JP3185723U - Road bridge floor slab structure - Google Patents

Abstract

[PROBLEMS] To provide a floor slab structure of a road bridge that can greatly extend the durable life of a floor slab excluding a heavy traffic highway and can be constructed efficiently and easily.
A waterproof layer formed on an upper surface of a floor slab body exposed by cutting an existing pavement layer, a new pavement layer 30 laminated on the upper surface of the waterproof layer, and a lower surface of the floor slab body. The reinforcing fiber sheet 40 was bonded, and the tensile rigidity per unit width of the reinforcing fiber sheet 40 was 11 kN / mm to 44 kN / mm. By providing a waterproof layer on the top surface of the floor slab, it is possible to prevent deterioration of the floor slab due to infiltrated water, and it can be reinforced with a reinforcing fiber sheet adhered to the bottom surface of the floor slab body. It is possible to greatly extend the durable life of the battery.
[Selection] Figure 1

Description

  The present invention relates to a floor slab structure of a road bridge for a general road slab that has a smaller traffic volume than a heavy traffic such as a general national road, a prefectural road, and a municipal road.

In Japan, where approximately 130,000 road bridges are in service with only bridges with a length of 15m or more, most of them are road bridge specifications published by the Ministry of Construction (Ministry of Land, Infrastructure, Transport and Tourism) in the 1950s. ) Designed and constructed based on
The existing road bridges designed and constructed according to the old specifications are aging due to the following factors.
<a> Infiltration of rainwater Since the road bridge designed and constructed in the old specifications does not have sufficient waterproof measures for the slab, rainwater that has penetrated into the slab corrodes the reinforcing bars.
<B> Increasing load burden With the increase in the weight of large vehicles compared to when the old specifications were issued, the load on the floor slab increased significantly.
<C> Fatigue failure As the traffic volume has increased significantly compared to the time when the old guidebook was issued, the number of repeated loads has increased significantly. Therefore, the floor slab tends to cause fatigue failure (punch shear failure).

On the other hand, fatigue durability is predicted based on a wheel load running test for floor slabs to which repeated loads are applied.
The test is to produce a floor slab that conforms to the old specifications, first damage it to the extent that bi-directional cracks occur by preliminary running, and then adhere a reinforcing fiber sheet impregnated with resin to the lower surface of the damaged floor slab. After the reinforcement, the procedure is carried out until the floor slab reinforced by the test breaks down.

Further, Patent Document 1 discloses a method for reinforcing a floor slab in which a reinforcing fiber sheet is bonded in a lattice shape to the lower surface of the floor slab and cracks are observed through the exposed surface of the floor slab surrounded by the reinforcing fiber sheet (Patent Document 1). 1).
In this reinforcing method, a plurality of reinforcing fiber sheets were laminated so that the sheet width was 15 to 35 cm and the tensile rigidity was 45 to 75 kN / mm. The amount of reinforcement is adjusted by the number of laminated reinforcing fiber sheets.

JP 2005-29953 A

The conventional road bridge reinforcement and repair technology has the following problems.
In the <1> wheel load running test, the test object is based on a heavy traffic floor slab that is equivalent to the Metropolitan Expressway in accordance with the old specifications, so it was necessary to increase the tensile rigidity of the reinforcing fiber sheet.
Design guidelines are not clearly specified for floor slabs of general roads with low traffic volume, so repairs are made in accordance with the specifications. When applied, it is uneconomical due to overdesign.
<2> When adhering reinforcing fiber sheets in a grid, not only does it take a lot of time and labor to bond and laminate multiple reinforcing fiber sheets in a single unit, but also mask the underside of the floor slab with masking tape. A lot of work and time are required for the pasting work with the masking tape and the peeling work of the masking tape, and the workability is very poor.
<3> Since the road bridge designed and constructed according to the old specifications is not adequately waterproofed, deterioration of the floor slab due to seepage water is inevitable.
In particular, when sodium or calcium chloride contained in the road surface anti-freezing agent penetrates into the floor slab through cracks or the like together with rainwater, the durable life of the floor slab is significantly shortened.

The present invention has been made in view of the above points, and its object is to provide at least one road bridge structure.
<1> The durability of floor slabs, excluding heavy traffic highways, can be significantly extended.
<2> Efficient and easy installation.

The present invention is a floor slab of a road bridge excluding a heavy traffic highway in which a pavement layer is formed above the floor slab body, and is formed on an upper surface of the floor slab body exposed by cutting an existing pavement layer. A waterproof layer, a new pavement layer laminated on the upper surface of the waterproof layer, and a reinforcing fiber sheet bonded to the lower surface of the floor slab body, and the tensile stiffness per unit width of the reinforcing fiber sheet is 11 kN / mm It comprised so that it might become -44kN / mm.
In one embodiment, one or two layers of reinforcing fiber sheets are bonded to the lower surface of the floor slab body.
In one embodiment, a reinforcing fiber sheet is bonded to the entire lower surface of the floor slab body.
In one form, the said reinforcing fiber sheet is made to cross | intersect the bridge | bridging axial direction of the lower surface of the said floor slab main body, and the orthogonal direction of a bridge | shaft axis | shaft at intervals.

The present invention has the following effects.
<1> By providing a waterproof layer on the upper surface of the floor slab body, it is possible to prevent deterioration of the floor slab due to infiltrated water, and it can be reinforced with a reinforcing fiber sheet adhered to the lower surface of the floor slab body. It is possible to greatly extend the durable life of the floor slab.
<2> Since a plurality of reinforcing fiber sheets are made into one layer without being laminated, it is possible to simplify the bonding work of the reinforcing fiber sheets, and there is no need for curing with a masking tape. And labor can be greatly reduced.

Partial enlarged sectional view of a floor slab of a road bridge with a portion omitted according to the present invention It is explanatory drawing of the repair method of a floor slab, (A) is a cutting process of an existing pavement layer, (B) is a formation process of a waterproof layer, (C) is an explanatory view of a formation process of a new pavement layer Partial sectional view of the underside of the floor slab body reinforced with a reinforcing fiber sheet Partial sectional view of the underside of the floor slab body with reinforcing fiber sheets bonded in a grid pattern

  Embodiments of the present invention will be described below with reference to the drawings.

<1> Target slab FIG. 1 shows an example of a reinforced slab of a road bridge.
The present invention is intended for floor bridges of road bridges of general traffic such as general national roads, prefectural roads, municipal roads, etc., and does not include floor boards of heavy traffic road bridges such as the Metropolitan Expressway.

<2> Configuration of Road Bridge The road bridge includes a floor slab body 10, a waterproof layer 20 formed on the upper surface 11 of the floor slab body 10, a new pavement layer 30 formed on the upper surface of the waterproof layer 20, and a floor slab body. 1 or 2 layers of reinforcing fiber sheets 40 adhered to the lower surface 12 of the steel sheet 10.
The waterproof layer 20 and the pavement layer 30 are newly formed by cutting an existing pavement layer.

<3> Floor slab The floor slab body 10 is a rigid member that directly receives the load of an automobile or the like and transmits it to the main girder, etc., for example, RC floor slab, PC floor slab, steel floor slab, synthetic floor slab, I-shaped steel lattice floor Includes editions.

<4> Waterproof Layer The waterproof layer 30 is intended to prevent the penetration of rainwater into the floor slab body 10 and improve the durability of the floor slab body 10.
The waterproof layer 30 may be a sheet system (flow pasting type, heat welding type, room temperature adhesive type), coating film type (asphalt heating type, rubber solvent type, reaction resin type, etc.), spraying type, coating type (synthetic resin (reaction) Type)) etc. are applicable.

<5> Reinforcing Fiber Sheet The reinforcing fiber sheet 40 is a strip-shaped reinforcing material impregnated with a resin to reinforce the floor slab body 10.
Conventionally, a number of reinforcing fiber sheets have been laminated, but in the present invention, the reinforcing fiber sheets 40 are not laminated, but one layer in one direction (bridge axis direction or a direction perpendicular to the bridge axis direction) or two directions (bridge axis). The two layers are bonded in the direction perpendicular to the direction and the bridge axis direction.

<5.1> Reinforcing Fiber As the reinforcing fiber, for example, carbon fiber, aramid fiber, PBO fiber, glass fiber or the like can be used.

<5.2> Resin As the resin impregnated into the reinforcing fiber, for example, an epoxy resin, a methyl methacrylate resin, a vinyl ester resin, an unsaturated polyester resin, a polyurethane resin, or the like can be used.

<5.3> Tensile Rigidity of Reinforcement Fiber Sheet Conventionally, since the road floor slab of heavy traffic was assumed, the tensile rigidity of the reinforcement fiber sheet was 45 to 75 kN / mm.

Since the present invention is intended for road decks with a general traffic volume that is not as heavy as heavy traffic, the tensile rigidity per unit width of the reinforcing fiber sheet 40 may be 44 kN / mm or less.
In other words, the tensile strength per unit width of the strong fiber sheet 40 is designed to be in the range of 11 kN / mm to 44 kN / mm.
Specifically, it is appropriately selected in consideration of the layer thickness of the existing floor slab body 10 and the travel amount of the vehicle.

  If the tensile stiffness of the reinforcing fiber sheet 40 is smaller than 11 kN / mm, the reinforcing effect is remarkably impaired, and if the tensile stiffness exceeds 44 kN / mm, the design becomes excessive and uneconomical.

[Construction method]
A method for repairing an existing road bridge will be described with reference to FIGS.

<1> Cutting an existing pavement layer (FIG. 2 (A))
As shown by the alternate long and short dash line, the existing pavement layer 30 ′ is cut by a known cutting means such as a road surface cutting machine to expose the upper surface 11 of the floor slab body 10.
In order to prevent the strength of the floor slab body 10 from decreasing, the cutting allowance is minimized as much as possible so as not to damage the floor slab body 10.

<2> Formation of waterproof layer (FIG. 2B)
After the fine pieces and dust remaining on the upper surface 11 of the floor slab body 10 are removed and cleaned cleanly, the waterproof layer 20 is formed on the entire upper surface 11 of the floor slab body 10.
At this time, it is important that the waterproof layer 20 absorbs the unevenness of the upper surface 11 of the floor slab body 10 and is fixed integrally, and the waterproof layer 20 is not damaged.

<3> Lamination of new pavement layer (Fig. 2 (C))
A new pavement layer (asphalt layer) 30 is laminated on the upper surface of the waterproof layer 20.

<4> Adhesion of reinforcing fiber sheet (FIG. 3)
Clean the lower surface 12 of the floor slab body 10. At this time, if there is a deteriorated portion on the lower surface 12, it is removed, and if a crack has occurred, it is filled with a caking material.
After the primer 41 is applied to the lower surface 12 of the floor slab body 10 subjected to the ground treatment, the reinforcing fiber sheet 40 impregnated with the resin is bonded. In the figure, 42 is a reinforcing fiber and 43 is an impregnated adhesive resin.

The reinforcing fiber sheet 40 is attached by adhering the reinforcing fiber sheet 40 over the entire lower surface 12 of the floor slab body 10 as shown in FIG. 1, or at a predetermined interval as shown in FIG. The plurality of strip-like reinforcing fiber sheets 40 are bonded in a lattice shape so as to intersect the bridge axis direction on the lower surface of the floor slab body 10 and the direction perpendicular to the bridge axis.
In consideration of workability and the like, it is desirable to bond the reinforcing fiber sheet 40 over the entire lower surface 12 of the floor slab body 10.
Although FIG. 1 shows a form in which one layer of reinforcing fiber sheet 40 is bonded to the lower surface 12 of the floor slab body 10, two layers of reinforcing fiber sheet 40 may be bonded so that the fiber directions are orthogonal to each other.

  In the present invention, since the reinforcing fiber sheet 40 is formed as a single layer without being laminated, the time and labor required for the bonding operation of the reinforcing fiber sheet 40 can be significantly reduced, and further, the masking tape does not need to be cured. Great effect of labor reduction.

<5> Waterproofness As shown in FIG. 1, the entire upper surface 11 of the floor slab body 10 is covered with a waterproof layer 20 having a high water-stopping property.
Therefore, even if rainwater penetrates the pavement layer 30, the waterproof layer 30 blocks the water and prevents water from entering the floor slab body 10, thereby suppressing deterioration of the floor slab body 10 due to corrosion of reinforcing bars due to the permeated water. it can.

<6> About durable life of floor slab Not only can the floor layer body 10 be prevented from being deteriorated by permeated water by the waterproof layer 30, but also the reinforcing fiber sheet 40 adhered to the lower surface 12 of the floor slab body 10 reinforces the floor slab body 10. .
Since the floor slab body 10 is a floor slab with a general traffic volume that is less than that of heavy traffic, even if the tensile stiffness of the reinforcing fiber sheet 40 is as low as 11 kN / mm to 44 kN / mm, the floor slab Can be extended to 100 years or more.
In other words, in order to extend the durable life (fatigue life) of the floor slab body 10 on a general paved road excluding a highway by 100 years or more, the tensile rigidity per unit width of the floor slab body 10 is 11 kN / mm to 44 kN. It is sufficient to reinforce with / mm reinforcing fiber sheet 40.

DESCRIPTION OF SYMBOLS 10 ... Floor slab body 11 ... Floor slab upper surface 12 ... Floor slab lower surface 20 ... Waterproof layer 30 ... Pavement layer 40 ...・ Reinforcing fiber sheet

Claims (4)

A floor slab of a road bridge excluding a heavy traffic highway with a pavement layer formed above the floor slab body,
A waterproof layer formed on the upper surface of the floor slab body exposed by cutting an existing pavement layer; and
A new pavement layer laminated on the upper surface of the waterproof layer;
Comprising a reinforcing fiber sheet bonded to the lower surface of the floor slab body,
The tensile strength per unit width of the reinforcing fiber sheet is configured to be 11 kN / mm to 44 kN / mm,
Road bridge floor slab structure.   The floor slab structure of a road bridge according to claim 1, wherein one or two layers of reinforcing fiber sheets are bonded to the lower surface of the floor slab body.   The floor slab structure of a road bridge according to claim 2, wherein a reinforcing fiber sheet is bonded to the entire lower surface of the floor slab body.   3. The floor slab structure of a road bridge according to claim 2, wherein the reinforcing fiber sheets are bonded so as to intersect with each other in a bridge axis direction on a lower surface of the floor slab body and a direction perpendicular to the bridge axis with a space therebetween.

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