WO2015146907A1

WO2015146907A1 - Beam member and framework employing same

Info

Publication number: WO2015146907A1
Application number: PCT/JP2015/058732
Authority: WO
Inventors: 弘之成原; 努平田
Original assignee: 大成建設株式会社
Priority date: 2014-03-24
Filing date: 2015-03-23
Publication date: 2015-10-01

Abstract

[Problem] To reliably integrate the end parts of a steel frame with end part reinforced concrete parts and increase the strength of the beam overall at a low cost. [Solution] A beam member (20) comprises a center steel frame part (30) and end part reinforced concrete parts (40), and a steel frame (31) of the center steel frame part (30) is embedded in the end part reinforced concrete parts (40) and integrated therewith. The beam member (20) has an end face steel plate (50) disposed on an end face of each end part reinforced concrete part (40), and each end face steel plate (50) has an aperture part (51) for passing the steel frame (31) therethrough and anchors end parts (41a) of main reinforcements (41) constituting part of the respective end part reinforced concrete part (40).

Description

Beam member and housing using the same

The present invention relates to a beam member and a frame using the beam member.

Patent Document 1 discloses a beam in which both ends of a steel frame constituting a central steel frame portion are embedded in an end reinforced concrete portion and both are integrated. This beam can reduce its own weight as compared with a reinforced concrete beam, and can realize a long span beam with a small beam formation.

Furthermore, the structure of patent document 1 welds a part of main reinforcement which comprises an edge part reinforced concrete part to the steel frame embed | buried under the edge part reinforced concrete part. In addition, the steel frame and the main reinforcing bar embedded in the end reinforced concrete part surround a reinforcing bar or a spiral PC (prestressed concrete) steel material. This reinforcing bar or spiral PC steel material is arranged more densely than the middle part at both ends of the embedded part with respect to the end reinforced concrete part in the steel frame. With these configurations, when a shearing force from above is applied to the beam, the force is sufficiently transmitted from the central steel part to the end reinforced concrete part, and the central steel part is embedded in the end reinforced concrete part. It prevents the concrete from splitting and breaking.
[Patent Document 1] Japanese Patent No. 2040954

However, in the configuration described in Patent Document 1, as described above, reinforcing bars or spiral PC steel materials are densely arranged at both ends of the portion where the steel frame is embedded in the end reinforced concrete portion. For this reason, at the time of construction, the concrete cast in this portion does not sufficiently turn to every corner of the end reinforced concrete portion.

In addition, spiral PC steel is not manufactured domestically in some regions (countries) and is difficult to obtain. Importing spiral PC steel will increase material costs.

An object of the present invention made there is to provide a beam member capable of reliably integrating the end portion of the steel frame into the end reinforced concrete portion and increasing the strength of the entire beam at low cost, and a frame using the same. That is.

The present invention employs the following means in order to solve the above problems.
That is, the beam member of the present invention includes a central steel frame portion and an end reinforced concrete portion, and is a beam member in which the steel of the central steel portion is embedded in the end reinforced concrete portion and integrated with each other. An end face steel plate that has an opening through which the steel frame is inserted and that fixes the end of the main reinforcing bar constituting the end reinforced concrete part is provided on the end face of the part reinforced concrete part.
According to such a configuration, when a shearing force from above acts on the central steel frame portion constituting the beam member, the shearing force from the steel frame is transmitted to the end surface of the end reinforced concrete portion via the end surface steel plate. . Then, the compressive force along the axial direction of the beam member is transmitted to the end reinforced concrete portion via the end face steel plate below the central steel frame portion. Further, below the central steel frame portion, a tensile force along the axial direction of the beam member is transmitted to the main bar whose end portion is fixed to the end face steel plate. The concrete that constitutes the end reinforced concrete portion is strong in compressive force, and the main reinforcing bar is strong in tensile force. Therefore, with such a configuration, it is possible to prevent the concrete constituting the end reinforced concrete portion from being destroyed by the shearing force acting on the central steel frame portion from above.
Moreover, it is not necessary to densely arrange the reinforcing bar or the spiral PC steel material at both ends of the portion where the steel frame is embedded in the end reinforced concrete part. Furthermore, it is not necessary to use a high-strength spiral PC steel material, and a sufficient strength can be ensured using a normal reinforcing bar.

Moreover, you may make it the inner edge part of the said opening part follow the upper surface and lower surface of the said steel frame at least.
Thereby, the force of an up-down direction can be efficiently and reliably transmitted from a steel frame to an end surface steel plate.

Further, the opening may have a shape corresponding to the cross-sectional shape of the steel frame.
Thereby, transmission of the force from the steel frame to the end face steel plate can be performed more reliably.
In addition, the end reinforced concrete portion can be covered with the end face steel plate, and the gap between the steel frame and the opening can be minimized. Therefore, it is possible to prevent rainwater or the like from entering the concrete from the surface of the concrete constituting the end reinforced concrete portion, and it is possible to maintain the durability of the concrete over a long period of time.
Moreover, an end surface steel plate can be used as a part of formwork at the time of casting of the concrete which comprises an edge part reinforced concrete part.

Moreover, you may make it the said end surface steel plate fix the edge part of the said main reinforcement arranged above the said steel frame, and the edge part of the said main reinforcement arranged below the said steel frame.
Thereby, the end surface steel plate can cover from the upper part to the lower part of the end reinforced concrete. Then, when a vertical force is applied to the central steel frame part constituting the beam member due to, for example, an earthquake or the like, the shearing force from the steel frame is transmitted to the main reinforcement whose end is fixed to the end steel sheet via the end steel sheet. be able to. Therefore, it is possible to ensure the proof strength against the vertical shearing force acting on the central steel frame portion.

Moreover, you may make it the said end surface steel plate comprise the formwork of the edge part of the said edge part reinforced concrete part.
Thereby, the number of parts of a formwork reduces, and the effort and cost of construction can be reduced.

Moreover, the housing of the present invention includes a plurality of columns and a beam laid between the columns adjacent to each other, and the beam is configured using the beam member as described above. It is characterized by.

According to the beam member and the frame of the present invention, it is possible to reliably integrate the end portion of the steel frame constituting the central steel frame portion with the end reinforced concrete portion, and to increase the strength of the entire beam at low cost.

It is a figure which shows schematic structure of the housing comprised using the beam member in 1st Embodiment. It is a front view which shows the beam member which comprises the beam of the said housing. It is a figure which shows the structure of the edge part of the said beam member, (a) is a front sectional view, (b) is sectional drawing orthogonal to the axis line of a beam member. It is a perspective view which shows the end surface steel plate provided in the said beam member. It is a figure which shows the flow of the construction method of a housing, (a) is a figure which shows the state in the middle of manufacture of the beam member 20, (b) is a figure which shows the state which mounted the beam member between pillars. . (A) is a model diagram of a beam member used for dimension setting examination of an end face steel plate, (b) is a diagram showing a distribution of bending moment in the model of (a), (c) is an end of the model of (a) It is a figure which shows the force which acts on a reinforced concrete part. It is a perspective view which shows the end surface steel plate with which the beam member which concerns on 2nd Embodiment was equipped.

Hereinafter, with reference to the accompanying drawings, an embodiment for carrying out a beam member according to the present invention and a housing using the same will be described based on the drawings.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a frame configured using beam members in this embodiment. FIG. 2 is a front view showing a beam member constituting the beam of the frame. 3A and 3B are diagrams showing the configuration of the end of the beam member, where FIG. 3A is a front sectional view and FIG. 3B is a sectional view orthogonal to the axis of the beam member.

(Body)
As shown in FIG. 1, a frame 10 constituting various building structures includes a plurality of columns 11, a beam 12 laid between

adjacent columns

11, 11, and a slab formed on the beam 12. 13.

The pillar 11 is provided so as to extend vertically upward. The column 11 is formed of a reinforced concrete structure or a steel reinforced concrete structure.

(Beam member)
The beam 12 is formed using a beam member 20 as shown below.
As shown in FIGS. 2 and 3, in the beam member 20, a central steel frame portion 30 and end reinforced concrete portions 40 formed at both ends of the central steel frame portion 30 are integrally formed.

The central steel frame portion 30 is composed of a steel frame 31 continuous in the axial direction of the beam 12. The steel frame 31 is a so-called H-shaped steel including

flange portions

32 and 32 formed vertically and a web portion 33 provided between the

flange portions

32 and 32. As for the steel frame 31, the

edge parts

31a and 31a of the both sides are embed | buried under the edge part reinforced concrete part 40. FIG.

As shown in FIG. 3, the end reinforced concrete portion 40 includes a main reinforcement 41, a reinforcing bar 42, and a concrete portion 43.
A plurality of main bars 41 are arranged above and below the beam 12, respectively. Each main bar 41 is continuous in the axial direction of the beam 12.
Moreover, you may provide the main reinforcement | strength 41s so that the upper and

lower flange parts

32 and 32 of the edge part 31a of the steel frame 31 may be followed. Further, the main reinforcement 41 s may be welded to the flange portion 32 at a portion along the flange portion 32 and integrally joined to the steel frame 31.

The barbs 42 are provided so as to surround the outer peripheral side of the plurality of main bars 41. A plurality of the barbs 42 are arranged at intervals in the axial direction of the main bar 41. Here, the gluteal muscles 42 are arranged at substantially equal intervals with an interval in the axial direction of the main muscle 41, and are not densely arranged at a specific portion.

The concrete portion 43 is formed by placing concrete so as to cover the end portion 31 a of the steel frame 31, the main reinforcement 41, and the reinforcement bar 42.
In such a concrete portion 43, the main reinforcement 41 is provided so as to protrude outward from the end faces 43 a and 43 b on both sides of the concrete portion 43 along the axial direction of the beam member 20.

In such a beam member 20, an end face steel plate 50 is provided along an end face 43b facing the central steel part 30 side of the concrete part 43 constituting the end reinforced concrete part 40.

FIG. 4 is a perspective view showing an end face steel plate provided on the beam member.
As shown in FIG. 4, the end surface steel plate 50 includes an opening 51 through which the steel frame 31 is inserted, and an insertion hole 52 through which the end 41 a of the main bar 41 protruding from the end surface 43 b of the concrete portion 43 is inserted. Yes.

In this embodiment, the opening 51 is formed in a rectangular shape that can be inserted through the steel frame 31. Further, the opening 51 has an opening dimension in the vertical direction that is slightly larger than the vertical dimension of the steel frame 31. Thereby, the opening 51 has the upper edge 51a and the lower edge 51b of the opening 51 in the state where the steel frame 31 is inserted into the upper and

lower flange portions

32 and 32 that form the upper surface and the lower surface of the steel frame 31, respectively. It has come along.

The end face steel plate 50 is disposed so as to abut against the end face 43 b of the concrete portion 43 in a state where the steel frame 31 is inserted into the opening 51 and the main bar 41 is inserted into each insertion hole 52. And the end surface steel plate 50 is integrally fixed to the concrete part 43 by the nut 53 fastened by the thread groove formed in the edge part 41a of the main reinforcement 41. As shown in FIG.

(How to build a frame)
Next, a method for constructing the housing 10 using the beam member 20 as described above will be described.
FIG. 5 is a diagram illustrating a flow of a method for constructing a frame, (a) is a diagram illustrating a state in the middle of manufacturing the beam member 20, and (b) is a diagram illustrating a state in which the beam member is placed between columns. FIG.
In order to construct the frame 10 as described above, the beam member 20 is manufactured in advance in a work yard provided at the construction site or a factory other than the construction site.
As shown in FIG. 5A, in order to manufacture the beam member 20, first, the main reinforcing bar 41 and the reinforcing bar 42 are arranged around the both ends of the steel frame 31, and the end face steel plate 50 is placed at a predetermined position. set. The steel frame 31 is inserted through the opening 51 of the end face steel plate 50, and the main bar 41 is inserted through the insertion hole 52. Then, the nut 53 is fastened to the thread groove formed at the end 41 a of the main bar 41.

Then, in order to form the concrete portion 43, the mold 60 is assembled so as to surround the end portion 31 a of the steel frame 31, the main reinforcing bar 41, and the reinforcing bar 42. At this time, a part of the mold 60 can be constituted by the end face steel plate 50.

Next, concrete is placed in the mold 60. After the cast concrete exhibits a predetermined strength after a predetermined curing period, the mold 60 is disassembled and removed. Thereby, as shown in FIG. 2, the concrete part 43 is formed and the beam member 20 is completed.

On the other hand, as shown in FIG.5 (b), the column reinforcement 11t which comprises the column 11 is arranged in the predetermined position of a construction site. Next, a mold frame (not shown) is assembled around the column reinforcement 11t, and the column concrete 11c is placed in the mold frame. The column concrete 11c is placed to a predetermined level such that the upper end of the column reinforcing bar 11t is exposed upward.
After the column concrete 11c exhibits a predetermined strength after a predetermined curing period, the formwork (not shown) is disassembled and removed.

Next, the manufactured beam member 20 is suspended and set between the

columns

11 and 11 adjacent to each other. At this time, the beam member 20 places the end portion of the end reinforced concrete portion 40 on the column concrete 11 c of the column 11.

Thereafter, a not-shown formwork is assembled to the joint portion between the column 11 and the beam 12 and the lower surface of the space surrounded by the plurality of beams 12, and as shown in FIG. Then, slab concrete 19 is placed. After the joint concrete 18 and the slab concrete 19 develop a predetermined strength after a predetermined curing period, the mold (not shown) is disassembled and removed. Thereby, the pillar 11 and the beam 12 are joined at the joint portion, and a slab 13 is further formed.

The series of operations described above will be repeated in the same manner on each floor of the building structure to be constructed.

In the above-described beam member 20 and the casing 10 configured using the beam member 20, when a shearing force from above is applied to the central steel frame portion 30 constituting the beam member 20, shearing from the steel frame 31 is performed. The force is transmitted to the end surface 43 b of the end reinforced concrete portion 40 through the end surface steel plate 50. Then, as shown in FIG. 3A, the compressive force P 1 along the axial direction of the beam member 20 is transmitted to the end reinforced concrete portion 40 via the end surface steel plate 50 below the central steel frame portion 30. The Further, above the central steel frame portion 30, the tensile force P 2 along the axial direction of the beam member 20 is transmitted to the main reinforcement 41 having the end portion 41 a fixed to the end surface steel plate 50. The concrete constituting the end reinforced concrete portion 40 is a material that is strong against compressive force, and the main bar 41 is a material that is strong against tensile force. Therefore, it can prevent that the concrete which comprises the edge part reinforced concrete part 40 is destroyed by the shear force which acted on the central steel frame part 30 from the upper direction.

(Examination example of dimension setting of end face steel plate)
Now, the setting conditions such as the dimensions of the end face steel plate 50 constituting the beam member 20 were examined.
6A is a model diagram of the beam member used for the study, FIG. 6B is a diagram showing the distribution of bending moment in the model of FIG. 6A, and FIG. 6C is the end reinforced concrete portion of the model of FIG. It is a figure which shows the force which acts.
As shown in FIGS. 6A to 6C, when a shearing force P is applied to the central position X1 of the central steel frame portion 30, the steel frame 31 of the central steel frame portion 30 is embedded in the end reinforced concrete portion 40. At the root position X2, a reaction force R1 of the following formula (1) is generated.
R1 = (L1 + L2 / L2) × P + Mc / L2 (1)
However, L1: Distance between the center position X1 and the embedded root position X2, L2: Distance between the embedded root position X2 and the embedded tip position X3 of the steel frame 31 in the end reinforced concrete portion 40, Mc: Embedment of the steel frame 31 This is the remaining moment at the tip position X3.

In order to cause a bending yield at the end X4 of the beam 12, the moment Md at the end X4 of the beam 12 satisfies the condition of the following expression (2).
Md = (L1 + L2 / L2) × P ≧ cMy (2)
Here, cMy is the yield moment of the cross section of the reinforced concrete portion in the end reinforced concrete portion 40.

From the above formulas (1) and (2), the reaction force R1 needs to satisfy the following formula (3).
R1 = (L1 + L2) / L2 × cMy / (L1 + L2 + L3) + Mc / L2 (3)

The reaction force R1 is a compressive strut C1 in which a tensile force T1 generated in the main bar 41 located above the steel frame 31 is generated in the concrete part 43 of the end reinforced concrete part 40 in a portion where the steel frame 31 is embedded in the end reinforced concrete part 40. Need to be generated and transmitted to balance.
In the case where the tensile force T1 cannot be transmitted, the concrete portion 43 is formed before reaching the yield moment of the cross section of the reinforced concrete structure in the end reinforced concrete portion 40 at the embedded root position X2 where the steel frame 31 is embedded in the end reinforced concrete portion 40. It will be split.

Therefore, it is preferable that the end face steel plate 50 has dimensions and materials such that the effective width b, the thickness t, and the yield point σy indicate the following formula (4).
b × t × σy ≧ R1 (4)

According to the beam member 20 and the frame 10 using the beam member 20 as described above, the end surface 43a of the end reinforced concrete portion 40 has the opening 51 through which the steel frame 31 is inserted, and the end 41a of the main bar 41 is fixed. An end face steel plate 50 is provided.
Thereby, it can prevent that the concrete part 43 which comprises the edge part reinforced concrete part 40 is destroyed by the shear force which acted on the center steel frame part 30 from the upper direction. At this time, unlike the conventional case, it is not necessary to densely arrange the reinforcing bar or the spiral PC steel material at both ends of the portion where the steel frame 31 is embedded in the end reinforced concrete portion 40. Furthermore, it is not necessary to use a high-strength spiral PC steel material, and a sufficient strength can be ensured by using a normal reinforcing bar. Therefore, the end 31a of the steel frame 31 can be reliably integrated with the end reinforced concrete portion 40, and the strength of the beam 12 as a whole can be increased at low cost.

The opening 51 is configured such that the upper edge portion 51 a and the lower edge portion 51 b of the opening portion 51 are along the upper and

lower flange portions

32 and 32 that form the upper surface and the lower surface of the steel frame 31.
Thereby, the force of an up-down direction can be efficiently and reliably transmitted from the steel frame 31 to the end surface steel plate 50.

Further, the barbs 42 are arranged at intervals in the length direction of the beam 12. Thus, a sufficient space for filling concrete can be secured between the plurality of reinforcing bars 42. Therefore, the concrete can be reliably distributed to every corner of the concrete portion 43 of the end reinforced concrete portion 40, and the strength of the end reinforced concrete portion 40 can be ensured.

Further, the end face steel plate 50 has an end portion 41 a of the main reinforcing bar 41 disposed above the steel frame 31 and an end portion 41 a of the main reinforcing bar 41 disposed below the steel frame 31 fixed thereto.
As a result, when a vertical force acts on the central steel frame portion 30 constituting the beam member 20 due to, for example, an earthquake, the shearing force from the steel frame 31 is transferred to the end surface steel plate 50 via the end surface steel plate 50 and the end 41a It can be transmitted to the fixed main muscle 41. Therefore, it is possible to ensure the proof strength against the vertical shearing force acting on the central steel frame portion 30.

Moreover, you may make it the end surface steel plate 50 comprise a part of the formwork 60 for placing the concrete which comprises the edge part of the edge part reinforced concrete part 40. FIG.
Thereby, the number of parts of the formwork 60 decreases, and the labor and cost of construction can be reduced.

(Second Embodiment)
Next, a beam member according to the present invention and a second embodiment of a casing using the beam member will be described. Note that in the second embodiment described below, the same reference numerals are given to the same components as in the first embodiment, and description thereof will be omitted.
FIG. 7 is a perspective view showing an end face steel plate provided in the beam member according to this embodiment.
As shown in FIG. 7, in the end face steel plate 50 B in this embodiment, the opening 51 B through which the steel frame 31 is inserted has a shape corresponding to the cross-sectional shape of the steel frame 31, that is, an H shape. Thereby, like the said 1st Embodiment, the end surface steel plate 50B has the upper edge part 51a and the lower edge part 51b of the opening part 51B in the upper and

lower flange parts

32 and 32 which form the upper surface and lower surface of the steel frame 31. It is formed along. Further, side plate portions 53 that enter between the upper and

lower flange portions

32, 32 of the steel frame 31 are formed on both sides in the width direction of the opening portion 51 B, and the side edge portion 53 a of the side plate portion 53 is disposed to face the web portion 33. Has been.

In the beam member 20 provided with the end face steel plate 50B having such a configuration, the force can be more reliably transmitted from the steel frame 31 to the end face steel plate 50 as in the first embodiment.
And the clearance gap between the steel frame 31 and the opening part 51 can be minimized by covering the edge part reinforced concrete part 40 with the end surface steel plate 50B. Therefore, it is possible to prevent rainwater and the like from entering the concrete portion 43 from the surface of the concrete portion 43 constituting the end reinforced concrete portion 40, and the durability of the concrete portion 43 can be maintained for a long time.
Further, the end face steel plate 50B can be used as a part of a formwork at the time of placing concrete that constitutes the end reinforced concrete portion 40.

(Other embodiments)
Note that the beam member of the present invention and the housing using the same are not limited to the above-described embodiments described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
For example, in the embodiment described above, the end face

steel plates

50 and 50B constitute a part of the mold 60, but the present invention is not limited thereto. You may set the end surface steel plate 50 to the internal peripheral surface of the formwork at the time of placing the concrete which forms the concrete part 43. FIG.

Although the main reinforcement 41 and the end

surface steel plates

50 and 50B are fastened by the nut 53, the present invention is not limited to this. For example, you may make it weld the main reinforcement 41 and the end

surface steel plates

50 and 50B.
Moreover, about arrangement | positioning, the installation number, etc. of the main reinforcement 41 or the gluteal reinforcement 42, it can change suitably.

Further, the beam 12 and the slab 13 may be integrated by projecting the upper portion of the reinforcing bar 42 upward from the concrete portion 43 and placing concrete forming the slab 13 on the upper surface thereof.

Furthermore, the slab 13 is not limited to cast-in-place concrete but may be precast or half precast.

Moreover, the building structure comprised with the housing 10 may be of any structure, application, and type.
In addition to this, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Frame 11 Column 12 Beam 20 Beam member 30 Center steel part 31 Steel frame 31a End part 40 End part reinforced

concrete part

41, 41s Main reinforcement 42 Reinforcement 43

Concrete part

43a,

43b End surface

50, 50B End

surface steel plate

51, 51B Opening part 60 Formwork

Claims

A beam member comprising a central steel part and an end reinforced concrete part, wherein the steel of the central steel part is embedded in the end reinforced concrete part, and both are integrated,
A beam member, comprising: an end steel plate having an opening through which the steel frame is inserted, and an end steel plate for fixing an end of a main reinforcing bar constituting the end reinforced concrete portion is provided on an end surface of the end reinforced concrete portion.
The beam member according to claim 1, wherein an inner edge of the opening is at least along an upper surface and a lower surface of the steel frame.
The beam member according to claim 2, wherein the opening has a shape corresponding to a cross-sectional shape of the steel frame.
The end face steel plate is fixed to an end portion of the main bar arranged above the steel frame and an end portion of the main bar arranged below the steel frame. The beam member as described in any one of Claims.
The beam member according to any one of claims 1 to 4, wherein the end face steel plate constitutes a form of an end portion of the end reinforced concrete portion.
Multiple pillars,
A beam erected between the pillars adjacent to each other,
The said beam is comprised using the said beam member as described in any one of Claim 1 to 5, The housing | casing characterized by the above-mentioned.