JP6863549B2 - Prestressed concrete tension material - Google Patents

Description

The present invention relates to a tension material for prestressed concrete that introduces a tension force in a prestressed concrete post-tension system, and in particular, an aggregate cable in which a plurality of PC steel strands (strands) such as 7 or more are bundled is made of resin, metal, or the like. The present invention relates to a tensioning material which is coated with a sheath formed by the above-mentioned material and is pre-filled with a resin compound which is cured after tensioning of the assembly cable between the assembly cable and the sheath. In the present invention, "pre-filled" is synonymous with "pre-applied".

At present, in prestressed concrete girders using the post-tension method for bridges, a cable assembly in which a plurality of PC steel stranded wires are bundled is frequently used as an inner cable. The post-tension method is a method of introducing prestress by tensioning the PC steel stranded wire inserted into the sheath portion of the concrete member after the concrete strength is developed. The inner cable is a cable that introduces prestress by transmitting the tension force of the PC steel stranded wire by adhering to concrete.

The cable is an aggregate cable in which 12 SWPR7BL 12.7 mm PC steel strands are bundled from 7 SWPR7BL, which is a class B steel material (tensile strength of ^{about 1,860 N / mm 2) in JIS G 3536, or SWPR7BL7.} In many cases, an aggregate cable in which 12 PC steel stranded wires of 15.2 mm from the book are bundled is used.
In prestressed concrete members using the general post-tension method, a polyethylene (resin) or metal sheath is placed before the concrete is placed, and the aggregate cable is placed in this sheath after the concrete is placed. After inserting and the strength of the concrete reaches the specified strength, the aggregated cable is tensioned and fixed, and finally, cement milk is used for the purpose of rust prevention treatment of the aggregated cable and adhesion and integration treatment of the aggregated cable and concrete. Etc. (a resin compound sometimes called grout) is injected between the assembly cable and the sheath. Such a general post-tension method is disclosed in, for example, Japanese Patent Application Laid-Open No. 2014-029088 (Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-029088

In the general post-tension method, the porosity (= (sheath cross-sectional area-aggregate cable cross-sectional area) / sheath breakage) is about 60% in cross-sectional area ratio so that grout such as cement milk is completely filled over the entire length. Area) is set to set the sheath diameter. Since it is necessary to stabilize the quality of filling property of cement milk or the like after tension, it is necessary to use a sheath having a large porosity.

However, since it is necessary to ensure the porosity of grout such as cement milk after tension, the ratio of the area (void) obtained by subtracting the aggregate cable cross-sectional area from the sheath cross-sectional area to the sheath cross-sectional area. The porosity to be represented must be as large as about 60%, and the sheath diameter is considerably larger than the aggregate cable diameter required for mechanics. Therefore, it may not be preferable in construction in a narrow construction location or the like.

Further, as the aggregate cable used in the general post-tension method, as described above, an aggregate cable in which 12 PC steel strands are bundled is adopted, and the configuration is such that three inner layers surround the inner layer. It is composed of 9 outer layers.
However, since the 12-strand bundled cable is formed in this way, the three PC steel stranded wires (inner layer strands) in the inner layer are surrounded by the nine PC steel stranded wires (outer layer strands) in the outer layer. , The gap between the outer layer strands where the grout such as cement milk can enter is only three directions per inner layer strand, and the area where the strand and the grout such as cement milk come into contact is hardly obtained, and the tension of the PC steel stranded wire is applied to concrete. It may not be possible to obtain a reasonable adhesive force in the inner cable that transmits and introduces prestress due to adhesion with.

The present invention has been developed in view of the above-mentioned problems of the prior art, and an object of the present invention is a tension material for prestressed concrete that introduces tension in a prestressed concrete post-tension method. Preferable properties (preferably workability even in narrow construction sites, and preferable workability by omitting the sheath placement work and the grout filling work such as cement milk), rust prevention by the filled grout, etc. It is to provide a tension material for prestressed concrete that can introduce sufficient prestress by improving the quality stability and realizing a rational adhesion force of PC steel stranded wire to concrete. ..

In order to achieve the above object, the tension material for prestressed concrete according to the present invention takes the following technical measures.
That is, the tension material for prestressed concrete according to the present invention is a tension material for prestressed concrete that introduces tension force in the post-tension method of prestressed concrete, and an aggregate cable composed of a plurality of PC steel stranded wires is sheathed. The assembly is covered with a resin formulation that cures after tension of the assembly cable between the PC stranded wire and the PC steel stranded wire and between the PC steel stranded wire and the sheath. As the body cable, a high-strength PC steel stranded wire capable of introducing a tension force equal to or higher than the 12-wire configuration of the PC steel stranded wire specified in JIS G 3536 with a 7-wire configuration was adopted.

Preferably, the aggregate cable is equivalent to a 12-piece configuration of PC steel stranded wires having a name defined by JIS and having a name of 7 to 12.7 mm or a 12-line configuration of PC steel stranded wires having a name of 7 to 15.2 mm. The above tension force can be configured to adopt a high-strength PC steel stranded wire that can be introduced in a seven-piece configuration.
More preferably, the 7-strand high-strength PC steel stranded wire configuration of 15.2 mm from 7 is adopted as opposed to the 12-strand PC steel stranded wire configuration of 12.7 mm from the 7-strand, and 15 from the 7-strand. In contrast to the 12-strand configuration of .2 mm PC steel stranded wire, a 7-strand configuration of 17.8 mm high-strength PC steel stranded wire from 19 is adopted so as to introduce a tension force equal to or higher than that. Can be done.

More preferably, said line than 12 configuration of PC steel a B type steel defined by the JIS, the tensile strength of the high-strength PC steel stranded wires are of the PC strand of Class B steel material It can be configured to be 115% to 125% with respect to the tensile strength.
More preferably, the 12-piece structure can be configured to have 3 inner layers and 9 outer layers, and the 7-line structure can be configured to have 1 inner layer and 6 outer layers.

More preferably, in the above seven configurations, the cross-sectional area of the tension material for prestressed concrete is about the space formed between the high-strength PC steel stranded wire of one inner layer and the high-strength PC steel stranded wire of six outer layers. It can be configured such that the resin compound is filled in a ratio of 50% or more.

According to the tension material for prestressed concrete according to the present invention, the workability is preferable (the workability is preferable even in a narrow construction place, and the sheath arranging work is omitted and the grout filling work such as cement milk is omitted. (Preferably), improve quality stability such as rust prevention by filled grout, and realize sufficient prestress by realizing rational adhesion of PC steel stranded wire to concrete. It is possible to provide a tension material for prestressed concrete that introduces tension in a post-tension system of prestressed concrete.

It is a figure for demonstrating the schematic structure of the tension material for prestressed concrete which concerns on embodiment of this invention. FIG. 1 is a cross-sectional view (B) of the prestressed concrete tension material of FIG. 1, and a cross-sectional view (A) of the prestressed concrete tension material according to the prior art corresponding to the tension material. FIG. 1B is a cross-sectional view (B) of a prestressed concrete tension material according to an embodiment different from FIG. 1, and a cross-sectional view (A) of a prestressed concrete tension material according to a prior art corresponding to the tension material. 2 (A) and 2 (B) and 3 (A) and 3 (B) are views for explaining the characteristics of the prestressed concrete tensioning material.

Hereinafter, the prestressed concrete tension material according to the embodiment of the present invention (hereinafter, may be referred to as a concrete tension material or simply a tension material) will be described in detail with reference to the drawings. The hatching applied to the stranded PC steel wire (strand) in FIGS. 1 to 4 does not represent the cross section of the strand, but indicates the inner layer strand. Further, the resin compound (hardened after tensioning of the assembly cable) filled or applied between the PC steel stranded wire and the PC steel stranded wire and between the PC steel stranded wire and the sheath is not hatched.

First, the tension members 100 and 200 for prestressed concrete according to the present embodiment will be roughly described. The tension materials 100 and 200 for prestressed concrete are tension materials for prestressed concrete that introduce tension force in the post-tension method of prestressed concrete. These tension members 100 and 200 are an aggregate cable composed of a plurality of (7 in this case) high-strength PC steel stranded wires 110 and 210 (high-strength PC steel stranded wire 110 × 7 wires or a high-strength PC). (Structure of 210 x 7 stranded steel wires) is covered with sheaths 130 and 230. Then, after the tension of the aggregate cable, between the high-strength PC steel stranded wires 110 and 210 and the high-strength PC steel stranded wires 110 and 210 and between the high-strength PC steel stranded wires 110 and 210 and the sheaths 130 and 230. The curable resin formulations 120 and 220 are pre-filled (the resin formulations 120 and 220 are pre-coated on the high-strength PC steel stranded wires 110 and 120).

Here, in the present invention, as this aggregate cable (high-strength PC steel stranded wire 110 × 7 or high-strength PC steel stranded wire 210 × 7), the PC steel stranded wire specified by JIS G 3536 It is characterized by adopting a high-strength PC steel stranded wire that can introduce a tension force equal to or higher than that of the 12-strand structure in the 7-strand configuration. More specifically, as an aggregate cable, the name specified by JIS is equal to or higher than the 12-wire configuration of PC steel stranded wire of 7 to 12.7 mm or the 12-wire configuration of PC steel stranded wire of 15.2 mm from 7. High-strength PC steel stranded wire that can introduce the tension force of 7 is adopted.

More specifically, with respect to the 12-strand configuration of 12.7 mm PC steel stranded wire shown in FIG. 2 (A) as the conventional technique, the tension force of 7 to 15 (which can realize a tension force equal to or higher than this configuration) is 15-strand. FIGS. 1 and 2 (B) show a tension material 100 for prestressed concrete according to the present embodiment, which employs a configuration of seven stranded wires of high-strength PC steel of .2 mm.
Further, with respect to the 12-strand configuration of 15.2 mm PC steel stranded wire from 7 as shown in FIG. 3 (A) as a conventional technique, 17.8 mm from 19 (which can realize a tension force equal to or higher than this configuration). FIG. 3 (B) shows another tension material 200 for prestressed concrete according to the present embodiment, which employs the configuration of seven high-strength PC steel stranded wires.

Here, as a conventional technique, the 12-piece PC steel stranded wire 1110 (from 7 lines) used for the tension material 1100 shown in FIG. 2 (A) and the tension material 2200 shown in FIG. 3 (A) The 12-strand PC steel stranded wire 2210 (from 7) used is a class B steel material specified by JIS. On the other hand, the seven high-strength PC steel stranded wires 110 (from seven) used for the tension material 100 shown in FIG. 2 (B) and the tension material 200 shown in FIG. 3 (B). seven construction of high-strength PC steel stranded wires 210 used (from 19 pieces) is a line from the high-strength PC steel, the tensile strength of the line from the high-strength PC steel, PC strand of B type steel material It is 115% to 125% with respect to the tensile strength of.

Then, as a prior art, the 12-strand PC steel stranded wire 1110 (from 7) in the tension member 1100 shown in FIG. 2 (A) and the 12-strand configuration in the tension member 2200 shown in FIG. 3 (A). In the PC steel stranded wire 2210 (from 7), 3 inner layers (inner layer strand 1110C in FIG. 2 (A) and inner layer strand 2210C in FIG. 3 (A)) and 9 outer layers (FIG. 2 (A)). It is composed of the outer layer strand 1110S of No. 3 and the outer layer strand 2210S) of FIG. 3 (A). On the other hand, as the present embodiment, the high-strength PC steel stranded wire 110 (from 7) of the tension material 100 shown in FIG. 2 (B) and the high-strength PC steel stranded wire 110 (from 7) shown in FIG. 3 (B). In the 7-strength PC steel stranded wire 210 (from 19) of the tension material 200, one inner layer (inner layer strand 110C in FIG. 2B and inner layer strand 210C in FIG. 3B) and It is composed of six outer layers (outer layer strand 110S in FIG. 2B and outer layer strand 210S in FIG. 3B).

More specifically, as the present embodiment, in the seven-piece configuration (one inner layer and six outer layers) of the tension material 100 shown in FIG. 2 (B) and the tension material 200 shown in FIG. 3 (B), the inner layer 1 With respect to the space formed between the high-strength PC steel stranded wire of the book and the six high-strength PC steel stranded wires of the outer layer, the resin compound is 50% or more in the cross-sectional area ratio of the prestressed concrete tensioning materials 100 and 200. It is filled.

Roughly speaking, the prestressed concrete tensioning materials 100 and 200 according to the present embodiment having such characteristics will be described in more detail.
FIG. 1 (A) is a perspective view of the tension member 100, and FIG. 1 (B) is a high-strength PC steel strand 110 (1) constituting an aggregate cable (7-piece configuration) of the tension member 100. The outer view of the inner layer strand 110C and the six outer layer strands 110S) of the book is shown, and FIG. 1 (C) shows a cross-sectional view of one high-strength PC steel stranded wire (strand) 110.

In this prestressed concrete tension material 100, an aggregate cable composed of seven high-strength PC steel stranded wires 110 (PC steel stranded wire 110 × 7 wires) is covered with a sheath 130, and the high-strength PC steel is used. A resin compound 120 that cures after tension of the aggregate cable is pre-filled between the stranded wire 110 and the high-strength PC steel stranded wire 110 and between the high-strength PC steel stranded wire 110 and the sheath 130. That is, the tension material 100 is composed of seven high-strength PC steel stranded wires 110, a sheath 130, and a resin compound 120. It should be noted that such a configuration itself is common to the tension member 100 and the tension member 200. Further, as shown in FIG. 1 (B), the high-strength PC steel stranded wire 110 is made by twisting seven high-strength PC steel wires 112 (in the high-strength PC steel stranded wire 210, 19 high-strength PC steel wires). Is formed. However, FIG. 1 (A) does not show the twisted state. Here, the intrusion of the resin compound between the tightly twisted PC steel wires is not considered in the present invention. That is, because they are tightly twisted together, it is not realistically possible for the resin compound to enter between the PC steel wire 112 and the PC steel wire 112, for example.

With reference to FIG. 2, the detailed configuration of the tension material 100 will be described with reference to the tension material 1100 (conventional technique) capable of introducing a tension force equal to or higher than that of the tension material 100. The tension material 1100 shown in FIG. 2 (A) and the tension material 100 shown in FIG. 2 (B) are basically different in the aggregate cable and the PC steel stranded wire (strand), and the plurality of PC steel stranded wires and the sheath are basically different. And the resin compound are the same, and the high-strength PC steel stranded wire 110 has a PC steel stranded wire 1110, the sheath 130 has a sheath 1130, and the resin compound 120 has a resin compound 1120, respectively. Correspond.

The PC steel stranded wire (strand) 1110 shown in FIG. 2 (A) (both the inner layer strand 1110C and the outer layer strand 1110S) is a PC steel stranded wire (class B steel material) having a name defined by JIS and having a name of 12.7 mm. Is. Three PC steel strands (strands) 1110 are arranged on the inner layer side (inner layer strand 1110C) and nine on the outer layer side (outer layer strand 1110S).

On the other hand, the high-strength PC steel stranded wire (strand) 110 shown in FIG. 2 (B) (both the inner layer strand 110C and the outer layer strand 110S) is a high-strength PC steel stranded wire of 15.2 mm from seven. One high-strength PC steel stranded wire (strand) 110 is arranged on the inner layer side (inner layer strand 110C) and six on the outer layer side (outer layer strand 110S).
With reference to FIG. 3, the detailed configuration of the tension material 200 is compared with the tension material 2200 (conventional technique) capable of introducing a tension force equal to or higher than that of the tension material 200 (separate from the tension material 100). explain. The tension material 2200 shown in FIG. 3 (A) and the tension material 200 shown in FIG. 3 (B) are basically different in the aggregate cable and the PC steel stranded wire (strand), and the plurality of PC steel stranded wires and the sheath are basically different. And the resin compound are the same, and the high-strength PC steel stranded wire 210 has the PC steel stranded wire 2210, the sheath 230 has the sheath 2230, and the resin compound 220 has the resin compound 2220, respectively. Correspond.

Figure 3 (A) to indicate PC steel stranded wires (strands) 2210 (inner layer strands 2210C also the outer layer strands 2210S also), PC steel stranded wires of 15.2mm from nickname is seven defined by JIS (B species steel) Is. Three PC steel strands (strands) 2210 are arranged on the inner layer side (inner layer strand 2210C) and nine on the outer layer side (outer layer strand 2210S).

On the other hand, the high-strength PC steel stranded wire (strand) 210 shown in FIG. 3 (B) (both the inner layer strand 210C and the outer layer strand 210S) is a high-strength PC steel stranded wire of 17.8 mm from 19 lines. One high-strength PC steel stranded wire (strand) 210 is arranged on the inner layer side (inner layer strand 210C) and six on the outer layer side (outer layer strand 210S).
As described above, the tension material 100 according to the present embodiment shown in FIG. 2 (B) can introduce the same tension force as the tension material 1100 shown in FIG. 2 (A), and the tension material 100 shown in FIG. 3 (B) can be introduced. The tension material 200 according to the form can introduce a tension force equivalent to that of the tension material 2200 shown in FIG. 3 (A). This will be described in more detail below. In the following, the difference between the tension material 1100 and the tension material 2200 having a 12-strand structure (both of the prior art) and the tension material 100 and the tension material 200 having a 7-strand structure (both in the present embodiment) will be described. It is the same except for the wire diameter of the PC steel stranded wire, and it is a major feature that the 12-strand structure is changed to the 7-strand structure. Therefore, the action and effect associated therewith will be described.

The 12-strand configuration shown in FIGS. 2 (A) and 3 (A) is composed of 3 inner-layer strands and 9 outer-layer strands. When the resin formulation is applied to 12 strands and then inserted into the sheath (or when the resin formulation is filled after inserting the 12 strands into the sheath), 9 for the 3 inner layer strands. The resin compound penetrates between the outer strands of the book as shown by the white arrows. Therefore, the resin compound only invades from only three directions per inner layer strand.

As a result, in the 12-piece configuration (3 inner layers and 9 outer layers) of the tension material 1100 shown in FIG. 2 (A) and the tension material 2200 shown in FIG. 3 (A), three PC steel stranded wires in the inner layer are used. With respect to the space formed between the outer layer and the nine PC steel strands of the outer layer, the resin compound is not filled in more than 50% in the cross-sectional area ratio of the prestressed concrete tension members 1100 and 2200. As a result, the resin compound cannot be sufficiently applied (or filled) to the inner layer strand, so that the adhesive force between the strand and the resin compound cannot be reasonably secured. The tension material 1100 shown in FIG. 2 (A) and the tension material 2200 shown in FIG. 3 (A) (arrangement of the PC steel wire (112) forming the stranded PC steel wire in the PC steel wire (112)) have a V-axis as an axis of symmetry. It is not line-symmetrical with the H-axis as the axis of symmetry, nor is it point-symmetrical with the cross-sectional center of the tensioning material (the intersection of the V-axis and the H-axis) as the center of symmetry.

On the other hand, in the 7-strand configuration shown in FIGS. 2 (B) and 3 (B), the configuration is composed of one inner layer strand and six outer layer strands. When the resin compound is applied to 7 strands and then inserted into the sheath (or when the resin compound is filled after inserting the 7 strands into the sheath), 6 is applied to one inner layer strand. The resin compound penetrates between the outer strands of the book as shown by the white arrows. Therefore, the resin compound invades from 6 directions per inner layer strand.

As a result, in the seven-piece configuration (one inner layer and six outer layers) of the tension material 100 shown in FIG. 2 (B) and the tension material 200 shown in FIG. 3 (B), one inner layer is made of high-strength PC steel. With respect to the space formed between the stranded wire and the high-strength PC steel stranded wire of the six outer layers, the resin compound is filled in 50% or more of the cross-sectional area ratios of the prestressed concrete tensioning materials 100 and 200. .. As a result, the resin compound can be sufficiently applied (or filled) to the inner layer strand, so that the adhesive force between the strand and the resin compound can be reasonably secured. The tension member 100 shown in FIG. 2B and the tension member 200 shown in FIG. 3B (arrangement of the PC steel wire (112) forming the PC steel stranded wire in the tension member 200) have a V-axis as an axis of symmetry. It is line symmetry with the H axis as the axis of symmetry, and point symmetry with the center of the cross section of the tension material (the intersection of the V axis and the H axis) as the center of symmetry.

As described above, in the case of the tension member 1100 and the tension member 2200 according to the prior art, the diameter of the aggregate cable (the diameter of the circle shown by the dotted line in FIGS. 2 and 3) must be larger than the diameter required for mechanics. In addition, the adhesive force of the resin compound to the inner layer strand cannot be reasonably secured.
On the other hand, in the case of the tension material 100 and the tension material 200 according to the present embodiment, the configuration of the aggregated cable in which 12 bundles are bundled as in the prior art is not used (three strands in the inner layer are nine outer layers). Since the structure is surrounded by strands, the resin compound can penetrate between the outer layer strands (rather than the structure in which there are only three directions per inner layer strand), and the structure is a bundled cable consisting of seven bundles in the inner layer. Since one strand is surrounded by six outer layer strands, there are six directions for each inner layer strand between the outer layer strands through which the resin compound can penetrate. Therefore, the resin compound and the inner layer strand are used. Since a sufficient area in contact with the material can be secured, a reasonable adhesive force can be obtained.

Further, referring to FIGS. 2 and 3,
In FIG.
(L (1100A) x 6 + L (1100B) x 3)> (L (100) x 6),
((L (1100A) x 6 + L (1100B) x 3) / 9) <L (100),
In FIG.
(L (2200A) x 6 + L (2200B) x 3) <(L (200) x 6),
((L (2200A) x 6 + L (2200B) x 3) / 9) <L (200),
It has become.

That is, in FIG. 3, the total outer surface area of the outer layer strands is large, and the outer surface area (average surface area) per strand is large. Therefore, in FIG. 2, the total outer surface area of the outer layer strands is large. However, since the outer surface area (average surface area) per strand is large, the adhesion area of the resin compound per (at least) outer layer strand can be increased. As a result, a sufficient area in contact between the resin compound and the outer layer strand can be secured, so that a reasonable adhesive force can be further obtained. In the present invention, at least one of the total outer surface area of the outer layer strands and the outer surface area (average surface area) per outer layer strand is larger than that of the conventional 12-layer configuration (3 inner layers and 9 outer layers). As a result, there is no particular limitation as long as a sufficient area in contact between the resin compound and the outer layer strand can be secured and a reasonable adhesive force can be further obtained.

Further, with respect to the prior art disclosed in Patent Document 1, the porosity, which represents the ratio of the area (void) obtained by subtracting the steel cross-sectional area from the sheath cross-sectional area to the sheath cross-sectional area, is set to about 60%. In order to secure the porosity of the grout such as cement milk later, a sheath diameter considerably larger than the sheath diameter (tension material diameter) required mechanically was required, but the tension material according to the present embodiment was required. In the case of 100 and tension material 200, between the high-strength PC steel strands 110, 210 and the high-strength PC steel strands 110, 210 and between the high-strength PC steel strands 110, 210 and the sheaths 130, 230. , Since the resin formulations 120 and 220 that cure after tension of the aggregate cable are pre-filled, a diameter having a large porosity with respect to the aggregate cable as in the prior art disclosed in Patent Document 1. There is no need to adopt a large sheath.

FIG. 4 shows the characteristics of the prestressed concrete tensioning material shown in FIGS. 2 (A) and 2 (B) and FIGS. 3 (A) and 3 (B), respectively.
As shown in FIG. 4,
-Related to the present embodiment in which a 7-strand high-strength PC steel stranded wire configuration of 15.2 mm from 7 is adopted as opposed to a 12-strand configuration (conventional technique) of PC steel stranded wire of 7 to 12.7 mm. Although the tension material 100 for prestressed concrete has a small diameter and a light unit weight, it can introduce a tension force equal to or higher than that of the prior art.
-Related to the present embodiment in which a 7-strand high-strength PC steel stranded wire configuration of 19 to 17.8 mm is adopted as opposed to a 12-strand configuration (conventional technique) of PC steel stranded wires of 7 to 15.2 mm. Another tension material 200 for prestressed concrete can introduce a tension force equal to or higher than that of the prior art, despite its small diameter and light unit weight.
You can see that.

As described above, the tension material 100 and the tension material 200 according to the present embodiment can exhibit the following effects.
(1) By adopting high-strength PC steel stranded wire instead of PC steel stranded wire of class B steel specified by JIS G 3536, the required number of strands constituting the aggregate cable can be increased (12 to 7). The diameter of the assembly cable can be reduced, and the unit weight can be lightened and suppressed.
(2) One inner layer strand by changing the strand configuration (number and arrangement) of the aggregate cable from 12 (3 inner layers and 9 outer layers) to 7 (1 inner layer and 6 outer layers). Reasonable adhesive force can be realized due to the improvement of the filling property of the resin compound and the increase of the adhesion area, and the increase of the adhesion area of the resin compound per outer layer strand.
(3) By applying the resin compound to the aggregate cable before construction, a porosity of about 60% for ensuring the filling property of grout such as cement milk becomes unnecessary (disclosed in Patent Document 1). The outer diameter of the sheath can be reduced (compared to the prior art).

As described above, it is a tension material for prestressed concrete that introduces tension force in the post-tension method of prestressed concrete, and is preferable in workability (preferably workability even in a narrow construction place, and further, sheath placement work is omitted. (Preferably workability by omitting grout filling work such as cement milk), improving quality stability such as rust prevention by filled grout, and rational tension of PC steel stranded wire with concrete. It is possible to provide a tension material for prestressed concrete that can realize adhesive force and introduce sufficient prestress.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The present invention is preferable for a tension material for prestressed concrete that introduces a tension force in a post-tension method of prestressed concrete, and is preferable in workability (preferably workability even in a narrow construction site, and further, sheath placement work is omitted and cement is used. Workability is preferable by omitting the grout filling work of milk etc.), improving the quality stability such as rust prevention by the filled grout, and making the tension of the PC steel stranded wire a reasonable adhesion to concrete. It is particularly preferable in that it can be realized and sufficient prestress can be introduced.

100, 200 Prestressed concrete tension material 110, 210 PC steel stranded wire 120, 220 Resin compound 130, 230 sheath

Claims (6)

A tension material for prestressed concrete that introduces tension in the post-tension system of prestressed concrete.
An aggregate cable consisting of multiple PC steel stranded wires is coated with a sheath.
A resin formulation that cures after tension of the assembly cable is filled between the PC steel stranded wire and the PC steel stranded wire and between the PC steel stranded wire and the sheath.
As the aggregate cable, a tension force equal to or higher than that of 12 PC steel stranded wires specified in JIS G 3536 is applied to 7 cables because the tensile strength per wire is higher than that of the PC steel stranded wire. A tension material for prestressed concrete that uses high-strength PC steel stranded wire that is not specified in JIS G 3536 and has a different name and can be introduced in the configuration. As the aggregate cable, the name specified in JIS G 3536 is equal to or higher than the 12-wire configuration of PC steel stranded wires of 7 to 12.7 mm or the 12-strand configuration of PC steel stranded wires of 15.2 mm from 7 wires. The tension material for prestressed concrete according to claim 1, wherein the tension force of the above is not specified by JIS G 3536 which can be introduced in a 7-piece configuration, and a high-strength PC steel stranded wire having a different name is used. In contrast to the 12-strand PC steel stranded wire configuration of 12.7 mm from the 7-strand, a 7-strand PC steel stranded wire configuration of 15.2 mm from 7 is adopted.
In contrast to the 12-strand configuration of 15.2 mm PC steel stranded wire from the above 7, a 7-strand configuration of high-strength PC steel stranded wire of 19 to 17.8 mm was adopted.
The tension material for prestressed concrete according to claim 2, which introduces a tension force equal to or higher than that. The 12-piece PC steel stranded wire is a class B steel material defined by JIS G 3536.
Tensile strength of the high-strength PC steel stranded wires is 115% to 125% with respect to the tensile strength of the PC strand of Class B steel material, prestressed according to any one of claims 1 to 3 Tension material for concrete. The 12-piece configuration consists of 3 inner layers and 9 outer layers.
The tension material for prestressed concrete according to any one of claims 1 to 4, wherein the seven-piece structure has one inner layer and six outer layers. In the 7-piece configuration, the space formed between the high-strength PC steel stranded wire of one inner layer and the high-strength PC steel stranded wire of six outer layers is 50% of the cross-sectional area ratio of the prestressed concrete tension material. The tensioning material for prestressed concrete according to claim 5, further filled with the resin compound.

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