and the suspension work takes time. There is no risk that it will be necessary or that the hanging itself will be difficult.

On the other hand, when the connecting units 1 and 1 are arranged in the slit 114 in two upper and lower stages, in the lower stage, the force distribution bars 167a are divided and arranged in the slit 114 as in the upper stage and sandwiched between the protruding ends thereof. Instead of arranging the force distribution muscles 167b in the space, the force distribution muscles 167b are continuously arranged in the slit 114 and arranged so as to overlap the slits 114. Therefore, it is not necessary to secure the protruding length L by the divided arrangement, and the cutting in the lower range. It is possible to narrow the width W of the notch 114.

Therefore, the cross-sectional area of the notch 114 can be suppressed to the same extent as in the case where the width is constant with respect to the depth, that is, a rectangular cross section, and the facing inner surfaces 166 and 166 of the notch 114 are upright. Therefore, the contact area area between the tensile force transmitting portion 113 and the precast concrete member 103b is larger than that in the case of the rectangular cross section, and therefore the length of the notch 114 required to secure the same contact area area is increased. Therefore, the volume of the notch 114, and thus the amount of concrete used, can be reduced as compared with the case of the rectangular cross section.

Further, according to the precast concrete member 103b according to the present embodiment, since the facing inner surfaces 166 and 166 of the notch 114 are each stepped inner surfaces, the contact area area between the tensile force transmitting portion 113 and the precast concrete member 103b is further increased. It can be increased, and as a result, the total length of the notch 114 can be shortened to further reduce the amount of concrete used.

In addition, since the tenon action (dowel action) is exerted by the stepped inner surface, the shear resistance force is increased by continuously arranging the force distribution muscles 167b in the slit 114, and the upper surface 162a and the lower surface 162b are formed. On the other hand, the resistance to external force in the orthogonal direction is also improved.

Further, according to the connection structure 104 of the precast concrete member according to the present embodiment, the fixing plate 3a attached to one end of the PC steel rod 2 is embedded in the precast concrete member 103a and attached to the other end. The fixed fixing plate 3b was embedded in the tensile force transmitting portion 113 provided continuously integrally with the precast concrete member 103b, and the precast concrete members 103a and 103b were attracted to each other by the tensile force of the PC steel rod 2. Therefore, 2 Since the PC steel material had to be inserted through one precast concrete member, the PC steel material could be made shorter than the conventional configuration, which had to be lengthened, and each work such as transportation, loading, and installation was possible. In addition to greatly improving the properties, it is not necessary to insert the PC steel material into the two precast concrete members at the construction site, so that a scaffold for the insertion work becomes unnecessary, and the tensile force of the PC steel rod 2 is increased. Since it is sufficient to release what has been introduced in advance at the factory or the like at the construction site, a scaffold for releasing the tensile force is not required, and the tensile force management or the tension force management at the construction site is also unnecessary.

In the present embodiment, the precast concrete members 103a and 103b are made of prestressed concrete, but instead of this, they may be made of reinforced concrete or fiber reinforced concrete.

Further, in the present embodiment, the joint portion 116 is interposed between the precast concrete members 103a and 103b, but even if the joint portion is omitted together with the ridges provided on the joint side end faces 115a and 115b, the precast concrete As long as the load transmission of the members 103a and 103b is surely performed, these may be omitted.

Further, in the present embodiment, each fixing means of the present invention is composed of a single fixing plate 3a as well as a single fixing plate 3a, but instead of this, each fixing means is fixed by a plurality of fixing means. It may be composed of boards.

Further, in the present embodiment, in the connecting unit 1, the central plate 11 is placed on both sides of an appropriate base material with PTFE (polytetrafluoro) so that the contact surface between the central plate 11 and the side plates 12a and 12b becomes a sliding surface. The side plates 12a and 12b are each made of stainless steel plates while being coated with (ethylene), but the materials and combinations of materials for reducing friction are arbitrary, and the stainless steels mentioned in the embodiment are used. In addition to the combination of steel plate and PTFE coated steel plate, there are configurations such as stainless steel plate and resin coated steel plate, PTFE coated steel plate to each other, resin coated steel plate to resin, and lubricant coated steel plate to each other. It is possible. By appropriately selecting the shapes and materials of the female screw members 5a and 5b, even when the female screw members 5a and 5b are rotated and their facing surfaces are in contact with each other, the frictional force generated on the facing surfaces is generated. If the rotation operation is not hindered by the above method, the annular sliding member 10 may be omitted.

Further, in the present embodiment, it is assumed that when the female screw members 5a and 5b are rotated, a load is generated on which the opposing ends 8a and 8b of the tubular reaction force members 4a and 4b are laterally displaced from each other. If there is no risk of lateral displacement load, the material end guide member 6 may be omitted.

Further, in the present embodiment, the reaction force generation / release mechanism of the present invention is composed of female screw members 5a and 5b in which right-handed screws are formed on the inner peripheral surfaces, respectively, but instead, both are left-handed screws. It does not matter, and one may be a right-handed screw and the other may be a left-handed screw.

Here, in the above-described modification in which one of the pair of female screw members is a right-hand screw and the other is a left-hand screw, the pair of female screw members do not rotate relative to each other when a reaction force is generated and released. A configuration corresponding to an annular sliding member is not required, and as shown in FIG. 13, it can be replaced with a coupler 74 as a reaction force generation releasing mechanism in which a left-hand screw and a right-hand screw are formed at each end. is there.

Further, in the present embodiment, the connection unit 1 has a PC steel rod 2, fixing plates 3a and 3b attached to each end thereof, and a reaction force for introducing a tensile force into the PC steel rod 2. A pair of tubular reaction force members 4a and 4b as reaction force members arranged coaxially with the PC steel rod so that the PC steel rod 2 is inserted so as to be transmitted to the vicinity of each end of the steel rod, and the said The above-mentioned reaction force is generated by restraining the material axial deformation of the tubular reaction force member in the contracted state, and the reaction force can be released by releasing the restrained state. By providing the female screw members 5a and 5b as the generation and release mechanism, the tensile force of the PC steel rod 2 is released to the surrounding concrete via the bearing pressure on the fixing plates 3a and 3b. Instead of the connecting unit 1, as shown in FIG. 14, the tubular PC steel rod 81 and the reaction force for introducing a tensile force into the tubular PC steel rod are transmitted to the vicinity of each end of the PC steel rod. By restraining the rod-shaped reaction force member 82 arranged coaxially with the PC steel rod so as to be inserted through the tubular PC steel rod and the material axial deformation of the rod-shaped reaction force member in a contracted state. Precast concrete using a connecting unit 84 including a reaction force generation / release mechanism 83 that can release the reaction force by generating the above-mentioned reaction force and releasing the restrained state. The members 103a and 103b may be connected.

In such a modification, the length range of about half of the tubular PC steel rod 81 (about the left half in FIG. 14) is defined as the precast concrete member 103a, and the remaining length range (also the right half) is defined as the precast concrete member 103b. It is embedded in each of the tensile force transmitting portions 113 provided continuously and integrally, and the tensile force of the tubular PC steel rod 81 is released to the surrounding concrete through adhesion on the peripheral surface thereof, and the reaction force is also provided. The generation / release mechanism 83 is provided at the other end of the tubular PC steel rod 81. Except for these points, the connection process is the same as when the connection unit 1 is used. Is omitted.

Further, in the present embodiment, in addition to forming the facing inner surfaces 166, 166 of the notch 114 in a stepped shape as a whole, the lower range is a portion whose width gradually narrows downward by including the slope. However, instead of this, as shown in FIG. 15 (a), by setting the lower range as an upright wall, the opposing inner surfaces 171 and 171 forming a simple stepped inner surface as a whole can be used. It doesn't matter.

Further, in the present embodiment, the insertion side opening 163 is provided on the upper surface 162a of the notch 114, and the non-insertion side opening 164 is provided on the lower surface 162b, but there is no problem in the concrete filling property of the notch 114. For example, as shown in FIG. 15B, the non-insertion side opening 164 may be omitted.

Further, in the present embodiment, the facing inner surfaces 166, 166 of the notch 114 are formed in a stepped shape as a whole, but the notch of the present invention has a width W maximum at the insertion side opening and is deep from the insertion opening. It suffices if it is formed so as to decrease continuously or discontinuously as it becomes, and it is not limited to a stepped shape in the first place, and as shown in FIG. 15 (c), the insertion opening 163 The width W may be continuously reduced from the beginning to the depth, that is, the facing inner surfaces 172 and 172 formed of slopes may be used.

In the present embodiment, the facing inner surfaces 166 and 166 of the notch 114 are formed so as to be symmetrical with respect to the width center, but instead, they can be formed so as to be asymmetrical.

[Second Embodiment]
Next, the second embodiment will be described, but the components substantially the same as those of the first embodiment are designated by the same numbers and the description thereof will be omitted.

FIG. 16 is an overall view showing a state in which the connection structure of the precast concrete member according to the present invention is applied to the floor slab 141 of the bridge, (a) is a plan view, and (b) is a view from the direction of the I-I line. It is a view of the arrow.

As shown in the figure, the floor slab 141 has rectangular precast concrete members 143a and 143b juxtaposed with each other in the direction perpendicular to the bridge axis and bridged over the main girder 102 of the bridge, and these are bridged in the direction of the bridge axis. Although they are laid in rows along the bridge, the precast concrete members 143a and 143b are connected to each other in the direction orthogonal to the bridge axis by using the connecting structure 144 of the precast concrete members.

Here, as shown in FIG. 17, the precast concrete members 143a and 143b are connected so that the end faces 115a and 115b on the joint side face each other, but they are all the same as the precast concrete member 103b of the first embodiment. The detailed description thereof will be omitted here.

For convenience of explanation, in the precast concrete members 143a and 143b, the notch 114 is referred to as a notch 114a and 114b, and the tensile force transmitting portion 113 is referred to as a tensile force transmitting portion 113a and 113b.

As shown in FIG. 17, the connecting structure 144 of the precast concrete member is provided in the notch 114a so that the fixing plate 3a attached to one end of the PC steel rod 2 is continuously integrated with the precast concrete member 143a. A tensile force made of post-cast concrete provided in a notch 114b so that a fixing plate 3b attached to the other end of the tensile force transmitting portion 113a made of post-cast concrete is continuously integrated with the precast concrete member 143b. In addition to being embedded in the transmission portion 113b, a joint portion 116 also made of post-cast concrete is provided between the joint side end faces 115a and 115b of the precast concrete members 143a and 143b to provide bearing pressure on the fixing plates 3a and 3b. By balancing the tensile force of the PC steel rod 2 with the compressive force generated in the surrounding concrete, and further taking the compression reaction force from the joint side end faces 115a, 115b of the precast concrete members 143a, 143b, the PC steel rod The precast concrete members 143a and 143b are attracted to each other by a tensile force and connected to each other.

As can be clearly seen in FIG. 6B, the PC steel material 2 and the fixing plates 3a and 3b are arranged in two sets in two upper and lower stages along the thickness direction of the precast concrete members 143a and 143b.

The joint-side end surface 115a of the precast concrete member 143a is formed with ridges in the width direction of the notch 114a so that the adhesion strength between the precast concrete member and the joint portion 116 is increased, and the precast concrete member 143b is joined. As for the side end surface 115b, a ridge is formed in the width direction of the notch 114b so that the adhesion strength between the precast concrete member and the joint portion 116 is increased.

The PC steel rod 2 and the fixing plates 3a and 3b are a part of the elements constituting the connecting unit 1, and other components belonging to the connecting unit are also connected to the tensile force transmitting portions 113a and 113b and the joint portion 116. Although it is buried, such other components are omitted from FIG. 17 because they do not exert a special effect as a connecting structure.

Next, a case where the method of connecting the precast concrete members 143a and 143b using the connecting unit 1 is applied to the replacement of the floor slab of the bridge will be described.

First, a tensile force is introduced into the PC steel rod 2 in the same procedure as in the first embodiment.

Next, the two precast concrete members are manufactured so that notches 114a and 114b are formed in the two precast concrete members 143a and 143b, respectively. The precast concrete members 143a and 143b may be manufactured either earlier or at the same time as the step of introducing the tensile force into the PC steel rod 2.

Next, the connecting unit 1 and the precast concrete members 143a and 143b are transported and carried into the floor slab replacement site of the bridge, which is the construction site.

Next, as described in FIG. 8 of the first embodiment, of the existing floor slabs 121a and 121b to be replaced, first, only the existing floor slab 121b is removed, and the precast concrete member 143b is placed at the removed portion. The precast concrete members 143a and 143b are juxtaposed by installing the existing floor slab 121a and then installing the precast concrete member 143a at the removed portion.

Next, the two connecting units 1 and 1 are installed in two upper and lower stages so as to straddle the two precast concrete members 143a and 143b. At that time, as shown in FIG. 18, the cut formed on the precast concrete member 143a is installed. The connecting units 1 and 1 are inserted so that the fixing plate 3a of the PC steel rod 2 is positioned in the notch 114a and the fixing plate 3b of the PC steel rod 2 is positioned in the notch 114b formed in the precast concrete member 143b. Deploy.

Here, regarding the width W _max of the notches 114a and 114b, the width Sw of the step portion and the depth Sd of the step portion, the lower connecting unit 1 of the connecting units 1 and 1 is the same as in the first embodiment. It can smoothly pass through the arrangement space sandwiched between the protruding portions of the distribution muscles without hitting the distribution muscles 167a protruding into the notches 114a and 114b, and can be stacked directly above the distribution muscles 167b. Projection of the force distribution muscle 167a so that the connecting unit 1 of the above can be smoothly positioned in the arrangement space sandwiched between the protrusions of the force distribution muscle without hitting the force distribution muscle 167a protruding into the notches 114a and 114b. Since the setting is appropriately made while considering whether or not the length L and the post-casting concrete can be filled around the protruding portion of the force distribution bar, the connecting units 1 and 1 can be smoothly inserted and arranged.

Next, as shown in FIG. 19, concrete is placed in the notches 114a and 114b, and the precast concrete members 143a and 143b are provided except for the operation work area 151 for operating the female screw members 5a and 5b. Concrete is placed in the space extending to the end faces 115a and 115b on the joint side.

The above-mentioned concrete to be cast as post-casting concrete is preferably a room temperature hardening type ultra-high strength fiber reinforced concrete.

In this way, the notch 114a is provided with the tensile force transmitting portion 113a in a form of being continuously integrated with the precast concrete member 143a, and the fixing plate 3a is embedded in the tensile force transmitting portion. Similarly, the notch 114b is provided with a tensile force transmitting portion 113b in a form of being continuously integrated with the precast concrete member 143b, and a fixing plate 3b is embedded in the tensile force transmitting portion.

Further, in the space extending to the joint side end faces 115a and 115b of the precast concrete members 143a and 143b, the joint portion 116 is provided in a form of being continuously integrated with the precast concrete members 143a and 143b.

Next, after the concrete strength of the tensile force transmitting portions 113a and 113b and the joint portion 116 is developed, the female screw so that the contracted state of the tubular reaction force members 4a and 4b is released in the same manner as in the first embodiment. The members 5a and 5b are operated to release the compressive force generated in the tubular reaction force members 4a and 4b and the tensile force of the PC steel rod 2 which is the reaction force.

In this way, the tensile force of the released PC steel 2 is balanced with the compressive force of the surrounding concrete through the bearing pressure of the fixing plates 3b and 3a, as described in FIG. 12 (b), and the concrete. The compressive forces of the precast concrete members 143a, 143b are balanced by the compressive reaction forces received from the joint side end faces 115a, 115b, respectively, and thus the two precast concrete members 143a, 143b are connected to their joint side via the joint portion 116. The PC steel materials 2 are attracted to each other and connected by the tensile force of the PC steel material 2 having the compressive force acting on the end faces 115a and 115b as a reaction force.

The unboxed operation work area 151 may be appropriately filled with concrete or mortar after the tensile force is released.

As described above, according to the precast concrete members 143a and 143b according to the present embodiment, the connecting units 1 and 1 are inserted into the notches 114a and 114b as in the precast concrete member 103b described in the first embodiment. The width W is widened at the insertion side opening 163.

Therefore, when the connecting units 1 and 1 are suspended from the juxtaposed precast concrete members 143a and 143b, the connecting units interfere with the force distribution bars 167a protruding from the facing inner surfaces 166 and 166 of the notches 114a and 114b and suspended. There is no risk that the work will take time or the hanging itself will be difficult.

On the other hand, when the connecting units 1 and 1 are arranged in the slits 114a and 114b in two upper and lower stages, the force distribution bars 167a are divided and arranged in the slits 114a and 114b as in the upper stage and are arranged at the protruding ends thereof. Instead of arranging the force distribution bars 167b in the sandwiched arrangement space, the force distribution muscles 167b are continuously arranged in the slits 114a and 114b and arranged so as to overlap each other, so that it is not necessary to secure the protrusion length L by the divided arrangement. It is possible to narrow the width W of the notches 114a and 114b in the lower range.

Therefore, the cross-sectional area of the notches 114a and 114b can be suppressed to the same extent as in the case where the width is constant with respect to the depth, that is, a rectangular cross section, and the facing inner surfaces 166 and the notches 114a and 114b are formed. Since the 166 is not upright, the contact area area between the tensile force transmitting portions 113a, 113b and the precast concrete members 143a, 143b is larger than that in the case of a rectangular cross section, and is therefore necessary to secure an equivalent contact area area. The lengths of the notches 114a and 114b can be shorter than those of the rectangular cross section, and thus the volume of the notches 114a and 114b and the amount of concrete used can be reduced as compared with the case of the rectangular cross section. Become.

Hereinafter, the effects of the notches 114a and 114b are the same as those of the notches 114 described in the first embodiment, and thus the description thereof will be omitted here.

Further, the action and effect of the connecting structure 144 of the precast concrete member according to the second embodiment is almost the same as the action and effect of the first embodiment, and the modified example described in the first embodiment is described in the second embodiment. The same can be applied to the embodiments, but the details thereof will be omitted in order to avoid duplication.

1 Connecting unit 2 PC steel rod (PC steel material)
3a, 3b fixing plate (fixing means)
4a, 4b Cylindrical reaction force member 5a, 5b Female screw member (reaction force generation / release mechanism)
74 Coupler (reaction force generation release mechanism)
84 Connection unit 103a, 103b Precast concrete member 104 Connection structure of precast concrete member 113 Tensile force transmission part 114 Notch 115a, 115b Joint side end face 143a, 143b Precast concrete member 113a, 11b Tensile force transmission part 114a, 114b Notch 144 Precast Connecting structure of concrete member 161 Joint side opening 162a Upper surface (one non-joined surface)
163 Insertion side opening 164 Non-insertion side opening 166, 166 Opposing inner surface 167a Force distribution muscle (first distribution muscle)
167b Force distribution muscle (second distribution muscle)
168a Main rebar (first main rebar)
168b Main rebar (second main rebar)
171,171 Opposing inner surface 172,172 Opposing inner surface

Claims (6)

It opens as a joint-side opening on the side of the joint-side end face and opens as an insertion-side opening on the side of one of the non-joint surfaces extending in the orthogonal direction from the joint-side end face so as to be back to back. A notch is provided, and a tensile force transmission portion made of post-cast concrete is provided in the notch, and a predetermined range including an end portion of a PC steel material is embedded in the post-cast concrete, or a fixing means attached to the end portion is embedded. It is a precast concrete member that can be installed in a state of being
The facing inner surface distance of the notch along the direction parallel to the pair of non-joining surfaces and parallel to the joining side end surface is maximum at the insertion side opening, and is continuous or non-continuous as it becomes deeper from the insertion opening. A precast concrete member characterized in that the notch is formed so as to decrease continuously. The precast concrete member according to claim 1, wherein the facing inner surfaces of the notches are stepped inner surfaces. Reinforcing bars parallel to the pair of non-joining surfaces and along the direction parallel to the joining side end faces are arranged in two stages, and the reinforcing bars on the side closer to the insertion side opening are the first force distribution bar, the insertion side. The reinforcing bar on the side far from the opening is used as the second force distribution bar, and the reinforcing bars along the direction orthogonal to the joint side end face are arranged in two stages and the reinforcing bar on the side close to the insertion side opening is used as the first reinforcing bar. The main reinforcing bar and the reinforcing bar on the side far from the insertion side opening are used as the second main reinforcing bar, and the first force distribution bar is divided and arranged so that the portions extending from the opposite inner surfaces of the notches are separated from each other as protruding ends. The precast concrete member according to claim 1 or 2, wherein the second force distribution bars are continuously arranged so as to extend from one of the opposing inner surfaces of the notch to the other. The precast concrete member according to any one of claims 1 to 3, which is made of prestressed concrete. Any one of claims 1 to 4 as a first precast concrete member and a second precast concrete member juxtaposed so that the joint side end face and the joint side end face of the first precast concrete member face each other. A predetermined range including the described precast concrete member, a tensile force transmitting portion provided with post-cast concrete in the notch so as to be continuously integrated with the second precast concrete member, and one end, or one of the two. The fixing means attached to the end of the first precast concrete member is embedded in the first precast concrete member, and the remaining range including the other end or the fixing means attached to the other end is attached to the tensile force transmitting portion. The tension force of the PC steel material provided with the embedded PC steel material, and the compressive force acting on the joint side end faces of the first precast concrete member and the second precast concrete member as a reaction force. A connecting structure of precast concrete members, characterized by being attracted to each other. The precast concrete member according to any one of claims 1 to 4 as a third precast concrete member, and the joint side end face and the joint side end face of the third precast concrete member are juxtaposed so as to face each other. The precast concrete member according to any one of claims 1 to 4 as the precast concrete member of No. 4 and the third precast concrete member and the fourth precast concrete member are continuously integrated with each other. Two tensile force transmitting portions provided with post-cast concrete in each of the notches belonging to each precast concrete member, and a tensile force transmitting portion belonging to the third precast concrete member among the respective tensile force transmitting portions. A predetermined range including one end or a fixing means attached to the one end is embedded, and the tensile force transmitting portion belonging to the fourth precast concrete member has the remaining range including the other end. A PC steel material in which a fixing means attached to the other end is embedded is provided, and the third precast concrete member and the fourth precast concrete member are compressed to act on their joint side end faces. A connecting structure of precast concrete members, characterized in that they are attracted to each other by the tensile force of the PC steel material with a force as a reaction force.

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