JP2002088908A - Construction method of concrete structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a concrete structural body capable of controlling the direction of a fiber for a fiber reinforced concrete. SOLUTION: The construction method of the concrete structural body making the fiber reinforced concrete as a material is to move the fiber to the direction to be required while rotating a rotatable disc put on a rectifier in the concrete to be cast during and directly after the cast of the fiber reinforced concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing a concrete structure using fiber reinforced concrete as a material.

[0002]

2. Description of the Related Art When constructing a concrete structure using fiber-reinforced concrete as a material, a fiber-reinforced concrete is poured into a formwork to construct a concrete structure, as in the case of casting concrete. The fibers in the concrete structure thus constructed are oriented in various directions, and it is preferable for a structure subjected to loads from various directions because the resistance of the concrete structure in all directions is reinforced by the fibers. Was something.

[0003]

On the other hand, if the direction of the load acting on the concrete structure or the direction of deformation is clear, the fibers are aligned in a predetermined direction to increase the resistance in that direction. It is preferable to maximize the fiber reinforcement effect. However, if fiber reinforced concrete is cast in a conventional manner, the fibers in the concrete structure will face various directions. And it was difficult to control the direction of the fiber in an arbitrary direction.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method for constructing a concrete structure capable of controlling the direction of fibers of fiber-reinforced concrete. .

[0005]

Means for Solving the Problems To achieve the above object, a method for constructing a concrete structure according to the present invention is directed to a method for constructing a concrete structure using fiber-reinforced concrete as a material. A method characterized in that a rectifier provided with a rotatable disk is moved in a direction in which fibers are to be directed while rotating the disk in the poured concrete during or immediately after the casting. When a plurality of disks are used, the disks are provided in parallel with the rectifier.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

<A> Rectifier The rectifier 2 is a machine for adjusting the direction of the fibers 11 of the fiber reinforced concrete 1. The rectifier 2 is composed of one disk 21 or a plurality of disks 21 arranged in parallel at a predetermined interval. The number and size of the disks 21 are adjusted according to the type of concrete structure to be constructed. For example, in the case of using a thin and wide member such as a panel, the diameter of the disk 21 is reduced and the number of disks 21 is increased. In addition, when used for a member having a large width and a small width such as a beam member, the diameter of the disk 21 is increased and the number of disks 21 is reduced. The disk 21 is configured to be rotatable. The rotation may be performed manually or using a motor or the like. In the case of a motor, it is preferable to configure so that the number of rotations can be changed. Alternatively, the disk 21 may be simply rotated with the movement of the rectifier 2 without applying an external rotational force.

<B> Fiber-reinforced concrete Fiber-reinforced concrete 1 is concrete in which the properties such as tensile strength, bending strength, and toughness are improved by mixing fibers of metal or synthetic resin into concrete. The fiber reinforced concrete 1 used in the present invention preferably has high fluidity and a long setting time. As fiber-reinforced concrete, for example, cement and silica powder, silica fume, silica sand, high-performance water reducing agent and water per unit volume (per finished concrete volume 1 m ³ )
Compressive strength of 200 to 220 MPa, flexural strength of 40 to 45 MPa obtained by mixing about 2% by volume of high-strength steel fiber into a high-strength concrete matrix to which about 180 kg (water / cement ratio is about 22%) is added. , Adhesion strength 10-90 MPa, air permeability coefficient 2.5 × 10
^-18 m ² , water absorption 0.05 kg / m ³ , salt diffusion coefficient 0.0
Fiber-reinforced ultrahigh-strength concrete having characteristics of 2 × 10 ⁻¹² m ² / sec and an elastic modulus of 55 GPa can be used.

<C> Casting of fiber reinforced concrete The fiber reinforced concrete 1 is poured into a mold. During or immediately after placing the fiber reinforced concrete 1,
For example, the handle 22 of the rectifier 2 is put into the fiber reinforced concrete 1. Then, the rectifier 2 is moved, for example, in the direction B (the direction in which the fibers 11 are desired to be directed) while the disk 21 is being rotated (for example, in the direction A). The rectifier 2 may be moved, for example, in the direction B (the direction in which the fibers 11 are to be directed) with the disk 21 being freely rotatable. Fiber 11 of fiber reinforced concrete passed between disks 21
Are aligned in the direction along the disk 21, in other words, in the direction of travel of the rectifier 2. Here, by rotating the disk 21 at a low speed, only the orientation of the fibers can be adjusted without scattering concrete or entraining air. Also,
When the width of the concrete structure is wider than the width of the rectifier 2, the direction of the fibers in the entire concrete structure is adjusted by moving the rectifier 2 several times. For example, by moving the rectifier 2 from one end of the concrete structure to the other, an aligned portion 31 in which the directions of the fibers are aligned is formed, and the rectifier 2 is moved to the unaligned portion 32 adjacent to the rectifier 2 and unaligned similarly to the aligned portion. The fiber direction of the part 32 is adjusted.

[0010]

[Effect of the present invention] Since the method for constructing a concrete structure of the present invention is as described above, the following effects can be obtained. <A> The direction of the fiber can be set arbitrarily in the moving direction of the rectifier. For this reason, it is possible to construct a concrete structure having excellent resistance to a load or deformation in a specific direction. That is, the effect of fiber reinforcement can be maximized. <B> The fiber direction of fiber-reinforced concrete can be set to any direction simply by moving the rectifier while rotating the disk. For this reason, it is easy to partially align the fiber directions of the concrete structure. Moreover, in the concrete structure integrally constructed, the direction of the fiber can be easily designated arbitrarily by the portion. <C> The method for constructing a concrete structure of the present invention can be easily applied not only to a factory but also to a site. Further, since the equipment to be used has a simple structure and a simple structure, it can be constructed at low cost. <D> For example, in the case of a rigid frame structure, fibers are arranged in the same direction as the longitudinal direction of the tensile beam in the beam portion subjected to bending, and the even-angle portions serving as hinges at the time of fracture direct the fibers in various directions. The most effective reinforcing effect can be obtained by arranging them. Therefore, if a ramen structure is constructed by the method for constructing a concrete structure of the present invention, the fiber direction can be specified as described above.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a method for constructing a concrete structure according to the present invention.

[Explanation of symbols]

 1 Fiber-reinforced concrete 11 Fiber 2 Rectifier 21 Disk

Claims (1)

[Claims] 1. A method for constructing a concrete structure using fiber reinforced concrete, wherein a rectifier provided with a rotatable disk is placed in or on the concrete while the fiber reinforced concrete is being poured. A method of constructing a concrete structure, characterized by moving a fiber in a desired direction while rotating a disk.