JP7611004B2 - Wall beam and full precast concrete slab joint structure - Google Patents

Description

The present invention relates to a joint structure between a wall beam and a full precast concrete slab.

Conventionally, full precast concrete slabs installed on beams are joined to beams by placing a pair of full precast concrete slabs on both ends of the beam in the beam width direction with their end faces facing each other, connecting the slab main bars protruding from the end faces of the opposing full precast concrete slabs with lap joints or the like, and then pouring concrete between the end faces of the opposing full precast concrete slabs (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 9-165860

However, when the beam width is small, such as in the case of wall beams in a wall structure, sufficient length cannot be secured between the end faces of opposing full precast concrete slabs, making it difficult to connect the slab main bars that protrude from the end faces of opposing full precast concrete slabs with the main bars.

Taking the above facts into consideration, the present invention aims to efficiently join a full precast concrete slab to a wall beam with a small beam width.

The joint structure between the wall beam and the full precast concrete slab in the first embodiment includes a wall beam with jaws formed on both sides, a full precast concrete slab with an overhanging part that overhangs from the underside to form a step surface between the upper surface and is supported by the jaws, joint members that connect the slab main reinforcements that overhang from the step surfaces on both sides, and concrete poured between the step surfaces on both sides.

According to the joint structure between the wall beam and the full precast concrete slab in the first embodiment, the slab main reinforcements protruding from the step surfaces of the full precast concrete slabs on both sides are connected with joint members, and concrete is poured between the step surfaces of the full precast concrete slabs on both sides, allowing the full precast concrete slab to be joined to the wall beam. This allows the full precast concrete slab to be efficiently joined to the wall beam with a small beam width, improving workability.

The joint structure between the wall beam and the full precast concrete slab in the second embodiment is the same as the joint structure between the wall beam and the full precast concrete slab in the first embodiment, except that a shear cotter is provided on the step surface.

According to the joint structure between the wall beam and the full precast concrete slab in the second embodiment, the shear cotter provided on the step surface of the full precast concrete slab can reliably transmit the in-plane shear force generated in the full precast concrete slab to the wall beam.

The joint structure between a wall beam and a full precast concrete slab in the third embodiment is the same as the joint structure between a wall beam and a full precast concrete slab in the first or second embodiment, in which a convex portion that protrudes outward is formed on the upper part of the step surface.

According to the third embodiment of the joint structure between the wall beam and the full precast concrete slab, the convex portion formed on the upper part of the step surface of the full precast concrete slab can improve the efficiency of transmission of the downward force acting from the full precast concrete slab to the wall beam.

The present invention has the above configuration, so that a full precast concrete slab can be efficiently joined to a wall beam with a small beam width.

FIG. 2 is an elevational cross-sectional view showing the joint structure between a wall beam and a full precast concrete slab according to one embodiment. This is a cross-sectional view taken along line 2-2 of Figure 1. FIG. 2 is a cross-sectional plan view showing a method of connecting slab main bars and tie main bars according to one embodiment. This is a cross-sectional view taken along line 4-4 in Figure 2. This is a cross-sectional view taken along line 5-5 in Figure 2. 6(A) to (D) are elevational cross-sectional views showing a method for joining a wall beam and a full precast concrete slab according to one embodiment.

Below, we will explain the joint structure between a wall beam and a full precast concrete slab in one embodiment, with reference to the drawings.

(Wall beam and full precast concrete slab joint structure)
As shown in the vertical cross-sectional view of Figure 1 and in Figure 2, which is a cross-sectional view along line 2-2 of Figure 1, a full precast concrete slab made of reinforced concrete (hereinafter referred to as "full PCa slabs 16, 18") is joined to a wall beam 14 that constitutes a wall-type reinforced concrete building 12 by a joint structure between the wall beam and a full precast concrete slab (hereinafter referred to as "wall beam slab joint structure 10").

The wall beams 14 are reinforced concrete beam members formed from cast-in-place concrete and are installed on the reinforced concrete wall 20. The full PCa slabs 16, 18 are full precast floor members made of reinforced concrete fabricated in a factory.

The wall beam slab joint structure 10 is composed of a wall beam 14, full PCa slabs 16, 18, connecting bars 22 as joint members, and concrete 24.

Groove portions 26 are formed on both sides of the wall beam 14 so as to recess from both sides toward the inside of the wall beam 14, and the undersides of the groove portions 26 form jaw portions 28. In other words, jaw portions 28 are formed on both sides of the wall beam 14 so as to protrude from the bottom surfaces of the groove portions 26 to the outside of the wall beam 14.

At the ends of the full PCa slabs 16, 18, a step 30 is formed that is lower than the upper surface of the full PCa slabs 16, 18, and the rear surface of this step 30 forms a step surface 32, and the lower portion forms an overhang 34. The overhang 34 is placed on and supported by the jaw 28 of the wall beam 14. In other words, the full PCa slabs 16, 18 have an overhang 34 that overhangs from the lower surface side of the full PCa slabs 16, 18, forms a step surface 32 between them and the upper surface of the full PCa slabs 16, 18, and is supported by the jaw 28 of the wall beam 14.

The full PCa slab 16 and the full PCa slab 18 are positioned opposite each other at a specified distance by supporting the protruding portion 34 on the jaw portion 28 of the wall beam 14.

Slab main reinforcement 36 and slab distribution reinforcement 38 are embedded in the upper and lower ends of the full PCa slabs 16 and 18. As shown in the planar cross-sectional views of Figures 1, 2, and 3, the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 16 and the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 18 (the slab main reinforcement 36 protruding from the step surfaces 32 on both sides) are connected by the tie reinforcement 22. Specifically, the end of the slab main reinforcement 36 and the end of the tie reinforcement 22 are connected by a lap joint, so that the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 16 and the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 18 are connected by the tie reinforcement 22.

Vertical reinforcement 40 and horizontal reinforcement 42 are embedded in the wall 20, and vertical reinforcement 40, horizontal reinforcement 42, and wall beam main reinforcement 44 are embedded in the wall beam 14.

Concrete 24 is poured between the step surface 32 of the full PCa slab 16 and the step surface 32 of the full PCa slab 18 (between the step surfaces 32 on both sides).

As shown in Figures 1, 2, and Figure 4, which is a cross-sectional view of line 4-4 of Figure 2, a shear cotter 46 is provided on the lower part of the step surface 32. The shear cotter 46 is composed of a cotter groove 48 formed on the lower part of the step surface 32 so as to be recessed toward the inside of the full PCa slabs 16, 18, and concrete 24 filled into this cotter groove 48 and hardened.

As shown in Figures 1, 2, and 4, a protrusion 50 is formed on the upper part of the step surface 32, protruding outward from the full PCa slabs 16, 18 (toward the wall beam 14).

As shown in Figure 2 and Figure 5, which is a cross-sectional view of line 5-5 in Figure 2, adjacent full PCa slabs 16 are joined by filling the gap 54 formed between the end faces 52 of the adjacent full PCa slabs 16 with grout G and allowing it to harden.

A shear cotter 56 is provided on the end face 52 of the full PCa slab 16. The shear cotter 56 is configured to have a cotter groove 58 formed in the middle of the end face 52 of the full PCa slab 16 so as to be recessed toward the inside of the full PCa slab 16, and grout G that has been filled into the cotter groove 58 and hardened.

This shear cotter 56 ensures that the in-plane shear force generated in the full PCa slab 16 can be transmitted between adjacent full PCa slabs 16. Adjacent full PCa slabs 18 are also joined together in the same manner as adjacent full PCa slabs 16.

(Method of joining wall beams and full precast concrete slabs)
In the method for joining a wall beam and a full precast concrete slab according to this embodiment (hereinafter referred to as the "beam-wall slab joining method"), full PCa slabs 16, 18 are joined to a beam wall 14 through first to fourth steps as shown in Figures 6(A) to 6(D). Note that this beam-wall slab joining method is only one example, and the full PCa slabs 16, 18 may be joined to a beam wall 14 by other methods.

First, as shown in the elevational cross-sectional view of FIG. 6(A), in the first step, the lower end of the wall beam 14 (the portion up to the height of the upper surface of the jaw portion 28) is constructed on the wall 20. That is, concrete is poured on the wall 20 up to the height of the upper surface of the jaw portion 28 to form the lower end of the wall beam 14.

Next, as shown in the elevational cross-sectional view of Figure 6 (B), in the second step, the ends of the full PCa slabs 16 and 18 are placed on the jaw portion 28.

Next, as shown in the elevational cross-sectional view of Figure 6 (C), in the third step, the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 16 and the slab main reinforcement 36 protruding from the step surface 32 of the full PCa slab 18 are connected by the connecting main reinforcement 22.

Next, as shown in the elevational cross-sectional view of Figure 6 (D), in the fourth step, concrete 24 is poured between the step surface 32 of the full PCa slab 16 and the step surface 32 of the full PCa slab 18. Then, as the concrete 24 hardens, the joining of the full PCa slabs 16, 18 to the wall beam 14 is completed.

(effect)
Next, the effects of this embodiment will be described.

According to the wall beam slab joint structure 10 of this embodiment, as shown in FIG. 1, the slab main reinforcements 36 protruding from the step surface 32 of the full PCa slab 16 and the step surface 32 of the full PCa slab 18 are connected to each other with the connecting main reinforcements 22, and concrete 24 is poured between the step surface 32 of the full PCa slab 16 and the step surface 32 of the full PCa slab 18, thereby joining the full PCa slabs 16, 18 to the wall beam 14. This allows the full PCa slabs 16, 18 to be efficiently joined to the wall beam 14, which has a small beam width, improving workability.

In addition, according to the wall beam slab joint structure 10 of this embodiment, as shown in Figures 1, 2, and 4, the shear cotter 46 provided on the step surface 32 can reliably transmit the in-plane shear force generated in the full PCa slabs 16, 18 to the wall beam 14.

Furthermore, according to the wall beam slab joint structure 10 of this embodiment, as shown in Figures 1, 2, and 4, the convex portion 50 formed on the upper portion of the step surface 32 of the full PCa slabs 16, 18 can improve the efficiency of transmission of the downward force acting from the full PCa slabs 16, 18 to the wall beam 14.

(Modification)
Next, a modification of the above embodiment will be described.

In the above embodiment, as shown in Figures 1, 2, and 3, an example was shown in which the slab main reinforcement 36 and the tie reinforcement 22 were connected by a lap joint, but the slab main reinforcement 36 and the tie reinforcement 22 may be connected by other reinforcing bar joints. For example, the slab main reinforcement 36 and the tie reinforcement 22 may be connected by gas pressure welding joints, welded joints, mechanical joints, etc.

In the above embodiment, as shown in FIG. 1, an example was shown in which the wall beams 14 were formed from cast-in-place concrete, but the wall beams 14 may also be precast concrete members.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and one embodiment and various modified examples may be used in appropriate combination, and the present invention may of course be embodied in various forms without departing from the spirit of the present invention.

10. Wall beam slab joint structure (joint structure between wall beam and full precast concrete slab)
14 Wall beam 16, 18 Full PCa slab (full precast concrete slab)
22 Tie main reinforcement (joint member)
24 Concrete 28 Jaw 32 Step surface 34 Overhang 36 Slab main reinforcement 46 Shear cotter 50 Convex portion

Claims (4)

A wall beam is provided on the wall and has wall beam main reinforcement embedded therein ;
A groove portion formed in the wall beam, recessed from both side surfaces toward the inside, and a lower surface of the groove portion serving as a jaw portion;
A full precast concrete slab having an overhanging portion that overhangs from the lower surface side to form a step surface between the upper surface and the overhanging portion and is supported by the jaw portion;
A joint member that connects the slab main reinforcements protruding from the step surfaces on both sides;
Concrete poured between the step surfaces on both sides;
A joint structure consisting of a wall beam and a full precast concrete slab. The joint structure between a wall beam and a full precast concrete slab according to claim 1, in which a shear cotter is provided on the step surface. The joint structure between a wall beam and a full precast concrete slab according to claim 1 or 2, in which a protruding portion that protrudes outward is formed on the upper part of the step surface. The joint member is a connecting main bar that connects the slab main bars with a reinforcing bar joint.
A joint structure between a wall beam and a full precast concrete slab according to any one of claims 1 to 3.