JP6050094B2 - Column / beam joint reinforcement method - Google Patents

Description

  The present invention relates to a method for reinforcing a column / beam joint suitable for reinforcing a joint between a column and a beam in a concrete building.

  In order to improve the earthquake resistance and the like for the columns of the existing concrete building, reinforcement that improves the strength and toughness may be performed. As a conventional reinforcing method, there is a method (Patent Document 1) in which mortar is applied to the surface of a column to reinforce, or a grouting material such as mortar is filled in a gap between a steel plate and a casing disposed around the casing. A construction method (Patent Document 2) is known.

JP 2010-159611 A JP 2006-063608 A

  By the way, when the column to which the beam is joined is reinforced, it is necessary to increase the strength of the end portion of the beam, that is, the joint portion of the beam to the column (column / beam joint portion). In order to reinforce the column / beam joint using reinforcing bars, a method of forming a hole through which the reinforcing bar passes through the column or beam and fixing the hole through the reinforcing bar can be cited. However, this type of reinforcement method is difficult to construct because it forms holes in the existing reinforced concrete, and the formation of holes through which the reinforcing bars pass causes damage to the structure and involves the problem of risk. is there.

  The present invention has been made in view of the above circumstances, and the main technical problem thereof is a construction method that can easily and firmly reinforce a column / beam joint without damaging an existing structure. It is to provide.

  The column / beam joint reinforcing method of the present invention is a reinforcing method of an existing concrete column / beam joint constructed of reinforcing bars and / or steel frames as reinforcing members, and has a loop bar having a loop portion. A loop reinforcing step for arranging the loop portion along the side surface of the beam and in a state in which the loop portion is close to the column; and a steel plate construction step for covering the side surface of the loop reinforcing member and the column / beam connecting portion with a steel plate. And a grout material filling step of filling a grout material between the side surface of the column / beam joint and the steel plate to embed a loop line in the grout material.

  According to the present invention, the column / beam joint is reinforced by increasing the bending resistance by the loop streaks in the grout material. Further, a structure is obtained in which loop bars are connected via a grout material to the reinforcing bars in the existing column / beam joint structure. With this reinforcement structure, the stress (for example, due to earthquakes) applied to the reinforcing bars in the existing column / beam joint structure is transmitted and distributed to the loop bars via the grout material, and the stress of the entire column / beam joint The continuity of transmission is effectively generated, and the integration of the column / beam joint, the strengthening, and the horizontal restraint effect are improved. As a result, resistance to stress such as pulling and shearing at the column / beam joint is improved, and reinforcement can be achieved. Further, there is an advantage that the column / beam joint can be easily reinforced without damaging the existing structure.

  The present invention includes a mode in which an anchor is inserted and fixed to a side surface of the beam in an inner region of the loop portion, and the anchor is embedded in the grout material in the grout material filling step.

  In this invention, the form which has a fiber sheet adhesion | attachment process which stretches and adheres a fiber sheet on the surface of the said steel plate is included.

  In this invention, the form which has the mortar construction process which apply | coats mortar as a finishing material on the surface of the said fiber sheet stuck on the surface of the steel plate at the said fiber sheet adhesion process is included.

  According to the present invention, it is possible to provide a construction method that can easily and firmly reinforce a column / beam joint without damaging an existing structure.

It is a partial cross section side view which shows the state where the pillar-beam junction part was reinforced by one Embodiment of this invention. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a partial cross section side view which shows another embodiment of the loop reinforcement which concerns on this invention. It is a cross-sectional view showing a state in which a column / beam joint is reinforced by horizontal reinforcing bars.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 and 2 show a column / beam joint in which horizontal beams 2 are orthogonally joined to four surfaces of a column 1 having a rectangular cross section standing upright in a reinforced concrete structure, and an upper surface of the beam 2. The floor slab 3 is shown. The pillar 1, the beam 2 and the floor slab 3 are all skeletons of existing reinforced concrete structures. The width of the beam 2 is smaller than the width of the column 1 and is orthogonal to the state in which the centers in the width direction coincide with each other, and the four corners of the column 1 are exposed.

  A plurality of column reinforcing bars are embedded in the column 1 as reinforcing members, and a plurality of beam reinforcing bars are embedded in the beam (all are not shown). 2 and the outer shape of the floor slab 3 are formed. The column / beam joint is reinforced by the reinforcing method of one embodiment, and the procedure will be described below.

  First, a plurality of fixing anchors 21 are inserted and fixed to both side surfaces of the reinforcing region set in the beam 2. The reinforcement region is a region inside the loop reinforcement to be constructed next. The fixing anchor 21 is constructed by inserting it into an anchor hole drilled in the concrete 10 of the beam 2 to expose the head side for a predetermined length and fixing the inserted state with an adhesive filled in the anchor hole.

  Next, a loop bar 31 formed in a substantially rectangular shape by bending a reinforcing bar is arranged on the side surface of the beam 2 so as to surround the fixing anchor 21 (loop bar arranging step). The loop line 31 has U-shaped loop portions 311 and 312 at both ends in the longitudinal direction, one loop portion 311 is brought close to the pillar 1, and the whole is parallel to the side surface of the beam 2, and , And disposed at a predetermined distance from the side surface.

  The butting portion 313 that butts both ends of the reinforcing bar in the loop reinforcement 31 is disposed at the center of one loop portion 312. The loop line 31 has the loop portion 312 on the other side without the butt portion 313 close to the column 1, the long side portion 314 extending in the longitudinal direction is parallel to the extending direction of the beam 2, and the short side portion 315 is in the vertical direction It arrange | positions as a state along. The arrangement position of the loop line 31 is held by a support work. The size of the loop reinforcement 31 is selected according to the region where reinforcement is required, the reinforcement condition, and the like, and the number of anchor anchors 21 embedded in the inner area of the loop reinforcement 31 and the embedded position are also set according to various conditions.

  Next, a plurality of ribs 41 are fastened to the upper and lower short sides 315 of the loop bar 31. Both ends of the stirrup 41 are bent at a predetermined angle (for example, about 135 °), and these bent portions are engaged with the upper and lower short sides 315 to be bridged and fixed to the short sides 315. The streaks 41 are arranged and fixed between the fixing anchors 21 at intervals in the lateral direction.

  In addition, at the positions corresponding to the four corners 11 around the column 1, four column reinforcing bars 45 are placed in parallel with the column 1 at a predetermined interval, and the state is maintained. The column reinforcing steel bars 45 are arranged on an extension of a diagonal line in the cross section of the column 1, and hold a standing state by a predetermined support provided on the beam 2 or the floor slab 3, for example. The number and arrangement positions of the column reinforcing bars 45 are arbitrary, and are selected according to the reinforcing conditions and the like.

  Next, all the side surfaces of the column / beam joint from the column 1 to the beam 2 are covered with the side surface steel plate 51, and the lower surface of the beam 2 is covered with the lower surface steel plate 52 (steel plate construction process). Further, the columns 1 at the upper and lower portions of the column / beam joint are covered with a column reinforcing steel plate 55.

  As shown in FIG. 2, the side surface steel plate 51 has a flat plate portion 512 and end portions along the side surfaces of the beams 2 on both sides orthogonal to each other from the L-shaped plate-shaped central portion 511 along the corner portion of the column 1. The part 513 is formed continuously, and four are arranged around the pillar 1. As shown in FIG. 3, the lower steel plate 52 is joined to the lower end of the side steel plate 51 by closing the lower opening formed by the side steel plates 51 on both sides. The loop reinforcement 31 and the fixing anchor 21 are disposed inside the side surface steel plates 51 on both sides.

  The column reinforced steel plate 55 that covers and arranges the column 1 in the upper and lower parts of the column / beam joint portion is formed in an L-shaped plate shape that can cover the entire four surfaces of the column with one set of four pieces, The horizontal lengths of the flat plate portions 551 on both sides of the right-angled corner are equal. Horizontal ribs 552 and vertical ribs 553 that are bent inward are formed on the upper and lower end portions and side end portions of the column reinforcing steel plate 55, respectively. Then, the four sides of the column are covered with four column-reinforced steel plates 55 with the vertical ribs 553 overlapped, and the column-reinforced steel plate 55 stacked vertically is placed with the upper side rib 552 on the lower side rib 552. As a result, the plurality of column-reinforced steel plates 55 are laminated and applied so as to cover the side surfaces of the columns 1. Further, the column reinforcing steel plate 55 is joined to the side surface steel plate 51 by causing the horizontal rib 552 to abut on the horizontal ribs 514 formed at the upper and lower ends of the side surface steel plate 51 in the same manner.

  When the steel plates 51, 52, and 55 are constructed so as to cover the column 1 and the beam 2, the fiber sheet 61 is stretched and bonded to the surfaces of these steel plates (fiber sheet bonding step). In order to bond the fiber sheet 61, a continuous fiber sheet 61 processed into a strip shape is impregnated with an adhesive and attached to a steel sheet in a tensioned state. The fiber sheet 61 can be adhered to the outer surface of the steel sheet at the same time as being adhered by an impregnating adhesive. Examples of the fiber material of the fiber sheet 61 include polyethylene, carbon, glass, vinylon, aramid, and the like, and polyethylene and carbon excellent in alkali resistance are preferable. When the application of the fiber sheet 61 is completed, the side steel plate 51 is fixed to the beam 2 and the floor slab 3 with the fixed anchor 22.

  Next, the grout material 71 is filled between the side surface of the concrete 10 at the column / beam joint and the side surface steel plate 51 and the bottom surface steel plate 52 and between the concrete of the column 1 and the column reinforcing steel plate 55 (grouting material filling step). ). Examples of the grout material 71 include mortar, cement, and concrete, and an appropriate one is selected. By filling the grout material 71, the fixing anchor 21, the loop line 31, and the stirrup line 41 are embedded in the grout material 71.

  The above is the reinforcing method of one embodiment, and according to this method, the column / beam joint is reinforced by increasing the bending resistance by the loop bars 31 in the grout material 71. In addition, the reinforcing bars in the existing column / beam joint structure are connected to the loop bars 31 via the grout material 71, and this connection structure allows the existing pillar / beam joint structure in the structure of the existing pillar / beam joint. The stress (for example, due to an earthquake or the like) received by the reinforcing bars is transmitted to the loop bars 31 through the grout material 71 and dispersed. For this reason, the continuity of the stress transmission of the entire column / beam joint is effectively generated, and the integration of the column / beam joint, high strength, and improvement of the horizontal restraint effect are achieved. As a result, resistance to stress such as pulling and shearing at the column / beam joint is improved, and reinforcement can be achieved.

  Further, since the loop bars 31 are embedded in the grout material 71 to be placed without making a hole through the existing concrete 10, the column / beam joint can be easily formed without damaging the existing structure. There is an advantage that it can be reinforced. Further, by burying the anchor 21 embedded in the concrete 10 of the beam 2 in the grout material 71, the adhesion strength of the grout material 71 to the beam 2 is improved by adhering via the anchor 21 and the existing reinforcing bars The connection strength with the loop muscle 31 is also improved by the anchoring anchor 21.

  Furthermore, the anchoring anchor 21 increases the shearing resistance force that directly transmits the stress acting on the reinforcing bar to the beam 2, thereby enhancing the reinforcement effect. Further, the stirrup 41 connected to the loop stirrer 31 can also provide a reinforcing effect accompanying an increase in shear resistance.

  In the said embodiment, although the fiber sheet 61 is adhere | attached on the surface of the steel plates 51, 52, and 55, you may add the mortar construction process which apply | coats mortar as a finishing material to the surface of the fiber sheet 61 further.

  The loop streak according to the present invention has a loop portion arranged in a state close to the pillar 1 and is not limited to the shape of the above embodiment. For example, as shown in FIG. 4, the loop portion 321 is formed in a U-shape that is formed only on one side and the other side is open, and is disposed on the side surface of the beam 2 with the loop portion 321 close to the column 1. The form to do is mentioned.

  In FIG. 5, a reinforcing structure using an L-shaped horizontal reinforcing bar 81 instead of the loop bar is also effective. The horizontal reinforcing bars 81 are arranged in an L shape across the adjacent beams 2 orthogonal to each other, and a central portion passing between the corners of the columns 1 and the column reinforcing bars 45 is 45 ° with respect to the beams. It has the bending part 811 bent at the angle. The horizontal reinforcing bars 81 are arranged in a pair of upper and lower states corresponding to, for example, the upper end portion and the lower end portion of the beam 2, and in the grout material 71 filled between the steel plate and the concrete like the loop reinforcing bars 31. Buried.

  Similarly to the loop reinforcement 31, the horizontal reinforcement 81 also has a structure in which the reinforcement in the existing column / beam joint structure is connected via the grout material 71, and the stress applied to the existing reinforcement is the horizontal reinforcement. 81, the continuity of the stress transmission of the entire column / beam joint is achieved, and an effective reinforcing structure can be obtained.

  The present invention can also be applied to column / beam joints in steel concrete or steel / reinforced concrete structures, in which case the stress generated in the steel and / or rebar is applied to the loop reinforcement via the grout material. introduce.

  DESCRIPTION OF SYMBOLS 1 ... Column, 2 ... Beam, 21 ... Fixation anchor, 31 ... Loop reinforcement, 311 ... Loop part, 51 ... Side surface steel plate, 52 ... Bottom steel plate, 61 ... Fiber sheet, 71 ... Grout material.

Claims (4)

Reinforcement method for pillar / beam joints made of existing concrete built with reinforcing bars and / or steel frames as reinforcing members,
A loop line arrangement step of arranging a loop line having a loop part along a side surface of the beam and in a state where the loop part is close to the column;
A steel sheet construction process of covering the side surface of the loop reinforcement and the column / beam joint with a steel sheet;
A grout material filling step of filling a grout material between the side surface of the column / beam joint and the steel plate, and embedding loop lines in the grout material,
Reinforcement method for column / beam joints characterized by comprising   The column / beam according to claim 1, wherein an anchor is inserted and fixed to a side surface of the beam in an inner region of the loop portion, and the anchor is embedded in the grout material in the grout material filling step. Reinforcement method for joints.   The method for reinforcing a column / beam joint according to claim 1, further comprising a fiber sheet bonding step in which a fiber sheet is stretched and bonded to the surface of the steel plate. The reinforcement of a column / beam joint according to claim 3, further comprising a mortar construction step in which mortar is applied as a finishing material to the surface of the fiber sheet attached to the surface of the steel sheet in the fiber sheet bonding step. Construction method.

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