JP2019073847A - Method for fixing precast floor slab steel girder - Google Patents

Abstract

To provide a method for fixing a precast floor slab steel girder which ensures drying time while applying a full surface coating of a prescribed thickness in a corrosion prevention treatment, and allows moving to a next process of floor slab erection without delaying the process.SOLUTION: A new floor slab 3 is placed on a steel girder 1 with a height adjustment jig 2 interposed without waiting for a corrosion prevention treatment to dry after being passed through a steel girder treatment process. The steel girder 1 and the new floor slab 3 are connected using a fixing jig 4 to allow fixing in a state without a concrete form installed. In a concrete form installation process, a concrete form material 12 having an L-shaped cross section is brought into contact with the steel girder 1 using a concrete form support material 8. A non-contracting mortar 14 is filled in a the gap between the new floor slab 3 and the steel girder 1 per one span. After the mortar hardens, the fixing jig 4, the concrete form support material 8, and the like are all removed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steel girder fixing method for a precast floor slab in a steel bridge renewal work in which a concrete floor slab is placed on a steel girder and an existing concrete floor slab is replaced with a precast floor slab.

  Aging of road infrastructure is remarkable, and among them, as a measure for prolonging the life of steel bridges, precast concrete reinforced concrete floor slabs that are damaged due to fatigue caused by repeated loading of automobile load and salt damage caused by antifreeze agent spraying. A large-scale renewal work is being carried out to replace the floor slab.

  The target bridge is a basic infrastructure that is essential for economic activities, such as expressways and highways, so long-term construction can not be carried out for a long period of time, and existing floors can not be constructed within a very short construction period such as one to two months. It is necessary to set up a new floor slab and to carry out construction such as paving from removal of a plate etc.

  In this renewal work, first remove the existing deteriorated reinforced concrete floor slab, remove concrete etc. adhering to the upper surface of the flange of the steel girder, clean it and clean it, and then, in the axial direction of the upper surface bridge of multiple steel girder. , 1.5m ~ 2.5m is to lay a precast floor slab divided.

  When installing this precast floor slab, a new floor slab will be installed with a gap from the top of the upper flange of the steel girder to absorb the vertical cross slope of the bridge and construction errors, and between the new floor slab and the steel girder It is filled with non-shrink mortar with a thickness of about 40 mm.

  The most important quality-relevant work types in the renewal work are kerens and anti-corrosion treatment on the upper surface of the steel girder upper surface after removal of the existing floor slab, and a clearance between the upper surface of the steel girder upper surface and the lower surface of the precast floor surface There are two types of filling, non-shrinkage mortar filling, in particular the installation of formwork for mortar.

As a conventional mortar form, for example, a form having elastic force such as hard rubber sandwiched between a floor plate and a flange of a steel girder as described in Patent Document 1 has been adopted.
JP 10-96209 A

  In the case of this formwork material, a prismatic hard rubber or hard sponge (hereinafter referred to as sponge rubber) is adhered to the upper surface of the upper flange of the steel girder with glue. The conventional construction method of steel bridge renewal work using such a formwork material is demonstrated using FIG.3 and FIG.4. FIG. 3 is a bottom view showing the installation situation of precast floor slabs in the conventional steel bridge renewal work, and FIG. 4 is an explanatory view showing a process in the case of performing the conventional steel bridge renewal work.

  As shown in FIG. 4 (a), after removing the existing concrete floor slab (not shown) placed on the steel girder 1, the steel girder treatment is performed to remove rust from the upper surface 1b of the upper flange 1a. The process precedes. This is because the outer edge portion of the upper flange 1a which may touch the external environment after cleaning the concrete and the like attached to the steel girder 1, that is, the location where the form material 100 made of sponge rubber and the upper flange 1a contact. On the other hand, anti-corrosion treatment was carried out with anti-corrosion paint such as quick-drying organic zinc rich paint and Loval.

  After this steel girder treatment process, a form material 100 made of square pillar-shaped sponge rubber is attached to the upper surface 1b of the upper flange 1a (FIG. 4 (b)), and the height adjusting jig 2 is further mounted on the upper flange 1a. Place the new floor 3 made of precast concrete while placing it properly (Fig. 4 (c)), and then fill the gap between the new floor 3 and the upper surface of the upper flange 1a with the non-shrinkage mortar 14 There was (Fig. 4 (d)).

  By the way, in such renewal work of steel bridges, in order to complete the replacement of the floor under the constraints such as very short construction period, 1 crane per removal from the existing floor to installation of the new floor is required. It is necessary to carry out at a construction speed of about six days. On the other hand, in order to proceed with construction, it is necessary for the type of work that is important for quality to be subject to the inspection confirmation of the road administrator, and such work type must be done during the daytime when visual confirmation can be made. Therefore, after the anticorrosion treatment on the upper surface of the upper flange of the steel girder and the installation of a mold for mortar were completed in the daytime, the next process could not be advanced unless these inspections were confirmed.

  For this reason, in the conventional renewal work, the daytime weir to remove the existing floor slab-installation of the kelen, anti-corrosion treatment and mortar formwork, and the nighttime to install the new floor slab thereafter-stud molten metal and mortar filling It had a two-shift system with the nephew. In this case, the two quality-important work types mentioned above are biased in the latter half of the daily work contents in the daytime weir.

  In order to find the rationality of construction, cases have been increasing in which stud molten metal and mortar filling, which is a small amount of work, are consolidated into one span unit of a steel bridge.

  In the case of fixing the precast floor slab to the steel girder with stud molten metal and mortar filling every day in the renewal work of the conventional steel bridge, it is necessary to quickly install the mortar formwork for the next process, so drying There was a problem that the coating of the predetermined thickness was not completed in consideration of the time.

  On the other hand, when placing a new precast floor slab in one span unit, the precast floor slab already installed moves due to the deflection or shaking of the steel girder by the construction vehicle at the time of construction, and the floor slab completion form is secured There is also a demand that it be fixed promptly each time the floor plate is erected because there is a concern that it will not be possible.

  In addition, when mortar is filled in one span unit, the number of days elapses until the flange surface is covered with the mortar, and the steel flange which has been fully surfaced will be re-rusted before the floor plate construction It is necessary to apply anticorrosion measures to the entire surface of the flange. Considering the drying time of the coating, there is a problem that a delay occurs in the installation of the formwork and the construction of the new floor slab.

  By the way, when sponge rubber was not used by the conventional formwork material, steel angle steel was sometimes welded to a steel flange, but when welding an angle steel to make a formwork, on-site welding work In addition, it is difficult to absorb errors in accordance with the shape of the existing bridge, and it is also difficult to coat the angle steel.

  On the other hand, when sponge rubber was used as a mold, there was a possibility of absorbing some errors, but when the plate thickness of the steel girder upper flange changed, it tended to be difficult to follow. In the case of a new steel bridge, for example, in the case of a precast floor slab of the Shin-Tomei Expressway, the design is considered in consideration of the workability with sponge rubber, such as changing the plate thickness change of the upper flange downward and smoothing the upper surface However, in the case of the old bridge to be subjected to the renewal work, not only the plate thickness change is on the upper side, but also the plate width change is very large, especially the welded joint 1c of the steel girder as shown in FIG. In the current situation, it was impossible to install sponge rubber considering the fog of the high strength bolt because the joint plate and the high strength bolt were placed close to the upper flange outer edge.

  Therefore, neglect the fog of high strength bolt in the joint part and cut out and install the sponge rubber of the part that interferes with the bolt, or temporarily weld the steel rubber supporting steel sheet to the steel flange of the joint part At present, no method has been found to satisfy the quality and quality of the products although various improvements have been made such as securing the fog of the bolt by means of the attachment widening portion 1c of FIG.

  The present invention has been made to solve the above-mentioned problems with the method of fixing steel girder of precast floor slab in the conventional steel bridge renewal work. A method of fixing steel girders of precast floor slabs with no delay in the process compared to the conventional method, as it is possible to move to floor plate construction of the next process while securing high drying time and securing the drying time of painting. It is intended to be provided.

  Also, each time a precast floor slab is erected, it can be safely and promptly installed, and the precast floor slab can be securely fixed to ensure completion of the floor slab at the time of completion, and high precision of floor slab construction can be achieved. The purpose is to provide a method for fixing steel girder of precast floor slabs.

  In addition, it is an object of the present invention to provide a method of fixing steel girder of a precast floor slab using a formwork material which enables filling confirmation of the mortar part when transparent formwork material is used and there is no risk of falling off after deterioration in the future. And

  In order to solve the above problems, the method for fixing steel girder of precast floor slab according to the present invention is to replace the existing concrete floor slab with the precast floor slab by steel bridge which mounts the concrete floor slab on the steel girder. After removal of the concrete floor slab, the steel girder treatment process to carry out anti-corrosion treatment with kerens on the upper flange upper surface of the steel girder, and a new construction in which a new precast floor slab is placed with a clearance from the upper flange upper surface. Precast floor having a floor plate setting process, a frame installation process for installing a frame material for closing the gap between the new floor plate and the upper surface of the upper flange, and a mortar filling process for filling non-shrinkage mortar in the gap In the method of fixing a steel girder of a plate, the new-floor-placement step includes the step of treating the steel girder, and then interposing a height adjustment jig between the new-build floor and the upper flange upper surface. New floor A new installation floor fixation step of fixing the new installation floor to the steel girder by contacting a fixing jig attached to the lower flange and affixing the suspension to the lower surface of the upper flange, and the form installation process is performed on the new installation floor It is characterized in that it is a formwork installation process which abuts and fixes the lower part of the above-mentioned formwork material to the side of the above-mentioned upper flange using the formwork support material which attaches and hangs down.

  The height adjustment jig can be appropriately placed on the upper surface of the upper flange to make it a material that can be embedded in the mortar, or it can be adjusted in height by inserting and screwing a new floor plate and contacting the tip with the upper surface of the upper flange Use a bolt or the like.

  Fixing jigs are made by hanging a bolt to be screwed to the insert that is pre-filled on the lower surface of the new floor, attaching a fixing plate to this, arranging one end on the lower surface side of the upper flange, steel girder and new floor Connect and fix the plate.

  The formwork support material is obtained by hanging down a bolt screwed to an insert pre-filled on the lower surface of the new floor slab, to which a formwork pressing material to be in contact with the formwork material and the new floor slab, and this formwork presser material It has a horizontal end material and a fastening material to support.

  In the method for fixing a steel girder of a precast floor slab according to claim 2, the installation and fixing process of the new gullet performs the treatment process for the steel girder, and then waits for the rust prevention treatment to dry. It is characterized by fixing. Installation of the formwork material is carried out after receiving an inspection confirmation from the road administrator after the anticorrosion treatment on the upper surface of the steel girder upper flange is completed.

  The mold installation step in the method for fixing steel girder of precast floor slab according to claim 3 is a molding material having an L-shaped cross section in which one side abuts the side surface of the upper flange and the other side abuts the lower surface of the new floor slab It is characterized by using. The form material is preferably a material that is easy to process, and is removed after mortar hardening.

  In the method for fixing a steel girder of a precast floor slab according to claim 4, a form material having an L-shaped cross section is characterized by using a transparent form material capable of directly visually confirming the mortar filling condition. It is desirable to use a synthetic resin material having permeability for the form material.

  The method of fixing steel girder of precast floor slab according to the present invention comprises using a form supporting member which is attached to a new floor version and suspended, and providing a form setting process of fixing the lower part of the form material in contact with the side of the upper flange Therefore, it is possible to demold after hardening of the mortar, and there is no risk of falling off after deterioration in the future because it is not necessary to keep foreign substances such as sponge rubber in the floor plate.

  In addition, because the new floor slab is fixed to the steel girder, it becomes possible to install safely and promptly each time of erection, and the floor slab completion form at the time of completion such as plane and height is secured, and the height of floor slab construction is high. Accuracy can be improved. In addition, since the formwork has a retrofit structure, the drying time of the rustproof coating on the upper surface of the upper flange of the steel girder can be secured, so that the entire surface can be coated with a predetermined thickness, and high durability of the steel girder can be expected.

  In the method of fixing steel girder of precast floor slab according to claim 2, after carrying out the steel girder treatment process, the new girder is fixed to the steel girder without waiting for drying of the anticorrosion treatment. Construction speed can be expected.

  In the method of fixing a steel girder of a precast floor slab according to a third aspect of the present invention, since the L-shaped cross section is used, the work of assembling and disassembling the form becomes easy.

  In the method of fixing a steel girder of a precast floor slab according to claim 4, since the transparent formwork material is used, the mortar filling condition can be directly visually confirmed, and the filling defect of the mortar is prevented, and the appearance and maintenance management are excellent.

It is a bottom view of the precast floor slab placement situation in steel bridge renewal construction. It is explanatory drawing which shows the process in the case of performing steel bridge update construction. It is a bottom view of the precast floor slab mounting condition in the conventional steel bridge renewal construction. It is explanatory drawing which shows the process in the case of performing the conventional steel bridge update construction.

  Next, an embodiment of the present invention will be described in detail based on the attached drawings. FIG. 1 is a bottom view of a precast floor slab installation situation in steel bridge renewal work, and FIG. 2 is an explanatory view showing a process of steel bridge renewal work.

  As shown in FIG. 2 (a), after removing the existing concrete floor slab (not shown) placed on the steel girder 1, the steel girder treatment is performed to remove rust from the upper surface 1b of the upper flange 1a. The process precedes. After cleaning the concrete and the like adhering to the steel girder 1 and cleaning it, anti-corrosion treatment is performed with anti-corrosion paint. For coating on the flange surface, an organic zinc rich paint is applied by, for example, about 60 μm by spraying or brushing.

  After passing through the steel girder treatment process, the new floor slab 3 is placed with the height adjustment jig 2 interposed (FIG. 2 (b)). The height adjusting jig 2 uses a height adjusting bolt or a height adjusting rubber plate. The fixing jig 4 is attached to the lower surface 3 a of the newly installed floor slab 3 which is floated by this. The fixing jig 4 has the ceramic insert 5 previously embedded in the lower surface 3 a of the new floor plate 3, the mounting bolt 6 screwed to this, and the fixing plate 7 supported below the mounting bolt 6. One end of the plate member 7 is inserted into the lower surface 1d of the upper flange 1a, and the tip of the first fixing bolt 7a to be inserted abuts against the lower surface 1d, and the other fixing member 7 also has a second fixing bolt 7b. The steel girder 1 and the new floor plate 3 are connected and fixed by bringing the tip into contact with the lower surface 3a of the new floor plate 3 and connecting the steel girder 1 and the new floor plate 3 to each other. In the case where the precast floor slab is fixed to the steel girder by stud welding and mortar filling every one day, fixing using the fixing jig 4 may be omitted.

  The newly installed floor slab is constructed in a state in which no formwork is installed, and is fixed to the steel girder 1 sequentially using the fixing jig 4. This new floor slab mounting step is to be carried out without waiting for the rust prevention treatment performed in the steel girder treatment step to dry. When rust prevention treatment of a predetermined thickness is applied to the entire surface of the flange, there is no risk of re-eating even if the days have passed, so the installation process of a new floor slab for one span is performed while receiving inspection confirmation from the road administrator Then, the process proceeds to a form setting process (FIG. 2 (c)).

  The frame support member 8 used in this step utilizes the mounting bolt 6 screwed to the ceramic insert 5 described above, and the fastening member 9 is inserted into the bolt 6 to support the lateral end thick member 10, and the lateral end The form holding members 11 are disposed on the thick material 10 at appropriate intervals. The mold presser member 11 has its front end in contact with the mold member 12 with an L-shaped cross section, and the spacer 13 is interposed on the upper surface of the rear end so as to be in contact with the lower surface 3 a of the new floor slab 3.

  The formwork member 12 is an L-shaped member whose one side abuts the side surface of the upper flange 1a and the other side abuts the lower surface 4 of the new floor slab 3 and is a material easy to process, for example, an angle made of polyvinyl chloride Use an angle made of transparent acrylic resin or the like. By using such a material, it is possible to easily install the mold even at a place where the plate width changes due to the joint widening portion 1c, which is very often found in old bridges as shown in FIG. The mold supporting members 8 are installed at appropriate intervals, but they can also be used by inserting the fastening members 9 in advance through the mounting bolts 6 that support the fixing plate 7 with the fixing jig 4.

  Parallel to this form setting process, rebar assembly (not shown) of the floor slab joint 3b and assembly of the bottom form frame are carried out, and within the gap between the new floor 4 and the upper surface of the upper flange 1a The mortar is filled with non-shrinkage mortar 14 (FIG. 2 (d)), and after the mortar is hardened, all the fixing jig 4 and the form support 8 are removed (FIG. 2 (e)).

1 Steel gir 2 Height adjustment jig 3 New floor version 4 Fixing jig 8 Formwork support material 12 Formwork material 14 Non-shrink mortar

Claims (4)

After removing the existing concrete floor slab in order to replace and fix the existing concrete floor slab to the precast floor slab by the steel bridge where the concrete floor slab is placed on the steel girder, the kerren and prevention of the upper flange upper surface of the steel girder A steel girder treatment step for rusting treatment, a new floor plate placement step for placing a new precast floor plate with a gap from the upper surface of the upper flange, and a gap between the new floor plate and the upper flange surface In the steel girder fixing method of a precast floor slab having a mold installation process for installing a mold material to be closed and a mortar filling process for filling a non-shrink mortar in the gap, the new floor slab mounting process includes the steel girder installation process After performing the treatment process, while interposing a height adjustment jig between the newly installed floor slab and the upper flange upper surface, a fixing jig attached to the newly installed floor slab and suspended is brought into contact with the lower flange lower surface In the above It is a new floor plate placement fixing process which fixes a floor slab to a steel girder, and the formwork installation process uses the formwork support material which is attached to the new build floorboard and hangs down, the lower part of the formwork material is the above A method of fixing a steel girder of a precast floor slab, characterized in that it is a form installation step of fixing by abutting against the side surface of the upper flange. The precast as set forth in claim 1, wherein the new deck installation and fixing step fixes the new deck to the steel girder without waiting for the anticorrosion treatment to dry after performing the steel girder disposal step. How to fix steel girder of floor slabs. In the formwork installation step, a formwork member having an L-shaped cross section in which one side abuts on the side surface of the upper flange and the other side abuts on the lower surface of the new floor slab is used. Method of fixing steel girder of precast floor plate as described. The method for fixing a steel girder of a precast floor slab according to claim 3, characterized in that the form material of the L-shaped cross section is a transparent form material capable of directly visually confirming the mortar filling condition.

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