JP2019100090A - Anticorrosive structure for expansion device - Google Patents

Abstract

To provide an anticorrosive structure for an expansion device which can provide a sufficient corrosion-proof effect for a face plate.SOLUTION: An expansion device 1 is provided with two face plates 3, 3 made of steel which are fixed by a bolt 12 at ends of two floor slabs 2 opposed to each other across a joint gap G; a gutter 6 made of stainless steel which is fixed together with the face plates 3 by the bolt 12 to the floor slabs 2 and arranged within the joint gap G; a sacrificial anode 4 made of an Al-1Zn alloy and arranged on a backup member 7 that is arranged inside the gutter 6; a conductive wire 5 electrically connecting the sacrificial anode 4 to the face plates 3; and sediments 8 accumulated on the backup member 7 to cover the sacrificial anode 4 and also come into contact with the underside surface of the face plates 3. The gutter 6, the face plates 3, and the sacrificial anode 4 are electrically connected to one another so as to form the potentials which become lower in this order, and then corrosion current flows to the sediment 8 so as to generate an anode reaction at the sacrificial anode 4, thereby preventing the corrosion of the face plate 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a corrosion prevention structure of a telescopic device installed at a seam of a bridge.

  Conventionally, in order to absorb the displacement of the floor slab caused by temperature change, deflection, etc., between stretches formed between the floor slab of the bridge and the floor slab or between the floor slab and the abutment etc, a telescopic device is installed It is done. The telescopic device comprises a steel face plate fixed respectively to the floor plate or the upper end of the abutment opposite the play area, the surface being arranged in series with the surface of the pavement. The face plate has a plate-like base fixed to the floor slab or the abutment, and a plurality of combs extending from the base to the free space, and the combs of the face plates disposed opposite to each other are engaged alternately It forms a road surface connected to the surface of the pavement.

  In such a telescopic device, there is a problem that a steel face plate is easily rusted by rain water or an anti-freeze agent, and a portion of the cross section reduced due to the rust is damaged by the load of a vehicle traveling on the road surface. In order to solve such a problem, a telescopic device has been proposed in which an L-shaped anticorrosive thin metal plate is disposed in contact with the lower surface of the face plate and the end face of the web plate facing the gap (patented) Reference 1). In this expansion and contraction device, a water blocking material is disposed so as to be in contact with the lower surface and the side surface of the corrosion-resistant thin metal plate, and is configured to prevent water leakage from the expansion and contraction device. This stretching device prevents corrosion of the web plate in contact with the corrosion-resistant thin metal plate by forming the corrosion-resistant thin metal plate with zinc, aluminum, magnesium or their alloys having a sacrificial anodic action. .

JP, 2008-57284, A

  However, since the conventional expansion and contraction apparatus arranges the L-shaped anticorrosive thin metal plate in contact with the lower surface of the face plate and the end face of the web plate, the space between the face plate and the anticorrosive thin metal plate is Water is difficult to enter and tends to be dry. In addition, the face plate and the corrosion-resistant thin metal plate come into contact with each other in point contact when they have a normal surface finish. In the face plate and the corrosion-resistant thin metal plate that make point contact in the dry state, the current based on the potential difference between the face plate and the corrosion-resistant thin metal plate concentrates on the point contact point, while the non-contact area is dry Because of this, it is difficult for the corrosion resistant thin metal plate to have a sufficient anodic reaction. Therefore, it is difficult for the corrosion resistant thin metal plate to sufficiently exhibit the sacrificial anode action, and there is a problem that the anticorrosion effect of the face plate becomes insufficient. If the anticorrosive effect of the thin metal plate is insufficient, localized corrosion may occur on the face plate.

  Then, the subject of this invention is providing the corrosion prevention structure of the expansion-contraction apparatus in which the anti-corrosion effect of a face plate is fully acquired.

In order to solve the above problems, the corrosion prevention structure of the expansion and contraction device according to the present invention is a corrosion prevention structure of the expansion and contraction device provided between the bridges of the bridge,
A metal face plate disposed at the upper end of the play area and having a road surface formed on the surface;
A sacrificial anode electrically connected to the face plate by a conductive wire and disposed in non-contact with the face plate and capable of staying in contact with the face plate and in contact with a corrosion current medium And providing.

  The corrosion prevention structure of the above configuration relates to a telescopic device installed in the free space formed between the floor plate of the bridge and the floor plate, between the floor plate and the abutment, etc. To prevent corrosion of the metal face plate on which the road surface is formed. In the corrosion prevention structure of this expansion and contraction device, the sacrificial anode is electrically connected to the face plate with a conductive wire and disposed in non-contact with the face plate. Furthermore, between the sacrificial anode and the face plate, the anticorrosion current medium is formed in contact with the sacrificial anode and the face plate so as to be able to stay. As a result, a potential difference can be formed between the face plate and the sacrificial anode through the conductive wire, and a corrosion current can be supplied to the corrosion current medium, so that the anode reaction can be effectively generated in the sacrificial anode. As a result, it is possible to effectively prevent corrosion of the portion of the face plate in contact with the anticorrosion current medium. Here, the sacrificial anode is formed of a metal having a lower ionization tendency than the metal of the face plate. Further, the corrosion resistance current is a cathode reaction that occurs on the face plate that contacts the corrosion current medium or another metal that has a higher ionization tendency than the face plate, and an anode reaction that occurs on the sacrificial anode that contacts the corrosion current medium It refers to the current that flows apparently in the anticorrosion current medium. When the corrosion current medium is brought into contact with a metal having a higher ionization tendency than the face plate, the metal and the face plate need to be connected by a conductive wire. In addition, as the anticorrosion current medium, for example, an electrolyte corresponds.

  In one embodiment, the sacrificial anode is disposed under the face plate at a passing position of wheels of a vehicle traveling on a road surface on the face plate.

  According to the above embodiment, since the sacrificial anode is disposed under the face plate at the passing position of the wheels of the vehicle traveling on the road surface on the face plate, the sacrificial anode is easily damaged by the load from the vehicle. Anticorrosion of the face plate portion can be effectively performed. The sacrificial anode may have a length corresponding to at least the passing position of the wheel, and may not have a length corresponding to the entire width of the road surface.

  In the corrosion prevention structure of an expansion and contraction device according to one embodiment, a weir for collecting or stopping water is disposed below the face plate.

  According to the above-mentioned embodiment, by using the weir arranged below the face plate, the water from the road surface is collected and collected, or the expansion and contraction device performs the water stop to prevent the water from falling into the play space from the road surface , Can effectively prevent corrosion of the face plate. In such an expansion device provided with a weir, although the water is easily accumulated inside and on the weir, and the face plate becomes an environment susceptible to corrosion, the sacrificial anode of the present invention effectively corrodes the face plate. Can be prevented.

In one embodiment of the corrosion prevention structure of the expansion device, the sacrificial anode is disposed inside the crucible.
The anticorrosion current medium contains at least one of earth and sand, water, an antifreeze agent, a snow melting agent, and seawater, and stays inside the weir.

  According to the above embodiment, the sacrificial anode is disposed inside the weir, and inside this weir, earth and sand, water, antifreeze agent, snow melting agent, sea water, etc. carried by the vehicle traveling on the road surface or by wind etc. Stay. At least one of the earth, sand, water, antifreeze agent, snow melting agent, and seawater functions as an anticorrosion current medium, thereby causing the anticorrosion current medium to flow an anticorrosion current to promote the anode reaction of the sacrificial anode. it can. As a result, corrosion protection of the face plate can be effectively performed.

In the corrosion prevention structure of an expansion device according to one embodiment, a water blocking member is disposed on the inside of the weir, and the sacrificial anode is disposed on the water blocking member,
The anticorrosion current medium is retained on the water blocking member, and the retained anticorrosion current medium is formed so as to embed the sacrificial anode and to be in contact with the face plate.

  According to the above-described embodiment, the sacrificial anode is disposed on the water blocking member disposed inside the weir, and the anticorrosion current medium is retained on the water blocking member. The stagnant anticorrosion current medium sinks the sacrificial anode and contacts the face plate. Therefore, the anticorrosion current can be effectively applied to the anticorrosion current medium, and the face plate can be effectively corroded.

  In one embodiment of the corrosion prevention structure of the expansion device, the face plate is formed of steel, and the sacrificial anode is formed of an alloy containing zinc and aluminum.

  According to the above embodiment, the sacrificial anode formed of an alloy containing zinc and aluminum has a lower ionization tendency than the steel forming the face plate, so that corrosion of the face plate can be effectively performed.

  In the corrosion prevention structure of the expansion device according to one embodiment, the cross section of the sacrificial anode is formed to be wider than the height.

  According to the above embodiment, since the cross section of the sacrificial anode is formed to be wider than the height, the contact area between the sacrificial anode and the anticorrosive current medium is obtained even if the amount of the anticorrosion current medium contacting the sacrificial anode is small. Can be increased. Therefore, the anticorrosion current flowing through the sacrificial anode can be effectively ensured, and the corrosion of the face plate can be effectively performed.

  In one embodiment, the face plate is a comb-like finger plate having comb teeth extending in the bridge axial direction.

  According to the above embodiment, the sacrificial anode can effectively prevent corrosion of the comb-like finger plate having the comb teeth extending in the bridge axis direction. As a result, the cross-sectional area of the root portion of the comb teeth is reduced due to the corrosion of the finger plate, and the disadvantage that the root portion of the comb teeth is broken under the load of the vehicle in that state can be effectively prevented.

1 is a cross-sectional view showing a telescopic device having a corrosion prevention structure according to an embodiment of the present invention. It is a top view which shows the expansion-contraction apparatus which has a corrosion prevention structure of embodiment. It is a top view which shows the part corresponded to one lane of the expansion-contraction apparatus which has the corrosion prevention structure of embodiment. It is sectional drawing which shows the expansion-contraction apparatus which has the corrosion prevention structure of other embodiment.

  Hereinafter, the present invention will be described in detail by the illustrated embodiments.

  FIG. 1 is a cross-sectional view of an expansion device having a corrosion prevention structure according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of an expansion device having a corrosion prevention structure according to the embodiment. The telescopic device 1 is disposed at the upper end of the play gap G formed between the floor slab 2 and the floor slab 2 of the bridge, and a road surface on which the vehicle travels is formed on the surface. The road surface is kept passable while being absorbed.

  The telescopic device 1 includes two face plates 3 and 3 fixed by bolts 12 at the ends of two floor slabs 2 facing each other with a gap G therebetween. The face plate 3, 3 has a plate-like base 3a in contact with the end of the floor slab 2 and extends in the axial direction of the bridge from the base 3a and extends over the free space G from the edge of the floor slab 2 , And a plurality of comb portions 3b, 3b,... The surface of the face plate 3 is continuously disposed on the surface of the pavement 13 provided on the floor plate 2 and forms a road surface continuous with the surface of the pavement 13. The face plates 3, 3 fixed to the floor slabs 2, 2 are meshed with each other in the bridge axial direction with the comb portions 3b, 3b,... They are axially displaceable relative to one another, with possible maintenance.

  The floor slab 2 is a steel floor slab formed of a steel member, and has a plate-like deck plate 11 and longitudinal ribs 17 provided on the lower side surface of the deck plate 11 and extending in the bridge axial direction. An end cross beam 18 extending in a direction perpendicular to the bridge axis is provided at the lower end surface of the deck plate 11 at the bridge axial end of the floor slab 2. The floor slab 2 is supported by a main girder 19 provided on the lower surface of the deck plate 11 and extending in the bridge axial direction. The face plate 3 of the telescopic device 1 is fixed to the end of the floor plate 2 via a filler plate 10 disposed on the upper side surface of the deck plate 11. A pavement 13 formed of a base layer 14 and a surface layer 15 is laid on the upper side surface of the deck plate 11 of the floor slab 2, and a road surface is formed on the surface of the pavement 13.

  In the play space G between the two floor slabs 2 and 2, on the lower side of the face plate 3, a weir 6 is arranged to prevent water from the road surface from falling below the play space. The crucible 6 is formed of SUS304 which is an austenitic stainless steel and has a U-shaped cross section and is disposed in the clearance G from the upper end edge of both sides of the crucible main body 6a in the horizontal direction It is formed including the extending plate-like attachment parts 6b and 6b. The hook attachment parts 6b, 6b are fixed to the ends of the two floor slabs 2, 2, respectively. The hook attachment portion 6 b is sandwiched between the filler plate 10 and the face plate 3 of the floor plate 2 and is fixed to the deck plate 11 by the bolt 12 together with the face plate 3.

  A backup member 7 as a water blocking member is disposed inside the crucible main body 6a of the crucible disposed in the play space G, and the sacrificial anode 4 is disposed on the backup member 7. The backup member 7 is formed of a highly elastic urethane foam. Soils 8 are deposited on the backup member 7 so as to cover the sacrificial anode 4 and to be in contact with at least the lower surface of the face plate 3. The earth and sand 8 is a deposit of earth and sand adhering to the wheels of a vehicle traveling on the surface of the face plate 3 and earth and sand flying from the ground. Soil 8 contains water due to rainfall or the like, and the wet state is maintained. The earth and sand 8 includes an antifreeze agent or a snow melting agent sprayed on the road surface, or an electrolyte such as seawater flying from the sea. At least one of the soil 8, water, antifreeze agent, snow melting agent, and seawater functions as an anticorrosion current medium. In addition, the earth and sand 8 may adhere to the wheel of the vehicle, or may fly from the ground, or may be disposed from the beginning when the telescopic device 1 is installed. When the earth and sand 8 is arranged from the beginning, it is preferable to set to a particle size distribution that can retain water and continue the wet state. Also, between the backup member 7 and the face plate 3, only the sacrificial anode 4 is initially placed and left hollow, and even with the passage of time, sediment may be deposited by passage of the vehicle or supply by wind. Good. Alternatively, a flexible filler is initially filled between the backup member 7 and the face plate 3, and the filler disappears due to passage of the vehicle, deformation of the crucible main body 6 a accompanying displacement of the floor slab 2, etc. Then, it becomes a cavity, and thereafter, the sediment 8 may be deposited by passage of a vehicle or supply by wind. Further, the weir 6 may have a water collecting function of collecting water from the road surface by securing the function of flowing water to the inside, in addition to preventing water from falling from the road surface. In this case, the inside of the weir is formed so that the earth and sand are accumulated while contacting the face plate 3 and the sacrificial anode 4 while securing the function of collecting water. The weir is widely used as long as it is a member that collects or stops water from the road surface, the shape and material are not particularly limited, and the name of the member is not limited to weir.

  The sacrificial anode 4 is formed of an Al-1Zn alloy. The sacrificial anode has a circular cross section and is disposed at a position corresponding to the passing range of the wheels of a vehicle traveling on the road surface. Specifically, in the lane set on the surface of the pavement 13 as shown in FIG. 3, under the wheel passing ranges T1, T2 which is a range where the wheels of the vehicle traveling in this lane pass frequently, A sacrificial anode 4 set to a length slightly longer than the width of the wheel passing ranges T1, T2 is disposed. That is, two sacrificial anodes 4 are disposed for each face plate 3 of one lane, and the sacrificial anodes 4 respectively connected to the two opposing face plates 3 have a predetermined interval in the bridge axis direction. It is arranged. The sacrificial anode 4 is electrically connected to the face plate 3 by a conductive wire 5 formed of a coated copper wire. The face plate 3 is in close contact with a crucible 6 made of stainless steel and a bolt 12 and is electrically connected. Thus, the weir 6, the face plate 3 and the sacrificial anode 4 are electrically connected in this order. The crucible 6, the face plate 3 and the sacrificial anode 4 are all in contact with the soil 8 in the crucible 6.

  The expansion device 1 having the above-described corrosion prevention structure is electrically connected to the weir 6, the face plate 3 and the sacrificial anode 4 in this order, and in contact with the wet soil 8 containing an electrolyte. , A three-pole battery is formed. The crucible 6 formed of stainless steel has a higher ionization tendency than the face plate 3 formed of steel, and the face plate 3 formed of steel has a ionization tendency more than the sacrificial anode 4 formed of Al-1Zn alloy Is high. As a result, when the crucible 6, the face plate 3 and the sacrificial anode 4 are electrically connected in this order, a potential difference which decreases in this order is formed between the crucible 6, the face plate 3 and the sacrificial anode 4. As a result, an anodic reaction occurs in the sacrificial anode 4, and a cathodic reaction occurs in the crucible 6, so that a corrosion current flows between the sacrificial anode 4 and the crucible 6 of the soil 8. As a result, corrosion of the face plate 3 can be prevented.

  As described above, the steel face plate 3 placed in contact with the crucible 6 formed of stainless steel has different tendency to be ionized than steel because the steel has a lower ionization tendency than the stainless steel. Among the lower side surfaces, corrosion particularly progressed in the gap portion formed with the weir 6 and the portion in contact with the earth and sand 8 including the electrolyte. To solve such problems, according to the embodiment of the present invention, the sacrificial anode 4 having a lower ionization tendency than the weir 6 and the face plate 3 is disposed on the sand 8 containing the anticorrosion current medium, Since the face plate 3 and the face plate 3 are in contact with each other, the face plate 3 can be effectively protected against corrosion.

  Although the sacrificial electrode 4 having a circular cross section is used in the above embodiment, a sacrificial anode having a cross section of another shape may be used. For example, as described in FIG. 4, a sacrificial anode 41 having a triangular cross section and a sacrificial anode 42 having a horizontally long elliptical cross section can be used. Each of these sacrificial anodes 41 and 42 has a cross section with a width larger than the height, so that the surface of the sacrificial anodes 41 and 42 can be sufficiently contacted with water even if the amount of water contained in the soil 8 is small. Anticorrosion current can be applied. As a result, the anodic reaction of the sacrificial anodes 41 and 42 can be sufficiently promoted, and the corrosion of the face plate 3 can be effectively performed.

  Moreover, in the said embodiment, although the expansion-contraction apparatus 1 was equipped with the crucible 6 formed with stainless steel, the crucible 6 may be formed with materials other than stainless steel, such as resin and rubber | gum. For example, when the crucible 6 is formed of resin, the cathode reaction occurs on the face plate 3 formed of steel, and the anode reaction occurs on the sacrificial anode 4 formed of Al-1Zn alloy. Anticorrosion can be performed.

  Also, the face plate 3 is made of steel, and the sacrificial anode 4 is made of Al-1Zn alloy, but if the metal forming the sacrificial anode 4 has a lower ionization tendency than the metal forming the face plate 3, the sacrificial The anode 4 and the face plate 3 may be formed of other metals.

  In addition, the corrosion prevention structure of the expansion and contraction device of the present invention may be installed from the beginning on the newly installed expansion and contraction device 1 or may be retrofitted to the existing expansion and contraction device 1.

  Moreover, although the said embodiment demonstrated the expansion-contraction apparatus 1 installed in the play space G formed between the floor slab 2 and the floor slab 2, it installed in the play space formed between the floor slab 2 and the abutment. The present invention is also applicable to a telescopic device.

Reference Signs List 1 telescopic device 2 floor plate 3 face plate 3a face plate base 3b comb portion of face plate 4 sacrificial anode 5 conductive wire 6 樋 6 a 樋 main body 6 b 取 付 attachment portion 7 backup member 8 earth and sand 10 filler plate 11 deck plate 12 bolt 13 paving 14 base layer 15 surface 17 longitudinal rib 18 end cross girder 19 main girder G free space T1, T2 wheel passing range

Claims (8)

A corrosion prevention structure of a telescopic device provided between bridge bridges,
A metal face plate disposed at the upper end of the play area and having a road surface formed on the surface;
A sacrificial anode electrically connected to the face plate by a conductive wire and disposed in non-contact with the face plate and capable of staying in contact with the face plate and in contact with a corrosion current medium And a corrosion-preventing structure for a telescopic device. In the corrosion prevention structure of a telescopic device according to claim 1,
A corrosion prevention structure of a telescopic device, wherein the sacrificial anode is disposed under the face plate and at a passing position of wheels of a vehicle traveling on a road surface on the face plate. In the corrosion prevention structure of a telescopic device according to claim 1,
The corrosion prevention structure characterized in that a weir for water collection or water stop is disposed below the face plate. In the corrosion prevention structure of a telescopic device according to claim 3,
The sacrificial anode is disposed inside the crucible,
The corrosion prevention structure of a telescopic device, wherein the anticorrosion current medium contains at least one of earth, sand, water, an antifreeze agent, a snow melting agent, and seawater, and stays inside the weir. In the corrosion prevention structure of a telescopic device according to claim 4,
A water blocking member is disposed inside the weir, and the sacrificial anode is disposed on the water blocking member,
The corrosion prevention of the expansion / contraction device characterized in that the anticorrosion current medium is retained on the water blocking member, and the retained anticorrosion current medium is embedded in the sacrificial anode and in contact with the face plate. Construction. In the corrosion prevention structure of a telescopic device according to claim 1,
A corrosion prevention structure for an expansion device, wherein the sacrificial anode is formed of an alloy containing zinc and aluminum. In the corrosion prevention structure of a telescopic device according to claim 1,
A corrosion prevention structure for an expansion device, wherein the cross section of the sacrificial anode is formed to be wider than the height. In the corrosion prevention structure of a telescopic device according to claim 1,
The corrosion prevention structure of a telescopic device, wherein the face plate is a comb-like finger plate having comb teeth extending in a bridge axial direction.

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