JP5443079B2 - Joint structure of precast composite slab - Google Patents

Description

  The present invention relates to a joint structure of a precast composite floor slab, and more particularly to a joint structure that increases the joint strength of the joint structure and reduces the cost of the joint structure.

  Synthetic floor slabs that combine bottom steel plates and reinforced concrete slabs are widely used as bridge slabs and viaduct slabs. For composite slabs, reinforced concrete slabs are placed by placing concrete bars after construction at the construction site. Some are manufactured by a forming method, and some are manufactured in a block shape of a predetermined size by a precast method. The precast composite slab is formed in a block shape having a width of 2 to 2.5 m in the bridge axis direction and a width of the entire width (for example, 10 m) or a width of 2 in the width direction.

  In this precast composite slab, the end of the bottom steel plate protrudes from the edge of the reinforced concrete plate by a predetermined length, and the end of the reinforcing bar also protrudes from the edge of the reinforced concrete plate. When assembling bridges at the site, precast composite floor slabs are arranged in series in the bridge axis direction on the main girder, the edges of the bottom steel plates are brought into contact or close to each other, and the end faces of the concrete slabs are filled with concrete. Provide a structure to increase the bonding strength between the reinforcing bar ends and the interstitial concrete, etc. at the ends of the multiple reinforcing bars projecting from the end face of the concrete slab with a gap between them, and connect the ends of the bottom steel plates together The attachment plate is disposed on the lower surface side of the bottom steel plate, and the attachment plate is fastened to the bottom steel plate with a plurality of bolts and nuts in two to four rows. Thereafter, concrete is placed in the space between the concrete placements.

  Various structures have been put to practical use as structures for increasing the bonding strength between the reinforcing bar ends and the interstitial concrete. As a first example, a structure in which a reinforcing bar end projecting from one precast composite floor slab and a reinforcing bar end projecting from the other precast synthetic floor slab are overlapped and joined is known. As a second example, a structure in which a bump-shaped large-diameter portion is integrally formed at the tip portion of a reinforcing bar to increase the connection strength between the reinforcing bar end portion and the interstitial concrete is known. As a third example, a structure is known in which a nut is fastened to the tip of a reinforcing bar to form a large-diameter portion and the connection strength between the reinforcing bar end and the interstitial concrete is increased.

  In the connection structure of the precast concrete floor slab described in Patent Document 1, a plurality of reinforcing bar ends protruding from one concrete floor slab and a plurality of reinforcing bar ends protruding from the other concrete floor slab are viewed in side view. Wrap and place them alternately facing each other, attach washers and nuts to the ends of the reinforcing bars, place a flat bar in a horizontal position on the ends of the reinforcing bars wrapped in the side view, and one concrete floor A plurality of washers and nuts corresponding to the plate are fastened and locked to an end surface of the other concrete floor slab side of the flat bar, and a plurality of washers and nuts corresponding to the other concrete floor slab are attached to one concrete of the flat bar. It is fastened and locked to the end face on the floor slab side, so that the ends of multiple reinforcing bars on one concrete floor slab side and the multiple on the other concrete floor slab side And a reinforcing bar end via the plurality of washers and nuts and flat bar are connected.

  In Patent Document 2, a plurality of reinforcing bars are arranged in two upper and lower stages on a reinforced concrete slab of a precast concrete floor slab, and a rectangular loop protruding from the concrete slab is formed at the end of the two reinforcing bars. When assembling a bridge, a plurality of rectangular loops of one precast composite floor slab and a plurality of rectangular loops of the other precast composite floor slab are arranged adjacent to each other, and perpendicular to the inner surface of one and the other rectangular loop A joint structure of a precast concrete slab is described in which bearing plates (flat bars) facing each other are arranged and embedded in interstitial concrete.

  In Patent Document 3, a plurality of reinforcing bars are arranged in two stages on the reinforced concrete slab of a precast concrete floor slab, and a T-shape is seen in plan view at the tip of the upper or lower reinforcing bar where a tensile load acts on the road surface load. The joint structure of a precast concrete slab is described in which the rib plates are welded together and the connection strength between the reinforcing bar ends and the interstitial concrete is increased with these T-shaped rib plates.

JP 58-21008 A JP-A-8-326197 Japanese Patent Laid-Open No. 2004-324211

  In the case of the structure in which the ends of the reinforcing bars are lap-joined as in the first example, the length of the reinforced joints to be lap-joined is about 500 mm, so that the gap between the stuffed concrete is about 700 mm wide. As a result, the amount of interstitial concrete used becomes large. Since the interstitial concrete costs about 2 to 10 times as much as normal concrete per unit volume, the cost of the joint structure becomes very expensive in the above structure. In the second and third examples, the contact area between the large-diameter portion of the reinforcing bar end and the nut and the interstitial concrete cannot be increased so much that the bonding strength between the reinforcing bar end and the interstitial concrete can be sufficiently strengthened. difficult.

  Since the flat bar of Patent Document 1 is arranged in a horizontal posture with its width direction oriented in the horizontal direction, it is not only disadvantageous for narrowing the gap between concrete placement concrete, but also the width of the vertical end face of the flat bar This is also disadvantageous in terms of transmitting a horizontal load from the flat bar to the padded concrete.

  Since the joint structure of Patent Documents 2 and 3 is used for a precast floor slab that does not have a bottom steel plate, upper and lower two-stage reinforcing bars are adopted. This joint structure is not suitable because it is often arranged in one stage. Moreover, in the joint structure of Patent Document 2, a rectangular loop is formed in the reinforcing bar, so that the manufacturing cost is expensive. In the joint structure of Patent Document 3, since the T-shaped rib is welded to the end of the reinforcing bar, the manufacturing cost becomes expensive.

The joint structure of the precast composite floor slab according to claim 1 includes a bottom steel plate and ends of the precast composite floor slab having a plurality of reinforcing bars arranged in a mesh shape and formed on the bottom steel plate. In the joint structure of the precast composite floor slabs to be connected, the edges of the bottom steel plates of the first and second precast composite floor slabs contact or approach each other and the end surfaces of both reinforced concrete slabs are filled with concrete. A plurality of first reinforcing bar end portions of the first precast composite floor slab and a plurality of second reinforcing bar end portions of the second precast composite floor slab are arranged in the space between the above-mentioned stuffed concrete placing spaces. And a plurality of first through-holes having a substantially equilateral triangle shape, and a plurality of second through-holes having a substantially inverted equilateral triangle shape that is upside down with respect to the first through-hole. Every other and alternate The steel strip-shaped reinforcing plate formed in advance so as to be positioned is arranged so that the width direction thereof is orthogonal to the bottom steel plate, and the plurality of first reinforcing bar ends are respectively inserted into the plurality of first through holes. A second precast composite floor in a belt-shaped reinforcing plate includes a second structure in which a plurality of second reinforcing bar end portions are respectively inserted into a plurality of second through holes, and a nut member screwed into each of the plurality of first reinforcing bar end portions. A third structure in which nut members that are locked to the first surface on the plate side and screwed to the ends of the plurality of second reinforcing bars are locked to the second surface on the first precast composite floor plate side of the belt-like reinforcing plate A steel attachment plate that is attached to the lower surface of the bottom steel plate to connect the ends of the bottom steel plates of the first and second precast composite slabs, and the interstitial concrete placing gap The bottom plate of the bottom steel plate of the first and second precast composite slabs A plurality of first to respectively fastened, is characterized in that a second high-strength bolts and nuts.

The joint structure of the precast composite floor slab according to claim 2 includes a bottom steel plate and ends of the precast composite floor slab including a plurality of reinforcing bars arranged in a mesh shape and formed on the bottom steel plate. In the joint structure of the precast composite floor slabs to be connected, the edges of the bottom steel plates of the first and second precast composite floor slabs contact or approach each other and the end surfaces of both reinforced concrete slabs are filled with concrete. A plurality of first reinforcing bar end portions of the first precast composite floor slab and a plurality of second reinforcing bar end portions of the second precast composite floor slab are arranged in the space between the above-mentioned stuffed concrete placing spaces. And a plurality of first through-holes having a substantially equilateral triangle shape, and a plurality of second through-holes having a substantially inverted equilateral triangle shape that is upside down with respect to the first through-hole. Every other and alternate The steel strip-shaped reinforcing plate formed in advance so as to be positioned is arranged so that the width direction thereof is orthogonal to the bottom steel plate, and the plurality of first reinforcing bar ends are respectively inserted into the plurality of first through holes. A second precast composite floor in a belt-shaped reinforcing plate includes a second structure in which a plurality of second reinforcing bar end portions are respectively inserted into a plurality of second through holes, and a nut member screwed into each of the plurality of first reinforcing bar end portions. A third structure in which nut members that are locked to the first surface on the plate side and screwed to the ends of the plurality of second reinforcing bars are locked to the second surface on the first precast composite floor plate side of the belt-like reinforcing plate with the door, the first, the steel spliced plate which is spliced to the lower surface of the bottom steel plate for connecting the ends of the bottom steel plate of the second precast synthesis slab, the ends of the spliced plate One end is embedded in the reinforced concrete plate of the first precast composite floor slab at the part corresponding to A plurality of first single-sided construction high-strength bolts that are fixed to the bottom steel plate in a penetrating manner and that fasten the attachment plate to the first precast composite floor slab. And a plurality of second single-sided construction heights in which one end portion is embedded in the reinforced concrete plate of the second precast composite floor slab and the bottom steel plate is fixed to the bottom steel plate in a penetrating manner at a portion corresponding to the end portion of the attachment plate. It is a force bolt and is provided with a plurality of high strength bolts for second single-sided construction that fasten attachment plates to the second precast composite floor slab.

The joint structure of the precast composite floor slab according to claim 3 is the invention according to claim 1 or 2 , further comprising: interstitial concrete that is placed in the interstitial concrete placement gap after fastening the attachment plate. It is a feature.

According to the first aspect of the present invention, the strip-shaped reinforcing plate is disposed in parallel to the bottom steel plate because the steel strip-shaped reinforcing plate is oriented in the direction perpendicular to the bottom steel plate by the second structure. Compared to the case, it is possible to reduce the gap between concrete placement concrete.
According to the second and third structures, the ends of the first and second reinforcing bars can be connected to each other so as to be able to transmit the tension via the plurality of nut members and the belt-like reinforcing plate, and the plurality of first and second reinforcing bars can be connected. The transmission performance of transmitting the load in the direction parallel to the bottom steel plate from the end of the reinforcing bar to the interstitial concrete via the belt-like reinforcing plate can be enhanced, and the joint strength of the joint structure can be significantly increased. In this way, it is a simple structure that makes effective use of a strip-shaped reinforcing plate and a plurality of nut members, and can significantly reduce the amount of space-filled concrete used by significantly narrowing the space for placing space-filled concrete. Cost can be significantly reduced.
A plurality of first through holes are formed in a substantially equilateral triangle shape, and a plurality of second through holes are formed in a substantially inverted equilateral triangle shape.
Therefore, the positioning error of the plurality of second reinforcing bar ends with respect to the plurality of first reinforcing bar ends when the first and second precast composite floor slabs are arranged is caused through the plurality of second through holes having a substantially inverted equilateral triangle shape. Therefore, a reduction in work efficiency can be prevented.

According to the second aspect of the present invention, the second and third structures provide the same effect as the first aspect, and the plurality of first and second through holes formed in the belt-shaped reinforcing plate provide the first and second through holes. The same effect can be obtained. In addition, since the plurality of first and second single-sided construction bolts can be arranged outside the range of the space-filled concrete placing gap, it is necessary to fasten the plurality of first and second single-sided construction bolts within the space-filled concrete placing gap. Since there is no gap, it can be set so that the gap between the concretes to be placed is further narrowed, so that the amount of concrete to be placed on site can be significantly reduced.

According to the invention of claim 3 , since the interstitial concrete is provided in the interstitial concrete placing gap after fastening the joint plate , the fastening operation of the joint plate in the field is simplified.

It is a perspective view of the precast synthetic floor slab of Example 1 of this invention, and its joint structure. It is a principal part expansion perspective view of the joint structure of FIG. It is a principal part expansion perspective view of the joint structure of FIG. It is a principal part perspective view of the strip | belt-shaped reinforcement board and reinforcing bar end part of the joint structure of FIG. It is a side view of the strip | belt-shaped reinforcement board of the joint structure of FIG. It is sectional drawing of the joint structure of FIG. It is a perspective view of the precast synthetic floor slab of Example 2, and its joint structure. It is a principal part expansion perspective view of the joint structure of FIG. It is a principal part expansion perspective view of the joint structure of FIG. It is sectional drawing of the joint structure of FIG. It is a figure of a single-sided construction bolt. It is a side view of the strip | belt-shaped reinforcement board of Example 3. FIG. 6 is a side view of another belt-like reinforcing plate of Example 3. FIG. It is a perspective view of the precast synthetic floor slab of Reference Example 1 and its joint structure. It is a principal part expansion perspective view of the joint structure of FIG. It is sectional drawing of the joint structure of FIG.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

  Before describing the joint structure of the precast composite floor slab, the precast composite floor slab will be briefly described. As shown in FIGS. 1 to 3, the precast composite floor slab 1 constitutes a road surface structure of a bridge or a viaduct. The precast composite floor slab 1 includes a bottom steel plate 2 and a reinforced concrete plate 4 formed on the bottom steel plate 2 including a plurality of reinforcing bars 3 arranged in a mesh shape. And is transported to the construction site by a trailer and built on a plurality of main girders arranged in the bridge axis direction of the site. At the time of the construction, the joint structure 10 of the precast composite floor slab that connects the ends of the precast composite floor slab 1 is manufactured.

In FIG. 1, a precast composite floor slab 1 is formed in an elongated shape in the width direction of the road, the dimension in the bridge axis direction (A direction) is about 2.0 to 2.5 m, for example, and the width direction (B direction) in the road is the width. In the case of the full width, for example, 10.0 to 11.0 m. In FIG. 1, the first precast composite slab 1A on the left side is shown in a state where the concrete layer is seen through.
As shown in FIGS. 1 to 3, the bottom steel plate 2 protrudes a predetermined length from an end surface orthogonal to the bridge axis of the reinforced concrete plate 4, and a plurality of reinforcing bar end portions 5 are also end surfaces orthogonal to the bridge axis of the reinforced concrete plate 4. Projecting longer than the bottom steel plate 2. A male screw portion 5c (see FIG. 3) for screwing a nut is formed at a front end portion of the protruding reinforcing bar end portion 5 by a predetermined length.

Next, the joint structure 100 of the precast composite floor slab that connects the ends of the precast composite floor slab 1 will be described.
As shown in FIGS. 1 to 3, this precast composite floor slab joint structure 100 has the first and second precast composite floor slabs 1 a and 1 b in contact with or close to the edges of the bottom steel plates 2 a and 2 b. The first precast composite floors are arranged so that they face each other and the end faces 4A, 4B of the reinforced concrete plates 4a, 4b of the first and second precast composite floor slabs 1a, 1b are opposed to each other with a gap concrete placing gap 6 therebetween. The plurality of first reinforcing bar ends 5a of the plate 1a and the plurality of second reinforcing bar ends 5b of the second precast composite floor slab 1b are alternately positioned in the interstitial concrete placing gap 6. .

  After the first and second precast composite floor slabs 1a and 1b are manufactured in the factory, the belt-like reinforcing plate 7 is temporarily attached to the first precast composite floor slab 1a with the width direction set to the vertical direction. At this time, the plurality of first rebar end portions 5a are inserted into the plurality of first through holes 7a of the band-shaped reinforcing plate 7, and the band-shaped reinforcing plate 7 is positioned near the end surface 4A of the first reinforced concrete plate 4a with a wire or the like. It may be temporarily fixed and transported to the site.

  In the first step, the first and second precast composite floor slabs 1a and 1b are arranged adjacent to each other in the bridge axis direction and assembled on a plurality of main girders at the installation site. At this time, the first and second precast composite floor slabs 1a and 1b are brought into contact with each other or close to each other, and the reinforced concrete plates of the first and second precast composite floor slabs 1a and 1b are brought into contact with each other. A plurality of first rebar end portions 5a of the first precast composite floor slab 1a and second precast composite floor slabs are arranged so that the end surfaces 4A, 4B of 4a, 4b face each other with a space between the concrete inserts 6 The plurality of second rebar end portions 5b of 1b are alternately positioned at equal intervals in the gap concrete placing gap 6. Thus, the first structure is realized.

  The joint structure 100 of the precast composite floor slab further includes a plurality of first and second through holes formed in a steel belt-like reinforcing plate 7 whose width direction is perpendicular to the bottom steel plates 2a and 2b (vertical direction). 7a, 7b or a second structure in which a plurality of first and second reinforcing bar end portions 5a, 5b are respectively inserted into the notches.

  As shown in FIGS. 4 and 5, the belt-shaped reinforcing plate 7 is provided with a plurality of first through holes 7a having a substantially equilateral triangle shape that penetrates the plurality of first reinforcing bar end portions 5a of the first precast composite floor slab 1a in advance. And a plurality of second through holes 7b penetrating the plurality of second reinforcing bar end portions 5b of the second precast composite floor slab 1b, wherein the first through holes 7a are turned upside down (substantially inverted equilateral triangular shape). The plurality of second through holes 7b are alternately formed.

  Next, in the second step, in the state where the first and second precast composite floor slabs 1a and 1b are assembled on the plurality of main girders at the local construction site as described above, the band-shaped reinforcing plate 7 is Temporarily attached to a plurality of first rebar end portions 5a of the first precast composite floor slab 1a. Therefore, the plurality of first reinforcing bar end portions 5a are moved by moving the band-shaped reinforcing plate 7 by a predetermined distance toward the second precast composite floor slab 1b in a state where the band-shaped reinforcing plate 7 is slightly lifted after being temporarily fixed. The plurality of second reinforcing bar end portions 5b are allowed to pass through the plurality of second through holes 7b while the plurality of first through holes 7a are passed through, and then the belt-shaped reinforcing plate 7 is lowered to form the plurality of first The second rebar end portions 5a and 5b are supported. Thus, the second structure described above is realized.

  The joint structure 100 of the precast composite floor slab further includes a washer and a nut member 8a screwed into the plurality of first reinforcing bar end portions 5a, and a first surface 7c on the second precast composite floor slab 1b side of the belt-shaped reinforcing plate 7. And a washer and a nut member 8b that are respectively screwed into the plurality of second rebar end portions 5b and are locked to the second surface 7d of the belt-like reinforcing plate 7 on the first precast composite floor slab 1a side. It has a structure.

  Next, in the third step, after the second structure is realized, a washer and a nut member 8a are screwed to the plurality of first reinforcing bar end portions 5a, respectively, so that the second precast synthesis in the belt-like reinforcing plate 7 is performed. Fastened and locked to the first surface 7c on the floor slab 1b side. Similarly, a washer and a nut member 8b are screwed into the plurality of second reinforcing bar end portions 5b, respectively, and fastened and locked to the second surface 7d of the strip-shaped reinforcing plate 7 on the first precast composite floor slab 1a side. Thus, the third structure is realized.

  In order to connect the ends of the bottom steel plates 2a, 2b of the first and second precast composite floor slabs 1a, 1b after the first step and before the second step, the bottom surfaces of the bottom steel plates 2a, 2b A steel attachment plate 9 is attached to the bottom, and the attachment plate 9 is placed on the end of the bottom steel plates 2a and 2b below the interstitial concrete placing gap 6, and a plurality of first and second high-strength bolts and nuts 10a. , 10b, respectively. The width of the connecting plate 9 in the bridge axis direction is formed smaller than the width of the interstitial concrete placing gap 6 in the bridge axis direction. The bolts of the first and second high-strength bolts and nuts 10a and 10b are inserted into the bolt holes of the bottom steel plates 2a and 2b and the attachment plate 9 from the inside of the interstitial concrete placing gap 6, and are high below the attachment plate 9. Tighten the nut with a force bolt tightening machine.

  Finally, in the fourth step, in the interstitial concrete placing gap 6, the reinforcing bar members 11a are assembled on the upper surfaces of the plurality of first reinforcing bar end portions 5a, and the reinforcing bar members 11b are mounted on the upper surfaces of the plurality of second reinforcing bar end portions 5b. After the assembly, when the compacted concrete is cast in the compacted concrete placing gap 6, the joint structure 100 of the precast composite floor slab is completed. However, the reinforcing bar members 11a and 11b are not essential.

  Next, the action and effect of the joint structure 100 of the precast synthetic slab will be described. With the second structure, the strip-shaped reinforcing plate 7 made of steel is oriented in the direction perpendicular to the bottom steel plates 2a, 2b, so that the strip-shaped reinforcing plate 7 is arranged in parallel with the bottom steel plates 2a, 2b. Compared with the case where it does, the interstitial concrete placement gap 6 can be narrowed.

  With the second and third structures, the plurality of first and second reinforcing bar end portions 5a and 5b can be connected to the plurality of nut members 8a and 8b and the belt-like reinforcing plate 7 so as to transmit tension. The transmission performance of transmitting a compressive load from the plurality of first and second reinforcing bar end portions 5a and 5b to the interstitial concrete via the belt-like reinforcing plate 7 can be improved, and the joint strength of the joint structure 100 can be significantly increased. it can. Thus, since it is the simple structure which used the strip | belt-shaped reinforcement board 7 and several nut member 8a, 8b effectively, and the space | gap concrete placement space 6 can be narrowed to about 160 mm, use of space | gap concrete The amount can be significantly reduced, and the manufacturing cost of the joint structure 100 can be significantly reduced.

  A plurality of first through holes 7a and a plurality of second through holes 7b are formed in the belt-shaped reinforcing plate 7, and the first through holes 7a are formed as substantially equilateral triangular through holes. When the first and second precast composite floor slabs 1a and 1b are manufactured, the plurality of reinforcing bar end portions 5a and 5b are positioned through the mold material, so that the interval between the plurality of first reinforcing bar end portions 5a, and A dimensional error generated in the interval between the plurality of second reinforcing bar end portions 5b is very small. Therefore, the plurality of first reinforcing bar end portions 5a can be reliably inserted into the plurality of first through holes 7a.

  However, when the first and second precast composite slabs 1a and 1b are arranged adjacent to each other in the direction of the bridge axis and assembled on the main girder of a plurality of strips at the construction site, the first and second precast composite slabs 1a , 1b may cause an error in the relative position (position in the width direction), the second through hole 7b through which the second rebar end 5b on the second precast composite floor slab 1b side is inserted is reversed. It formed in the equilateral triangle through-hole, and it comprised so that it might become easy to insert the some 2nd reinforcing bar end part 5b in the some 2nd through-hole 7b. Thereby, the some 2nd rebar end part 5b can be smoothly penetrated to the some 2nd through-hole 7b, and the fall of work efficiency can be prevented.

  Since the attachment plate 9 and the plurality of first and second high-strength bolts and nuts 10a and 10b can be constructed on site before placing concrete-filled concrete, the first and second precast composite slabs 1a and 1b are used in the factory. There is no need to attach bolts or the like to the first and second precast composite slabs 1a and 1b, which is advantageous in terms of production and transportation.

  The joint structure 200 of the precast synthetic floor slab according to Example 2 will be described with reference to FIGS. The joint structure 200 of the precast composite floor slab of Example 2 is that the interstitial concrete placing gap 6A is narrowed to about 100 mm, and the width of the attachment plate 9A is larger than the width of the interstitial concrete placing gap 6A. The joint structure 100 differs from the joint structure 100 in three points, that is, a structure in which the attachment plate 9A is fixed to the first and second precast composite floor slabs 1a and 1b with a plurality of single-sided construction bolts 20a and 20b. Therefore, the same constituent members (components) as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different configurations will be described.

  In the first and second precast composite floor slabs 1a and 1b, the length at which the ends of the bottom steel plates 2a and 2b protrude from the end surfaces 4A and 4B of the reinforced concrete plates 4a and 4b in the bridge axis direction is formed as short as about 50 mm. The protruding lengths of the reinforcing bar end portions 5a and 5b are also formed as short as about 80 mm. When manufacturing the first and second precast composite floor slabs 1a and 1b in the factory, as shown in FIG. 10, the ends of the bottom steel plates 2a and 2b of the first and second precast composite floor slabs 1a and 1b In the portion corresponding to the end portion of the steel attachment plate 9A attached to the lower surface of the bottom steel plates 2a and 2b, one end portion is embedded in the reinforced concrete plate 4a of the first precast composite floor slab 1a. In addition, a plurality of first single-side construction high-strength bolts 20a fixed to the bottom steel plate 2a in a penetrating manner, and a plurality of first plates for fastening the attachment plate 9A to the first precast composite floor slab 1a. A single-side construction high-strength bolt 20a is provided on the first precast composite floor slab 1a.

  Similarly, in a portion corresponding to the end portion of the attachment plate 9A, a plurality of one end portions are embedded in the reinforced concrete plate 4b of the second precast composite floor slab 1b and the bottom steel plate 2b is fixed to the bottom steel plate 2b in a penetrating manner. A plurality of second high-strength bolts 20b for fastening the attachment plate 9A to the second precast composite floor slab 1b, the second precast composite floor slab 1b. Provided.

  As shown in FIG. 11, the high-strength bolts 20a and 20b for first and second single-side construction include a bolt member 21 having a flange portion 21a in the middle in the length direction, and a bolt member 21 on both sides of the flange portion 21a. And a washer 22 and a nut 23 to be screwed together.

  As shown in FIG. 10, in the factory, before placing the concrete of the first precast composite floor slab 1a, the first single-side construction high-strength bolt 20a is inserted from the lower surface side of the bottom steel plate 2a, and the flange portion 21a is inserted. The first steel plate 2a is fastened and fixed to the bottom steel plate 2a by engaging the bottom steel plate 2a and fastening the washer 22 and the nut 23 on the upper surface side of the bottom steel plate 2a. By forming the reinforced concrete plate 4a, the first precast composite floor slab 1a is manufactured. The second precast composite floor slab 1b is manufactured in the same manner as described above.

  First and second precast synthetic slabs 1a. The first structure similar to the first structure is realized by transporting 1b to the site and performing the first process similar to the first process. Next, a second process similar to the second process is performed to realize a second structure similar to the second structure. Next, a third process similar to the third process is performed to realize a third structure similar to the third structure.

  Next, in parallel with the third step, as shown in FIG. 10, on the lower side of the bottom steel plates 2a and 2b, the connecting plate 9A is disposed below the interstitial concrete placing gap 6A and its both sides in the bridge axis direction. The plurality of first single-side construction high-strength bolts 20a are inserted into the bolt holes of the attachment plate 9A, and the plurality of first single-side construction high-strength bolts 20a are attached to the plurality of first single-side construction high-strength bolts 20a on the lower side of the attachment plate 9A. 23 is fastened to fix the attachment plate 9A to the bottom steel plate 2a. Similarly, a plurality of second single-side construction high-strength bolts 20b are inserted into the bolt holes of the attachment plate 9A, and a plurality of second single-side construction high-strength bolts 20b on the lower side of the attachment plate 9A are fitted with washers 22 and nuts. 23 is fastened to fix the attachment plate 9A to the bottom steel plate 2b.

Next, when the fourth step similar to the fourth step is performed and the interstitial concrete is placed in the interstitial concrete placing gap 6A, the joint structure 200 of the precast composite slab is completed.
In this precast composite floor slab joint structure 200, a plurality of first and second high-strength bolts 20a, 20b for single-sided construction are arranged in a portion that is disengaged from the interstitial concrete placing gap 6A in the bridge axis direction. Since the first and second high-strength bolts 20a and 20b for single-sided construction are fixed in advance to the first and second precast composite floor slabs 1a and 1b, the interstitial concrete placing gap 6A is narrowed to about 100 mm. be able to. Therefore, it is possible to remarkably reduce the amount of placing concrete. In addition, the same operation and effect as the joint structure 100 can be obtained.

  In the joint structures 100 and 200, instead of the belt-like reinforcing plate 7, belt-like reinforcing plates 7A and 7B as shown in FIGS. 12 and 13 may be employed. However, other structures are unchanged. In the belt-like reinforcing plate 7A shown in FIG. 12, a circular hole 7m having a diameter 2.0 to 3.0 times the diameter of the reinforcing bar ends 5a, 5b is formed at a position corresponding to the reinforcing bar ends 5a, 5b. The first reinforcing bar end 5a is inserted into each of the plurality of circular holes 7m, and the nut member screwed to the first reinforcing bar end 5a is fastened to the side surface of the belt-like reinforcing plate 7A on the second precast composite floor slab 1b side.・ It is locked. Similarly, the second rebar end portions 5b are inserted into the remaining plurality of circular holes 7m, and the nut members screwed into the second rebar end portions 5b are the first precast composite floors of the belt-like reinforcing plates 7A. Fastened and locked to the side surface on the plate 1a side. The structure of the belt-like reinforcing plate 7A is simplified.

  In the belt-like reinforcing plate 7B shown in FIG. 13, a plurality of inverted V-shaped notches 7n are formed at positions corresponding to the plurality of reinforcing bar ends 5a, 5b, and every other plurality of notches 7n. The first reinforcing bar end portion 5a is inserted, and the nut member screwed into the first reinforcing bar end portion 5a is fastened and locked to the side surface of the belt-like reinforcing plate 7B on the second precast composite floor slab 1b side. Similarly, the second rebar end portions 5b are inserted into the remaining plurality of notch portions 7n, and the nut members screwed into the second rebar end portions 5b are the first precast composites of the belt-like reinforcing plates 7B. Fastened and locked to the side surface of the floor slab 1a. The structure of the belt-like reinforcing plate 7B is simplified.

  The notch portion 7n has a top portion that can be freely fitted with the reinforcing bar end portions 5a and 5b, and a lower end width that is 2.0 to 3.0 times the diameter of the reinforcing bar end portions 5a and 5b.

The belt-like reinforcing plate 7B may be temporarily fixed to the first precast composite floor slab 1a at the factory and transported to the site. However, this is not always necessary, and the first and second precast composite floor slabs 1a, After 1b is mounted adjacently and the said 1st structure is comprised, the strip | belt-shaped reinforcement board 7B can be assembled | attached to the some 1st, 2nd reinforcement end part 5a, 5b from the upper direction.
However, the first and second reinforcing bar end portions 5a and 5b are not necessarily fitted into the tops of the notches 7n, and positioning errors in the width direction of the first and second precast composite floor slabs 1a and 1b occur. The first and second reinforcing bar end portions 5a and 5b are fitted into the middle portion of the notch portion 7n in the height direction.

Reference example 1

The joint structure 300 of the precast synthetic floor slab according to Reference Example 1 will be described with reference to FIGS. The joint structure 300 of the precast composite floor slab is only different from the joint structure 100 in that a reinforcing bar member 7C is used instead of the belt-like reinforcing plate 7 of the joint structure 100, and therefore only the different configuration will be mainly described. Constituent members (constituent elements) similar to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the joint structure 300 of the precast composite floor slab, the first and second precast composite floor slabs 1a and 1b are in contact with or close to each other at the edges of the bottom steel plates 2a and 2b, and both reinforced concrete plates 4a and 4b. Are arranged in a state in which the end surfaces of the first and second precast composite floor slabs 1a face each other with the interstitial concrete placing gap 6 therebetween. It has a fourth structure in which the reinforcing bar ends 5b are alternately positioned in the interstitial concrete placing gap 6. This fourth structure is the same as the first structure of the joint structure 100.

  The joint structure 300 further has a fifth structure in which the reinforcing bar member 7C is placed on the upper surfaces of the first reinforcing bar ends 5a and the plurality of second reinforcing bar ends 5b. This fifth structure corresponds to the second structure of the joint concrete 100. The reinforcing bar member 7C may be a reinforcing bar member having the same diameter as the reinforcing bar 3 used in the first and second precast composite slabs 1a and 1b or a larger diameter than the reinforcing bar 3. In addition, if a reinforcing bar member (not shown) is provided symmetrically with the reinforcing bar member 7C with respect to the first and second reinforcing bar end parts 5a and 5b also on the lower surface side of the first and second reinforcing bar end parts 5a and 5b, This is advantageous in improving the performance and strength of the joint structure 300.

  In the joint structure 300, the nut members 8a screwed into the plurality of first reinforcing bar end portions 5a are further engaged with the side surface 7e of the second precast composite floor slab side 1b of the reinforcing bar member 7C and the plurality of second reinforcing bar ends are engaged. The nut member 11b screwed to the part 5b has a sixth structure in which the nut member 11b is engaged with the side surface 7f of the first precast composite floor slab side 1a of the reinforcing bar member 7C. The sixth structure corresponds to the third structure in the joint structure 100.

  The connection plate-related structure in which the ends of the bottom steel plates 2a and 2b are connected to the attachment plate 9 by a plurality of first and second bolts and nuts 10a and 10b is the same as the joint structure 100. After producing the plate-related structure and then placing the compacted concrete into the concrete-filled gap 6, the joint structure 300 is completed. However, the same structure as that of the second embodiment may be adopted as the structure related to the attachment plate.

  The joint structure 300 of the precast composite floor slab basically exhibits the same operations and effects as the joint structure 100. Although the reinforcing bar member 7C is employed instead of the belt-like reinforcing plate 7, the operation and effect of connecting the first and second reinforcing bar end portions 5a and 5b so as to transmit tension are the same as those of the joint structure 100. However, since the vertical width of the reinforcing bar member 7C is smaller than the vertical width of the belt-like reinforcing plate 7, the action and effect of transmitting a load from the reinforcing bar member 7C to the padded concrete is somewhat weaker than that of the joint structure 100. Conceivable.

  However, most of the plurality of nut members 11a and 11b protrude below the reinforcing bar member 7C and are embedded in the interstitial concrete. Therefore, the plurality of nut members 11a and 11b are also composed of interstitial concrete. Greatly contributes to the transmission of compressive loads. In particular, the reinforcing bar member 7C is advantageous in terms of manufacturing cost because the structure is simple and inexpensive compared to the belt-like reinforcing plate 7 of the joint structure 100.

  It can be applied to the joint structure of precast composite slabs that connect precast composite slabs when building bridges and viaducts.

1a, 1b First and second precast composite floor slabs 2a, 2b Bottom steel plate 3 Reinforcing bars 4a, 4b Reinforced concrete slabs 5a, 5b Reinforcing bar ends 6 Filled concrete placing gaps 7, 7A, 7B Strip-like reinforcing plates 8a, 8b Nut members 9, 9A Joint plates 10a, 10b First and second high-strength bolts and nuts 20a, 20b High-strength bolts for first and second single-sided construction 100, 200 Joint structure of precast composite floor slab

Claims (3)

In the joint structure of the precast composite floor slab that connects the ends of the precast composite floor slab having the bottom steel plate and the reinforced concrete plate formed on the bottom steel plate including a plurality of reinforcing bars arranged in a mesh shape,
The first and second precast composite slabs are arranged in such a manner that the edges of both bottom steel plates abut or approach each other and the end surfaces of both reinforced concrete plates face each other with a gap between concrete placement concrete, A first structure in which a plurality of first reinforcing bar ends of the first precast composite floor slab and a plurality of second reinforcing bar ends of the second precast synthetic floor slab are alternately positioned in the gap concrete placing gap; ,
A plurality of first through holes having a substantially equilateral triangle shape and a plurality of second through holes having a substantially inverted equilateral triangle shape that is upside down with respect to the first through hole are formed in advance so as to be alternately arranged at predetermined intervals. The steel strip-shaped reinforcing plate is arranged so that the width direction thereof is perpendicular to the bottom steel plate, and the plurality of first reinforcing bar ends are respectively inserted into the plurality of first through holes and the plurality of second reinforcing bar ends. A second structure in which the portion is inserted through each of the plurality of second through holes;
A nut member screwed to each of the plurality of first reinforcing bar ends is locked to the first surface of the belt-like reinforcing plate on the second precast composite floor slab side and screwed to each of the plurality of second reinforcing bar ends. A third structure locked to the second surface of the first precast composite floor slab side in the belt-shaped reinforcing plate ,
In order to connect the end portions of the bottom steel plates of the first and second precast composite slabs, a steel attachment plate attached to the lower surface of the bottom steel plate, and a lower side of the interstitial concrete placing gap A precast composite floor slab comprising a plurality of first and second high-strength bolts and nuts for fastening the splicing plates to the ends of the bottom steel plates of the first and second precast composite floor slabs, respectively. Joint structure. In the joint structure of the precast composite floor slab that connects the ends of the precast composite floor slab having the bottom steel plate and the reinforced concrete plate formed on the bottom steel plate including a plurality of reinforcing bars arranged in a mesh shape,
The first and second precast composite slabs are arranged in such a manner that the edges of both bottom steel plates abut or approach each other and the end surfaces of both reinforced concrete plates face each other with a gap between concrete placement concrete, A first structure in which a plurality of first reinforcing bar ends of the first precast composite floor slab and a plurality of second reinforcing bar ends of the second precast synthetic floor slab are alternately positioned in the gap concrete placing gap; ,
A plurality of first through holes having a substantially equilateral triangle shape and a plurality of second through holes having a substantially inverted equilateral triangle shape that is upside down with respect to the first through hole are formed in advance so as to be alternately arranged at predetermined intervals. The steel strip-shaped reinforcing plate is arranged so that the width direction thereof is perpendicular to the bottom steel plate, and the plurality of first reinforcing bar ends are respectively inserted into the plurality of first through holes and the plurality of second reinforcing bar ends. A second structure in which the portion is inserted through each of the plurality of second through holes;
A nut member screwed to each of the plurality of first reinforcing bar ends is locked to the first surface of the belt-like reinforcing plate on the second precast composite floor slab side and screwed to each of the plurality of second reinforcing bar ends. A third structure locked to the second surface of the first precast composite floor slab side in the belt-shaped reinforcing plate,
A steel attachment plate attached to the lower surface of the bottom steel plate to connect the ends of the bottom steel plates of the first and second precast composite slabs, and a portion corresponding to the end of the attachment plate A plurality of high-strength bolts for first-side construction in which one end portion is embedded in the reinforced concrete plate of the first precast composite floor slab and the bottom steel plate is fixed to the bottom steel plate in a penetrating manner. A plurality of high-strength bolts for first-side construction for fastening a contact plate, and one end portion is embedded in a reinforced concrete plate of a second precast composite floor slab and a bottom steel plate is penetrated in a portion corresponding to the end portion of the attachment plate A plurality of second high-strength bolts for single-sided construction that are fixed to the bottom steel plate, and a plurality of second high-strength bolts for single-sided construction that fasten the attachment plate to the second precast composite floor slab. precast composite floor version of the joint and Elephants. The joint structure for precast composite floor slabs according to claim 1 or 2 , further comprising: interstitial concrete cast in the interstitial concrete placing gap after fastening the attachment plate .