JP2014240575A - Embedment type joint part structure for bridge and construction method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the embedment type joint part structure of a bridge capable of holding a water stopping function in a long term while satisfactorily absorbing the expansion/contraction displacement of a bridge and the construction method of the embedment type joint part structure.SOLUTION: An embedment type joint part structure of a bridge is configured of: a first bridge member 12; a second bridge member connected to the first bridge member 12, that is, a second bridge member 14 facing via an expansion gap 16 between itself and the first bridge member 12; a recess 18 formed along the expansion gap by notching long the opposed upper parts of the first bridge member 12 and the second bridge member 14 in an opposed line direction between the first bridge member and the second bridge member; and a joint part 20 formed by filling a bonding material 22 in which an aggregate is mixed with an elastic binder having elasticity after solidification in the recess 18 in an embedding state for absorbing the expansion/contraction displacement of the bridge members 12 and 14. The aggregate of the bonding material 22 contains a flat aggregate 38 of 8 to 15% in a weight ratio to the whole aggregate.

Description

  The present invention relates to a buried joint structure of a bridge that absorbs expansion and contraction displacement of the bridge and a construction method thereof.

  Bridges are built for people and cars to cross over traffic, rivers, seas, roads, railroads, and other traffic. For example, as shown in FIG. 2, the bridge 100 has a structure in which a bridge upper structure including a bridge girder 106 is supported by a bridge lower structure of an abutment 102 at both ends and a bridge pier 104 that is arranged separately between the abutments 102. It has become. The bridge member constituting the bridge upper structure such as the bridge girder 106 expands and contracts in the longitudinal direction due to a temperature change due to the season and the climate, and a live load by a moving body such as a person or an automobile. In order to absorb the expansion and contraction displacement of the bridge, a gap called a gap is provided between the bridge girder, the abutment, and the bridge girder. Furthermore, in order to cover the gap and ensure the continuity of the running surface of a person or a car, a joint portion (or also called an expansion device or an expansion joint) is provided that expands and contracts according to the expansion and contraction displacement of the bridge. . The joint structure of the bridge needs to have durability for a long period of time while maintaining the function of expanding and contracting according to the expansion and contraction of the bridge girder. Furthermore, if rainwater or snow enters and flows through the gaps between the bridge girders, the concrete structure of the abutments and piers in the bearings on the lower structure side and metal structures such as reinforcing bars are oxidized, and the durability of the substructure of these bridges is significantly impaired. For this reason, the expansion and contraction device is required to be waterproof.

  Conventionally, various techniques related to the joint structure of a bridge have been proposed. For example, Patent Document 1 discloses an embedded joint structure. The structure of the buried joint of Patent Document 1 is such that the aggregate pavement member is composed of aggregates of aggregates coated with a binder made of asphalt or the like, and the pavement surface is continuous between the pavement members. The structure was intended to absorb the expansion and contraction of the bridge by deformation of the aggregate pavement member.

JP 2004-124456 A

  However, in the conventional buried joint structure of bridges, there is a gap that is not filled with binder such as asphalt between aggregates, so the expansion and contraction displacement is totally dispersed depending on the presence or absence of the binder at the joint. However, the expansion and contraction action was biased, and the expansion and contraction could not be sufficiently absorbed, and cracks were likely to occur. Also, even when trying to fill the gap between the aggregates, because the gap between the aggregates is relatively small and the gaps are relatively small, it is difficult to fill the fluid binder with some viscosity, It was difficult to sufficiently fill the binder between the aggregates. Therefore, in the conventional buried joint structure of a bridge, if the expansion and contraction of the bridge is repeated, the buried joint structure is likely to crack in the buried joint structure relatively early and the water stop function is impaired. There was a problem that rainwater leaked down from the crack and deteriorated, corroded, or damaged the substructure such as the abutment, pier, and support. In addition, it is necessary to frequently monitor the joints and to perform frequent repairs and maintenance. As a result, the construction of the joints will cause road congestion and cost, and road management will be necessary. It was a big problem.

  The present invention has been made in view of the above-described conventional problems, and one object of the present invention is a bridge embedded joint structure for a bridge that can retain a water-stop function for a long time while satisfactorily absorbing expansion and contraction displacement of the bridge. It is to provide a construction method.

  In order to solve the above problems, the present invention is a bridge joint structure for connecting bridge members including bridge girders or abutments, and includes a first bridge member 12 and a second bridge member connected to the first bridge member 12. 14, the second bridge member 14 facing the first bridge member 12 with a gap 16 interposed therebetween, and the upper portion of the first bridge member 12 and the second bridge member 14 facing the first bridge member 12. The concave portion 18 is formed by mixing a concave portion 18 formed along the gap 16 with a long notch in a direction opposite to the second bridge member 14 and an aggregate and a stretchable binder having a stretchability after solidification. A joint portion 20 that is provided in an embedded state and absorbs expansion / contraction displacement of the bridge members 12 and 14, and the aggregate of the bonding material 22 is 8 to 15% by weight with respect to the total aggregate. Bridge-type buried joint including flat aggregate 38 Consisting of structure 10.

  The joint portion 20 includes a stretchable backup material 28 inserted into the gap 16, a gap plate 30 installed across the gap 16 on the bottom surface of the recess 18, and a bottom surface of the recess 18 so as to cover the gap plate 30. Are applied to the inner wall surface of the concave portion 18 on the first bridge member 12 side and the inner wall surface of the second bridge member 14 side before the filling material 22 is filled, and the concave portion 18 is filled. It is also possible to include a binder layer 36 that is integrated with the bonding material 22.

  Moreover, the recessed part 18 is formed in the rectangular shape by the longitudinal cross-sectional view, and the binder layer 36 of the joint part 20 is a side wall surface including a corner part about the 1st bridge member side and the 2nd bridge member side of the recessed part 18, respectively. It is good also as applying and forming on a bottom wall surface.

  Furthermore, the present invention is a method for constructing a buried joint structure of a bridge for connecting bridge members including a bridge girder or an abutment. The first bridge member 12 and the second bridge member are connected to face each other with a gap 16 therebetween. A process of forming a recess 18 along the clearance 16 by notching the opposing upper part of the bridge member 14 in the direction of the opposing line between the first bridge member 12 and the second bridge member 14, and a step of applying a primer to the inner surface of the recess 18 A step of inserting a stretchable backup material 28 into the gap 16, a step of installing a gap plate 30 across the gap 16 on the bottom surface of the recess 18, and a gap plate 30 installed on the bottom surface of the recess 18. A step of installing the sheet body 32 so as to cover the inner surface of the first bridge member 12 and the inner wall surface of the second bridge member 14 on the first bridge member 12 side of the recess 18 to apply a stretchable binder. And filling the concave portion 18 with a bonding material 22 in which an aggregate containing a flat aggregate having a weight ratio of 8 to 15% with respect to the entire aggregate and a stretchable binder having a stretchability after solidification are mixed. And a step of compacting the joining material 22 filled in the concave portion 18 from above by pressing the joining material 22 so that the flat direction of the flat aggregate is oriented in the lateral direction. Consists of construction methods.

  According to the buried joint structure of a bridge according to the present invention, the bridge joint structure connects bridge members including bridge girders or abutments, and the first bridge member and the second bridge connected to the first bridge member. A second bridge member that is opposed to the first bridge member with a gap between the first bridge member, and an opposing upper portion of the first bridge member and the second bridge member between the first bridge member and the second bridge member. A bridge member that is provided by filling a recess with a joint formed by mixing a recess formed along the gap between the recesses formed in the opposite line direction and an aggregate and a stretchable binder having stretchability after solidification. A joint portion that absorbs the expansion and contraction displacement of the joint, and the aggregate of the joining material includes 8 to 15% of the flat aggregate in a weight ratio with respect to the entire aggregate, and thus is joined by including the flat aggregate. Filled with an elastic binder between the aggregates Since parts can be configured, without expansion and contraction of the bonding material upon expansion and contraction displacement of the bridge member is biased in a part, it can be absorbed satisfactorily stretchable displacement, it is possible to improve the durability. Further, by making the flat direction of the flat aggregate lateral, it is possible to resist lateral tension and compression due to expansion and contraction, and durability can be improved. As a result, the water stop function by the joint portion can be maintained for a long time while maintaining the expansion and contraction function at the joint portion.

  The joint part includes a stretchable backup material inserted between the gaps, a gap plate installed across the gap on the bottom surface of the recess, and a sheet body installed on the bottom surface of the recess so as to cover the gap plate, A structure including a binder layer that is applied to the inner wall surface on the first bridge member side and the inner wall surface on the second bridge member side of the recess before filling with the bonding material and is integrated with the bonding material filled in the recess. As a result, the binder layer improves the bonding force between the bonding material and the first and second bridge members, prevents the bonding material surface from being disconnected from the first and second bridge members, and improves the durability. it can.

  Further, the concave portion is formed in a rectangular shape in a longitudinal sectional view, and the binder layer of the joint portion is formed on the side wall surface and the bottom wall surface including the corners on each of the first bridge member side and the second bridge member side of the concave portion. By adopting a structure formed by coating, the bonding force between the bonding material and the first and second bridge members can be improved and the durability can be maintained.

  Furthermore, according to the construction method of the buried type joint part structure of the bridge according to the present invention, it is a construction method of the buried type joint part structure of the bridge that connects the bridge members including the bridge girder or the abutment, and is opposed to each other through a gap. Forming a recess along the gap by notching the opposing upper part of the first bridge member and the second bridge member that are connected to each other long in the direction of the opposing line between the first bridge member and the second bridge member; A step of applying a primer, a step of inserting a stretchable backup material between the play, a step of installing a gap plate across the play on the bottom of the recess, and a gap plate installed on the bottom of the recess A step of installing a sheet body so as to cover, a step of applying a stretchable binder to the inner wall surface of the concave portion on the first bridge member side and the inner wall surface of the second bridge member side, respectively, and forming a binder layer; Overall Then, the step of filling the concave portion with a bonding material in which the aggregate containing the flat aggregate of 8 to 15% by weight and the elastic binder having elasticity after solidification is filled, and the bonding material filled in the concave portion from above A joint structure that improves durability and retains the expansion and contraction function and the water stop function for a long period of time by including a step of compacting the flat aggregate by rolling so that the flat direction is aligned in the lateral direction. Can be installed easily. In addition, when the joint structure needs to be repaired, it can be easily repaired.

It is longitudinal cross-sectional explanatory drawing which shows the principal part of the buried type joint part structure of the bridge concerning one Embodiment of this invention. It is a schematic explanatory drawing of a bridge. It is an enlarged view of a flat aggregate, (a) Side view, (b) Plan view. It is a construction process of the buried type joint part structure of the bridge of FIG. It is a construction process of the buried type joint part structure of the bridge of FIG. It is a side view of the apparatus which tests the test body which concerns on the buried type joint part structure of a bridge. It is a top view of the apparatus which tests the test body which concerns on the buried type joint part structure of a bridge. It is a longitudinal cross-sectional explanatory drawing of other embodiment of the buried type joint part structure of a bridge. It is a table | surface of the test result in a full size specimen test.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a buried joint structure for a bridge and its construction method according to the present invention will be described below with reference to the accompanying drawings. The buried joint structure of a bridge according to the present invention is, for example, a joint structure in a bridge girder or a connection part between a bridge girder and an abutment in a bridge, and is embedded in the connection part to absorb expansion and contraction of the bridge. It is an embedded type telescopic device. FIG. 1 to FIG. 5 show an embodiment of a bridge embedded joint structure and its construction method according to the present invention. In addition, about the schematic structure of a bridge, the same code | symbol as what was demonstrated by background art is attached | subjected. As shown in FIG. 1, in the present embodiment, a bridge embedded joint structure 10 is connected to a first bridge member 12 in a state of facing the first bridge member 12 with a gap 16 therebetween. It includes a second bridge member 14, a recess 18 provided in the first and second bridge members 12, 14, and a joint 20 provided in the recess 18.

  As shown in FIG. 2, for example, the bridge 100 includes abutments 102 disposed at both ends of the bridge and a bridge pier 104 disposed therebetween, and the support portion 105 is formed by a substructure formed by the abutment 102 and the pier 104. A bridge girder 106, which is an upper structure, is installed. The bridge embedded joint structure 10 according to the present embodiment is supported on a connecting portion 200 between the abutment 102 and one end of the bridge girder 106 and a pier 104, which are cut portions of each component. This is applied to the connecting portion 202 between the opposite ends of the bridge beam 106.

  The first and second bridge members 12 and 14 are structural members of a bridge including a bridge abutment or bridge girder, a floor slab 108 formed on the upper side thereof, and a pavement portion 110 formed on the upper surface side thereof. In the present embodiment, a case will be described in which both the first bridge member 12 and the second bridge member 14 include a bridge girder 106 and the bridge joint portion structure 10 connects the bridge beams. As shown in FIG. 1, for example, the first and second bridge members 12 and 14 have a concrete floor slab 108 formed on a main girder and a pavement portion 110 made of asphalt or the like on the surface side. . One of the first bridge member 12 and the second bridge member 14 may include an abutment. The end portions of the first and second bridge members 12 and 14 are opposed to each other with a gap 16 of about several centimeters interposed, for example.

  The concave portion 18 is formed in a long concave shape along the clearance 16 by cutting out a part of each of the opposing portions sandwiching the clearance 16 between the first bridge member 12 and the second bridge member 14. The bonding material 22 is filled. As shown in FIG. 1 and FIG. 4A, the concave portion 18 is formed so that the opposing upper part of the first bridge member 12 and the second bridge member 14 is long in the direction of the opposing line between the first bridge member 12 and the second bridge member 14. A first notch 24 that is formed by cutting out and forms the inner surface of the recess 18 on the first bridge member 12 side; a second notch 26 that forms the inner surface of the recess 18 on the second bridge member 14 side; It is comprised by those opposing space | gap parts. In the present embodiment, the first and second cutout portions 24 and 26 are notched in an L-shaped stepped portion on the upper pavement portion 110 on the opposite connection end side of the first and second bridge members 12 and 14. For example, the recess 18 is provided in a rectangular shape in a longitudinal sectional view.

  As shown in FIG. 1, the joint portion 20 is provided by filling the concave portion 18 with a bonding material 22 so as to cover the clearance 16 and is connected to the first bridge member 12 and the second bridge member, respectively. This is the main part of the expansion joint that connects the first bridge member 12 and the second bridge member 14, and absorbs the expansion and contraction displacement of the first and second bridge members 12 and 14. In the present embodiment, the joint portion 20 includes a backup material 28, a gap plate 26, and a sheet body 28 that are installed prior to the filling of the bonding material 22. As shown in FIG. 4B, the backup material 28 is, for example, a stopper member that is inserted into the gap 16 so as to be buried, and the gap 16 due to the expansion and contraction of the first and second bridge members 12, 14. It is made of an elastic material having elasticity so as to absorb the displacement. As shown in FIG. 4C, the gap plate 30 is made of, for example, a metal plate, is placed on the bottom surface of the recess 18 across the gap 16, and is fixed to the backup material 28 by the pins 34. . The gap plate 30 is installed so as to close the top of the play 16 across the bottom wall surfaces of the first and second cutout portions 24 and 26 of the first and second bridge members. And the load applied to the gap from the upper surface side of the joint portion is transmitted to the first and second bridge member sides. As shown in FIG. 4D, the sheet body 32 is, for example, a bottom surface of the recess 18 so as to be interposed between the bonding plate 22 and the gap plate 30 that are filled later after covering the gap plate 30 from above. Placed in. The sheet body 32 is, for example, a sheet material made of an elastic material so as to absorb the expansion and contraction of the bonding material 22, and in particular in the present embodiment, is made of a heat-resistant and cold-resistant rubber sheet.

  Furthermore, as shown in FIG. 1 and FIG. 5 (e), the joint portion 20 includes a binder layer 36 that is applied to the inner surface of the recess 18 before the bonding material 22 is filled. The binder layer 36 is the same as the binder mixed with the bonding material 22, and is made of, for example, a stretchable binder that is in a fluid state with a certain degree of viscosity in a heat-melted state and has stretchability after solidification. An example of the stretchable binder is, for example, an asphalt binder made of an elastic rubber and blended with asphalt, oil, rubber, a filler made of sand, calcium carbonate, magnesium carbonate, or the like. The binder layer 36 includes a sidewall surface and a bottom wall surface including the corners of the notch 24 on the first bridge member 12 side of the recess 18, and a sidewall surface including a corner of the notch 26 on the second bridge member 14 side. It is applied to the bottom wall. The binder layer 36 is integrated with the bonding material 22 filled in the concave portion 18, and maintains good bonding between the both end portions of the bonding material 22 and the inner surface of the concave portion 18 on the first and second bridge member sides. It is possible to prevent the bridge member and the bonding material from separating or cracking due to expansion and contraction. In the present embodiment, for example, the binder layer 36 is applied to the portion where the sheet body 32 is not installed on the bottom surface side of the recess 18 to the same thickness as the gap plate 30. The binder layer 36 may be applied also to the lower layer side of the gap plate 30 or the sheet body 32.

  The bonding material 22 filled in the recess 18 is configured by mixing aggregates 38 and 40 and a stretchable binder 42. The stretchable binder 42 is made of a stretchable binder that has a fluidity with a certain degree of viscosity in the heat-melted state and has a stretchability and water-stopping property after solidification, for example, like the binder layer 36 described above. In the present embodiment, the stretchable binder is configured by blending, for example, asphalt, oil, rubber, filler made of sand, calcium carbonate, magnesium carbonate, and the like.

  The aggregate blended in the bonding material 22 is made of, for example, stones such as crushed stones of various shapes, and contains a flat-shaped flat aggregate 38 and a non-flat flat non-flat aggregate 40 at a predetermined ratio. It is configured. In the present embodiment, the flat aggregate is composed of a material having a thickness t sufficiently smaller than the width b or the length L, as shown in FIG. In addition, when the aggregate is placed on a horizontal plane, the view when seen from above in a stable state is a plan view, and the short side of the aggregate in the plan view (FIG. 3B) is the width b, the aggregate Is the length L, and the maximum distance from the horizontal plane in the side view (FIG. 3 (a)) to the aggregate surface parallel to the horizontal plane is the aggregate thickness t. In the present embodiment, as a specific example of whether or not the aggregate is a flat aggregate, for example, a value obtained by dividing the aggregate width b by the aggregate thickness t is 3 or more (width b / thickness t What is ≧ 3) is a flat aggregate. The flat aggregate 38 in the bonding material 22 is in a state in which the flat direction is directed sideways by rolling the bonding material 22 from above after the recess 18 is filled with the bonding material 22.

  Specifically, the aggregate of the bonding material 22 is 100% in total, with the flat aggregate 38 having a weight ratio of 8 to 15% with respect to the total aggregate and the non-flat aggregate 40 having a remaining weight ratio of 92 to 85%. Configured to be. In general, asphalt composite aggregates used for road pavement and the like are preferred to have as little flat aggregate content as possible because of problems such as durability and workability. However, in the buried joint structure 10 of the bridge according to the present embodiment, unlike ordinary pavement, in order to improve durability while maintaining the function of absorbing the expansion and contraction displacement of the bridge, as described above, The joining material is configured in such an aggregate configuration that the content ratio of the flat aggregate in the aggregate is 8 to 15% by weight. In this way, by including the flat aggregate in the bonding material 22 of the joint portion 20 at a predetermined ratio, it is easy to fill the fluidized stretchable binder having a certain degree of viscosity in the heat-melted state between the aggregates. Thus, in a state where the bonding material is solidified, the expansion and contraction of the bridge member is generated, and the expansion and contraction of the bonding material 22 is not easily biased to a part, and the expansion and contraction can be absorbed well while being dispersed throughout. In addition, the flattening direction of the aggregate can withstand the tensile or compressive direction in the lateral direction against the expansion / contraction displacement of the bridge member, thereby improving the durability. Therefore, the water stop function in the joint part 20 can be satisfactorily maintained without causing cracks in the bonding material 22 of the joint part 20 due to repeated expansion and contraction of the bridge member.

  For example, if the flat aggregate contained in the aggregate of the bonding material 22 is less than 8% by weight with respect to the total aggregate, it is difficult to fill the elastic binder between the aggregates, and the expansion and contraction displacement of the bridge member In this case, the expansion and contraction of the bonding material is biased, and cracks are likely to be generated. As a result, the water stop function in the joint portion structure is lost. On the other hand, for example, if the amount of flat aggregate contained in the aggregate is more than 15% by weight with respect to the aggregate as a whole, the gap between the aggregates is excessively increased. In addition, the expansion and contraction of the bonding material is biased when the bridge member expands and contracts, cracks are likely to occur, and settlement tends to occur, resulting in the loss of the water stop function in the joint structure. End up.

  The bonding material 22 may be charged in a plurality of times according to the depth of the recess 18 and filled while repeating rolling and rolling. That is, as shown in FIG. 8, the joint portion 20 may be formed by forming a plurality of layers of the bonding material 22 in the recess 18. At that time, the stretchable binder 46 may be applied between the lower layer side bonding material and the upper layer side bonding material. Further, a stretchable binder 46 may be applied to the uppermost surface of the bonding material 22.

  Next, the construction method of the bridge embedded joint structure according to this embodiment will be described with reference to FIGS. 4 and 5. As shown in FIG. 4 (a), the opposing upper part of the first bridge member 12 and the second bridge member 14 is notched long in the direction of the opposing line between the first bridge member 12 and the second bridge member 14, so A concave portion 18 is formed. In the present embodiment, for example, the pavement portion 110 formed on the upper layer side of the first and second bridge members 12 and 14 is cut with a cutter blade or the like, or hung with a chipper or the like, and has a rectangular shape in a longitudinal sectional view. A recess 18 is formed. In addition, after forming the recessed part 18, if there is an unevenness | corrugation, a level | step difference, etc. in the bottom face etc. of a recessed part, you may adjust to cement, mortar, etc. if necessary. As shown in FIG. 4 (b), a stretchable backup material 28 is inserted into the gap 16 between the floor slabs 108 of the first and second bridge members 12 and 14 to perform a water stop treatment. A primer 44 is applied to the inner surface of the recess, that is, the side wall surface and the bottom wall surface of the inner surface of each notch portion on the first and second bridge member sides. As shown in FIG. 4C, the gap plate 30 is installed on the bottom surface of the recess 18 across the gap 16, and the gap plate 30 is fixed to the backup material 28 with pins 32. Note that a binder may be applied to the inner surface of the recess 18 before the gap plate 30 is installed. As shown in FIG. 4D, the sheet body 32 is installed on the bottom surface of the recess 18 so as to cover the gap plate 30. As shown in FIG. 4 (e), a stretchable binder is provided on the side wall surface and the bottom wall surface of the corner portion of the recess 18 on the side of the first bridge member 12 and on the side wall surface and the bottom wall surface of the corner portion on the side of the second bridge member 14, respectively. The binder layer 36 is formed by coating. The bottom wall portion of the concave portion 18 of the binder layer 36 is applied to a portion where the sheet body 12 is not installed corresponding to the thickness of the gap plate 30.

  On the other hand, for example, an elastic binder having elasticity after heating is preliminarily solidified to be in a fluid state, and then the aggregate and the elastic binder are mixed with a rotary mixer. The aggregate is composed of 8 to 15% of a flat aggregate in a weight ratio with respect to the total aggregate and the remaining 92 to 85% of a non-flat aggregate. The aggregate and the stretchable binder are mixed while being heated, and mixed sufficiently so that the aggregate is coated on the binder in a heated and melted state. As shown in FIG. 5 (f), the bonding material 22 is placed in the recess 18 in a heated state and filled in an embedded state. After that, as shown in FIG. 5 (g), the bonding material 22 filled in the recess 18 is compacted by rolling with the vibration roller VR from above, and the flat aggregate is flattened while being aligned so that the flat direction is in the lateral direction. . By curing for a certain period of time and solidifying the bonding material, the joint portion 20 is formed, and the first bridge member 12 and the second bridge member 14 are connected. In the present embodiment, the bonding material 22 may be filled in the concave portion 18 at once, and the bonding material 22 is poured into the concave portion 18 in several times and repeatedly pressed and pressed into the concave portion 18. The joint portion 20 may be provided by forming a plurality of 22 layers. At this time, a binder may be applied between the bonding material layers, or the bonding material may be placed, rolled, and the binder may be repeatedly formed. By throwing the bonding material 22 into the recess 18 in a plurality of times, the flat direction of the flat aggregate in the bonding material 22 can be easily turned sideways when rolling.

  Next, a test conducted using a full-scale specimen instead of an actual bridge will be described as an example of a bridge embedded joint structure. In this example, it was manufactured based on the NEXCO test method (East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd., West Japan Expressway Co., Ltd.) “Full-scale test method for buried joint (Test method 4370-2011)”. The full-scale specimen of the buried joint structure of the bridge was subjected to a stretch performance test (tensile test, compression test), a durability performance test (continuous test), and a water filling test. In the stretching performance test and the durability performance test, the verification years required for the joint structure of the bridge were set as 15 years.

  <Preparation of Specimen> In this specimen test, a concrete mold 48 was produced as the first and second bridge members 12 and 14. The mold frame was composed of two mold frame members 48a and 48b opposed to each other with a clearance of 50 mm, and a recess was formed in the upper part of the mold. The dimensions of the recess 18 formed in the mold 48 were set to have a length of 1050 mm, a width of 500 mm, and a depth of 75 mm. The joint portion 20 was constructed in a range of 700 mm in length in the recess. The formation of the joint portion is based on the construction method of the buried joint structure of the bridge described in the above embodiment, insertion of a backup material into the gap, application of a primer, installation of a gap plate, installation of a sheet body, binder A specimen 10T was manufactured by applying a layer, filling a bonding material, and rolling and curing the bonding material. The bonding material was prepared by mixing in a heated state at a ratio of 3.4 kg of stretchable binder to 20 kg of aggregate. The elastic binder is composed of 50% asphalt, 30% sand, calcium carbonate and magnesium carbonate, 10% oil, and 10% tire recycled rubber. S. A commercial product manufactured by BROWN was used. Aggregates were stones produced in the United States. For the specimen 10T, twelve specimens having different weight ratios of the flat aggregate in the bonding material to the entire aggregate (hereinafter referred to as flat aggregate content ratio) from 0.8 to 17% were prepared. Specifically, specimen No. 1-No. Up to 12, the content ratio of flat aggregate is 0.8%, 3%, 5%, 7%, 7.5%, 8%, 10%, 12%, 14%, 15%, 16%, 17% The set one was produced (see FIG. 9). White paint is applied on the entire surface of the joint material of the joint part of the prepared specimen to check the expansion and contraction during the test and the cracking after the test. I hit it.

  <Test Apparatus> A test was performed with the specimen 10T set in a test apparatus 50 as shown in FIGS. The test apparatus 50 is configured, for example, by attaching an electric actuator 54 and a jack to a machine casing 52. On the machine frame 52, a fixed base 56 and a movable base 58 that slides left and right on a horizontal plane and moves close to and away from the fixed base 54 are installed, and the actuator 54 is connected to the movable base 58. . One mold member 48a of the prepared specimen 10T is fixed to the fixed base 56, and the other mold member 48b is fixed to the movable base 58. The actuator 54 is electrically connected to a control box, and automatically slides the mold member 48b fixed to the movable table 58 by the actuator 54 based on a sequencer set under a predetermined condition. By moving close to or away from the formwork member 48a, the bridge is caused to undergo an expansion / contraction displacement in a pseudo manner.

  <Continuous test> The continuous test is a test assuming repeated annual displacement of the bridge member due to a temperature difference of one day. Move the actuator of the test device to “initial state (expansion amount ± 0 mm) → predetermined tension amount → initial state (expansion amount ± 0 mm) → predetermined compression amount → initial state (expansion amount ± 0 mm)” a predetermined number of times Repeatedly. The conditions in this test were: expansion / contraction amount ± 7.5 mm (compression amount 7.5 mm, tensile amount 7.5 mm, total amplitude 15 mm), number of repetitions 6000 times, expansion / contraction speed 1.5 mm / sec, temperature condition 15 ° C. ± 5 ° C).

  <Compression test> The compression test is a test assuming the extension of the bridge member due to a temperature rise in summer or the like. The actuator of the test apparatus was driven to repeat “initial state (expansion / contraction amount ± 0 mm) → predetermined compression amount → initial state (expansion / contraction amount ± 0 mm)” a predetermined number of times. The conditions in this test were a compression amount of 20 mm, a repetition count of 15 times, an expansion / contraction speed of 0.02 mm / sec, and a temperature condition of 60 ° C. or higher. The number of repetitions was set as the number of years of verification (15 years) × 1.

  <Tensile test> The tensile test is a test assuming shrinkage of the bridge member due to a temperature drop in winter or the like. The actuator of the test apparatus was moved to repeat “initial state (expansion / contraction amount ± 0 mm) → predetermined tension amount → initial state (expansion / contraction amount ± 0 mm)” a predetermined number of times. The conditions in this test were as follows: tensile amount 20 mm, number of repetitions 15 times, expansion / contraction speed 0.02 mm / sec, temperature condition −10 ° C. or lower. The number of repetitions was set as the number of years of verification (15 years) × 1.

  <Water-filling test> The water-filling test is a test for confirming whether or not the water-stopping function is maintained after performing a continuous test, a compression test, and a tensile test, that is, the presence or absence of water leakage. The specimen is kept in a tensile state with a tensile amount of 20 mm, and a weir is provided so that water can be stretched at the boundary between the joint portion and the mold of the specimen, and water with a depth of 10 cm or more is stretched at room temperature (0 ° C. The water filling state was continued for 24 hours or more.

  <Test result> Specimen No. 1-No. Each of the above-mentioned tests was conducted on No. 12. In the continuous test, compression test, and tensile test, during the test, the change in the grid-like ink pattern on the joint surface due to expansion and contraction, the presence or absence of cracks in the joint part of the specimen, and adhesion of the end of the joint part after the test The presence or absence of cutting and subsidence was confirmed visually. In the water filling test, the presence or absence of water leakage from the joint portion of the specimen was visually confirmed. The result is shown in FIG.

  <Evaluation> As shown in FIG. 9, when the flat aggregate contained in the aggregate of the bonding material is 8 to 15% by weight, the first, first, 2 The expansion and contraction of the joint part is not biased with respect to the expansion and contraction of the bridge member, and the entire structure expands and contracts, cracks do not occur during the test, and there is no water leakage in the water filling test and the water stop function is maintained well. did it. Therefore, it can be determined that it can be used even if it is applied as an actual joint structure of a bridge. On the other hand, when the flat aggregate contained in the aggregate of the joining material is 7.5% or less by weight, or when the flat aggregate is 16% or more, the first test is performed in the continuous test, compression test, and tensile test. The expansion and contraction of the second bridge member expands and contracts only at both ends of the joint material of the joint, and both ends crack and subsidence. The water function could not be maintained. Therefore, it cannot be put into practical use in the expected number of years of verification (15 years) as an actual joint structure of a bridge, and is determined to be unacceptable. Based on this test result, it is possible to absorb the expansion and contraction of the bridge well by setting the flat aggregate to 8 to 15% by weight with respect to the aggregate as a whole in the joint material of the joint part of the buried joint structure of the bridge. It can be seen that the durability can be improved and the water stop function can be maintained for a long time.

  The bridge embedded joint structure and the construction method thereof according to the present invention described above are not limited to the configuration of the above-described embodiment alone, and do not depart from the essence of the present invention described in the claims. Any modification may be made.

  The buried joint structure of a bridge according to the present invention and its construction method are used for construction such as connection between a bridge girder and abutment, connection between bridge girder, etc., and repair maintenance.

DESCRIPTION OF SYMBOLS 10 Bridge-type joint part structure 12 1st bridge member 14 2nd bridge member 16 Spacing 18 Recess 20 Joint part 22 Joining material 28 Backup material 30 Gap plate 32 Sheet body 36 Binder layer 38 Flat aggregate 40 Non-flat aggregate 42 Elastic binder 44 primer

Claims (4)

It is a bridge joint structure that connects bridge members including bridge girders or abutments,
A first bridge member;
A second bridge member connected to the first bridge member, the second bridge member being opposed to the first bridge member with a gap therebetween;
A concave portion formed along the gap by cutting out the upper part of the first bridge member and the second bridge member long in the direction of the opposing line between the first bridge member and the second bridge member;
A joint that mixes an aggregate and a stretchable binder having a stretchability after solidification is embedded in a recess and is embedded, and includes a joint portion that absorbs the displacement of the bridge member,
The buried joint structure of a bridge, wherein the aggregate of the bonding material includes 8 to 15% of flat aggregate in a weight ratio with respect to the total aggregate. The joint part is a stretchable backup material inserted between
A gap plate installed across the gap between the bottom of the recess,
A sheet body installed on the bottom surface of the recess to cover the gap plate;
A binder layer that is applied to the inner wall surface on the first bridge member side and the inner wall surface on the second bridge member side of the recess before filling with the bonding material and is integrated with the bonding material filled in the recess. The buried joint structure of a bridge according to claim 1. The recess is formed in a rectangular shape in a longitudinal sectional view,
The binder layer of the joint portion is formed by applying to the side wall surface including the corner portion and the bottom wall surface for each of the first bridge member side and the second bridge member side of the concave portion. Bridge-type buried joint structure. It is a construction method for the buried joint structure of bridges that connect bridge members including bridge girders or abutments,
The upper part of the first bridge member and the second bridge member, which are connected to face each other with a gap between them, is cut out long in the direction of the opposing line between the first bridge member and the second bridge member to form a recess along the gap. Forming, and
Inserting a stretchable backup material between the play; and
Applying a primer to the inner surface of the recess;
Installing a gap plate across the gap on the bottom of the recess;
Installing the sheet body so as to cover the gap plate installed on the bottom surface of the recess;
Applying a stretchable binder to each of the inner wall surface on the first bridge member side and the inner wall surface on the second bridge member side of the recess to form a binder layer;
Filling a recess with a bonding material in which an aggregate containing 8 to 15% of a flat aggregate in a weight ratio with respect to the entire aggregate and a stretchable binder having a stretchability after solidification are mixed;
A method of constructing a buried joint structure of a bridge, comprising: rolling the bonding material filled in the recesses from above to compact the flat aggregate so that the flat direction is aligned in the lateral direction. .

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