Method for connecting PC steel strands

Abstract

To provide a connector for a PC steel stranded wire that prevents penetration of corrosion factors even when voids occur due to the amount of wedge set on the primary side of the connector.SOLUTION: A PC steel strand connector 100 comprises: a connector primary side holding portion (connector primary side wedge 114 and connector primary side sleeve 116) that holds an anchorage member of a primary side PC steel strand 10 in tension; a connector secondary side holding portion (connector secondary side wedge 124 and connector secondary side sleeve 126) that holds a secondary side PC steel strand 20 in tension, and an elastic buffer 110 provided on the side of the primary side PC steel wire 10 rather than the connector primary side holding portion and compressed in excess of a set amount of the connector primary side wedge 114 that occurs when the secondary side PC steel wire 20 is tensed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a connector for prestressing post-tensioned prestressed concrete, and particularly to a connector of a direct embedding connection type. In the connector of the direct embedding connection type, even if a gap due to the set amount of the connector primary side holding occurs, it is possible to prevent the intrusion of corrosion factors that cause corrosion of the connector, etc. Or, in the case where the coupler sheath is fixed to the connection bottom plate with bolts (as a separate member from the support pressure plate) on the primary side of the connector in the coupler sheath type connector, the wedge on the primary side of the connector is not fixed. It is possible to prevent the occurrence of a gap between the connection bottom plate and the primary side of the connector due to the play. (Ultimately, the connection bottom plate can be appropriately fixed and the coupler sheath can be easily attached, and resin leakage during resin filling into the coupler sheath can be prevented.) The present invention relates to a connector for PC steel materials (in the present invention, this PC steel material refers to a wire rather than PC steel).

Background Art

[0002] Conventionally, in a post-tensioned prestressed concrete (PC) structure, in a concrete joint portion for connecting PC steel materials used to prestress concrete, after connecting each PC steel material of the prior construction area A and the subsequent construction area B using a connector, when tensioning the PC steel material of the subsequent construction area B, a direct embedding type connector or a coupler sheath type connector has been used so that the connector is not restricted from moving by the concrete.

[0003] ​​​​​​​Japanese Patent Publication No. 2007-046313 (Patent Document 1), filed by the applicant of the present application, discloses a connection method using a directly embedded type connector. The directly embedded connection method for PC steel materials disclosed in Patent Document 1 is a tension connection method for PC steel materials in which PC steel materials are connected by a direct embedding method using a connection device having a primary side connection part and a secondary side connection part at a concrete joint between a preceding work section and a succeeding work section, characterized in that when tensioning the PC steel materials of the succeeding work section, a bearing pressure relief means is provided in relation to the terminal part of the secondary side connection part so that the connection device can move against the restraining force due to the bearing pressure of the concrete, while an outer covering layer is attached to the outer circumference of the connection device in order to avoid direct fixing of the connection device to the concrete.

[0004] According to this direct embedding connection method for PC steel members, when connecting PC steel members under tension (meaning the primary PC steel members are already tensioned and anchored) at the concrete joint between the preceding section A and the succeeding section B using the direct embedding method, a bearing pressure relief means with a simple structure is attached in relation to the terminal end of the secondary connection part of the connection device, and corrosion-resistant tape is used as the outer layer. The process involves simply attaching an outer sheath to the outer circumference of the connector using a simple method such as spiral winding, eliminating the need for a space-forming casing tube (coupler sheath) that covers the entire connector, and also eliminating the need to fill the space around the connector with resin on-site. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-046313 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The direct embedding connection method for PC steel materials disclosed in Patent Document 1 has been highly praised and well received for its significant improvement in workability, as it eliminates the need for a coupler sheath and the requirement to fill the space around the connection device (coupler sheath) with resin on-site. However, if a component consisting of a wedge 14 and a sleeve 16 (anchoring member) is used on the primary side of the connector 300, and the secondary PC steel material is tensioned and anchored before the primary PC steel material is tensioned and anchored (this case is the only one that can occur), the problems shown in Figure 10 may occur. In the following, it will be stated that after the PC steel material has been tensioned and anchored using such an anchoring member, the wedge is fixed or held by the sleeve. Conversely, before the PC steel material is tensioned and anchored, the wedge is not fixed or held by the sleeve, and there may be play between the wedge and the sleeve, or a set amount may occur when the PC steel material is tensioned.

[0007] As shown in Figure 10, in the direct embedding connection method of PC steel materials disclosed in Patent Document 1, a connector 300 is used to connect the primary PC steel strand 10 of the preceding section A of the concrete structure to the secondary PC steel strand 20 of the succeeding section B. In Patent Document 1, which is common practice, the primary PC steel strand 10 is tensioned before being connected to the secondary PC steel strand 20, which is the secondary steel material, by the connector 300. Fixing member ( Here, the primary PC steel strand 10 is anchored by a wedge 14 and sleeve 16) to maintain tension, and is then connected to the secondary PC steel strand 20, which is the secondary steel material, to tension the secondary PC steel strand 20. However, this is not the case in general, but rather the case before the primary PC steel strand 10, which is the primary PC steel material, is tensioned and anchored. The primary PC steel member is connected by a connector 300. When the secondary PC steel strand 20, which is the secondary PC steel material, is tensioned, the primary PC steel strand 10 Fixing members (wedge 14 and sleeve 16) that tension and fix the components. The amount of material used creates a void G, which (even though it is embedded in concrete) may allow corrosive factors to enter and cause corrosion of the connector 300.

[0008] Furthermore, as shown in Figure 11, when a new connector 400 is used (separate from the wedge 14 and sleeve 16 that anchor the primary PC steel strands 10, which are the primary steel materials), and the connector is a primary wedge 114 and a primary sleeve 116 on its primary side (an anchoring member), even in the general case where the secondary PC steel strands 20, which are the secondary PC steel materials, are tension-anchored after the primary PC steel strands 10, which are the primary PC steel materials, have been tension-anchored by the wedge 14 and sleeve 16, the following problems may occur.

[0009] As shown in Figure 11, in the state before tensioning the secondary PC steel strands 20, which are the secondary PC steel material, the primary PC steel strands 10, which are the primary PC steel material, are tensioned and fixed by the wedge 14 and sleeve 16, while the primary wedge 114 of the connector 400, which is the primary fixing member, is fixed by the primary sleeve 116 of the connector. (Establishment) Because it is not done, when the secondary PC steel strand 20 is tensioned, the connector primary side The retaining part (fixing member consisting of the primary side wedge 114 and the primary side sleeve 116 of the connector) The resulting gap G (due to the amount of material used) may allow corrosive factors to enter, potentially causing corrosion of the connector 400 (even though it is embedded in concrete).

[0010] Furthermore, as shown in Figure 12, in a new connector 500, if the primary side of the connector 500 uses a component (fixing member) consisting of a primary side wedge 114 and a primary side sleeve 116, and is a coupler sheath type rather than a directly embedded type, and in the connector 500, if the coupler sheath 220 is connected to the connection bottom plate 210 (a separate component from the bearing plate) with a bolt 214 on the primary side of the connector 500, there is a possibility that a gap G may occur between the connection bottom plate 210 and the primary side of the connector when connecting the primary side PC steel wire 10, which is the primary side PC steel material, and the secondary side PC steel wire 20, which is the secondary side PC steel material, using the connector 500 (more specifically, until the coupler sheath 220 is fixed to the connection bottom plate 210 with a bolt 214), due to play caused by the primary side wedge 114 not being fixed. In other words, this refers to a case where the connecting base plate 210 cannot be properly fixed during the process of connecting the primary PC steel material, which is the primary PC steel strand 10, and the secondary PC steel material, which is the secondary PC steel strand 20, using the connector 500.

[0011] When such a gap G occurs, as shown in Figures 12(A) and 12(B), it may become impossible to properly fix the connecting bottom plate 210 (before tensioning the secondary PC steel strands 20, which are the secondary PC steel material). This may make it difficult to easily attach the coupler sheath 220, or may cause resin leakage when filling the coupler sheath 220 with resin. Here, this resin leakage means that even if the coupler sheath 220 can be connected to the connecting bottom plate 210, due to the presence of the gap G shown in Figures 12(A) to 12(B) caused by the play resulting from the primary side wedge 114 of the connector not being fixed, the coupler sheath 220 can move in the longitudinal direction of the PC steel material together with the connecting bottom plate 210, as indicated by the black arrow in Figure 12(C), which may cause a gap G to occur between the bearing plate 18 and the connecting bottom plate 210, and resin may leak from the gap G shown in Figure 12(D).

[0012] This invention was developed in view of the above-mentioned problems of the prior art, and its purpose is to provide a connection for PC steel strands used to apply prestress to post-tensioned prestressed concrete. method In a direct buried connection type connector, the primary side of the connector Retaining part (fixing member) Even if a gap occurs due to the set amount, it prevents the intrusion of corrosive factors that cause corrosion of the connector, or, in the case of a coupler sheath type connector, when the coupler sheath is fixed to the connection bottom plate (a separate component from the bearing plate) with a bolt on the primary side of the connector, the wedge on the primary side of the connector is not fixed. (The primary side retaining portion of the connector (the fixing member consisting of the wedge 114 and the primary side sleeve 116 of the connector) is not fixed.) PC steel strands prevent the occurrence of a gap between the connecting base plate and the primary side of the connector due to play (ultimately allowing the connecting base plate to be properly fixed, making it easy to attach the coupler sheath, and preventing resin leakage when resin is filled into the coupler sheath). the connection The objective is to provide a follow-up method. [Means for solving the problem]

[0013] To achieve the above objective, the present invention relates to RuP The method for connecting stranded steel wires comprises the following technical means. In other words, the connection of PC steel strands according to the present invention method This is a connection method for connecting a primary PC steel strand and a secondary PC steel strand using a connector, wherein the connector is a fixing member for the primary PC steel strand. and the primary side PC steel strand A primary side holding portion of the connector, including a primary side wedge and a primary side sleeve of the connector, which tensions and holds the PC steel strands, and a secondary side holding portion of the connector, which tensions and holds the secondary side PC steel strands. It is a plate-like object that is divided or not divided, and has a hole through which the primary sleeve of the connector is inserted. The connection method includes an elastic cushioning material, In the state in which the primary PC steel strands are tensioned and fixed, The contact Before attaching the primary side sleeve of the connector, or after attaching the primary side sleeve of the connector, on the side of the primary side PC steel strands that is closer to the primary side holding portion of the connector, This occurs because the primary PC steel strands are tensioned and fixed, but the primary side holding portion of the connector is not fixed. The primary side of the aforementioned connector Holding part Install an elastic cushioning material that has been compressed beyond its set amount. The process includes an installation step and a tensioning step after the installation step in which the secondary PC steel strands are tensioned, wherein after the tensioning step, the compressed and installed elastic cushioning material expands by the amount of settling generated at the primary side holding portion of the connector, so as not to create a gap between the primary side of the connector and the bearing plate. It is characterized by the following:

[0014] Preferably, the elastic buffer material can be configured to be provided so as to contact an end surface on the wire side of the primary PC steel wire in the primary sleeve of the connector. More preferably, the elastic buffer material can be configured such that an anti-rust material or an epoxy resin is impregnated or coated thereon. More preferably, the connector is a directly embedded type connector, an outer skin layer is adhered to the outer periphery of the connector, a pressure buffer material is provided at the secondary terminal of the connector, and when the compressed elastic buffer material expands, the primary side of the connector generated when the wire of the secondary PC steel wire is tensioned Holding part It can be configured so as not to generate a gap corresponding to the set amount.

[0015] More preferably, the connector is a coupler sheath type connector, a coupler sheath is connected to the outer periphery of the connector using a connection bottom plate, and when the compressed elastic buffer material expands, This occurs because the primary PC steel strands are tensioned and fixed, but the primary side holding portion of the connector is not fixed. voids and the gap between the connecting bottom plate and the primary side of the connector are not generated like It can be configured to restrict the longitudinal movement of the wire of the PC steel wire of the connection bottom plate.

Effect of the Invention

[0016] According to the present invention ru connection According to the continuous method, when connecting the PC steel wire used to apply prestress to post-tensioned prestressed concrete of In the case of using a directly embedded connection type connector, even if a gap is generated due to the set amount on the primary side of the connector, it prevents the intrusion of corrosion factors that cause corrosion of the connector, or, in the case of fixing the coupler sheath to the connection bottom plate (as a separate member from the pressure plate) with bolts on the primary side of the connector in a coupler sheath type connector, the wedge on the primary side of the connector is not fixed Retaining part (fixing member) (The primary side retaining portion of the connector (the fixing member consisting of the wedge 114 and the primary side sleeve 116 of the connector) is not fixed.) ​This prevents gaps from forming between the connecting base plate and the primary side of the connector due to play (ultimately, it allows the connecting base plate to be properly fixed, making it easy to attach the coupler sheath and preventing resin leakage when filling the coupler sheath with resin). [Brief explanation of the drawing]

[0017] [Figure 1] (A) A cross-sectional view of a portion of the side view (primary side holding portion of the connector) showing the state before the secondary PC steel strands are tensioned, and (B) A side cross-sectional view showing the state after the secondary PC steel strands are tensioned, relating to the connector 100 according to the first embodiment of the present invention. [Figure 2] (A) Two-view drawing of the elastic cushioning material 110 in Figure 1, and (B) Two-view drawing of the split-type split elastic cushioning material 111. [Figure 3] This is a diagram (part 1) illustrating the procedure for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 100. [Figure 4] This is a diagram (part 2) illustrating the procedure for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 100. [Figure 5] This is a diagram (part 3) illustrating the procedure for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 100. [Figure 6] (A) A cross-sectional view of a portion of the side view (primary side holding portion of the connector) showing the state before the secondary PC steel strands are tensioned, and (B) A side cross-sectional view showing the state after the secondary PC steel strands are tensioned, relating to the connector 200 according to the second embodiment of the present invention. [Figure 7] (A) Two views of the elastic cushioning material 110 in Figure 6, and (B) Two views of the connecting bottom plate 210 in Figure 6. [Figure 8] This is a diagram (part 1) illustrating the procedure for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 200. [Figure 9]This is a diagram (part 2) illustrating the procedure for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 200. [Figure 10] This diagram illustrates the problems that arise when connecting a primary PC steel strand to a secondary PC steel strand using a conventional connector 300. [Figure 11] This diagram illustrates the problems that arise when connecting a primary PC steel strand to a secondary PC steel strand using a conventional connector 400. [Figure 12] This diagram illustrates the problems that arise when connecting a primary PC steel strand to a secondary PC steel strand using a conventional connector 500. [Modes for carrying out the invention]

[0018] In the following, the connector and method for connecting PC steel strands according to embodiments of the present invention will be described in detail with reference to the drawings, divided into a first embodiment of a directly embedded type and a second embodiment of a coupler sheath type. The primary side steel material, the primary side PC steel strand 10, is tensioned and fixed by anchoring members (wedge 14 and sleeve 16) to maintain tension in the primary side PC steel strand 10 before it is connected to the secondary side steel material, the secondary side PC steel strand 20, by the connector 100 (or connector 200). The figures referenced in the following description are basically schematic diagrams that omit detailed structures for the sake of easy understanding of the present invention. In some cases, parts that should be represented by their external shape are shown as if the interior is visible, parts that should be represented by a cross-section are shown as external shapes, parts that should be represented by an external shape are shown as cross-sections, and hidden lines are shown as solid lines instead of dotted lines.

[0019] <First Embodiment> A direct-embedded PC steel strand connector 100 according to the first embodiment of the present invention and a method for connecting PC steel strands using the connector 100 will be described in detail with reference to Figures 1 to 5. Figure 5(B) shows the connector 100 in a state in which a primary PC steel material, which is a primary PC steel strand 10 (hereinafter sometimes simply referred to as primary PC steel strand 10), and a secondary PC steel material, which is a secondary PC steel strand 20 (hereinafter sometimes simply referred to as secondary PC steel strand 20), are connected, and Figure 5(C) shows the connector 100 in a state in which the secondary PC steel strand 20 is tensioned in the state shown in Figure 5(B).

[0020] As shown in Figures 1 to 5, this connector 100 connects the primary PC steel strand 10 and the secondary PC steel strand 20. It includes a primary side holding section of the connector, including a primary side wedge 114 and a primary side sleeve 116, which tensionably hold the anchoring members (wedge 14 and sleeve 16) of the primary PC steel strand 10; a secondary side holding section of the connector (secondary side wedge 124 and secondary side sleeve 126) which tensionably holds the secondary PC steel strand 20; and a primary side holding section provided on the primary side of the connector closer to the primary PC steel strand 10 than the primary side holding section (primary side wedge 114 and primary side sleeve 116), which generates tension when the secondary PC steel strand 20 is tensioned. Retaining part (fixing member) The system includes an elastic cushioning material 110 (or a half-cut elastic cushioning material 111) that has been compressed to an extent exceeding the set amount.

[0021] Here, the thickness of this elastic cushioning material 110 (and the half-cut elastic cushioning material 111) is in the thickness direction. Let t(3) be the free thickness when there are no constraints, t(1) be the compressed thickness of the secondary PC steel strand 20 before tensioning, and t(2) be the thickness of the secondary PC steel strand 20 after tensioning. Then t(3) > t(2) and t(2) - t(1) > primary side of connector. Holding part (fixing member) This satisfies the set quantity. Furthermore, from these two conditions, t(3)-t(1)>t(2)-t(1)>connector primary side Holding part (fixing member)The set amount is met, and the amount of compression from the free thickness t(3) (t(3)-t(1)) exceeds the set amount, so the connector 100 is equipped with an elastic cushioning material 110 (or half-cut elastic cushioning material 111) that has been compressed beyond the set amount. This elastic cushioning material 110 (and the split elastic cushioning material 111) is provided so as to abut against the end face of the primary PC steel strand 10 on the primary sleeve 116 of the connector. More specifically, it is provided between the bearing plate 18 that abuts against the anchoring member (sleeve 16 in this case) and the primary sleeve 116 of the connector.

[0022] This connector 100 is a directly embedded type connector, and as shown in Figure 5(B), an outer layer 130 is attached to the outer circumference of the connector 100, and a bearing cushioning material 132 is provided at the secondary end of the connector 100. Here, this outer layer 130 corresponds to the outer layer 6 of Patent Document 1, and for example, rust-preventive tape is wrapped around the outer circumference of the connector 100. The bearing cushioning material 132 corresponds to the bearing relief means 5 of Patent Document 1, and for example, it is a donut-shaped plate about 5 mm to 40 mm thick, made of a material that is compressible, such as urethane, silicone, soft rubber, polystyrene resin, or a similar material that is sufficiently soft compared to concrete, and has a circular hole through which the secondary PC steel strand 20 is inserted, and is attached to the secondary end of the connector 100.

[0023] With this configuration, the elastic cushioning material 110 (or half-split elastic cushioning material 111), which was compressed to a thickness t(1), stretches to a thickness t(2) when the secondary PC steel strands 20 are tensioned, thereby generating tension on the primary side of the connector when the secondary PC steel strands 20 are tensioned. Holding part (fixing member) This prevents the generation of voids G corresponding to the set amount. This reduces the possibility of corrosive factors that could cause corrosion of the connector 100 (even though it is embedded in concrete) entering the device.

[0024] In Figures 1 to 5 illustrating the connector 100, the primary PC steel strand 10 is coated with resin and covered with a sheath 12, and the secondary PC steel strand 20 is also coated with resin and covered with a sheath 22. The primary sleeve 116 of the connector and the secondary fixing member (here, the secondary wedge 124 and the secondary sleeve 126 of the connector) are connected via a secondary joint 120 and a connecting plug 118. Furthermore, in the secondary fixing member, the longitudinal movement of the secondary PC steel strand 20 of the secondary wedge 124 is restricted by a wedge retainer 122.

[0025] As shown in Figure 2(A), the elastic cushioning material 110, like the bearing cushioning material 132, is a donut-shaped plate (for example, inner diameter = outer diameter of sleeve 16, outer diameter = outer diameter of primary side sleeve 116 of connector) with a circular hole 112 through which the sleeve 16 of the anchoring member of the primary side PC steel strand 10 is inserted, and is made of a material that is sufficiently soft compared to concrete, such as compressible urethane, silicone, soft rubber, polystyrene resin, or similar. Alternatively, as shown in Figure 2(B), it may be a half-split type elastic cushioning material 111 without a hole 112. In this case, the half-split elastic cushioning material 111 is roughly C-shaped with a semicircular hole 113 instead of a hole 112, and is used in pairs. A connection method for connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using such a connector 100 will be explained in detail with reference to Figures 3 to 5.

[0026] As shown in Figure 3, this connection method involves attaching the primary side sleeve 116 of the connector beforehand. The primary side of the connector is located on the side of the primary PC steel strand 10 (more specifically, so as to abut against the end face of the primary PC steel strand 10 on the primary PC steel strand 10 side of the primary sleeve 116 of the connector, and more specifically between the bearing plate 18 that abuts against the sleeve 16 and the primary sleeve 116 of the connector) where tension is generated when the secondary PC steel strand 20 is tensioned. Holding part (fixing member) An elastic cushioning material 110, compressed to a volume exceeding the set amount (as shown in Figure 2(A)), is attached.

[0027] Furthermore, as shown in Figure 4, this connection method involves attaching the primary side sleeve 116 (and primary side wedge 114) of the connector, and then placing the primary side holding portion (primary side wedge 114 and primary side sleeve 116) on the side of the primary side PC steel strand 10 (more specifically, so as to abut the end face of the primary side sleeve 116 on the side of the primary side PC steel strand 10, and more specifically between the bearing plate 18 that abuts the sleeve 16 and the primary side sleeve 116 of the connector) to the primary side of the connector that is generated when tension is generated in the secondary side PC steel strand 20. Holding part (fixing member) It is also acceptable to attach a halved elastic cushioning material 111 that has been compressed to exceed the set amount (as shown in Figure 2(B)).

[0028] A direct-buried connection method using a connector 100 will be explained with reference to Figure 3 when using a non-split elastic cushioning material 110, and with reference to Figure 4 when using a split elastic cushioning material 111, which is a split type. A connection method common to both the elastic cushioning material 110 and the split elastic cushioning material 111 will also be explained with reference to Figure 5. Figures 3(A) and 4(A) show the state before the primary PC steel strand 10 and the secondary PC steel strand 20 are connected by the connector 100, in which the primary PC steel strand 10 is already tensioned and fixed by the fixing members (wedge 14 and sleeve 16) and the tension of the primary PC steel strand 10 is maintained. As shown in Figure 3(B), the sleeve 16, which is the anchoring member for the primary PC steel strand 10, is inserted through the hole 112, and the elastic cushioning material 110 with a free thickness t(3) is brought into contact with the bearing plate 18.

[0029] Next, as shown in Figure 3(C), attach the primary side sleeve 116 of the connector. At this time, the elastic cushioning material 110 is attached to the primary side of the connector. Holding part (fixing member) The set amount is compressed to exceed the set amount, so that the compression amount (t(3)-t(1)) exceeds the set amount. Next, as shown in Figure 3(D), the primary side wedge 114 of the connector is attached to the primary side sleeve 116 of the connector. In this state, the thickness t(1) of the elastic cushioning material 110 is maintained. The case in which the split elastic cushioning material 111 is used instead of the elastic cushioning material 110 shown in Figures 3(B) to 3(D) will be explained with reference to Figures 4(B) to 4(D). As shown in Figure 4(B), attach the primary side sleeve 116 of the connector.

[0030] Next, as shown in Figure 4(C), the primary side wedge 114 of the connector is attached to the primary side sleeve 116 of the connector. At this time, the elastic cushioning material 110 is attached to the primary side of the connector. Holding part (fixing member) In a state where the set amount is exceeded and the compression is applied, a gap of t(1) is created between the bearing plate 18 and the primary side sleeve 116 of the connector so that the compression amount (t(3)-t(1)) exceeds the set amount. In this state, the gap between the bearing plate 18 and the primary side sleeve 116 of the connector is maintained at t(1).

[0031] Next, as shown in Figure 4(D), a split elastic cushioning material 111, which has semicircular holes 113, is compressed and fitted into the gap (t(1)) between the bearing plate 18 and the primary side sleeve 116 of the connector from both sides. At this time, the holes formed by the two semicircular holes 113 are inserted into the sleeve 16, which is the fixing member of the primary side PC steel strand 10. Also, the split elastic cushioning material 111 with a thickness of t(1) comes into contact with the bearing plate 18 and the primary side sleeve 116 of the connector. At this time, the split elastic cushioning material 111 is in contact with the primary side Holding part (fixing member) The set amount is exceeded by the amount of compression, and the compression amount (t(3)-t(1)) is greater than the set amount.

[0032] The elastic cushioning material 110 or half-split elastic cushioning material 111 shown in Figures 3(D) and 4(D) is on the primary side of the connector. Holding part (fixing member) With the set amount exceeded and the assembly compressed and installed, the primary sleeve 116 of the connector and the secondary fixing member (in this case, the secondary wedge 124 of the connector and the secondary sleeve 126 of the connector) are connected via the secondary joint 120 and the connecting plug 118, as shown in Figure 5(A). At this time, the secondary fixing member holds the secondary wedge 124 of the connector in place with the wedge retainer 122, restricting the movement of the secondary wedge 124 of the connector in the longitudinal direction of the secondary PC steel strand 20. Next, as shown in Figure 5(B), the outer layer 130 is attached to the outer circumference of the connector 100, and a bearing cushioning material 132 is provided at the secondary end of the connector 100.

[0033] Next, concrete is poured on the secondary side, and after the concrete hardens, the secondary side PC steel strands 20 are tensioned and fixed in place as shown by the white arrows in Figure 5(C). When tensioning the secondary side PC steel strands 20, the primary side of the connector Holding part (fixing member) A gap G corresponding to the set amount is generated, but the elastic buffer material 110 (and the half-split elastic buffer material 111), which was compressed to a thickness t(1), stretches to a thickness t(2) when the secondary PC steel strand 20 is tensioned (it stretches to a maximum free thickness t(3)). As a result, the primary side of the connector that is generated when the secondary PC steel strand 20 is tensioned Holding part (fixing member) This prevents the generation of voids G corresponding to the set amount. This reduces the possibility of corrosive factors that could cause corrosion of the connector 100 (even though it is embedded in concrete) entering the device.

[0034] As described above, according to the connector and connection method of this embodiment, when connecting PC steel strands used to apply prestress to post-tensioned prestressed concrete, the primary side of the connector before anchoring to the secondary side Holding part This eliminates the generation of voids G caused by the set amount, preventing the intrusion of corrosive factors that cause corrosion of the connectors.

[0035] <Modification in the first embodiment> In this first embodiment, it is preferable that the elastic cushioning material 110 or the split elastic cushioning material 11 is impregnated or coated with a rust inhibitor or epoxy resin. By impregnating or coating the elastic cushioning material 110 or the split elastic cushioning material 11 with a rust inhibitor or epoxy resin in this way, the rust prevention effect at the primary end portion of the connector 100 can be made more reliable. That is, in a directly embedded type connector 100, the primary end portion of the connector before the secondary side is fixed The retaining part (the fixing member, which is the primary side wedge 114 of the connector and the primary side sleeve 116 of the connector)In addition to preventing the generation of voids G due to the set amount, the elastic cushioning material 110 or the split elastic cushioning material 111 is pre-impregnated or coated with a rust inhibitor or epoxy resin, making it less susceptible to weaknesses such as corrosion.

[0036] <Second Embodiment> A coupler-sheath type PC steel strand connector 200 according to a second embodiment of the present invention and a method for connecting PC steel strands using the connector 200 will be described in detail with reference to Figures 6 to 9. In the following, the same structures and methods as those in the first embodiment described above will not be repeated. In particular, the same structures are denoted by the same reference numerals in the figures of the second embodiment as in the figures of the first embodiment, and will not be repeated in order to avoid overlap with the above description.

[0037] Figure 6(A) shows the primary fixing member of the connector 200 (connector primary wedge 114 and connector primary sleeve 116) attached together with the elastic cushioning material 110 and the connector bottom plate 210, and Figure 6(B) shows the secondary fixing member of the connector 200 (connector secondary wedge 124 Figures 6(A) and 6(B) show the state in which the connector's secondary sleeve 126 and wedge retainer 122 are connected via the secondary joint 120 and connection plug 118, and the coupler sheath 220 is further connected (fixed) to the connection bottom plate 210. When transitioning from the state in Figure 6(A) to the state in Figure 6(B) (proceeding with the connection work), the compressed elastic cushioning material 110 expands, thereby restricting the movement of the connection bottom plate 210 in the longitudinal direction of the primary PC steel strand 10, without the primary wedge 114 of the connector being fixed (the secondary PC steel strand 20 is not tensioned) and thus not generating a gap G due to its play. In other words, as the compressed elastic buffer material 110 stretches, the primary PC steel strands 10 are tensioned and fixed, but the primary side holding portion of the connector is not fixed, resulting in a gap G between the connecting bottom plate 210 and the primary side of the connector 200. This is achieved by restricting the longitudinal movement of the primary PC steel strands 10 of the connecting bottom plate 210.

[0038] Here, the free thickness t(3) mentioned above corresponds to the free thickness t(6) in this embodiment, the thickness t(2) corresponds to the free thickness t(5) in this embodiment, and the thickness t(1) corresponds to the free thickness t(4) in this embodiment. Therefore, t(6) > t(5) and t(5) - t(4) > primary side of connector. Holding part (fixing member) The set quantity is satisfied, and t(6)-t(4)>t(5)-t(4)>connector primary side Holding part (fixing member) The set amount is met, and the amount of compression from the free thickness t(6) (t(6)-t(4)) exceeds the set amount, so the connector 200 is equipped with elastic cushioning material 110 that has been compressed beyond the set amount. Note that the amount of compression from the free thickness t(6) (t(6)-t(4)) Holding part (fixing member) If the set amount is set to exceed this, it is possible to adequately accommodate the air gap G caused by the play in the primary side wedge 114 of the connector.

[0039] As shown in Figures 6 and 7(B), the connector 200 differs from the connector 100 described above in that it does not have an outer layer 130 and a bearing cushioning material 132, and instead comprises a coupler sheath 220, a connecting base plate 210 to which the coupler sheath 220 is connected by bolts 214, and epoxy putty 230. The coupler sheath 220 and epoxy putty 230 are known materials. The connector 200 is preferably used when the coupler sheath 220 is connected to the connecting base plate 210 (a separate component from the bearing plate 18) by bolts 214 on the primary side of the connector. As shown in Figure 7(B), the connecting base plate 210 is a thin, roughly rectangular metal plate with a circular hole 212 in the center through which the sleeve 16 of the fixing member for the primary PC steel strand 10 is inserted, and female screw holes 216 at the four corners for screwing in bolts 214.

[0040] This connector 200 is a coupler sheath type connector, and as shown in Figure 6(B), a coupler sheath 220 is connected to the outer circumference of the connector 200 using a connecting bottom plate 210. In addition to the configuration of the connector 100 described above (without the outer skin layer 130 and bearing cushioning material 132), it is equipped with a coupler sheath 220 and a connecting bottom plate 210 to which the coupler sheath 220 is connected. When connecting the primary PC steel strand 10 and the secondary PC steel strand 20 using the connector 200 (more specifically, until the coupler sheath 220 is fixed to the connecting bottom plate 210 with a bolt 214), even if a gap G is to be generated between the connecting bottom plate 210 and the primary side of the connector due to play caused by the fact that the primary side wedge 114 of the connector is not fixed, the elastic cushioning material 110, which has been compressed to a thickness t(4), expands, so that the gap G is not generated. This makes it possible to avoid the inability to fix the connecting bottom plate 210. As a result, the connecting bottom plate 210 can be properly fixed (before tensioning the secondary PC steel strands 20, which are the secondary PC steel material), the coupler sheath 220 can be easily attached, and resin leakage can be avoided when filling the coupler sheath 220 with resin.

[0041] Furthermore, as shown in Figure 8, the connection method using this connector 200 involves attaching the primary side sleeve 116 of the connector to the primary side holding part (connector primary side wedge 114 and connector). When tension is generated in the secondary PC steel strand 20, the tension occurs on the side of the primary PC steel strand 10 (more specifically, so as to abut against the end face of the primary PC steel strand 10 on the side of the primary PC steel strand 10 in the primary sleeve 116 of the connector, and even more specifically between the connecting bottom plate 210 and the primary sleeve 116 of the connector) Holding part (fixing member) An elastic cushioning material 110, compressed to a volume exceeding the set amount (as shown in Figure 7(A)), is attached. A coupler sheath type connection method using connector 200 will be explained with reference to Figures 8 and 9. Note that Figure 8(A) corresponds to Figures 3(A) and 4(A).

[0042] As shown in Figure 8(B), the sleeve 16, which is the anchoring member for the primary PC steel strand 10, is inserted through the hole 212, and the connecting bottom plate 210 is brought into contact with the bearing plate 18. Next, as shown in Figure 8(C), the sleeve 16, which is the fixing member for the primary PC steel strand 10, is inserted through the hole 112, and the elastic cushioning material 110 with a free thickness t(6) is brought into contact with the connecting bottom plate 210. Next, as shown in Figure 8(D), attach the primary side sleeve 116 of the connector, and then attach the primary side wedge 114 of the connector to the primary side sleeve 116. At this time, the elastic cushioning material 110 Holding part (fixing member) The elastic cushioning material is compressed beyond its set amount so that the compression amount (t(6)-t(4)) exceeds the set amount. In this state, the thickness t(4) of the elastic cushioning material 110 is maintained.

[0043] Next, the primary PC steel strand 10 and the secondary PC steel strand 20 are connected using the connector 200 to achieve the state shown in Figure 9(A). Specifically, the primary sleeve 116 of the connector and the secondary fixing member (in this case, the secondary wedge 124 and the secondary sleeve 126 of the connector) are connected via the secondary joint 120 and the connecting plug 118. When transitioning from the state in Figure 8(D) to the state in Figure 9(A) (proceeding with the connection work), the compressed elastic buffer material 110 expands, preventing the primary wedge 114 of the connector from being fixed (because the secondary PC steel strand 20 is not tensioned) and thus preventing the generation of a gap G due to its play, thereby restricting the movement of the connecting bottom plate 210 in the longitudinal direction of the primary PC steel strand 10.

[0044] Next, the coupler sheath 220 is attached so as to enclose the connector 200 that connects the primary PC steel strand 10 and the secondary PC steel strand 20, so that the state shown in Figure 6(B) is achieved. Specifically, the coupler sheath 220 is connected (fixed) to the connection base plate 210 by screwing a bolt 214 into the female screw hole 216 of the connection base plate 210. Note that adding white arrows to Figure 6(B) results in Figure 9(B), but Figure 6(B) is more accurate here because the secondary PC steel strand 20 has not yet been tensioned. When transitioning from the state in Figure 9(A) to the state in Figure 6(B) (proceeding with the connection work), the compressed elastic buffer material 110 expands, preventing the primary wedge 114 of the connector from being fixed (because the secondary PC steel strand 20 is not tensioned) and thus preventing the generation of a gap G due to its play, thereby restricting the movement of the connection base plate 210 in the longitudinal direction of the primary PC steel strand 10. In other words, as the compressed elastic buffer material 110 stretches, the primary PC steel strands 10 are tensioned and fixed, but the primary side holding portion of the connector is not fixed, resulting in a gap G between the connecting bottom plate 210 and the primary side of the connector 200. This is achieved by restricting the longitudinal movement of the primary PC steel strands 10 of the connecting bottom plate 210.

[0045] Thus, when transitioning from the state shown in Figure 8(D) to the state shown in Figure 9(A), and when transitioning from the state shown in Figure 9(A) to the state shown in Figure 6(B), the compressed elastic buffer material 110 expands, thereby restricting the movement of the connecting bottom plate 210 in the longitudinal direction of the primary PC steel strand 10, without the primary side wedge 114 of the connector being fixed (because the secondary side PC steel strand 20 is not tensioned) and without generating a gap G due to its play. Next, resin is filled into the coupler sheath 220, concrete is poured on the secondary side, and after the concrete hardens, the secondary side PC steel strands 20 are tensioned and fixed in place as shown by the white arrows in Figure 9(B).

[0046] As described above, the connector and connection method according to this embodiment prevent the generation of voids G caused by the play of the wedge on the primary side of the connector before the secondary side is anchored when connecting PC steel strands used to apply prestress to post-tensioned prestressed concrete. Therefore, it is possible to avoid the inability to fix the connection base plate 210. As a result, the connection base plate 210 can be properly fixed (before tensioning the secondary PC steel strands 20, which are the secondary PC steel material), the coupler sheath 220 can be easily attached, and resin leakage can be avoided when filling the coupler sheath 220 with resin.

[0047] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Industrial applicability]

[0048] The present invention is preferably a connector and connection method for PC steel members used to apply prestress to post-tensioned prestressed concrete, and is a direct embedded connection type connector, specifically for the primary side of the connector before anchoring. Holding part (fixing member) This design is particularly preferable because it prevents the intrusion of corrosive factors that cause corrosion of the connector even if a gap occurs due to the amount of set, or, in the case of a coupler sheath type connector, it prevents the occurrence of a gap between the bottom plate and the primary side of the connector due to play caused by the wedge on the primary side of the connector not being fixed when the coupler sheath is fixed to the bottom plate (a separate component from the bearing plate) with bolts on the primary side of the connector (ultimately, the bottom plate can be properly fixed, the coupler sheath can be easily attached, and resin leakage when resin is filled into the coupler sheath can be prevented). [Explanation of symbols]

[0049] 10. Primary PC steel strands 20 Secondary PC steel strands 100, 200 connectors 110 Elastic cushioning material 111 Half-split elastic cushioning material 112 Hole 113 Semicircular hole 114 Connector primary side wedge 116 Connector primary side sleeve 118 Connection Plug 120 Secondary joint 124 Connector secondary wedge 126 Connector secondary sleeve 130 Outer skin layer 132 Bearing pressure cushioning material 210 Connecting base plate 212 Hole 214 volts 216 holes 220 Coupler Sheath 230 Epoxy Putty 300, 400, 500 (conventional) connectors

Claims

1. A connection method for connecting a primary PC steel strand and a secondary PC steel strand using a connector, The connector includes a primary side retaining portion of the connector, which is a fixing member for the primary side PC steel strand and holds the primary side PC steel strand in a tensionable manner, including a primary side wedge and a primary side sleeve of the connector; a secondary side retaining portion of the connector, which holds the secondary side PC steel strand in a tensionable manner; and an elastic cushioning material, which is a divided or undivided plate-like object with a hole through which the primary side sleeve of the connector is inserted. The aforementioned connection method is In a state in which the primary PC steel strands are tensioned and fixed, before attaching the primary sleeve of the connector, or after attaching the primary sleeve of the connector, an installation step is to attach an elastic cushioning material that is compressed to an amount exceeding the set amount of the primary holding portion of the connector, which occurs because the primary PC steel strands are tensioned and fixed but the primary holding portion of the connector is not fixed, on the side of the primary PC steel strands that is closer to the primary holding portion of the connector than the primary holding portion of the connector. The installation step is followed by a tensioning step in which the secondary PC steel strands are tensioned, A connection method characterized in that, after the tensioning step, the elastic cushioning material that was compressed and attached expands by the amount of settling generated at the primary side holding portion of the connector, so as not to create a gap between the primary side of the connector and the bearing plate.

2. The connection method according to claim 1, characterized in that the elastic cushioning material is provided so as to abut against the end face on the side of the primary PC steel strand in the primary sleeve of the connector.

3. The connection method according to claim 1 or claim 2, characterized in that the elastic cushioning material is impregnated or coated with a rust inhibitor or epoxy resin.

4. The connector is a directly embedded type connector, and an outer layer is attached to the outer circumference of the connector, and a bearing cushioning material is provided at the secondary end of the connector. The compressed elastic cushioning material expands, preventing the generation of a gap corresponding to the set amount of the primary side holding portion of the connector that occurs when the secondary side PC steel strands are tensioned. The connection method according to claim 1 or claim 2.

5. The connector is a coupler sheath type connector, in which a coupler sheath is connected to the outer circumference of the connector using a connecting base plate. The connection method according to claim 1 or 2, characterized in that the movement of the PC steel strands of the connection bottom plate in the longitudinal direction is restricted so as the compressed elastic cushioning material expands, thereby preventing the creation of a gap between the connection bottom plate and the primary side of the connector, which occurs because the primary side PC steel strands are tensioned and fixed, but the primary side holding portion of the connector is not fixed.

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