Reinforcement material and reinforcement structure of structure and method of designing reinforcement material

Abstract

Disclosed is a reinforcing member, which comprises a woven body formed by a weaving process, or a tape-shaped or sheet-shaped body, having a high ductility and high bendability. The reinforcing member is adapted to be installed on a surface of a structure member or a boundary portion of the structure member, or inside a structure member, to reinforce the structure member. The woven body, or a tape-shaped or sheet-shaped body, has a Young's modulus equal to or less than that of the structure member, and a tensile fracture strain of 10% or more. The Young's modulus of the reinforcing member is preferably in the range of 1 / 2 to 1 / 20, more preferably 1 / 5 to 1 / 10, of that of the structure member. Specifically, the Young's modulus of the woven body is preferably in the range of 500 to 50000 MPa, more preferably 1000 to 10000 MPa. The present invention also provides a reinforced structure using the above reinforcing member.

Description

TECHNICAL FIELD The present invention relates to a reinforcing member for a structural body, a reinforced structure using the reinforcing member, and a method for designing the reinforcing member. BACKGROUND ART Heretofore, there have been known various techniques (reinforced structures, reinforcing members and reinforcing methods) for reinforcing a member of a structural body (hereinafter referred to as “structure member”). Among them, a conventional technique characterized by installing a reinforcing member on the surface of or inside a structure member subject to reinforcement includes (1) a technique of embedding a reinforcing bar in concrete as a substrate, or so-called reinforced concrete technique, (2) a technique of driving a bolt or nail into a substrate, (3) a technique of incorporating a high-strength steel rod inside concrete as a substrate and introducing a tensile force to the steel rod, (4) a technique of wrapping a steel plate around a structure member, or so-calle...

AI Technical Summary

Benefits of technology

The aforementioned reinforced structure may be formed by providing a reinforcing member to a structure member of an existing structural body, or may be formed by installing a reinforcing member to a structure member of a structural body to be newly constructed. When the reinforced structure is applied to a new structural body, the size and weight of the structure member can be reduced as compared to the conventional techniques to provide reduced seismic load. This makes it possible to achieve drastically reduced construction cost of the structural body, and significantly enlarged utilizable space of a living room or the like.

According to third and fourth aspects of the present invention, there are provided two types of reinforced structures for a structural body. The reinforced structures comprise the reinforcing members set forth in the first and second aspects of the present invention, respectively. In these reinforced structures, the reinforcing member is fixed on a surface of or inside a substrate which constitutes a structure member of the structural body and consists of at least one material, or on a surface of a boundary portion of the structure member or inside the structure member, to reinforce the structure member.

Problems solved by technology

Thus, if a substrate is locally subjected to a large strain, the reinforcing member cannot follow the local strain, resulting in loss of the reinforcement effect due to the occurrence of local fracture in the substrate or local buckling or cracks in the reinforcing member.

Further, while this reinforcing member is designed using a formula based on the assumption that it has only tensile rigidity, an intended reinforcement effect is actually likely to be lost due to occurrence of bending or local buckling in consequence of the flexural rigidity and shear rigidity of its own.

The material, such as carbon or aramid fibers, used in the techniques (5), (7), (11) and (16), has a fracture strain of 2% to several %, which is liable to cause damages by the corners of a substrate or the unevenness of the surface of a substrate.

Further, if the substrate has some cracks due to a certain external force, the reinforcing member will be locally broken, which leads to significant deterioration or disappearance of the reinforcement effect.

In the techniques (1) to (15), if a structure member contacting with another structure member or having a flat shape or a concavo-convex or irregular surface is reinforced by forming a through-hole therein and penetratingly inserting a reinforcing member into the through-hole, such a construction work will involve a problem of high cost and / or extended period, and a particular technology or tool will be required to fix the edge of the reinforcing member or insert the reinforcing member.

Therefore, if the strength of the substrate is lowered due to aged deterioration or such an aged deterioration is calculated, the above technique cannot be applied.

In the technique of introducing a tensile force to a steel rod, if it is applied to a substrate exhibiting significant creep, such as concrete, the tensile force of the steel rod will be reduced due to the creep, and the reinforcement effect will be lost across the ages.

Further, if the anchor portion of the steel rod is broken by a sudden external force due to earthquake or the like, the steel rod suddenly freed from the tensile force will be likely to jump out of the concrete and damage the surroundings.

Thus, the techniques (1) to (16) are required to install the reinforcing member by spending an extended time in association with professional engineers, which involves a high construction cost.

The application of these techniques is also limited to a specific substrate which can be formed to have a smooth surface as in reinforced concrete, and allows a reinforcing member to be brought into close contact therewith so as to form a structure capable of locally transmitting a shear force.

Thus, the above process has to be completed by taking a great number of days.

If an external force acts to cause the peeling between the resin and the continuous fibers, or the resin is defective in curing or deteriorated due to environmental conditions, the design performance of the reinforcing member will be significantly degraded.

Generally, if a structure member has a non-flat or irregular surface, such as a wall-mounted column, or is joined to or located very close to another member or non-structural material, such as a column having a window frame attached thereto, it is difficult to obtain a sufficient reinforcement effect.

Further, the interactions between a structure member and a reinforcing member and between the reinforcing member and the surrounding are likely to cause deterioration of the reinforcing member.

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