JPH083596Y2 - Anchor for concrete splicing - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a concrete splicing anchor anchored in existing concrete for the purpose of concrete splicing or seismic retrofitting.

[0002]

[Prior Art and Problems to be Solved by the Invention] For jointing existing concrete with newly-placed concrete or for seismic retrofitting of a building, it is inserted into an embedded hole drilled in the existing concrete. , The tip expands and becomes fixed,
Post-installed anchors are used, which are connected with joining rebars for joining with the new concrete, which are connected by lap joints to the rebars in the new concrete.

As shown in FIG. 5, this anchor is constructed by inserting a wedge-shaped plug into an embedding hole of an existing reinforced concrete structure in advance and driving an expansion part of the main body which can be opened into the plug. , While expanding the expansion part, it bites into the hole wall, and then, at the base of the anchor body, the joint reinforcing bar that is lap jointed with the rebar of the new concrete is screwed and connected. Since the cross section of the rebar is cut and reduced due to the cutting of the male screw that is screwed into the anchor body, there is a weakness that the tensile strength and shear strength are lower than the strength of the rebar itself. Production problems such as time-consuming cutting are also pointed out.

Further, in this anchor, in addition to the decrease in the proof stress of the joint rebar, the joint rebar is screwed into and connected to the anchor body after the anchor body is driven into the embedding hole. It cannot be directly connected to the anchor body, and must be separately lapped and joined to the joint reinforcement.

The present invention has been made in view of the problem of the conventional post-installed anchor, and it is intended to newly propose an anchor having a good manufacturability without lowering the yield strength.

[0006]

[Means for Solving the Problems] In the present invention, a threaded reinforcing bar is used as a joining reinforcing bar, and the joining reinforcing bar is inserted into a sleeve to be inserted into an embedding hole without processing the joining reinforcing bar, and a nut is inserted therein. By tightening and connecting, the loss of the cross section, that is, the reduction of the effective cross section is eliminated, and the tensile and shear strength of the joint rebar itself is effectively exerted.
Eliminates the time and effort of cutting the jointed reinforcing bar and the sleeve to which it is connected, and makes the jointed reinforcing bar also serve as the reinforcing bar in the new concrete, eliminating the need for bar arrangement by lap joints.

The anchor is inserted into an existing concrete embedding hole and has a sleeve having an expandable expandable portion at its tip, a joining rebar inserted through the sleeve along its entire length, and a base side of the sleeve. It is composed of a nut that is screwed to the joint rebar.

A cone nut having a shape in which the diameter gradually increases from the base side to the tip side is screwed onto the tip of the joining reinforcing bar, and the joining reinforcing bar is inserted into the sleeve with the cone nut inscribed in the expanded portion of the sleeve.

The sleeve is pushed and moved to the tip side of the joint rebar as the nut is rotationally tightened, and at the same time, the cone nut is pulled into the extension section from the tip side of the sleeve, so that the extension section is expanded and embedded in the expanded state. It is fixed in the hole. At the same time, the sleeve is clamped between the cone nut and the nut, and is integrally connected to the joint rebar.

The joint rebar retains tensile and shear strength,
Also, since the sleeve is fixed in the embedding hole only by tightening the nut, it is integrated with the sleeve and overhangs to the new concrete side as it is to become a reinforcing bar in the new concrete. Eliminates the need to reinforce the reinforcing bar separately.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment.

The anchor A of this invention is an existing concrete C1 and a newly placed concrete as shown in FIG.
Buried over the joint between C2 and both concrete
C1 and C2 are spliced together, the sleeve 1 inserted into the embedding hole h of the existing concrete C1, the joining rebar 2 of the screw rebar inserted into the sleeve 1, and the sleeve 1 of the joining rebar 2
And a nut 3 which is screwed to the base side and connects the joint rebar 2 to the sleeve 1.

The sleeve 1 has a tubular shape as shown in FIG.
An expanded portion 1a whose cross section can be expanded is formed at the tip. The expansion part 1a can be opened by inserting the slit 1b, and a groove 1c is formed on the outer peripheral surface around the expansion part 1a to improve the biting of the embedding hole h formed in the existing concrete C1 into the hole wall. To be done. The inner peripheral surface 1d of the expanded portion 1a will be described later,
In order to smoothly open the leg by the cone nut 4 at the tip of the joined reinforcing bar 2, the diameter is gradually increased toward the tip side.

The sleeve 1 is connected to the joint rebar 2 by a nut 3 arranged on the base side thereof, and the expanded portion 1a is expanded to fix the sleeve 1 in the embedding hole h. When the diameter of the joint reinforcing bar 2 is large and the embedding depth in the embedding hole h is large, the position of the nut 3 from the splicing surface is set between the nut 3 on the base side of the sleeve 1 as shown in the figure. A length adjusting pipe 1'for adjusting is arranged.

As shown in FIG. 3, the joining reinforcing bar 2 is a threaded reinforcing bar which is threaded over its entire length, and a wedge-shaped cone nut 4 whose diameter gradually increases from the base side to the tip side is screwed to the tip.

The joint rebar 2 inserted in the sleeve 1 is shown in FIG.
As shown in FIG. 4, a cone nut 4 is attached to the tip, and a nut 3 is screwed to the base side of the sleeve. The joint reinforcing bar 2 becomes a reinforcing bar in the new concrete C2 by giving the required length.

With the rotation of the nut 3, the sleeve 1 is pushed by the nut and moves from the state shown in FIG. 4 to the state shown in FIG. 1 toward the tip side of the joint rebar 2, and the expanded portion 1a moves from its tip to its inside. When the cone nut 4 is pulled in, the cone nut 4 is pushed and spread out, bites into the hole wall of the embedding hole h, and is fixed in the embedding hole h in an integrated state with the joint reinforcing bar 2.

By tightening the nut 3, the sleeve 1 is settled in the embedding hole h, and at the same time, the joint rebar 2 is integrally connected to the sleeve 1 to provide a new concrete C2.
It will stick out to the side and be arranged as it is.

Here, the procedure for constructing the anchor A will be described.

First, an embedding hole h having a predetermined diameter and depth is drilled in the existing concrete C1 to clean the inside thereof, while the joint rebar 2 is inserted into the sleeve 1 as shown in FIG.
Screw together.

The anchor A is inserted into the embedding hole h with the cone nut 4 shown in FIG. 4 simply inscribed in the expanded portion 1a of the sleeve 1.

Next, the nut 3 is tightened, the sleeve 1 is moved to the tip side of the joint rebar 2, and the cone nut 4 is expanded.
At the same time as it is pulled into 1a and expanded to bite into the hole wall of the embedding hole h, the sleeve 1 is sandwiched between the cone nut and the nut, integrated with the joint rebar 2, and the anchor A
The anchoring of the concrete and the reinforcement of the new concrete C2 side are completed.

At this time, as described above, when the diameter of the joint rebar 2 is large and the depth of the embedding hole h becomes large, the nut 3 and the sleeve 1 are prevented from becoming a weak point due to shearing force so that the joint surface of the nut 3 and the sleeve 1 does not become a weak point. In order not to position the joint 3 near the tapping surface c, the length adjusting pipe 1'is inserted between the two and the distance of the nut 3 from the tapping surface c is adjusted. Similarly, when the length adjusting pipe 1'is inserted, the joint surface between the length adjusting pipe 1'and the sleeve 1 is arranged at a position where it does not overlap the jointing surface c.

[0024]

The present invention is as described above. A threaded reinforcing bar is used as the joining reinforcing bar, and the expanded portion of the sleeve is expanded by a wedge-shaped cone nut connected to the tip of the reinforcing bar. Since it is fixed inside, it is possible to effectively exert the tensile and shear proof strengths of the joint rebar itself without reducing the effective cross section of the joint rebar. In addition, the sleeve is sandwiched between the cone nut and the nut to be integrated and connected with the joint rebar, so at the same time as the sleeve is settled, the rebar into the new concrete,
It can be fixed directly in the existing concrete and arranged.

Since it is not necessary to screw the joined reinforcing bar and the sleeve, and the cone nut that is manufactured in advance in a factory is used, it is possible to easily obtain the one having the desired tapered taper surface and the required size. Can be installed. Therefore, it is possible to achieve reduction in member cost and labor saving in bar arrangement work without requiring cutting or special processing.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state where an anchor is installed in an embedding hole.

FIG. 2 is an elevational view showing a sleeve and a nut.

FIG. 3 is an elevational view showing a joined reinforcing bar.

FIG. 4 is an elevational view showing an assembled state of the anchor.

FIG. 5 is a vertical cross-sectional view showing an installed state of a conventional anchor.

[Explanation of symbols]

A ... Anchor, 1 ... Sleeve, 1a ... Expansion, 1b ...
… Slits, 1c …… Grooves, 1d …… Inner circumferential surface, 1 ′ …… Length adjustment pipe, 2 …… Joined rebar, 3 …… Nut, 4 …… Cone nut, C1 …… Concrete, C2 …… Concrete, c ... Joint surface, h ... Embedding hole.

Claims (1)

[Scope of utility model registration request] 1. An anchor that is installed across a joint between an existing concrete and a newly placed concrete and connects both concretes, and is embedded in an embedding hole drilled in the existing concrete. A sleeve having an expandable expandable portion at its tip, a joining rebar of a screw rebar inserted through the entire length of the sleeve, and a nut screwed to the joining rebar on the base side of the sleeve. And, at the tip of the joint rebar, a cone nut of a shape whose diameter gradually increases from the base side to the tip side is screwed, and the sleeve is pushed and moved to the tip side of the joint rebar as the nut rotates, The cone nut is drawn into the expansion portion and fixed in the embedding hole in the expanded state, and the sleeve is sandwiched between the cone nut and the nut and integrally connected to the joint rebar. Anchor for concrete splicing.