JPH0768723B2 - Shear connector for composite beam - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shear connector for synthetic beams used for synthetic beams and other structures in building structures.

[Conventional technology]

Conventionally, as a shear connector for integrating steel frame and concrete, a cylindrical headed stud 15 and an improved prismatic headed stud 15 ′ shown in FIGS. 13a and 13b are conventionally used.
(As a prior art document, Japanese Utility Model Publication No. 58-41285) and Hilti Shah connector 16 shown in FIGS. 14a and 14b.
(As a publicly known document, there is a catalog of steel-framed reinforced concrete composite design using Hilti-Shah Connector HVB80-HVB105 issued by Hilti Japan Co., Ltd.).

[Problems to be Solved by the Invention]

By the way, the headed studs 15 and 15 'are widely used as shear connectors for composite beams.
It is necessary that 15 and 15 'have a certain size or more to strengthen the integration with the steel frame and especially to prevent lateral displacement in the steel frame.Normally, the diameter of the bolt part is 13 mm to 22 mm and the height is
70 mm to 150 mm is used. To weld this stud bolt on the steel frame, a special welding machine such as an arc stud welding machine must be used.

Also, in the case of Hilti Shah Connector 16, because it is a pin driving method using gunpowder with a dedicated gun,
Not only a special dedicated machine is required, but the qualification of the worker is also required and a notification is required each time the work is performed.

Therefore, the present invention is intended to provide a shear connector for a composite beam, which has an excellent function as a shear connector for integrating concrete and a steel frame and which can be easily attached to the steel frame.

[Means for Solving the Problems]

The shear connector for composite beams of the present invention for solving the above-mentioned problems is a shear connector having a hat-shaped thin steel plate in cross section, and a top portion and an inclined portion or a vertical portion extending downward from both side ends of the top portion. It has a horizontal portion that extends outward from the other end of the inclined portion or the vertical portion, and has a hole for plug welding at approximately the center of both horizontal portions.

[Action]

The shear connector for a synthetic beam of the present invention configured as described above is arranged and mounted in the longitudinal direction on the steel frame, and is fixed by plug welding at the hole for plug welding in the horizontal portion of the lower side, and fixed on the steel frame. Concrete is poured to build a composite beam. In the composite beam thus constructed, the shear connector is a hat type,
Concrete wraps around the bottom of the shear connector,
The integration of steel frame and concrete is strengthened. In particular, the shear connector has a large bending rigidity with respect to lateral displacement in the steel frame, and therefore has little deformation, and has a large proof stress on the bearing surface against the compressive stress received from concrete, so that bearing pressure crushing on concrete is unlikely to occur.

Further, since the shear connector for composite beams of the present invention can be fixed to the steel frame by plug welding, it does not require any special dedicated equipment as in the conventional case, only one worker is required, and the worker has a special qualification. Does not need Moreover, the worker does not need to be skilled,
Easy to install.

〔Example〕

An embodiment of the shear connector for a composite beam of the present invention will be described with reference to the drawings. The embodiment shown in FIGS. 1 a, b, and c is a shear connector 1 made of a thin steel plate having a hat-shaped cross section and a thickness of 2.3 mm, and has a flat top portion 2 with a length of 10 mm and a width of 30 mm and a flat top portion 2 thereof. Top side 30mm, bottom side 50mm, which extends downward from both ends of the top part 2,
It has a trapezoidal inclined part 3,3 with a height of 80 mm, and horizontal parts 4,4 with a length of 40 mm and a width of 50 mm extending outward from the other end of the inclined part 3,3. It has holes 5 and 5 for plug welding at approximately the center. still,
The inclination angle of the inclined portions 3 and 3 on both sides is 72 degrees, and the dimension between the lower ends of the inclined portions 3 and 3 is 65 mm.

The shear connector 1'for composite beams of another embodiment shown in FIGS. 2a, 2b and 2c has a flat top portion 2, slant portions 3 and 3 and horizontal portions 4 and 4 having the same size and shape as the above embodiment. In addition to having holes 5 and 5 for plug welding in the horizontal parts 4 and 4, ribs 6 and 8 mm in height rising at right angles are provided at both ends of the inclined parts 3 and 3 and the horizontal parts 4 and 4. , A circular hole 7 with a diameter of 8 mm is provided at the center of the flat top part 2 to strengthen the binding force with concrete, and a length of 45 mm is provided at the center of the inclined parts 3, 3.
A triangular long hole 8 having a lower side width of 18 mm is provided.

The shear connectors 1 and 1'for the composite beams of the above two embodiments are laterally arranged at regular intervals in the longitudinal direction on the beam 9 of the H-shaped steel as shown in FIGS. Fix it by plug welding at the holes 5 and 5 of the parts 4 and 4, and place the concrete 10 on the beam 9.
The composite beams 11 and 11 'were constructed by casting. In the composite beams 11 and 11 'thus constructed, the concrete connector 10 is shear connector 1,1' because the shear connector 1,1 'is hat type.
The area of contact with the concrete 10 of the shear connectors 1 and 1'becomes larger, and the beam 9 and the concrete 10
The integration with and becomes stronger. In particular, the shear connectors 1, 1 ′ have a large bending rigidity with respect to lateral displacement of the beam 9 in the longitudinal direction, so that the shear connectors 1 and 1 ′ are less deformed, and have a large bearing force against the compressive stress received from the concrete 10.
Bearing pressure collapse is unlikely to occur.

In order to prove that the shear connectors 1 and 1'of the above-described embodiment have excellent bending resistance and bearing capacity, the conventional headed stud (diameter 16 mm) shown in FIG. 13a and the Hilti shown in FIGS. 14a and 14b are used.・ A punching experiment was carried out by welding on a H-shaped steel beam together with a shear connector (HVB80), and the results are shown in Figs.
The results are shown in the graph. 5a shows the shear connector 1 of the embodiment of FIG. 1, FIG. 5b shows the shear connector 1'of the embodiment of FIG. 2, FIG. 5c shows the headed stud of FIG. 13a, and FIG. 14 It shows the amount of deformation of the Hilti Shear connector shown in Figures a and b.As is clear from these graphs, the Shear connector of the example is superior to the conventional Hilti Shear connector and is equivalent to the headed stud. It can be seen that it has bending resistance and bearing capacity.

The triangular long holes 8 of the inclined portions 3 and 3 of the shear connector 1'in FIG. 2 are circular holes of successively larger diameters as shown in FIG.
The 12a, 12b, 12c may be replaced by drilling the upper part, the middle part and the lower part at regular intervals.

Also, in the shear connector 1'of FIG.
Although ribs 6 and 6 are provided on both side ends of 4 and 4, if ribs 6 and 6 are also provided at the ends of the horizontal portions 4 and 4 as shown in FIG. 7, the bending rigidity against lateral displacement in the longitudinal direction of the beam is improved. Get bigger.

Further, the inclined portion of the shear connector 1'of FIG.
The upper ends of the ribs 6,6 of the ribs 3,6 and the ends of the ribs 6,6 of the horizontal portions 4,4 are
When it is formed into an arc shape as shown in FIG. 8, the corners are eliminated and it becomes easy to handle for transportation and work.

Further, if the ends of the horizontal portions 4, 4 of the shear connectors 1, 1'of FIGS. 1 and 2 are also arcuate as shown in FIGS. It will be easier.

Further, in each of the above-mentioned embodiments, the inclined portions 3, 3 extending downward from both side ends of the flat top portion 2 are provided, but as shown in FIG. 11 and FIG. In some cases, the vertical portions 13 and 13 extending to the vertical direction are provided, and the horizontal portions 4 and 4 extending outward from the other ends of the vertical portions 13 and 13 are provided.

Further, although the top portion 2 is flat in each of the above embodiments, it may be curved upward or downward in an arc shape.

〔The invention's effect〕

As described above, the shear connector for synthetic beams of the present invention is a hat type, so that the integration of the steel frame and the concrete can be strengthened. In particular, since the bending rigidity with respect to the lateral displacement in the steel frame direction is large, the deformation is small, and the structure receives from the concrete. Since the bearing surface has a large proof stress against compression stress, concrete bearing pressure collapse is unlikely to occur.

Further, since the shear connector for composite beams of the present invention can be fixed to the steel frame by plug welding, it does not require any special dedicated equipment as in the past, only one worker is required, and a special qualification for the worker. Does not need Moreover, the worker does not need to be skilled,
Easy to install.

[Brief description of drawings]

FIG. 1 shows an embodiment of a shear connector for a composite beam of the present invention, where a is a plan view, b is a front view, c is a right side view, and FIG. 2 shows another embodiment. a is a plan view, b
Is a front view, c is a right side view, FIGS. 3 and 4 are cross-sectional views showing a state in which a composite beam has been built using the shear connector for composite beam of FIGS. 1 and 2, FIG. 5a, b, c and d show the results of the punching experiment of the shear connector for composite beam of the embodiment of FIGS. 1 and 2, the conventional headed stud of FIG. 13a and the Hilti shear connector of FIG. Graphs, FIGS. 6 to 8 are views showing partially modified examples of the shear connector for a composite beam of FIG. 2, respectively, and FIGS. 9 and 10 are FIGS. 1 and 2.
FIG. 11 is a plan view showing a partially modified example of the composite beam shear connector shown in FIG. 11, FIG. 11 and FIG. 12 are front views showing another embodiment of the composite beam shear connector of the present invention, and FIGS. 14A and 14B are perspective views showing a conventional headed stud, and FIGS. 14A and 14B are a longitudinal sectional view and a right side view showing a conventional Hilti shear connector. 1,1 '... Shear connector for composite beam 2 ... Flat top part, 3 ... Inclined part 4 ... Horizontal part, 5 ... Hole for plug welding 13 ... Vertical part

Claims (1)

[Claims] 1. A shear connector having a hat-shaped thin steel plate in cross section, wherein a top portion, an inclined portion or a vertical portion extending downward from both side ends of the top portion, and an outer portion from the other end of the inclined portion or the vertical portion. A shear connector for a synthetic beam, which has a horizontal portion extending in one direction, and a hole for plug welding in approximately the center of both horizontal portions.