JPS6010061A - Pc steel anchoring construction in post-tension constructionmethod - 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 Field of Industrial Application This invention relates to a PC steel fixing method in a boss tension method.

In the prior art boss tension construction method, a fixing tool having a protrusion that projects laterally and is buried in concrete before hardening is used as a fixing tool for tensioning and fixing an unbonded PC steel material. This kind of anchorage is used after concrete hardens.
In order to tension the C steel material and cut the PC steel material, a filling part is recessed in the concrete at the end of the PC steel material, and after the tensioning work of the PC steel material is completed, the filling part is filled with mortar or concrete to protect the PC steel material. things are being done.

The mortar etc. that are post-cast in this filling part are not easily integrated with the surrounding existing concrete, and in some cases, the post-cast concrete may peel off.

Purpose of the Invention This invention was made to improve the above-mentioned drawbacks, and provides a boss that can integrate existing concrete with post-cast mortar or concrete at the anchorage part in the boss tension method. The purpose is to provide a method for fixing PC steel materials in the tension method.

Structure of the Invention The PC steel fixing method in the boss tension construction method according to the present invention is to install a concave part forming member having an uneven outer surface on the terminal end side of the PC steel material of a PC steel fixing tool and bury it in concrete to form a concave part in the rear leg of the concrete when it hardens. The above purpose is achieved by separating the member from the concrete, creating a recessed filling part, pouring mortar or concrete into the filling part, and integrating the post-cast mortar etc. with the existing concrete. be.

EXAMPLES Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

In the figure, 1t-1 is a fixing tool that fixes a PC steel material 2 under tension.

An insertion hole 11 of a PC steel material 2 is penetrated through the fixing tool 1 in the center. The inner peripheral surface of one end of the insertion hole 11 is formed in a tapered shape so that the inner diameter gradually increases toward the terminal end. A protrusion 12 is made to protrude from the outer surface of the fixing tool 1 in a direction perpendicular to the insertion hole 11.

This fixture 1 is buried in concrete 3 in the construction of bridges, slabs, etc. The fixing device 1 is buried so that the tapered inner peripheral surface of the insertion hole 11 is positioned on the outer surface side of the concrete 3, and the terminal end of the fixing device 1 is positioned slightly inside the surface of the concrete 3. There is.

A recess forming member 4 having a protrusion 41 on the outer surface is installed on the outer surface side of the concrete 3 of the fixing device 1 and is also buried in the concrete 3. Although various shapes can be considered for the shape of the fixing tool 1, the embodiment shown in the figure is cylindrical and has a truncated conical outer shape. Further, in the embodiment shown in FIGS. 2 and 3, the protrusion 41 is provided to protrude spirally from the outer periphery, and in the embodiment shown in FIG. A plurality of protrusions are provided on the outer surface from one end to the other. The smaller diameter side end of this recess forming member 4 is brought into contact with the fixing tool 1, and the larger diameter side end is made to substantially coincide with the outer surface of the concrete 3.

The same PC steel material 2 is buried in the concrete 3. The PC steel material 2 is bonded to the surrounding concrete 3 by means such as covering the outer periphery with a sheath or applying grease or the like to the outer periphery. As the PC steel material 2, a PC steel wire, a PC steel bar, etc. are used.

The PC steel material 2 is inserted through the insertion hole 11 of the fixing tool 1,
Concrete 3P! After being compressed, it is tightened and fixed by the wedge 5 which is in sliding contact with the tapered surface of the insertion hole 11, and the terminal end is positioned in the filling part 6 recessed by the recess forming member 4.

After the concrete 3 hardens, the recess forming member 4 is attached to the concrete 3
make them leave. The PC steel material 2 may be separated from the concrete 3 before or after it is fixed.

In the case of the recess forming member 4 shown in FIGS. 2 and 3, when it is rotated in the circumferential direction, the spiral protrusion 41 slides within the four parts 61 formed on the adhesive surface with the concrete 3 with the rotation, and the recess is formed. The forming member 4 is removed. The recess forming member 4 shown in FIGS. 4 and 5 can be easily removed by pulling it in the opposite direction to the fixing tool.

After the recess forming member 4 is removed, the filling portion 6 is recessed into the concrete 3, and a recess 61 is formed on the surface of the concrete 3 by the protrusion 41.

This filling portion 6 is filled with mortar or concrete. The mortar etc. also enters into the recess 61 formed by the protrusion 41 of the recess forming member 4, allowing the existing concrete 3 and the post-cast mortar etc. to be well integrated.

Although the present invention has the above configuration, the recess forming member 4 may have four groove-shaped parts instead of the protrusion 41. When such a four-part forming member 4 is used, the surface of the concrete 3 corresponding to the recess will protrude, and the other surfaces will be formed as the recess 61.

Further, the shape of the recess forming member 4 is not limited to a cylindrical shape, but may be a columnar shape, and the outer shape can be various shapes such as a cylindrical shape, a prismatic shape, a truncated pyramid shape, etc.

Effects of the Invention This invention has the above-mentioned configuration, and since mortar or concrete is poured after forming a recess in the filling part, the mortar, etc. enters the recess and mixes the existing concrete with the post-cast mortar. This makes it possible to achieve complete integration without compromising the protection of the prestressing steel material.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention in a construction state, Fig. 2 is a side view of an embodiment of the recess forming member, Fig. 3 is a front view, and Fig. 4 is a view of the recess forming member. Side view of the embodiment, fifth
The figure is a front view. 1. Fixing tool 2. PC steel 3. Concrete 4. Recess forming member 5. Rust 6. Filling section 41. Projection 61. Recess. Figure 2 4 \ Figure 3 Figure 4 Figure 5 360-

Claims (1)

[Claims] A four-part forming member having an uneven outer surface is installed on the end side of the PC steel material of the PC steel material fixing device and buried in concrete, and after the concrete hardens, the recess forming member is removed from the concrete and a filling part is recessed, and the PC A method for fixing PC steel materials in the boss tension construction method, which is characterized in that mortar or concrete is poured into the filling part after the steel material is tensioned and fixed.