JP2008169658A - Method of connecting steel beam to reinforced concrete column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of connecting a steel beam to a reinforced concrete column, which contributes to simplification of the structure of an end of the steel beam, easy precasting of the steel beam in the factory, and cost reduction of the same. <P>SOLUTION: The method is provided for setting the steel beam 4 having a precast reinforced concrete structure 5 at the end thereof, on an upper end of an existing column portion 2 of the reinforced concrete column 1. According to the method, reinforcement protruded portions 7a are formed by protruding reinforcements 7 from the precast reinforced concrete portion 5 at the end of the steel beam 4 in a beam lengthwise direction. Then the reinforcement protruded portions 7a are mounted on the upper edge of the existing column portion 2 of the reinforced concrete column 1, and while the end of the steel beam 4 is supported by the column 1, concrete for a portion 3 above the existing column portion 2 of the column 1 is poured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  This invention relates to the construction method to the beam of the said steel beam in the building in which the edge part of a steel beam is made from reinforced concrete, and a framework structure is comprised with a reinforced concrete pillar.

2. Description of the Related Art Conventionally, a construction method in which a steel beam is installed on the upper end of an already-constructed portion of a reinforced concrete column and a reinforced concrete column is further constructed thereon (see, for example, Patent Document 1). 8 and 9 show an example of such a construction method.
8 and FIG. 9, the precast reinforced concrete portion 54 at the end of the steel beam 53 is installed on the upper end of the existing column 51 of the reinforced concrete column 50, and then concrete is placed on the upper portion of the existing column 51. A new column (upper column) 52 is constructed, and this is repeated to construct a reinforced concrete building skeleton. The precast reinforced concrete portion 54 is provided with a beam lower end main reinforcing bar 55 and a beam upper end main reinforcing bar 56, and a part thereof protrudes to the front end portion of the precast reinforced concrete portion 54. Further, a part of the column main reinforcement 51 a protrudes from the upper end of the already-constructed column 51.

In the case of this example, a stepped jaw portion 54a is provided at the lower front end of the precast reinforced concrete portion 54, and this jaw portion 54a is placed on the upper end of the already-constructed column 51, whereby the end portion of the steel beam 53 is placed on the already-constructed column. In this state, the upper column 52 is constructed.
Further, in the case where the precast reinforced concrete portion 54 is not provided at the end portion of the steel beam 5, the above-described construction may be performed by placing the tip portion of the steel beam 53 as the jaw portion on the upper end of the existing column 51.
Japanese Patent Application Laid-Open No. 07-252882

  In the case of the construction method shown in FIGS. 8 and 9, as shown in FIG. 9, the jaw portion 54 a made of a part of the precast reinforced concrete 54 or a part of the steel beam 53 enters the reinforced concrete column 50. Therefore, a cross-type experiment or the like considering the influence is required, and development takes time. Moreover, the shape of the chin part 54a becomes complicated, and precasting at the factory becomes difficult.

An object of the present invention is to provide a method for constructing a steel beam to a reinforced concrete column that can simplify the structure of the end portion of the steel beam, facilitate precasting at a factory, and reduce costs. is there.
Another object of the present invention is to provide a method of constructing a steel beam to a reinforced concrete column that can simplify the structure of the end of the steel beam and reduce the cost.

The construction method of a steel beam on a reinforced concrete column according to the first aspect of the present invention is a construction method in which a steel beam having a precast reinforced concrete structure at the end is installed on the upper end of an already constructed part of a reinforced concrete column. By providing a reinforcing bar protruding part in which the reinforcing bar protrudes from the precast reinforced concrete part at the end of the steel beam in the beam length direction, and placing the reinforcing bar protruding part on the upper end of the existing construction part of the column, Concrete in the portion above the already-constructed portion of the column is placed with the end portion supported by the column.
According to this construction method, the end of the steel beam is supported on the reinforced concrete column by placing the reinforcing bar protruding from the precast reinforced concrete part at the end of the steel beam on the upper end of the existing construction part of the reinforced concrete column, In this state, concrete is placed in a portion above the already-constructed portion of the pillar. For this reason, it is not necessary to project a jaw part to the precast reinforced concrete part of the edge part of a steel beam, and the shape and structure of a precast reinforced concrete part become simple. Therefore, precasting at a factory can be easily performed. Moreover, since the reinforcing bar protrusion replaces the jaw part and only the reinforcing bar protrusion is required, the cost can be reduced. Furthermore, since the reinforcing bar is used for the part put on the already-constructed part of the reinforced concrete column, it is mechanically clear and advantageous for commercialization.

In this invention, the reinforcing bar protrusion is a part of the beam lower end main reinforcing bar of the precast reinforced concrete part, and protrudes obliquely downward from the precast reinforced concrete part, and the tip part is joined to the reinforcing bar protruding part of the main reinforcing bar. A reinforcing bar may be provided, and a reinforcing bar receiving member may be provided at the upper end of the already-executed portion of the column so as to receive the reinforcing bar protruding portion installed via an anchor so that the height can be adjusted.
In this way, when the tip of the truss-forming reinforcing bar that protrudes diagonally downward from the precast reinforced concrete part is joined to the reinforcing bar protruding part consisting of the beam bottom main reinforcing bar, the reinforcing bar protruding part is reinforced and more than the existing construction part. The combined integration of the reinforced concrete column formed by placing the concrete in the upper part and the steel beam is made stronger. Since a part of the main bar is a reinforcing bar protrusion, the configuration is further simplified. In addition, since the reinforcing bar protrusion can be received by the reinforcing bar receiving member installed at the upper end of the already installed part of the column via an anchor, the height can be adjusted according to the conditions at the site. It is easy and accurate.

Further, the construction method of the steel beam according to the second aspect of the present invention to the reinforced concrete column is a construction method in which the steel beam composed entirely of steel is installed at the upper end of the existing construction part of the column made of reinforced concrete, Reinforcing bar projecting part that protrudes the reinforcing bar in the beam length direction from the end part of the steel beam is provided, and this reinforcing bar projecting part is placed on the upper end of the already-constructed part of the column, so that the end part of the steel beam is attached to the column. In a state of being supported, concrete is placed in a portion above the already-constructed portion of the column and the concrete at the end of the beam.
This construction method is applied when the end of the steel beam is not a precast reinforced concrete structure, and the above-mentioned method is applied only by the reinforcing bar without placing the end of the steel beam itself on the upper end of the already-constructed column part. Therefore, the construction is simple, the construction is excellent, and it is advantageous for cost reduction and commercialization.

  The construction method of the steel beam to the reinforced concrete column according to the first aspect of the present invention is a construction method in which the steel beam having an end portion of a precast reinforced concrete structure is installed at the upper end of the existing construction portion of the reinforced concrete column. The end of the steel beam is provided by providing a reinforcing bar protruding part in which the reinforcing bar protrudes in the beam length direction from the precast reinforced concrete part at the end of the steel beam, and placing the reinforcing bar protruding part on the upper end of the existing part of the column. With the part supported by the pillar, the concrete in the upper part of the pillar is placed and the structure of the end of the steel beam is simplified, making it easy to precast at the factory. Further, the cost can be reduced, and further, since the reinforcing bar is used for the support portion of the steel beam, it is mechanically clear and advantageous in commercialization.

  The construction method of the steel beam according to the second aspect of the present invention for the reinforced concrete column is a construction method in which a steel beam composed entirely of steel is installed at the upper end of an already constructed part of a reinforced concrete column, wherein the steel beam The end of the steel beam was supported by the column by providing a reinforcing bar projection that protruded from the end of the beam in the beam length direction and placing the reinforcing bar projection on the upper end of the already-constructed part of the column. In this state, since the concrete in the portion above the already-constructed portion of the column is cast, the structure of the end portion of the steel beam is simplified and the cost can be reduced as described above. Furthermore, since a reinforcing bar is used for the support portion of the steel beam, it is mechanically clear and advantageous in commercialization.

  An embodiment of a method for constructing a steel beam according to the present invention on a reinforced concrete column will be described with reference to FIGS. In FIG. 1, a steel beam 4 having a precast reinforced concrete structure at an end 5 is installed at the upper end of an already-constructed portion 2 of a reinforced concrete column 1, and a column (hereinafter referred to as an already-constructed column) 2 of an already-constructed portion. A state is shown in which concrete is placed in the upper part to construct a pillar (hereinafter referred to as an upper story pillar) 3 in the upper floor part. Reinforcing bar column main reinforcing bars 2 a arranged in the already-constructed columns 2 protrude from the upper four corners of the already-constructed columns 2. Between the column main reinforcing bars 2a at the corners adjacent to the side where the steel beam 4 is installed on the upper surface of the already-constructed column 2, an L-shaped reinforcing bar receiver is provided via an anchor bolt 6a provided on the already-constructed column 2. A member 6 is installed. The reinforcing bar receiving member 6 is formed of a cut piece of an angle material or the like, and is supported by two nuts 6b screwed to the anchor bolt 6a so as to sandwich the upper and lower sides thereof so that the height can be adjusted. A hole-in anchor is used for the anchor bolt 6a. As this anchor, in addition to the anchor bolt 6a as illustrated, a chemical anchor or the like may be used.

  The steel beam 4 is made of H-shaped steel (or I-shaped steel), and a lower flange 4a of the steel beam 4 is provided at an end portion (hereinafter referred to as a precast reinforced concrete portion) 5 of the steel beam 4 having a precast reinforced concrete structure. Four beam bottom main bars 7 fixed by welding or the like along the lower surface of the beam and four beam upper bars 8 fixed by welding or the like along the upper surface of the upper flange 4b are arranged. A part of the beam lower main bar 7 and the beam upper main bar 8 are reinforcing bar protrusions 7 a and 8 a that protrude in the beam length direction from the front end part of the precast reinforced concrete part 5. Further, four truss forming reinforcing bars 9 projecting diagonally downward are provided at the front end portion of the precast reinforced concrete portion 5, and the tip end portions 9 a of the four truss forming reinforcing bars 9 are respectively provided on the lower end main reinforcement 7 of the beam. It is joined to the reinforcing bar protruding portion 7a by welding or winding a wire (not shown). A fixing plate 9c is fixed to the rear end portion 9b embedded in the precast reinforced concrete portion 5 of the truss forming rebar 9 so that the embedding strength of the truss forming rebar 9 with respect to the precast reinforced concrete portion 5 is enhanced.

  Next, a method for constructing the upper floor column 3 by installing the steel beam 4 on the upper end of the already-constructed column 2 prepared as described above and placing concrete on the upper portion of the already-constructed column 2 will be described. . As shown in FIGS. 1 and 2, the reinforcing bar protruding portion 7 a of the beam bottom main bar 7 in which the tip end 9 a of the truss forming reinforcing bar 9 is integrally joined is placed on the reinforcing bar receiving member 6 and positioned in the horizontal plane area direction. The height of the reinforcing bar receiving member 6 is adjusted by the nut 6b. Thus, the upper end corner of the already-constructed column 2 and the front end lower corner of the precast reinforced concrete portion 5 are temporarily placed and supported. In the same manner, the steel beam 4 is temporarily placed in the opposite two, three, or even four directions according to the construction site. In this manner, with the end of the steel column 4 supported by the upper end of the existing column 2, a reinforcing bar (not shown) for the upper floor column 3 is arranged above the existing column 2 and around it. A formwork (not shown) is assembled, and concrete is placed in the formwork.

FIG. 3 is a longitudinal sectional view of a reinforced concrete structure composed of the reinforced concrete column 1 and the steel beam 4 constructed by the above method. In the case where the opposite two-way steel beam 4 is installed on the upper end of the already-constructed column 2, FIG. An example is shown. Reinforcing bar projecting part 7a of beam lower end main reinforcing bar 7, reinforcing bar projecting part 8a of beam upper main bar 8 and protruding part of truss forming reinforcing bar 9 projecting from precast reinforced concrete part 5 of opposing steel beam 4 are reinforcing bar receiving member 6, anchor It is embedded in the cast concrete that constitutes the upper column 3 together with the bolt 6a and the nut 6b, and thereby, the already-constructed column 2, the opposing steel beams 4 and 4, the precast reinforced concrete parts 5 and 5, and the upper column 3 are strong. A reinforced concrete structure is formed in one.
In FIG. 3, the column main reinforcement 2 a (see FIGS. 1 and 2) arranged in the already-constructed pillar 2, the column main reinforcement arranged in the upper floor pillar 3, and the hoop reinforcement are not shown. Yes.

  FIG. 4 is a view similar to FIG. 2 in a modification of the above embodiment. In this example, the reinforcing bar receiving member 6 that receives the joint between the reinforcing bar protruding portion 7a of the beam lower end main reinforcing bar 7 and the tip end portion 9a of the truss-forming reinforcing bar 9 has an inverted C section (that is, a concave shape). The reinforcing bar receiving member 6 is superior in stability when the steel beam 4 is temporarily placed compared to the L-shaped member, but these shapes are cost-adjusted or height-adjusted using a tool with a nut 6b. In consideration of the workability, etc., it is selected and adopted as appropriate. The other configuration is the same as that of the example shown in FIGS. 1 to 3, and therefore, the same reference numerals are given to the common parts and the description thereof is omitted.

  FIG. 5 is a view similar to FIG. 2 of another modification of the above embodiment. In this example, the surface of the upper flange 4b of the steel beam 4 is exposed on the upper surface of the precast reinforced concrete part 5, and further a stepped notch 5a is provided on the upper part of the front end side of the precast reinforced concrete part 5, and the upper flange is formed on the notch 5a. 4b and a part of the web 4c are configured to be exposed. In this example, the precast reinforced concrete portion 5 does not have the beam upper main reinforcement 8 as described above. Instead, when the reinforcement is placed in the upper portion of the existing column 2 and the formwork is assembled, Another reinforcing bar 10 is placed on the notch 5a, and the reinforcing bar 10 is arranged with other reinforcing bars (not shown) so that a part of the reinforcing bar 10 is positioned above the already-constructed pillar 2. Assembling of the mold is performed so that concrete is also placed in a space portion formed by the stepped notch 5a. In the structure after the concrete is placed, the reinforced concrete structure of the concrete placed in the stepped notch 5a and the reinforcing bar 10 arranged in this portion, and the reinforcing bar protrusion of the beam lower main bar 7 similar to the above. A strong structure can be obtained by the synergistic effect of the reinforced concrete structure by integrating the projecting portions of the reinforcing bars 7a and the truss-forming reinforcing bars 9 with the concrete. Since other configurations are the same as the example shown in FIGS. 1 to 3, common portions are denoted by the same reference numerals, and description thereof is omitted here.

  6 and 7 show a second embodiment. In this embodiment, the steel beam 4 is entirely made of H-shaped steel (I-shaped steel), that is, the end of the steel beam 4 is not a precast reinforced concrete structure. A reinforcing bar 11 having a reinforcing bar protruding portion 11a protruding in the beam length direction from the end of the steel beam 4 is fixed to the upper surface of the lower flange 4a of the steel beam 4 by welding or the like. . Further, a base end portion 12b is formed on the lower surface of the upper flange 4b of the steel beam 4 and fixed by welding or the like, and protrudes obliquely downward from the end portion of the steel beam 4, and the distal end portion 12a is joined to the reinforcing bar protrusion portion 11a. Truss forming reinforcing bars 12 are provided. A rebar receiving member 6 having a cross-section C-shaped (concave shape) is provided at the upper end of the already-constructed column 2 via an anchor bolt 6a and two nuts 2b so that the height can be adjusted. The reinforcing bar receiving member 6 may have an L-shaped cross section as in FIG.

  When the steel beam 4 is applied to the already-constructed column 2, first, the reinforcing bar protrusion 11 a of the bonded reinforcing bar 11 and the tip part 12 a of the truss forming reinforcing bar 12 are placed on the reinforcing bar receiving member 6, and the horizontal plane direction Are positioned and the height of the reinforcing bar receiving member 6 is adjusted, and the steel beam 4 is temporarily placed and supported on the upper end of the already-constructed column 2. Next, reinforcement for forming the beam end reinforced concrete portion 3 </ b> A (see FIG. 7) is performed at the end of the steel beam 4. 6 and 7, a part of the main reinforcing bar 13 constituting the reinforcing bar is shown, and the hoop bars and the like are not shown. In addition, bar arrangements (not shown) for upper floor pillars are performed, a formwork (not shown) is assembled around these arrangements, and concrete is placed in the formwork.

  FIG. 7 is a longitudinal sectional view of a reinforced concrete structure composed of a reinforced concrete column 1 and a steel beam 4 constructed by the above-described method, and an example in the case where an opposing two-way steel beam 4 is installed at the upper end of an already-constructed column 2. Is shown. As shown in the drawing, the reinforcing bar protruding part 11a of the reinforcing bar 11 protruding from the end part of the opposing steel beam 4, the protruding part of the reinforcing bar 12 for truss formation and the predetermined range part of the end part of the steel beam 4 are the reinforcing bar receiving members. 6, embedded with the anchor bolt 6a and the nut 6b in the cast concrete constituting the upper column 3 and the beam end reinforced concrete portion 3A, whereby the already-constructed column 2, the opposing steel beams 4, 4 and the upper column 3 A reinforced concrete structure is constructed in which is firmly integrated.

  In any of the above-described embodiments, since the steel beam 4 is not installed in the installation part of the steel beam 4 with respect to the upper end of the existing column 2, the shape of the beam end part of the steel beam 4 is simple. Therefore, precasting at a factory becomes very easy. In addition, it eliminates the need for cross-type experiments that take into account the effects of part of the steel frame or part of the reinforced concrete entering the column, thereby reducing development time. Furthermore, since each of the above-mentioned reinforcing bars supports the steel beam 4 on the upper end of the already-constructed column 2 and bears the installation part thereof, it is not costly, is mechanically clear and easy to commercialize, Body strength is also sufficiently secured.

  3 and 7 show an example in which the opposite two-direction steel beam 4 is constructed on the column 1, but the steel frame corresponding to the type of column (side column, corner column, inter-column etc.) to be constructed The present invention can also be applied to other construction modes of the beam 4. In addition, the reinforcing bar arrangement of the upper floor pillar may be performed for each construction floor, or may be performed through a plurality of floors. In this invention, the concrete placement of the reinforced concrete pillar 1 is performed on each floor. This is done for each construction. Further, in the above-described embodiment, the example in which the truss-forming reinforcing bars 9 and 12 are provided has been described, but this may be omitted when sufficient strength is obtained.

It is a perspective view which shows the state of the temporary placement of the steel beam in the construction method to the reinforced concrete pillar of the steel beam which concerns on one Embodiment of this invention. It is a partial enlarged front view of the temporary placement state of the steel beam. It is the longitudinal cross-section of the reinforced concrete structure of the reinforced concrete pillar and steel beam constructed by the construction method. It is an enlarged front view of the same part as FIG. 2 which shows the modification of the embodiment. It is an enlarged front view of the same part as FIG. 2 which shows another modification of the embodiment. It is an enlarged front view of the same part as FIG. 2 which shows the state of temporary placement of the steel beam in the construction method to the reinforced concrete column of the steel beam which concerns on other embodiment of this invention. It is the longitudinal cross-section of the reinforced concrete structure of the reinforced concrete pillar and steel beam constructed by the construction method. It is a perspective view which shows the state of the temporary placement of the steel beam in the construction method to the reinforced concrete column of the conventional steel beam. It is a longitudinal section of a reinforced concrete structure of a reinforced concrete column and a steel beam constructed by the conventional construction method.

Explanation of symbols

1 ... Columns made of reinforced concrete 2 ... Existing columns (existing parts of reinforced concrete columns)
3 ... Upper column (upper part of the existing construction)
4 ... Steel beam 5 ... Precast reinforced concrete part (end of steel beam)
6 ... Reinforcing bar receiving member 6a ... Anchor bolt (anchor)
7 ... Beam bottom bar (rebar)
7a ... Reinforcing bar protruding part 9 ... Reinforcing bar reinforcing bar 9a ... Tip part 11 ... Reinforcing bar 11a ... Reinforcing bar protruding part

Claims (3)

  A construction method in which a steel beam having an end with a precast reinforced concrete structure is installed at the upper end of an existing construction part of a column made of reinforced concrete, and the reinforcement is provided in the beam length direction from the precast reinforced concrete part at the end of the steel beam. By providing a protruding reinforcing bar protrusion and placing the reinforcing bar protrusion on the upper end of the already-constructed part of the column, the end of the steel beam is supported by the column, and from the already-constructed part of the column. A method for constructing a steel beam to a reinforced concrete column, characterized by casting concrete in the upper part.   2. The truss according to claim 1, wherein the reinforcing bar protruding portion is a part of a beam lower end main reinforcing bar of the precast reinforced concrete portion, protrudes obliquely downward from the precast reinforced concrete portion, and a tip portion is joined to the reinforcing bar protruding portion including the main reinforcing bar. A method for constructing a steel beam to a reinforced concrete column, in which a reinforcing bar for forming is provided, and a reinforcing bar receiving member installed on an upper end of the already-executed part of the column via an anchor receives the reinforcing bar protruding portion in a height-adjustable manner.   A construction method in which a steel beam made entirely of steel is installed at the upper end of an existing construction part of a column made of reinforced concrete, and a reinforcing bar projection is provided by projecting the reinforcing bar in the beam length direction from the end of the steel beam. In addition, by placing the protruding portion of the reinforcing bar on the upper end of the already-constructed portion of the column, the end of the steel beam is supported by the column, and the portion above the already-constructed portion of the column and the beam end portion. A method of constructing steel beams on reinforced concrete columns, characterized by casting concrete.

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