JPH0458765B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses non-metallic ropes or belts having high strength and high elastic modulus, such as aramid fibers, bonded in a loop shape as a tension material. This invention relates to prestressed concrete and its manufacturing method.

[Conventional technology]

Prestressed concrete is made by applying compressive prestress to the concrete in advance.
It is designed to increase the apparent tensile strength of concrete, and is generally used to provide pre-stress for compression.
PC steel material is used.

[Problem that the invention seeks to solve]

The conventional prestressed concrete is
Because prestressing steel is used as a tendon, it is unavoidable that it will be corroded by seawater, etc., which causes delayed fracture and a decrease in load-bearing capacity. There is a problem in that it cannot be used in structures, or even if it is used, special measures must be taken to prevent corrosion.

The present invention aims to solve these drawbacks of conventional prestressed concrete and provide a prestressed concrete that is resistant to corrosion.

[Means for solving problems]

Pre-stressed concrete using non-metallic tendons of the first invention is produced by loop-shaped tendons 1 by wrapping non-metallic ropes or belts having high strength and high elastic modulus around opposing pulley-shaped hanging members 5, 5.
The tension member 1 is embedded in concrete 2 mixed with fibers such as plastic fibers, glass fibers, and carbon fibers.

In addition, the method for producing prestressed concrete using non-metallic tendons according to the second invention uses a non-metallic rope or belt having high strength and high elastic modulus as the tendon material 1, and forms it into a loop shape. End blocks 2a, 2a are formed by inscribing pulley-shaped hanging members 5, 5 at both ends, and pouring concrete mixed with fibers at both ends of the tendon 1 including the hanging members 5. Then, with prestress introduced into the tendon 1, both end blocks 2a,
The central block 2b is formed by pouring concrete mixed with plastic fibers between the blocks 2a, and the end blocks 2a, 2a and the central block 2b are integrally connected.

〔Example〕

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

Figures 1 and 2 show an embodiment of prestressed concrete according to the present invention, in which 1 is a tension material embedded in concrete 2 instead of conventional prestressed steel material, which has high strength and high elastic modulus. A rope or belt made of a non-metallic material, such as aramid fiber, having a It is curved in an arc. This hanging member 5 is made of a high-strength, corrosion-resistant non-metallic material such as resin concrete, and has shaft-shaped support rods 4, 4 installed at eccentric positions thereof.
The tension member 1 is buried under tension in the concrete 2 together with the hanging members 5, 5.

Concrete 2 uses fiber-mixed concrete to prevent local stress, shearing, and brittle failure. As will be described later, this concrete 2 is formed into the hanging member 5 of the tendon 1 depending on the molding order.
End blocks 2a, 2a cast at both ends including
and the central block 2b cast between them,
The outer end sides of the end blocks 2a, 2a are formed of the tension material 1 and shaping blocks 2c, 2c that cover the exposed parts of the hanging members 5, 5, and each of these blocks 2a, 2a, 2b , 2c, 2c are integrally connected.

FIG. 3 shows another embodiment of the prestressed concrete of the present invention. In this example, the above-mentioned pulley-shaped hanging member 5 and end block 2
In place of a, a hanging block 2d provided with a curved receiving part 6 for receiving the tendon 1 is applied. In this case, the hanging block 2d may be made of precast concrete.

Next, manufacturing of the prestressed concrete shown in FIGS. 1 and 2 will be explained.

First, as shown in Fig. 4A, a tension material 1 formed in the shape of a rope or belt is passed around pulley-shaped hanging members 5, 5 arranged at a required interval, and the ends are heated. They are joined 3 by pressure bonding or adhesive to form a loop shape. Next, as shown in FIG. 4B, fiber-containing concrete is placed at both ends of the tendon 1 including the hanging members 5 to form end blocks 2a, 2a in which the tendon 1 is embedded. In this case, it is preferable that the support rod 4 of the hanging member 5 come into contact with the end face of the block 2a as shown in the figure. Next, as shown in FIG. do. Thereby, prestress is introduced into the tendon 1. With the prestress introduced in this way, it is fixed to the pedestal 7 by appropriate means, for example, as shown in FIG. 2D, and the jacks are removed. Then, concrete mixed with fibers is placed between the end blocks 2a, 2a, and the center block 2b is formed.
The end blocks 2a, 2a and the central block 2b are integrally connected. After this binding,
Remove this from the pedestal 7, and remove the end block 2a,
Shaped block 2 with each outside of 2a covered with ordinary concrete or fiber-containing concrete
c and 2c are cast and molded. Through the above steps, prestressed concrete as shown in Figure 1 is manufactured.

Note that the means for introducing prestressed concrete into the tension members 1 is not limited to the above-mentioned method; for example, the hanging members 5 are directly indexed outward by using the support rods 4, etc. This can be done as appropriate.

〔Effect of the invention〕

As explained above, according to the present invention, since a high-strength, high-modulus non-metallic rope or belt is used as a tension material for prestressed concrete, it is not corroded by seawater etc. , prestressed concrete suitable for underwater structures, ports and coastal structures exposed to seawater can be obtained. This non-metallic tension material is
Since it is formed into a loop by hanging the hanging members formed in the shape of pulleys at both ends, there is no concentrated stress due to tension, and since the concrete used is fiber-containing concrete, the viscosity is reduced. This improves the resistance to tension, increases the resistance to tension, and also provides good physical bonding with the tendon material, allowing for good introduction of prestress. Furthermore, since the manufacturing method is easy, it is suitable for mass production and can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of prestressed concrete according to the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a side sectional view showing another embodiment of the same, and FIG. 4 is a side sectional view showing an embodiment of prestressed concrete according to the present invention. It is a diagram showing the production of prestressed concrete in the order of steps. 1... tension material, 2... concrete, 2a...
End block, 2b...Central block, 2c...
Orthopedic block, 5... hanging member, 7... pedestal.

Claims (1)

[Claims] 1. A non-metallic rope or belt having high strength and high elastic modulus is wound around opposing pulley-shaped hanging members to form a loop-shaped tension material, and this tension material is
Prestressed concrete made of non-metallic tendons, characterized by being embedded in concrete mixed with fibers. 2. A non-metallic rope or belt with high strength and high elastic modulus is used as a tension material, formed into a loop shape, and a pulley-shaped hanging member is inscribed in both ends of the loop, and this hanging member is Concrete mixed with fibers is cast at both ends of the tendons to form end blocks, and then concrete mixed with fibers is poured between both end blocks with prestress introduced into the tendons to form the center. A method for producing prestressed concrete using non-metallic tendons, which is characterized by forming blocks and integrally binding both end blocks and a central block.