JPH10121728A - Execution method of concrete joint part in inverted construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely transmit a shearing force at concrete joint, by forming a recess in a fitting part of a cotter after precast concrete has been placed and filling post-cast concrete in the recess to engage the precast and post-cast concrete parts. SOLUTION: A wooden cotter 1 is attached to one side of the bottom form of precast concrete part A, parallelly to a wall and a wooden cotter 3 is attached in the right-angles direction of the wall, between the wooden cotter 1 and vertical reinforcements 2 of the outside side wall. Then, the reinforcement 2 and reinforcements 5 of the inside wall are assembled and a wall form 7 is erected and then post-cast concrete is placed. After precast concrete has been placed, a recess is formed in the fitting part of the cotter and post-cast concrete is charged in the recess to mutually engage both concretes. The shearing force of the whole concrete structure is transmitted by the balance of the support strength of the face at the rising part of the recess and the shearing strength of the face at the root of protrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a concrete splicing portion of a reverse-casting method applied to concrete work of an underground structure of a building.

[0002]

2. Description of the Related Art In the method of treating voids in the above-mentioned back-casting method, a void is provided between a pre-cast body and a post-cast body, and an injection method in which an injection material is injected and filled through an injection pipe, or a pre-cast concrete. A gap of 10 to 15 cm is opened between the concrete and the post-cast concrete, the latence of the post-cast concrete is processed, and after the concrete is hardened, the formwork is installed, and the non-shrink mortar is filled to process the joint. The law is being enforced. Of these, the filling method has been frequently used because of its excellent performance, but recently, the direct method for the purpose of labor saving has been widely used.

[0003]

However, in the above-mentioned direct method, a gap is formed in the joint portion due to the sedimentation of the post-cast concrete, so that the transmission of the shearing force in the joint portion is incomplete. The present invention has been proposed in view of such problems, and an object of the present invention is to provide a concrete in a reverse-casting method in which a shear force is completely transmitted at a joint between a pre-cast concrete and a post-cast concrete. It is intended to provide a method for constructing a joint.

[0004]

In order to achieve the above-mentioned object, according to the construction method of the concrete splicing portion in the reverse construction method according to the present invention, the reverse striking applied to the concrete work of the underground structure of the building is performed. In the concrete splicing part in the construction method, a cotter is attached to the bottom of the pre-cast part, a recess is formed in the mounting part of the cotter after the pre-cast concrete is placed, the recess is filled with post-cast concrete, and the pre-cast, It is characterized in that the pour concrete portion is engaged.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below with reference to the drawings. On one side of the bottom formwork of the concrete pre-cast part A, a wooden cotter 1 with a taper made of square material is attached in parallel with the wall to fit the wall, and then between the wooden cotter 1 and the external side wall vertical reinforcing bar 2. A tapered wood cotter 3 made of a square timber that fits is attached in consideration of the rebar pitch so as to be in contact with the wood cotter 1 made of the previously installed square timber in a direction perpendicular to the wall.

Next, a waterproof rubber 4 is attached to the inside of the outer side wall vertical reinforcing bar 2, and the outer side wall vertical reinforcing bar 2 and the inner side wall vertical reinforcing bar 5 are assembled. The water rubber 6 is attached, the wall form 7 is erected, and post-cast concrete is poured. In the post-concrete portion B, air vent holes 8 are drilled at a pitch of about 1 meter above the joints, and concrete is poured while confirming that the concrete blows out from the air vent holes 8.

In the embodiment shown in the drawings, since the wooden cotters 1 and 3 are attached to the bottom of the concrete pre-casting section A, after the concrete pre-casting, the cotter mounting section is installed. A recess is formed in the
The concave portion is filled with post-cast concrete, and the two concretes mesh with each other, so that the balance between the bearing capacity of the rising portion of the concave portion and the shear strength of the base portion of the convex portion makes the entire concrete structure. It transmits the shearing force.

[0008]

According to the present invention, a concrete butt joint is applied to the underground construction of an underground structure of a building, and a cotter is attached to the bottom of the pre-cast part. Fill the recess formed in the mounting part of the cotter with post-cast concrete,
Thus, the shear strength of the entire concrete structure can be reliably transmitted with a simple construction by engaging the joint portions of the first and second cast concrete.

[Brief description of the drawings]

FIG. 1 is a plan view showing a cotter attachment portion of a concrete splicing portion in a reverse casting method according to the present invention.

FIG. 2 is a cross-sectional view showing the cotter mounting portion.

FIG. 3 is a cross-sectional view showing a state in which a post-molded wall form is built.

[Explanation of symbols]

 Reference Signs List A Ahead part of concrete B Ahead part of concrete 1 Wood cotter 2 Vertical reinforcing bar on outer side wall 3 Wood cotter 4 Rubber for water stopping 5 Vertical reinforcing bar on inner side wall 6 Water stopping rubber 7 Wall form 8 Air vent hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuaki Manada 4-6-115 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd.

Claims (1)

[Claims] 1. A concrete splicing part in a reverse striking method applied to concrete construction of an underground structural part of a building, a cotter is attached to the bottom of the pre-cast part, and a recess is formed in the mounting part of the cotter after the pre-cast concrete is cast. A method of constructing a jointed concrete portion in a reverse-casting method, characterized in that the concave portion is filled with post-cast concrete, and the pre-cast and post-cast concrete portions are engaged with each other.