Joining structure

Abstract

To exhibit sufficient water cut-off performance by a simple constitution, even when either compressive force or tensile force acts between concrete members, in a structure for connecting the concrete members.SOLUTION: A joining structure for joining a pair of concrete members, wherein a male joint portion is provided with a bridge portion protruding from a joining end surface of the one concrete member and an insertion portion formed by widening a distal end of the bridge portion, a female joint portion is provided with a slit hole opened in a joining end surface of the other concrete member and an insertion hole formed by widening an inner side of the slit hole, and the bridge portion is fitted into the slit hole, in addition, in a state where the insertion portion is fitted into the insertion hole, at least one waterproofing rubber is disposed in each of a gap between a front end surface of the insertion portion and an inner surface of the insertion hole and a gap between a rear end surface of the insertion portion and the inner surface of the insertion hole, and a curable material is filled in a gap between the male joint portion and the female joint portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a joint structure for concrete members. [Background technology]

[0002] When constructing various underground structures such as underground tunnels, utility conduits, and underground parking lots, as well as various other concrete structures, construction involves connecting multiple concrete members to construct the structure. In such cases, it is known that the concrete members used are pre-fabricated members, for example, in factories, i.e., so-called precast concrete members.

[0003] For example, Patent Document 1 discloses a technology for forming a joint structure by joining the joint portions of two cementitious molded bodies, each of which has a joint portion consisting of a convex portion and a concave portion and a main body portion, in order to improve workability and reduce work time when connecting multiple concrete members.

[0004] Furthermore, for example, Patent Document 2 discloses a technology for flexibly joining two adjacent box culverts by disposing a waterproof elastic body when joining a convex hood and a concave hood together. The technology described in Patent Document 2 makes it possible to respond to large relative displacements without damaging the waterproof elastic body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-159492 [Patent Document 2] Japanese Patent Application Publication No. 9-60100 Summary of the Invention [Problem to be solved by the invention]

[0006] As typified by Patent Documents 1 and 2, high water-stopping properties are required at the joints in connection structures between concrete members. For example, when constructing special facility structures such as underground passages, underground pits, and basements at steel or chemical plants, or water tank structures using precast concrete structures, water-stopping rubber is attached to the gaps between the concrete members, and the surrounding area is filled with a time-hardening material such as mortar or grout.

[0007] In such structures, watertight rubber reliably performs watertight functions when compressive forces are applied between concrete members. However, when tensile forces are applied between the concrete members, the watertight rubber tends to separate from the concrete surface, creating a gap that could prevent the watertight rubber from performing adequately. When watertight performance is not adequately achieved, the typical method is to use prestressed concrete (PC) steel rods to clamp the concrete members together, eliminating any gaps between the watertight rubber and the concrete surface. However, construction using PC steel rods poses challenges, such as an increased number of components, more complicated work, and higher costs. Therefore, there is a need for labor-saving and shorter construction times when constructing concrete structures.

[0008] In view of the above circumstances, an object of the present invention is to provide a joint structure for concrete members in a structure in which concrete members are connected, which has a simple configuration and is capable of exhibiting sufficient water-stopping performance regardless of whether compressive or tensile force acts between the concrete members. [Means for solving the problem]

[0009] In order to achieve the above object, according to the present invention, there is provided a joining structure for joining a pair of concrete members, wherein the joining end of one concrete member is provided with a male joint part molded integrally with said one concrete member, and the joining end of the other concrete member is provided with a female joint part molded integrally with said other concrete member, said male joint part having a bridge part protruding from the joining end face of said one concrete member and an insertion part formed by widening the tip of said bridge part, and said female joint part has a A joining structure for concrete members is provided, characterized in that a slit hole opening into the joining end surface of the concrete members and an insertion hole formed by widening the inside of the slit hole and the bridge portion is fitted into the slit hole, and when the insertion portion is fitted into the insertion hole, at least one or more water-stopping rubbers are arranged in the gap between the front end surface of the insertion portion and the inner surface of the insertion hole and the gap between the rear end surface of the insertion portion and the inner surface of the insertion hole, and a time-hardening material is filled in the gap between the male joint portion and the female joint portion.

[0010] An elastic member may be disposed in the gap between the tip end surface of the insertion portion and the inner surface of the insertion hole, and the rear end surface of the insertion portion may be pressed against the inner surface of the insertion hole.

[0011] An elastic member may be disposed in the gap between the rear end surface of the insertion portion and the inner surface of the insertion hole, and the front end surface of the insertion portion may be pressed against the inner surface of the insertion hole.

[0012] The male joint portions and the female joint portions may be provided alternately at the joint ends of the pair of concrete members. [Effects of the Invention]

[0013] According to the present invention, a joining structure for concrete members is provided that is capable of exhibiting sufficient water-stopping performance with a simple configuration, regardless of whether compressive or tensile force acts between the concrete members in a structure in which concrete members are connected.

[0014] The above effects are not necessarily limiting, and any of the effects shown in this specification or other effects that can be understood from this specification may be achieved in addition to or instead of the above effects. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic explanatory diagram showing an example of a conventional joining structure. [Figure 2] 1 is a schematic explanatory diagram of a joint structure for concrete members according to an embodiment of the present invention; [Figure 3] FIG. 2 is a schematic explanatory diagram illustrating the behavior of a watertight rubber. [Figure 4] FIG. 2 is a schematic explanatory diagram illustrating the behavior of a watertight rubber. [Figure 5] FIG. 2 is a schematic explanatory diagram illustrating the behavior of a watertight rubber. [Figure 6] FIG. 10 is a schematic explanatory view of a joint structure according to a first modified example of the present invention. [Figure 7] FIG. 10 is a schematic explanatory view of a joint structure according to a second modified example of the present invention. [Figure 8] FIG. 10 is a schematic explanatory view of a joint structure according to a third modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and drawings, components having substantially the same functional configuration may be designated by the same reference numerals to avoid redundant description. In this specification and drawings, a pair of concrete members to be joined are schematically illustrated as P1 and P2 to generally explain a portion of a structure (a connection portion between members). For the sake of explanation, some of the members may be omitted from the illustration, or the internal structure of the members may be illustrated.

[0017] <Conventional example of joint structure> Fig. 1 is a schematic explanatory diagram showing an example of a conventional joint structure 1a formed by joining a pair (two) concrete members P1 and P2. As shown in Fig. 1, in the conventional joint structure 1a, the flat surfaces that are the joining end faces of the concrete members P1 and P2 are opposed to each other, and a joint portion 5 is formed in the gap between them. Watertight rubber members 10 are arranged in multiple locations in this joint portion 5. The positions and number of the watertight rubber members 10 are arbitrary, and can be designed to have an optimal configuration when constructing the joint structure 1a.

[0018] A pair of concrete members P1 and P2 are placed facing each other to form a joint 5, and then a time-hardening material such as mortar or grout is injected and filled into the joint 5 to construct the joint structure 1a.

[0019] In the conventional joint structure 1a configured as described above, the resistance to separation between the concrete members P1 and P2 depends largely on the adhesive strength between the concrete surface and the time-hardening material. For example, when joining unreinforced concrete members, there is no problem when a compressive force is applied, but when a tensile force is applied, the adhesive resistance is very small and there is a risk that the members may separate.

[0020] Furthermore, the joint structure 1a is constructed by placing a water-stop rubber 10 in the joint portion 5 and filling it with a time-curing material. The water-stop rubber 10 can reliably exhibit water-stopping performance when a compressive force acts between the components, but when a tensile force acts, the water-stop rubber 10 and the concrete surface tend to separate, which may result in the water-stopping performance not being fully exhibited.

[0021] In order to solve the problems with the conventional joint structure 1a, the inventors have conducted extensive research into a structure that, when joining a pair of concrete members P1 and P2 to construct a joint structure, will reliably join the members and provide sufficient watertight performance in both cases where compressive force and tensile force act between the members. Below, we will explain the joint structure between concrete members according to this embodiment, which was developed based on the inventors' research.

[0022] <Joint structure according to an embodiment of the present invention> 2 is a schematic explanatory diagram of a joint structure 1 for concrete members according to an embodiment of the present invention, showing a schematic cross section of a joint portion. In the following description, components having the same functional configuration as those of the conventional joint structure 1a described above will be assigned the same reference numerals, and their description may be omitted.

[0023] As shown in Figure 2, in joint structure 1, when the joint ends of concrete members P1 and P2 are opposed to each other, a gap 20 is defined between the opposed joint ends. One of the joint ends of concrete member P1 is provided with one or more male joints 30 molded integrally with concrete member P1. The number and arrangement of male joints 30 can be designed arbitrarily, and will correspond to the number and arrangement of female joints 40 described below. For example, as shown in the figure, male joints 30 may be provided in two locations near both end portions of joint structure 1.

[0024] Male joint 30 is provided with bridge portion 32, which is configured to protrude from the joint end surface of concrete member P1, and insertion portion 35, which is configured by widening the tip of bridge portion 32. That is, male joint 30 is configured so that width L2 of insertion portion 35 is wider than width L1 of bridge portion 32. The shapes of bridge portion 32 and insertion portion 35 can be designed arbitrarily, but it is required that insertion portion 35 is at least wider than bridge portion 32.

[0025] The other concrete member P2 has one or more female joints 40 molded integrally with the concrete member P2 at its joint end. The number and arrangement of the female joints 40 can be designed as desired, and correspond to the number and arrangement of the male joints 30. For example, as shown in the figure, they may be provided at two locations near both end portions of the joint structure 1.

[0026] The female joint part 40 is provided with a slit hole 42 that opens into the joint end surface of the concrete member P2, and an insertion hole 45 that is formed by widening the inside of the slit hole 42. That is, the female joint part 40 is configured so that the width L4 of the insertion hole 45 is wider than the width L3 of the slit hole 42. The shapes of the slit hole 42 and the insertion hole 45 can be designed arbitrarily, but it is required that the insertion hole 45 is at least wider than the slit hole 42.

[0027] The male joint part 30 and the female joint part 40 are configured so that their shapes correspond to each other (so-called interlocking shapes), and the male joint part 30 is fitted inside the female joint part 40. In other words, the bridge part 32 is fitted inside the slit hole 42, and the insertion part 35 is fitted inside the insertion hole 45.

[0028] When the male joint portion 30 is fitted to the female joint portion 40, at least one waterstop rubber 10 is disposed in the gap between the tip end surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45, and one or more waterstop rubbers 10 are similarly disposed in the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45. The number and arrangement of the waterstop rubbers 10 may be arbitrarily designed, but one or more waterstop rubbers 10 are disposed in each of the above gaps. The waterstop rubbers 10 are disposed, for example, by adhering them to either the male joint portion 30 or the female joint portion 40 with an adhesive. The waterstop rubbers 10 can be disposed at any position in the gap 20 at the joint ends of the concrete members P1 and P2 and are not limited to the configuration shown in the figure. To prevent damage to the waterstop rubbers 10, it is preferable to dispose the waterstop rubbers 10 during on-site construction when constructing the joint structure 1.

[0029] The joint structure 1 is constructed by fitting the male joint part 30 into the female joint part 40 with the joint ends of the concrete members P1 and P2 facing each other as shown in Figure 2, placing the watertight rubber 10 as shown, and injecting and filling a time-hardening material such as mortar or grout into the gap between the concrete members P1 and P2, including the gap between the male joint part 30 and the female joint part 40.

[0030] The concrete members P1 and P2 for constructing the joint structure 1 may be so-called precast concrete members that are manufactured in advance in a factory or the like.

[0031] <Behavior of water-sealing rubber under compression and tension> Next, the behavior of the waterstop rubber 10 when a compressive force and a tensile force are applied to the joint structure 1 according to this embodiment will be described. Figures 3 to 5 are schematic explanatory diagrams of the behavior of the waterstop rubber 10, with Figure 3 showing a state in which no force is applied to the joint structure 1 (normal state), Figure 4 showing a state in which a compressive force is applied to the joint structure 1 (compressed state), and Figure 5 showing a state in which a tensile force is applied to the joint structure 1 (tensile state). Note that in Figures 3 to 5, components having the same functional configuration as those in the joint structure 1 shown in Figure 2 above are shown with the same reference numerals, and their description may be omitted.

[0032] 3 and 4, when a compressive force acts on the joint structure 1 (see the arrow in FIG. 4), the gap 20 is compressed in principle, and the members move in the direction that narrows the gap. In this state, the gap between the tip surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45 is narrower than in the normal state, the waterstop rubber 10 placed there is compressed, and the waterstop performance is improved. On the other hand, the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45 is wider than in the normal state, and the waterstop rubber 10 placed there is separated from the concrete surface, which may result in a decrease in waterstop performance.

[0033] 3 and 5, when a tensile force acts on the joint structure 1 (see the arrow in FIG. 5), the members move in the direction that widens the gap 20, as a general rule. In this state, the gap between the tip surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45 widens compared to the normal state, and the waterstop rubber 10 placed there becomes separated from the concrete surface, which may result in a decrease in watertightness. On the other hand, the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45 narrows compared to the normal state, and the watertight rubber 10 placed there is compressed, improving watertightness.

[0034] That is, when viewed as a whole joint structure 1, the gap 20 between the joint ends of concrete members P1 and P2 is prevented from narrowing or widening at any position, regardless of whether a compressive force or a tensile force acts between the concrete members. In other words, it is possible to prevent all of the disposed waterstop rubber 10 from separating from the concrete surface, which would result in a significant decrease in waterstop performance.

[0035] <Example of construction method> When constructing the joint structure 1 configured as described above with reference to FIGS. 2 to 5, the method (construction method) for joining the concrete members P1 and P2 is arbitrary, but it is preferable to perform construction as follows, for example.

[0036] As an example, before injecting and filling the gap between the concrete members P1 and P2 with a time-hardening material such as mortar or grout, the concrete members may be compressed in advance as shown in Figure 4, making the gap between the front end surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45 narrower than in the normal state, and making the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45 wider than in the normal state, and then injecting and filling the time-hardening material in this state. This prevents the gap between the concrete members P1 and P2 from narrowing any further even if a compressive force is applied to the joint structure 1, thereby improving structural safety as well as providing sufficient watertightness.

[0037] As another example, before injecting and filling the gap between the concrete members P1 and P2 with a time-hardening material such as mortar or grout, the concrete members may be placed in a tensioned state as shown in Fig. 5, so that the gap between the front end surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45 is wider than in the normal state, and the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45 is narrower than in the normal state, and the time-hardening material may be injected and filled in this state. As a result, even if a tension force acts on the joint structure 1, the gap between the concrete members P1 and P2 will not widen any further, thereby achieving sufficient watertightness and improved structural safety.

[0038] <Action and effect> According to the joining structure 1 of this embodiment described above, when joining a pair of concrete members P1, P2, the joining ends of the concrete members are provided with a male joint portion 30 and a female joint portion 40, which function as a mating member and a mated member. This ensures that stress is transmitted between the concrete members regardless of whether a compressive force or a tensile force acts between them, thereby improving structural safety.

[0039] Furthermore, when constructing the joining structure 1, with the male joint part 30 fitted into the female joint part 40, at least one waterstop rubber 10 is arranged in the gap between the tip end face 35a of the insertion part 35 and the inner surface 45a of the insertion hole 45, and one or more waterstop rubbers 10 are arranged in the gap between the rear end face 35b of the insertion part 35 and the inner surface 45b of the insertion hole 45. As a result, whether a compressive force acts on the joining structure 1 as shown in Figure 4 or a tensile force acts on the joining structure 1 as shown in Figure 5, at least one of the waterstop rubbers 10 is in a compressed state, and sufficient waterstop performance is exhibited.

[0040] When joining concrete members together, the concrete members are usually clamped together with PC steel rods to compress them together and construction is carried out so that no gaps occur between the watertight rubber and the concrete surface, but in the joint structure 1 according to this embodiment, by changing the design of the concrete members P1 and P2 in advance, the joint structure 1 can be constructed with a simple configuration and still exhibit sufficient watertight performance. In other words, a joint structure 1 with high watertight performance can be realized without construction using PC steel rods or rebars, etc., and productivity can be improved by reducing the number of people and labor required when constructing concrete structures, shortening construction time, and reducing construction costs.

[0041] While one embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0042] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that would be apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0043] <Modification> In the above embodiment, the number and arrangement of male joints 30 and female joints 40 are illustrated and described as being provided in two locations near both end portions of the joint structure 1 as shown in Figure 2, and a case is also illustrated and described in which one concrete member P1 is provided with a male joint 30 and the other concrete member P2 is provided with a female joint 40. However, the present invention is not limited to such a configuration. Modifications will be described below. Note that in the following modifications, components having the same functional configuration as those in the joint structure 1 described in the above embodiment are illustrated with the same reference numerals, and their description may be omitted.

[0044] (First Modification) Figure 6 is a schematic explanatory diagram of a joint structure 100 according to a first modified example of the present invention. As shown in Figure 6, the joint structure 100 may be configured so that male joint portions 30 and female joint portions 40 are provided alternately at the joint ends of concrete members P1 and P2. In other words, both concrete members P1 and P2 may be configured to function as both a mating member and a mated member.

[0045] In the configuration shown in Figure 6, the joint ends of the concrete members P1 and P2 are provided with many male joints 30 and female joints 40, and both members function as both a mating member and a mated member, allowing for a more reliable joint and significantly improving the structural safety of the structure. In particular, even when a tensile force is applied to the joint structure 100, separation is not easy. Furthermore, because the tensile resistance is improved, it is possible to reduce the amount of rebar used in joining reinforced concrete members by placing rebar in the concrete members P1 and P2 and connecting the rebars, thereby improving productivity.

[0046] (Second Modification) Fig. 7 is a schematic explanatory diagram of a joint structure 1b according to a second modified example of the present invention. As shown in Fig. 7, in addition to the configuration of the joint structure 1 described in the above embodiment, an elastic member 60 may be disposed in the gap between the tip surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45. The number and arrangement of the elastic members 60 can be designed arbitrarily, and they may be members different from the waterstop rubber 10, or the waterstop rubber 10 may also serve as the elastic member 60.

[0047] By disposing this elastic member 60, the rear end surface 35b of the insertion portion 35 is pressed against the inner surface 45b of the insertion hole 45 by the repulsive force of the elastic member 60. This improves the watertightness of the gap between the front end surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45, and also ensures the watertightness of the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45.

[0048] (Third Modification) Fig. 8 is a schematic explanatory diagram of a joint structure 1c according to a third modified example of the present invention. As shown in Fig. 8, in addition to the configuration of the joint structure 1 described in the above embodiment, an elastic member 60 may be disposed in the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45. The number and arrangement of the elastic members 60 can be designed arbitrarily, and they may be members different from the waterstop rubber 10, or the waterstop rubber 10 may also serve as the elastic member 60.

[0049] By disposing this elastic member 60, the tip surface 35a of the insertion portion 35 is pressed against the inner surface 45a of the insertion hole 45 by the repulsive force of the elastic member 60. This improves the watertight performance of the gap between the rear end surface 35b of the insertion portion 35 and the inner surface 45b of the insertion hole 45, and also ensures the watertight performance of the gap between the tip surface 35a of the insertion portion 35 and the inner surface 45a of the insertion hole 45. [Industrial Applicability]

[0050] The present invention can be applied to a joint structure of concrete members. [Explanation of symbols]

[0051] 1...Joining structure 5...Joint 10...Waterproof rubber 20…Gap 30...Male joint 32...Bridge section 35...insertion part 40...Female joint 42...Slit hole 45...insertion hole 60...Elastic member

Claims

1. A joint structure for joining a pair of concrete members, The joining end of one concrete member is provided with a male joint portion molded integrally with the one concrete member, The joint end of the other concrete member is provided with a female joint portion molded integrally with the other concrete member, The male joint portion is provided with a bridge portion protruding from the joint end surface of one of the concrete members and an insertion portion formed by widening the tip of the bridge portion, The female joint portion is provided with a slit hole that opens to the joint end surface of the other concrete member and an insertion hole that is formed by widening the inner side of the slit hole, when the bridge portion is fitted into the slit hole and the insertion portion is fitted into the insertion hole, at least one waterproof rubber is disposed in a gap between a front end surface of the insertion portion and an inner surface of the insertion hole and in a gap between a rear end surface of the insertion portion and an inner surface of the insertion hole, A joining structure for concrete members, characterized in that a time-hardening material is filled into a gap between the male joint portion and the female joint portion.

2. A concrete member joining structure as described in claim 1, characterized in that an elastic member is arranged in the gap between the tip surface of the insertion portion and the inner surface of the insertion hole, and the rear end surface of the insertion portion is pressed against the inner surface of the insertion hole.

3. A concrete member joining structure as described in claim 1, characterized in that an elastic member is arranged in the gap between the rear end surface of the insertion portion and the inner surface of the insertion hole, and the front end surface of the insertion portion is pressed against the inner surface of the insertion hole.

4. 4. The joint structure of concrete members according to claim 1, wherein the male joint portion and the female joint portion are alternately provided at the joint ends of the pair of concrete members.

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