JP2005048517A - Slab reinforcing structure and slab reinforcing construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slab reinforcing structure and a slab reinforcing construction method for separably constructing the upper-lower floors different in a construction period in the upper-lower floors, in spite of using a reinforcing steel plate embedded in a thickness of a slab and a bolt/a nut. <P>SOLUTION: This slab reinforcing structure is realized by a construction method comprising a process of forming a recessed part 6 by chipping off concrete of a slab upper surface in the prescribed depth, a process of forming a through-hole 12 in a prescribed position of a bottom surface of the recessed part by arranging the reinforcing steel plate 2 forming a plurality of bolt holes 11 in the recessed part, a process of a detent of the bolt 3 inserted over into the bolt holes 11 and the through-hole 12 to the reinforcing steel plate 2, a process of backfilling the recessed part by a cement type consolidating fluid object 5, and a process of fastening the reinforcing steel plate 2 and its lower slab part 1a by screwing the nut 4a to a lower end part of the bolt from the lower floor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention embeds a reinforcing steel plate in the slab wall thickness of a portion that becomes a weak point in strength, for example, a cold joint of slab concrete caused by extension or reconstruction of a building, a crack of slab concrete caused by an earthquake, etc. The present invention relates to a slab reinforcement structure and a slab reinforcement construction method in which slabs on both sides of a weak portion are connected by tightening with bolts and nuts.

Japanese Examined Patent Publication No. 64-11763 Japanese Examined Patent Publication No. 6-94734 Japanese Patent Publication No. 5-73862 Japanese Patent Laid-Open No. 4-118475

  A technique for reinforcing a slab by attaching a reinforcing steel plate to the concrete surface of the slab (lower surface of the slab) with an adhesive and an anchor bolt is known from Patent Documents 1 and 2 described above. In each of these conventional examples, the reinforcing steel plate is attached to the lower surface of the slab with an adhesive and anchor bolts, so the work is upward at a high place. Once the ceiling plate is removed, the bolt is drilled on the lower surface of the slab. A hole is formed, and then a heavy steel reinforced steel plate is lifted on the back of the ceiling, and fixing with an anchor bolt or injection of an adhesive must be performed, resulting in poor workability. In addition, when a reinforcing steel plate is attached to the upper surface of the slab for reinforcement, the head of the anchor bolt protrudes to the upper surface of the slab, which hinders the finishing of the floor surface.

  Therefore, by reinforcing the slab by embedding a reinforcing steel plate within the thickness of the slab by work from above the slab, for example, the concrete on the top surface of the slab is suspended to a predetermined depth to form a recess, and the recess is Install the reinforced steel plate, tighten the reinforced steel plate and the slab part located below it with a bolt that penetrates them and a nut that is screwed into the bolt, and then backfill the recess with non-shrinkable concrete, It can be said that the slab reinforcement method of flattening the steel plate is desirable in terms of floor finishing, because it eliminates the work of fixing the reinforced steel plate, which is a heavy object, to the back of the ceiling and fixing it to the lower surface of the slab.

  In Patent Document 3, the center of the span of the slab is pushed up with a jack or the like and bent upward, and a reinforcing long fiber is attached to the lower surface of the slab. And the repair method of the slab which introduce | transduces prestress into the reinforcing long fiber is disclosed. Patent Document 4 discloses a seismic reinforcement structure for a building in which a vibration damping material made of rubber, a high-viscosity material, or the like and a steel plate are attached to the lower surface of a slab. However, the former is a reinforcing technique against out-of-plane deformation of the slab, and is not shear reinforcement of the slab (reinforcement against in-plane deformation). The latter is a seismic control technology for buildings, which is not slab shear reinforcement (reinforcement against in-plane deformation).

  By the way, as mentioned above, when reinforcing the slab by tightening the reinforcing steel plate embedded in the thickness of the slab and the slab portion positioned below the steel plate with bolts and nuts penetrating them, it is a reinforcement target. Simultaneous construction on the upper and lower floors (work on the floor on the upper floor and work on the back of the ceiling on the lower floor) is required.

  Therefore, when a slab of an existing building is reinforced by the above-mentioned reinforcement method, a large-scale store that has a regular interior renovation plan for each tenant, such as a department store, Since there are many cases where the repair dates of the lower floor tenants do not match, it is practically difficult to install the upper and lower floors simultaneously. In addition, if the slab reinforcement work is carried out in accordance with the repair timing of one of the upper and lower floor stores, the other store will be accompanied by the original periodic interior repair and slab reinforcement work. Renovation costs for the required renovation work are required, resulting in an economic loss.

  The present invention has been made in consideration of the above-mentioned matters, and the purpose thereof is to use upper and lower floors in spite of the use of reinforcing steel plates and bolts and nuts embedded in the thickness of the slab. The purpose of this project is to provide a slab reinforcement structure and slab reinforcement method that can be separated from the lower floors, with different construction periods.

  In order to achieve the above object, the technical measures taken by the present invention are as follows. That is, the slab reinforcement structure according to the first aspect of the present invention includes a reinforcing steel plate embedded in the thickness of the slab by an operation from above the slab, and a lower end portion fixed to the reinforcing steel plate in a non-rotating state. Has a plurality of bolts penetrating the slab and nuts screwed to the lower end portions of the bolts, and the reinforcing steel plate and the slab portion below it are tightened by screwing the nuts into the lower end portions of the bolts. It is characterized by.

  The reinforcement structure of the slab according to the invention of claim 2 is prevented from rotating by the reinforcing steel plate embedded in the thickness of the slab by work from above the slab, the discard plate attached to the lower surface of the slab, and the discard plate A plurality of bolts whose upper end passes through the reinforcing steel plate and is positioned below the upper surface of the slab, and nuts screwed to the upper ends of the bolts. The reinforcing steel plate and the slab portion below the reinforced steel plate are tightened by screwing.

  The slab reinforcing method according to the invention described in claim 3 is a method for realizing the slab reinforcing structure according to the invention described in claim 1, wherein the concrete on the upper surface of the slab is suspended to a predetermined depth, and the recess is formed. A step of forming, a step of installing a reinforcing steel plate in which a plurality of bolt holes are formed in the recess and forming a through hole at a predetermined position on the bottom surface of the recess, and a bolt inserted across the bolt hole and the through hole. A step of preventing rotation with respect to the reinforcing steel plate, a step of refilling the concave portion with a cement-based caking fluid, and a nut from the lower floor to the lower end portion of the bolt to screw the reinforcing steel plate and its lower part It is characterized by a process for fastening the slab part.

  The slab reinforcing method according to the invention described in claim 4 is a method for realizing the slab reinforcing structure according to the invention described in claim 2, wherein a slab reinforcing structure is provided on the lower surface of the slab; Forming a plurality of bolt insertion holes that do not reach the upper surface, a step of preventing the bolts inserted into the bolt insertion holes from rotating against the discard plate, and suspending the concrete on the upper surface of the slab to a predetermined depth. A step of forming a recess and exposing an upper end side of the bolt on a bottom surface of the recess, a step of installing a reinforcing steel plate in which a bolt hole corresponding to the bolt is formed in the recess, and penetrating the reinforcing steel plate A step of screwing a nut onto an upper end of the bolt to tighten the reinforcing steel plate and a slab portion below the nut, and a step of filling the recess with a cement-based caustic fluid It is characterized by comprising.

  In addition, as a cement-type caking fluid which refills a recessed part, non-shrinkable concrete, resin mortar, etc. are used.

  The slab reinforcement structure according to the first and second aspects of the present invention has different construction timings on the upper and lower floors despite the use of a reinforcing steel plate and bolts and nuts embedded in the wall thickness of the slab. In addition, the lower floor can be separated.

  That is, in the case of reinforcing in advance from the upper floor of the slab to be reinforced, the slab reinforcing method according to the invention of claim 3 is adopted. For example, when the upper floor store is repaired, the concrete on the upper surface of the slab is predetermined. Suspended to the depth, leading from the step of forming the recess to the step of backfilling the recess with the cement-based caking fluid, and then at an appropriate time (for example, during the repair of the lower-floor store), A slab reinforcement structure according to the invention of claim 1 can be realized by screwing a nut from the lower floor to the lower end of the bolt and tightening the reinforcing steel plate and the slab portion below the steel plate.

  In the case of reinforcing in advance from the lower floor of the slab to be reinforced, the slab reinforcement method according to the invention of claim 4 is adopted, for example, when the lower floor store is renovated, the discarded plate is fixed to the lower surface of the slab. It precedes from the process to the process of preventing the bolt inserted into the bolt insertion hole from rotating against the discard plate. After that, the concrete on the upper surface of the slab is attached at an appropriate time (for example, when repairing the upper store). Claiming by forming to a predetermined depth to form a recess and exposing the upper end side of the bolt to the bottom surface of the recess to backfilling the recess with a cement-based caking fluid. The slab reinforcing structure according to the invention described in 2 can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereby.

  FIGS. 1 to 3 show, for example, parts that become weak points in strength when a plurality of buildings A, B, C, and D are connected to form a large-scale store building, that is, buildings A, B, C, The slabs 1 on both sides of a cold joint (indicated by the phantom line a) of the slab concrete generated in the connecting part of D are connected by a reinforcing steel plate 2 embedded in the thickness of the slab 1, bolts 3 and nuts 4a and 4b. The reinforcement structure of a slab is shown. Reference numeral 5 denotes a cement-based caking fluid in which the recess 6 formed in the slab 1 is backfilled, 7 is a beam, 8 is a ceiling board, and 9 is a ceiling base. As the cement-based caking fluid 5, resin mortar may be used, but non-shrinkable concrete is used in this example.

  The reinforcing steel plate 2 may be a long object corresponding to the length of the portion that is a weak point in strength, as in other embodiments described later. 6 so that the reinforcing steel plate 2 can be inserted into the recess 6 through the gap between the upper main bars (not shown) of the slab 1 so that the installation work on the slab 1 can be performed easily. A plurality of reinforced steel plates 2 having a long side formed in a rectangular shape of, for example, about 180 cm are used.

  The bolt 3 is fixed in a state of being prevented from rotating with respect to the reinforcing steel plate 2. Specifically, the upper end portion of the bolt 3 penetrating the reinforcing steel plate 2 and the nut 4a screwed to the bolt 3 are fixed by welding or the like, and the nut 4a and the reinforcing steel plate 2 are fixed by welding or the like. A nut 4b is screwed into a lower end portion of the bolt 3 penetrating the slab 1 via a washer 10 to fasten the reinforcing steel plate 2 and the slab portion 1a below it.

  Next, the slab reinforcement construction method which implement | achieves the reinforcement structure of the slab shown in FIGS. 1-3 is demonstrated. When reinforcing in advance from the upper floor of the slab to be reinforced, for example, the next process is performed in accordance with the repair plan of the upper floor store.

  First, as shown in FIG. 4A, the concrete on the upper surface of the slab 1 is suspended to a predetermined depth to form the recess 6. The depth of the concave portion 6 is a depth that can secure a concrete covering thickness for the reinforcing steel plate 2, the bolt 3, and the nut 4 b, and is usually about 50 mm or more.

  Thereafter, as shown in FIG. 4B, a reinforcing steel plate 2 in which a plurality of bolt holes 11 are formed in advance by factory processing or the like is installed in the recess 6 and a through hole is formed at a predetermined position on the bottom surface of the recess 6. 12 is formed. Either the formation (perforation) of the through hole 12 with respect to the bottom surface of the recess 6 or the installation of the reinforcing steel plate 2 with respect to the recess 6 may precede. For example, after marking the bottom surface of the recess 6 at a position corresponding to the bolt hole 11 and drilling with a drill, the reinforcing steel plate 2 may be installed in the recess 6, or the reinforcing steel plate 2 is installed in the recess 6. Thereafter, a drill may be passed through the bolt hole 11 to drill the bottom surface of the recess 6. In any of the procedures, it is desirable to perforate while sucking the concrete powder generated by the perforation so that the concrete powder does not fall so much on the ceiling plate.

  Next, as shown in FIG. 4C, the bolt 3 having the nut 4a screwed to the upper end portion is inserted over the bolt hole 11 and the through hole 12, and the nut 4a is welded. The rotation of the reinforcing steel plate 2 is prevented. Although not illustrated, a bolt with a head may be used as the bolt 3 and the nut 4a may be omitted. In this case, the head is welded to the reinforcing steel plate 2.

  In this state, as shown in FIG. 5A, a cement-based caking fluid 5 such as non-shrinkable concrete is placed in the recess 6 to refill the recess 6.

  Thereafter, the ceiling plate is peeled off at an appropriate time, for example, in accordance with the repair plan for the store on the lower floor, and the nut 4b is screwed onto the lower end of the bolt 3 from the lower floor as shown in FIG. Then, the reinforcing structure of the slab shown in FIG. 3 is realized by tightening the reinforcing steel plate 2 and the slab portion 1a below it.

  Although not shown, the slab reinforcement structure shown in FIG. 3 is welded to the reinforcing steel plate 2 in a state in which the bolt 3 is prevented from rotating in advance, and the through hole 12 is formed in the bottom surface of the recess 6, and then the reinforcement is performed. The steel plate 2 is installed in the recess 6 and the lower end side of the bolt 3 is inserted into the through-hole 12. In this state, the non-shrinkable concrete 5 is placed in the recess 6, and the recess 6 is backfilled. For example, in accordance with a renovation plan for a lower store, the ceiling plate is peeled off, and a nut 4b is screwed onto the lower end of the bolt 3 from the lower floor, and the reinforcing steel plate 2 and the slab portion 1a below it It can also be realized by the method of tightening.

  FIG. 6 shows a reinforcement structure of a slab reinforced in advance from the lower floor of the slab to be reinforced, the reinforcing steel plate 2 embedded in the thickness of the slab 1 by the work from above the slab 1, and the slab 1 A discard plate 14 attached to the lower surface, a plurality of bolts 3 fixed to the discard plate 14 so as to be prevented from rotating, and having an upper end penetrating the reinforcing steel plate 2 and positioned below the upper surface of the slab, and each bolt 3, and a nut 4 a screwed to the upper end portion of the bolt 3, and the reinforcing steel plate 2 and the slab portion 1 a therebelow are tightened by screwing the nut 4 a into the upper end portion of the bolt 3.

  Next, a slab reinforcement method for realizing this slab reinforcement structure will be described. When reinforcing in advance from the lower floor of the slab to be reinforced, for example, the next process is performed in accordance with the repair plan of the lower floor store.

  First, as shown in FIG. 7A, a discard plate 14 made of a thin iron plate is fixed to the lower surface of the slab 1 with a chemical anchor 15.

  Then, as shown in FIG. 7B, a plurality of bolt insertion holes 16 that do not reach the upper surface of the slab are formed at predetermined positions on the lower surface of the slab by drilling from below the discard plate 14.

  Next, as shown in FIG. 7C, the bolt 3 having a nut 4b screwed to the lower end is inserted into the bolt insertion hole 16, and the nut 4b and the discard plate 14, the nut 4b and the bolt 3 are inserted. By welding, the bolt 3 is prevented from rotating with respect to the discard plate 14. Although not shown, a bolt with a head may be used as the bolt 3 and the nut 4b may be omitted. In this case, the head is discarded and welded to the plate 14.

  After that, suitable time, for example, in accordance with the repair plan of the store on the upper floor, as shown in FIG. 8A, the concrete on the upper surface of the slab is suspended to a predetermined depth to form the recess 6, The upper end side of the bolt 3 is exposed on the bottom surface of the recess 6.

  Next, as shown in FIG. 8B, the reinforcing steel plate 2 in which a plurality of bolt holes 11 are formed in advance by factory processing or the like is installed in the recess 6, and the upper end portion of the bolt 3 is inserted into the reinforcing steel plate.

And as shown to (A) of FIG. 9, after screwing the nut 4a to the upper end part of the volt | bolt 3 which penetrates the reinforcement steel plate 2, and fastening the said reinforcement steel plate 2 and the slab part 1a below it, As shown in FIG. 9B, the concave portion 6 is backfilled with cement-based caking fluid 5 such as non-shrinkable concrete to realize the reinforcing structure of the slab shown in FIG.

  Although not shown, the slab reinforcing structure shown in FIG. 6 is a plurality of slabs that are welded to the discard plate 14 in a state in which the bolts 3 are previously prevented from rotating, and the bottom surface of the slab is directly drilled to reach the top surface of the slab. The bolt insertion hole 16 is formed, and then the discard plate 14 is fixed to the lower surface of the slab 1 with the chemical anchor 15 in a state where the bolt 3 is inserted into the bolt insertion hole 16. At an appropriate time, for example, in accordance with a refurbishment plan for an upper floor store, concrete on the upper surface of the slab is suspended to a predetermined depth to form a recess 6 and the upper end side of the bolt 3 is exposed on the bottom surface of the recess 6. Then, the reinforcing steel plate 2 in which a plurality of bolt holes 11 are formed in advance by factory processing or the like is installed in the recess 6, and the upper end of the bolt 3 is inserted into the reinforcing steel plate 2, and the bolt penetrating the reinforcing steel plate 2 is inserted. 3, the nut 4 a is screwed onto the upper end of the steel plate 3, the reinforcing steel plate 2 and the slab portion 1 a below the fastening steel plate 2 are tightened, and then the concave portion 6 is backfilled with the cement-based caking fluid 5. .

  In the present invention, as shown in FIG. 10, adjacent to an existing building A, another building B is constructed in a state where those slabs are connected to form one building having a large floor area. The present invention can be applied to the reinforcement of the connecting portion (cold joint a) between the existing slab and the newly built slab, and as shown in FIG. 11, it can also be applied to the reinforcement of slab concrete in which cracks b have occurred due to an earthquake or the like. 10 and 11, both the reinforcing steel plate 2 is formed in a long object in the longitudinal direction of a portion (cold joint a or crack b) that is a weak point in strength, but in FIGS. 1 and 2, Similarly to the illustrated embodiment, a rectangular reinforcing steel plate 2 having a long side in the longitudinal direction of the cold joint a or crack b and a long side in a direction perpendicular to the cold joint a or crack b may be used.

It is a schematic plan view explaining an example of the reinforcement structure of the slab which concerns on this invention. It is an enlarged plan view of the principal part. It is a vertical side view of the reinforcement structure of a slab. It is a vertical side view explaining the process of the slab reinforcement construction method which concerns on this invention. It is a vertical side view explaining the process of the said slab reinforcement construction method. It is a vertical side view explaining the other example of the reinforcement structure of the slab which concerns on this invention. It is a vertical side view explaining the process of the slab reinforcement construction method for implement | achieving the reinforcement structure of the slab of FIG. It is a vertical side view explaining the process of the said slab reinforcement construction method. It is a vertical side view explaining the process of the said slab reinforcement construction method. It is a schematic plan view which illustrates the application object of the slab reinforcement structure and slab reinforcement construction method concerning the present invention. It is a schematic plan view which illustrates the application object of the slab reinforcement structure and slab reinforcement construction method concerning the present invention.

Explanation of symbols

1 ... Slab
1a ... Slab part
2 ... Reinforced steel sheet
3 ... Bolt
4a, 4b ... nuts

Claims (4)

  Reinforced steel plate embedded in the thickness of the slab by work from the top of the slab, a plurality of bolts fixed to the reinforcing steel plate so as to be prevented from rotating and having a lower end passing through the slab, and a lower end of each bolt A reinforcing structure for a slab comprising: a nut screwed to the lower end portion of the bolt; and the reinforcing steel plate and a slab portion below the reinforcing steel plate are tightened by screwing the nut into the lower end portion of the bolt.   Reinforced steel plate embedded in the thickness of the slab by work from the top of the slab, a discarded plate attached to the lower surface of the slab, and fixed to a state where it is prevented from rotating around the discarded plate, and the upper end penetrates the reinforced slab. And a plurality of bolts positioned below the upper surface of the slab, and nuts screwed to the upper end portions of the bolts, and the reinforcing steel plate and the slab portion below the reinforcing steel plate are screwed into the upper end portions of the bolts. Slab reinforcement structure characterized by being tightened.   The concrete on the top surface of the slab is suspended to a predetermined depth to form a recess, and a reinforcing steel plate having a plurality of bolt holes is installed in the recess, and a through hole is formed at a predetermined position on the bottom surface of the recess. A step of preventing rotation of the bolt inserted between the bolt hole and the through hole with respect to the reinforcing steel plate, a step of backfilling the concave portion with a cement-based caking fluid, and a lower end portion of the bolt from a lower floor A slab reinforcing method comprising a step of screwing a nut onto the reinforcing steel plate and tightening the reinforcing steel plate and a slab portion below the reinforcing steel plate.   A step of fixing a discard plate to the lower surface of the slab, a step of forming a plurality of bolt insertion holes that do not reach the upper surface of the slab on the lower surface of the slab, and a bolt inserted into the bolt insertion hole are prevented from rotating with respect to the discard plate. Reinforced steel sheet in which concrete on the upper surface of the slab is suspended to a predetermined depth to form a recess, and an upper end side of the bolt is exposed on the bottom surface of the recess, and a bolt hole corresponding to the bolt is formed. A step of tightening the reinforcing steel plate and the slab portion below the nut, and a step of tightening the reinforced slab with a nut. A slab reinforcement method characterized by comprising a step of backfilling with a fluid.

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