JPH0634994Y2 - Pre-stress introduction Pre-cast steel reinforced concrete girder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a prestressed precast steel-framed reinforced concrete beam in a steel-framed reinforced concrete frame structure.

(Prior Art) The construction of the frame in the industrialized construction method (HPC construction method) of steel reinforced concrete construction is performed in the following procedure.

i) How to construct steel columns, ii) How to construct girder girders made of precast concrete members containing steel beams, iii) How to construct inter-beam earthquake-resistant walls made of precast concrete members containing steel beams, iv) Pre Construction of floor slab made of cast concrete members, v) Column-shaped rebar assembly, same formwork assembly and main girder top main bar assembly, vi) Column-shaped and joint concrete placement, of which girder direction girder is 8th As shown in the figure, I-type steel (c) is buried over the entire length of a precast concrete girder mainly having a beam lower end bar (a) and a stirrup (b) arranged along the entire length of the girder. At the same time, both ends of the same type I steel are made to project from both ends of the girder mainly, and the projecting ends are used as joints (e) to adjacent steel frame columns (d) on which the girders are erected. Conc It is composed from over preparative member.

In the figure, (f) is post-cast concrete.

(Problems to be solved by the invention) Recently, even high-rise homes tend to be individualized and upscale, the floor area dedicated to the dwelling unit is enlarged, and the floor plan of each unit is diversified. Requests for plans have also increased.

In order to support such a free plan and secure a living space for each house, it is not possible to deal with the conventional uniform floor plan, and even in the same ridge, it is necessary to adjust while widening the space in the girder direction (frontage). became.

However, when the spacing in the girder direction becomes longer, the beam formation becomes higher in response to stress, the floor height of the building becomes higher, and the height of the building is restricted, and like the conventional girder, the beam length is increased. In order to ensure structural performance with the I-shaped steel penetrated by
The amount of steel frames is increasing, which is a factor of increasing construction costs.

Further, in the conventional precast concrete large beam composed of the steel beam, the main beam of the beam, and the stapling, since the steel beam penetrates, highly accurate manufacturing control is required for the joint portion of the column and the beam, and the productivity of the member is also increased. descend.

The present invention has been proposed in view of the above problems of the prior art, and an object of the present invention is to provide a long span girder with excellent structural characteristics and when the building row size is not constant. The purpose of the present invention is to provide a precast cast steel reinforced concrete girder that can be made the same as adjacent short-span girders, reduce the amount of steel frame, reduce the height of the building, and save the construction cost.

(Means for Solving the Problems) In order to reduce the above-mentioned problems, a prestressed precast steel reinforced concrete girder according to the present invention is a precast concrete in which a beam lower end main bar and a stirrup are arranged over the entire length of the girder. I-type steel materials with stud bolts planted on the upper and lower flange surfaces are embedded at approximately 1/4 of the length of the main body from both ends of the main beam, and the ends of each I-type steel material are described above. It is constructed by projecting it from the end face of the main beam and arranging prestressing tension steel material over the entire length of the main beam.

(Operation) As described above, the precast steel reinforced concrete girder according to the present invention is mainly composed of a precast concrete girder having bar main ends and stirrup bars arranged over the entire length of the girder, and having a length of the same length from both ends thereof. Since both ends of the I-shaped steel material buried in about 1/4 of the projecting part project from both ends of the girder main body, the girder can be easily joined to the steel column through the projecting parts.

Further, the girder of the present invention has sufficient strength and rigidity by introducing prestress by the I-type steel and the tension steel material for prestress introduction arranged over the entire length of the beam, and between the pair of I-type steels. By eliminating the central steel frame, the prestress can be easily introduced into the girder.
Since the stud bolts are erected on the upper and lower flange surfaces of the shaped steel, the stress can be smoothly transmitted between the center portion and both end portions of the girder.

(Embodiment) The present invention will be described below with reference to the illustrated embodiment.

In the precast concrete girder main body (a) in which the beam lower end main bar (1) and the stirrup (2) are arranged over the entire length of the main beam, from the both ends of the main body, about the total length of the main body
At the 1/4 position, I type steel materials (4) having stud bolts (3) planted on the upper and lower flange surfaces are embedded, and the ends of each I type steel material (4) are connected to the main body (a). Of the girder main body (a), and the tension steel material (5) for prestress introduction is disposed over the entire length of the main girder main body (a). 5) A prestress is introduced into the main body (a) through the step 5) to form a prestressed precast steel frame reinforced concrete girder (A).

In the figure, (6) is a tensioning device arranged at both ends of the girder.

In the production of the girders, I type steel materials (4) are arranged at both ends of the girders at positions of about 1/4 of the girder length so that the ends thereof protrude from the end faces of the girders. A headed stud bolt (3) is welded to the upper and lower flanges (4) in advance.

Next, the beam lower end main bar (1) and the stirrup (2) are assembled over the entire length of the large beam, and the upper beam main bar (7) is temporarily fixed and placed in the mold.

Next, tension steel materials for introducing prestress (5) are arranged on the left and right sides of the beam width in the material length direction so that they are located in the lower part of the beam at the center of the girder and above the majority of both ends of the girder. Tighten the tensioning devices (6) at both ends of the girder.

Next, concrete is poured into the majority of the cross section of the beam, the cast concrete develops initial strength and then demolds, the concrete develops predetermined strength, and then the steel for tensioning (5) is subjected to predetermined tension. Applying force to introduce the required prestress into the concrete.

In addition to the post-tension method, the pre-tension method can be used for introducing the pre-stress.

Since the prestressed precast cast steel reinforced concrete girder shown in the illustrated embodiment is configured as described above, the projecting portion of the I-shaped steel material (4), which is carried into the construction site and projected from both ends of the girder, is made into a steel column. After joining, the beam top main bar (7) is laid out, and the post-cast concrete (b) is placed on the beam-column joint and the upper part of the girder main body (a).

Thus, the attachment performance between the I-shaped steel material (4) and the concrete portion is improved by the stud bolts (3) planted on the upper and lower flange surfaces of the I-shaped steel material (4) arranged at both ends of the girder. The stress is smoothly transmitted between the shaped steel material (4) and the central concrete portion of the girder.

Further, since the pair of I-shaped steel materials (4) are arranged at both ends of the girder and the central steel frame is omitted, it becomes easy to introduce prestress to the girder by the tension steel material (5), and And a precast concrete large beam which has the advantages of prestressed reinforced concrete, and can be applied to long span frames, and the beam cross-section performance will be high.

FIGS. 6 and 7 show a part of the girder direction of Frames Using the girders (A), by adjusting the Frontage, it can correspond to a plane plan to diversify, this time, the long span L ₂ By applying the cross beam (A), originally,
As indicated by the dotted line, the beam formation h ₂ that increases corresponding to the long span L ₂ can be made equal to the beam formation h ₁ of the large beam (A ′) with the adjacent short span L ₁ , and the height H of the building is restricted. It alleviates.

(Effect of the invention) As described above, the prestressed precast steel-framed reinforced concrete girder according to the present invention does not penetrate the steel frame mainly in the precast concrete girder in which the beam bottom main bar and the stirrup are arranged over the entire length of the girder. I-type steel materials are embedded in about 1/4 of the length of the main body, and the end of each I-type steel material is projected from the end of the main girder main body, and is joined to the steel column through the protruding portion. Make it easy.

By omitting the steel frame in the central part of the girder in this way, the amount of steel frame can be reduced, the manufacturing of members can be facilitated, and the prestressing can be facilitated by the tension steel material for prestressing the girder concrete.

The pair of I-shaped steel materials are integrated with the concrete through the stud bolts protruding from the upper and lower flange surfaces, and the stress is transmitted between the I-shaped steel materials at both ends of the girder and the concrete in the central part of the girder.

Thus, according to the present invention, a prestressed precast cast steel reinforced concrete girder having the advantages of prestressed reinforced concrete and steel beam is constructed, the cross-section performance is improved, the beam formation can be reduced, and the girder size of different lengths is achieved. It can be applied to a frame with a long span without changing the beam composition, and can be adapted to the variety of floor plans without being restricted by the height of the building.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a prestressed precast cast steel reinforced concrete girder according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a side view thereof, and FIGS. 4 and 5 are respectively. FIG. 1 is a view in the direction of arrow IV-IV, and is also a view in the direction of arrow V-V, and FIGS. 6 and 7 are plan views showing a part of the girder direction of the frame using the girders and front views are the same. FIG. 1 is a vertical cross-sectional view showing a conventional precast steel-framed reinforced concrete girder in use. (A) …… Main beam mainly, (1) …… Main bar of lower beam (2) …… Stap, (3) …… Stud bolt (4) …… I type steel (5) …… Tensile steel for introducing prestress

Claims (1)

[Scope of utility model registration request] 1. A precast concrete concrete girder main body in which a beam bottom main bar and a stirrup are laid out over the entire length of the girder at about 1/4 the length of the main body from both ends of the precast concrete girder, and on the upper and lower flange surfaces respectively While embedding the I-shaped steel material in which the bolts were erected, the end portions of the respective I-shaped steel materials were made to project from the end surface of the girder main body, and tensioned steel material for prestress introduction was arranged over the entire length of the girder main body. A pre-stressed pre-cast steel-framed reinforced concrete girder characterized by: