JP2018003399A - Concrete layer removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete layer removal method that can detach a concrete layer formed on a steel material through a thermosetting resin adhesive.SOLUTION: A concrete layer removal method for removing a concrete layer 3 laid on a steel material (steel plate floor 1) through a resin adhesive (adhesive layer 2) comprises: a first removal step of removing a surface part 3a of the concrete layer 3; a heating step of heating the steel material (steel plate floor 1) by using an electromagnetic induction heating device 16 so as to heat the adhesive; and a second removal step of removing a remainder 3b of the concrete layer 3 and the heated adhesive ( adhesive layer 2). In the heating step, heating is preferably performed in a state where the concrete layer 3 is crushed coarsely by a breaker 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for removing a concrete layer.

  Steel bridges on which vehicles run are constructed with asphalt pavement on the road surface by forming the basic structure of the bridge with steel frames and steel slabs (base steel plates). In this case, since there is a possibility that the asphalt pavement and the steel floor slab are peeled off, the asphalt mixture is laid after applying a solvent-type rubber asphalt pressure-sensitive adhesive as an adhesive (binder) to the surface of the steel floor slab.

  Asphalt pavement surfaces are damaged due to factors such as the accumulation of passing loads of vehicles and aging and wear due to temperature changes after a long period of time. Therefore, it is necessary to repair the asphalt pavement surface. In the renovation work, the asphalt mixture is peeled off and disassembled, and then the asphalt mixture is laid again. The asphalt mixture is peeled and disassembled because the asphalt mixture is firmly bonded to the steel floor slab via an adhesive, and thus requires a lot of time and labor.

  Therefore, the present inventors have invented a heating apparatus for efficiently removing and disassembling the asphalt mixture by heating and softening the adhesive (see Patent Document 1). This heating device is provided with an induction coil along the asphalt pavement surface in the traveling device, and the surface of the steel deck is induction-heated by induction magnetic flux generated from the induction coil, and the adhesive layer in contact with the steel deck is heated and softened. This is an induction heating device.

JP 2007-146458 A

  In Patent Document 1, since a rubber asphalt pressure-sensitive adhesive is used as an adhesive, the adhesive can be softened by heating. Therefore, since the relatively soft asphalt layer and the adhesive layer can be peeled together, the peeling work can be easily performed.

  By the way, in recent years, a road in which a concrete layer such as steel fiber reinforced concrete (SFRC) is formed on a steel floor slab via an adhesive layer and an asphalt layer is formed thereon has been constructed. Such a road adhesive is not softened by heat because an epoxy resin-based thermosetting resin is used. Therefore, the repair work described in Patent Document 1 cannot be performed.

  It is known that an epoxy resin-based adhesive is thermally deteriorated when it is heated to a thermal decomposition temperature (about 200 to 300 ° C.), and the adhesive strength is weakened. However, heating the adhesive or steel material to the pyrolysis temperature may adversely affect the steel material or other members. Therefore, it has not been considered to heat and peel off the epoxy resin adhesive.

  Moreover, since the pavement itself using SFRC is a new technology and there are no examples of repair work, a technology for efficiently separating the adhesive and the concrete layer has not been established. Therefore, in order to renovate the road with the current technology, the concrete layer is peeled off so as not to damage the steel slab with a hand-held breaker, which requires a lot of labor and time.

  Therefore, the present invention was devised in view of these problems, and provides a new concrete layer removal method capable of peeling a concrete layer formed on a steel material through a resin-based adhesive. Let it be an issue.

  The present invention for solving the above problems is a concrete layer removing method for removing a concrete layer laid on a steel material via a resin-based adhesive, and a first removal for removing a surface portion of the concrete layer A heating step of heating the adhesive by heating the steel material using an electromagnetic induction heating device; and a second removal step of removing the remainder of the concrete layer and the heated adhesive. It is characterized by that.

  According to such a method, since the ground adhesive force can be reduced by heating the resin adhesive, the adhesive can be crushed together with the concrete and easily peeled from the steel material. Therefore, an adhesive agent and a concrete layer can be removed efficiently.

  Moreover, in the concrete layer removal method of this invention, it is preferable to heat in the said heating process in the state by which the said concrete layer was roughly divided by the breaker. According to such a method, it is possible to prevent the concrete from bursting due to expansion of moisture in the concrete.

  Furthermore, in the concrete layer removing method of the present invention, it is preferable that in the second removing step, the concrete layer and the adhesive are peeled off by a heavy machine having a bucket with a claw. According to such a method, the concrete layer and the adhesive can be peeled together, and the working efficiency becomes good.

  In the concrete layer removing method of the present invention, the adhesive is an epoxy resin adhesive, and in the heating step, the adhesive is preferably heated to a range of 80 to 120 ° C.

  When the epoxy resin adhesive is heated to the thermal decomposition temperature, the adhesive is weakened due to thermal degradation, and when the adhesive or the steel material is heated to the thermal decomposition temperature, the steel material and other members are adversely affected. We paid attention to the possibility of influence. And the temperature which reduces the adhesive force of an adhesive agent without having a bad influence on steel materials etc. was earnestly researched and derived. That is, if the adhesive is heated to a range of 80 to 120 ° C. as in the above method, the adhesive strength of the adhesive can be reduced without adversely affecting the steel material.

  According to the present invention, a concrete layer formed on a steel material via an adhesive layer can be peeled off.

It is sectional drawing which showed the cross section of the paved road to repair. It is the flowchart which showed the concrete layer removal method which concerns on embodiment of this invention. It is the side view which showed the asphalt layer removal process. It is sectional drawing which showed the road cross section of the state which removes an asphalt layer. It is the side view which showed the 1st removal process of the concrete layer. It is sectional drawing which showed the road cross section of the state which removes the surface part of a concrete layer. It is the side view which showed the heating process and the 2nd removal process of the concrete layer. It is sectional drawing which showed the road cross section of the state which removes the remainder of a concrete layer, and an adhesive agent.

  A concrete layer removing method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, as shown in FIG. 1, a case where a concrete layer 3 is formed on a steel floor slab 1 via an adhesive layer 2 and a road 5 having an asphalt layer 4 formed thereon is repaired is taken as an example. Name and explain the road improvement work. The concrete layer 3 is made of steel fiber reinforced concrete (SFRC). The adhesive layer 2 is made of a resin-based adhesive. In the present embodiment, the adhesive is an epoxy resin adhesive and is made of a two-component epoxy resin.

  The concrete layer removal method according to the present embodiment is included in the road repair work. As shown in FIG. 2, the road repair work includes asphalt layer removal step S1, first removal step S2, heating step S3, second removal step S4, surface treatment step S5, concrete pavement step S6, and asphalt pavement step S7. It has. The concrete layer removing method is a method of removing the concrete layer 3 laid on the steel floor slab 1 through the adhesive of the adhesive layer 2. The concrete layer removing method includes a first removing step, a heating step, and a second removing step among the steps.

  The asphalt layer removing step is a step of peeling off and removing the asphalt layer 4 on the surface of the road 5 as shown in FIGS. 3 and 4. In the asphalt layer removal step, the asphalt layer 4 is cut by the cutting machine 10 and loaded on the dump truck 11 that moves forward. Asphalt layer 4 can be peeled relatively easily from the surface of concrete layer 3 as shown in FIG.

  A 1st removal process is a process of removing the surface part 3a of the concrete layer 3, as shown in FIG.5 and FIG.6. In the first removal step, first, the surface portion 3a of the concrete layer 3 is roughly divided by the preceding breaker 12. Thereafter, the surface portion 3 a of the concrete layer 3 roughly divided by the backhoe 13 is scraped off. Specifically, the surface portion 3a of the concrete layer 3 is hooked and peeled off with the claws 15 of the bucket 14 of the backhoe 13. At this time, the bottom of the concrete layer 3 is adhered to the adhesive layer 2 and remains without being peeled off (see FIG. 6). The concrete pieces scraped off by the backhoe 13 are loaded on the dump truck 11 moving in front of the backhoe 13.

  The heating process is a process of heating the adhesive layer 2 by heating the steel deck 1 using the electromagnetic induction heating device 16. The electromagnetic induction heating device 16 includes an induction coil (not shown), and induction heating is performed on the surface of the steel deck 1 by generating an induction magnetic flux from the conductive coil so as to face the steel deck 1. It is. The electromagnetic induction heating device 16 is loaded on the track 17. The induction coil is provided on a coil support portion 16a that protrudes from the rear of the truck so as to face the road surface. The adhesive layer 2 is heated to 80 to 120 ° C, preferably 100 to 120 ° C.

  The inventors of the present invention have characteristics that the epoxy resin-based adhesive is easily peeled off when heated to the thermal decomposition temperature, and that the steel floor slab 1 and other members may be adversely affected when the adhesive or steel material is heated to the thermal decomposition temperature. Focused on the point. And the present inventors derived the temperature which reduces the adhesive force of an adhesive agent without affecting the steel deck 1 etc. by performing a demonstration experiment. In the demonstration experiment, it was found that when the temperature of the adhesive exceeds 80 ° C., the adhesive strength starts decreasing, and when it exceeds 100 ° C., the strength of the adhesive decreases, the adhesive ability decreases, and it becomes easy to peel off. That is, even if the adhesive is heated to the thermal decomposition temperature and is not completely thermally deteriorated, the adhesive can be easily peeled from the steel deck 1 by heating to 80 to 120 ° C. That is, in this embodiment, the adhesive strength of the adhesive is reduced without affecting the structural strength of the steel deck 1.

  The temperature of the adhesive layer 2 may be such that at least the bottom of the adhesive layer 2 in contact with the steel deck 1 is heated to the above temperature. The temperature of the adhesive layer 2 is controlled by the heating time. Specifically, heating is performed while the track 17 is traveling at a constant speed, so that the heating time becomes constant, so that the heating temperature of the adhesive layer 2 can be made constant. As a result, the adhesive becomes brittle as the adhesive ability decreases. Note that the adhesive ability of the adhesive does not return to the original state when the temperature is lowered to 100 ° C. or lower after the heating is completed, although it tries to be restored.

  The second removal step is a step of removing the remaining part of the concrete layer 3 and the heated adhesive layer 2. In the second removal step, the remaining portion 3b of the concrete layer 3 and the adhesive layer 2 whose bonding ability is reduced are integrally scraped with the peeling backhoe 13a disposed immediately after the electromagnetic induction heating device 16. A flat bucket is used as the bucket 14 of the peeling backhoe 13a. At this time, the claws 15 of the bucket 14 of the peeling backhoe 13 a are moved along the surface of the steel deck 1, and the adhesive layer 2 is peeled off from the surface of the steel deck 1. As described above, the flat portion of the steel slab 1 is used to peel the concrete layer 3 and the adhesive layer 2 using the peeling backhoe 13a. Is performed manually by a worker using a small jig. Also in this case, since the adhesive ability of the adhesive is lowered, it is easy to peel off.

  A dump truck 11 and a recovery backhoe 13b are disposed behind the peeling backhoe 13a. The remaining portion 3b of the concrete layer 3 and the adhesive layer 2 scraped off by the peeling backhoe 13a are loaded on the dump truck 11 moving in front of the collecting backhoe 13b.

  The surface treatment step is a step for polishing the surface of the steel deck 1. In the present embodiment, the surface treatment of the steel deck 1 is performed by shot blasting. Thereby, the surface of the steel deck 1 can be made into a state in which a new adhesive layer (not shown) can be laid.

  The concrete pavement process is a process of building a concrete layer on the steel deck 1 via an adhesive. The asphalt pavement process is a process for constructing an asphalt layer on a new concrete layer. The surface treatment process, the concrete pavement process, and the asphalt pavement process are the same as conventional known processes.

  According to the concrete layer removing method as described above, since the remaining portion 3b of the concrete layer 3 and the adhesive layer 2 are scraped off after the adhesive is heated, the adhesive layer is in a state where the adhesive ability of the adhesive is lowered. 2 can be peeled off. And the adhesive bond layer 2 is crushed with concrete, and can peel easily from the surface of the steel deck 1. Therefore, the adhesive layer 2 and the concrete layer 3 can be efficiently removed from the surface of the steel deck 1. Furthermore, since the remaining portion 3b of the concrete layer 3 and the adhesive layer 2 can be easily peeled off using the peeling backhoe 13a, work involving vibration can be greatly reduced, and noise reduction can also be achieved. Therefore, the influence on the surrounding area can be greatly reduced.

  Moreover, in this embodiment, since the adhesive bond layer 2 is heated in the range of 80-120 degreeC by a heating process, the steel deck 1 is not heated too much and the structural intensity | strength of the steel deck 1 falls. There is nothing to do. Furthermore, since the heating is performed in a state where the concrete layer 3 is roughly divided by the breaker 12 in the heating step, it is possible to prevent the concrete layer 3 from expanding and the concrete from bursting. Thereby, damage to the electromagnetic induction heating device 16 can be prevented.

  Furthermore, in the second removal step, the claw 15 of the peeling backhoe 13a is moved along the surface of the steel deck 1 so that the remaining portion 3b of the concrete layer 3 and the adhesive layer 2 are peeled off. 3 and the adhesive layer 2 can be peeled together, and the working efficiency is improved.

  Further, by disposing the peeling backhoe 13a immediately after the electromagnetic induction heating device 16, the remaining portion 3b of the concrete layer 3 and the adhesive layer 2 are scraped off before the temperature of the adhesive layer 2 decreases. Can do. Further, since the separation backhoe 13a and the recovery backhoe 13b are separately operated, the separation backhoe 13a can quickly perform the separation operation without waiting for the collection operation. Also by this, the temperature fall of the adhesive layer 2 at the time of peeling work can be suppressed. Thereby, the adhesive layer 2 can be smoothly peeled off.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not the meaning limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention. For example, in the said embodiment, although the concrete layer 3 is comprised with the steel fiber reinforced concrete, it is not limited to this. The concrete layer may be high-strength concrete having another configuration, or may be general concrete.

  Moreover, in the said embodiment, although the concrete layer removal method was demonstrated taking the example of the repair work of the road 5 in which the asphalt layer 4 was formed on the concrete layer 3, the repair work which removes the concrete pavement which the concrete layer exposed Of course, it is applicable.

  Furthermore, in the said embodiment, although the peeling backhoe 13a is used in order to peel the concrete layer 3 and the adhesive bond layer 2, it is not limited to this. For example, another heavy machine such as a wheel loader may be used.

  Moreover, in the said embodiment, although an adhesive agent is an epoxy resin type, it is not limited to this.

1 Steel slab (steel)
2 Adhesive layer 3 Concrete layer 12 Breaker 13 Backhoe (heavy equipment)
14 Bucket 15 Claw 16 Electromagnetic induction heating device

Claims (4)

A concrete layer removing method for removing a concrete layer laid on a steel material via a resin-based adhesive,
A first removal step of removing the surface portion of the concrete layer;
A heating step of heating the adhesive by heating the steel using an electromagnetic induction heating device;
A second removal step of removing the remaining part of the concrete layer and the heated adhesive; and a method for removing the concrete layer. The method for removing a concrete layer according to claim 1, wherein, in the heating step, heating is performed in a state where the concrete layer is roughly divided by a breaker. The concrete layer removing method according to claim 1 or 2, wherein, in the second removing step, the concrete layer and the adhesive are peeled off by a heavy machine having a bucket with a claw. The adhesive is an epoxy resin adhesive,
The concrete layer removing method according to any one of claims 1 to 3, wherein in the heating step, the adhesive is heated to a range of 80 to 120 ° C.

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