JPS63147608A - Prestressed concrete by nonmetallic stretching material and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 a product in which compressive prestress is applied to concrete in advance to increase the apparent tensile strength of the concrete, and PC steel is generally used to apply compressive prestress.

[Problems to be Solved by the Invention] Since the conventional prestressed concrete uses PC steel as a tendon material, it is unavoidable that it will be corroded by seawater, etc., which causes delayed fracture and a decrease in load-bearing capacity. Therefore, there is a problem that it cannot be used in underwater structures, ports and coastal structures exposed to seawater, 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 the Problems) The prestressed concrete using non-metallic tendons of the first invention has a pulley-like hanging member 5.5 that faces a non-metallic rope or belt having high strength and high elastic modulus. to form a loop-shaped tension material 1, and this tension material 1,
For example, plastic mN, glass ms, carbon I
It is characterized by being buried in concrete 2 mixed with ll/f1.

Further, 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 tendons 1,
This is formed into a loop shape, and a pulley-shaped can support member 5.5 is inscribed at both ends thereof, and concrete mixed with fibers is cast at both ends of the tension material 1 including this can support member 5. The end blocks 2a, 2a are formed, and then, with prestress introduced to the tendon 1, concrete mixed with plastic fibers is cast between the end blocks 28 and 28 to form the center block 2b, and then the center block 2b is formed. , 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 PC steel material, which has high strength and high elasticity. A rope or belt made of a non-metallic material such as aramid fiber having a constant coefficient is connected in a loop shape 3, and a pulley-shaped can support member 5.5 is attached to both ends of the loop.
is inscribed and curved into a semicircular arc shape. The can support member 5 is made of a high-strength, corrosion-resistant non-metallic material such as resin concrete, and has a shaft-shaped support rod 4.4 protruding from its eccentric position.

The tension member 1 is buried under tension in the concrete 2 together with the can support member 5.5.

Concrete 2 uses fiber-mixed concrete to prevent local stress, shear, and brittle failure. As will be described later, this concrete 2 is formed by forming end blocks 2a, 2a cast at both ends of the tendon 1 including the can support members 5, and a center block 2b cast between them, depending on the forming order. and tension material 1 on the outer end side of the end blocks 2a, 2a.
and a shaping block 20.2C that covers the exposed portion of the can holder member 5.5, and these blocks 2a, 2a, 2b, 2c, and 2c are integrally connected. There is.

FIG. 3 shows another embodiment of the prestressed concrete of the present invention. In this example, a supporting block 2d provided with a curved receiving portion 6 for receiving the tension material 1 is used instead of the pulley-shaped can supporting member 5 and the end block 2a.

In this case, the support 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. 4(A), a tension member 1 formed in the shape of a rope or belt is passed around pulley-shaped can support members 5.5 arranged at a required interval, and the end portion are joined 3 by thermocompression bonding or adhesive to form a loop shape. Then,
As shown in the same figure (b), concrete mixed with a binder is placed at both ends of the tendon 1 including the can support members 5, to form end blocks 2a, 2a in which the tendon 1 is embedded. do. In this case, as shown in the figure, the support rod 4 of the can support member 5 is connected to the block 2a.
It is best to hit the edge of the Next, as shown in FIG. 2C, for example, jacks (not shown) are installed between the opposing surfaces of the end blocks 2a, 2a, and the end blocks 2a are
, 2a outward in the direction of the arrow. This introduces prestress into the tendon 1. With the prestress introduced in this way, it is fixed to the pedestal 7 by an appropriate means, for example as shown in FIG. 7(d), and the jacks are removed. Then, mH mixed concrete is placed between the end blocks 2a, 2a to form the center block 2b, and the end blocks 2a, 2a and the center block 2b are integrally connected. After this bonding, it is removed from the base 7, and shaped blocks 2C, 2C are cast and formed by covering the outer sides of the end blocks 2a, 2a with ordinary concrete or fiber-containing concrete. Through the above steps, prestressed concrete as shown in Figure 1 is manufactured.

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

〔Effect of the invention〕

As explained above, according to the present invention, since a non-metallic O-pu or belt with high strength and high elastic modulus 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. Since this non-metallic tension material is formed into a loop by wrapping the pulley-shaped can support members at both ends, it does not generate concentrated stress when pulled, and can be used as a concrete material. is I
Since IN-containing concrete is used, the viscosity is improved and the resistance to tension is increased, and the physical bond with the tendon material is good, so that prestress can be introduced well. In addition, since the manufacturing method is easy,
It is suitable for mass production and can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of prestressed concrete according to the present invention, FIG. 2 is a plan view thereof, FIG. FIG. 2 is a diagram showing the production of concrete in the order of steps. 1... Tension material 2... Concrete 2a... End block 2b... Center block 2C... Shaping block 5... Can support member 7... Pedestal Fig. 1 □ Fig. 2 Figure 3

Claims (2)

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