JP2508677B2 - Reinforcement method of bridge reinforced concrete slab - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of reinforcing a bridge reinforced concrete floor slab.

[Prior Art] Reinforced concrete slabs that form bridges, etc., must be reinforced because they deteriorate over a long period of time and cause internal cracks.

A conventional method of reinforcing a bridge reinforced concrete floor slab will be described with reference to FIGS. 3 and 4.

FIG. 3 is an explanatory view of a method for reinforcing a bridge reinforced concrete floor slab by bonding steel plates.

A bridge made by constructing a reinforced concrete floor slab 2 on a main girder 1 made of I-shaped steel extending in the axial direction of the bridge arranged at required intervals and laying an asphalt 3 on the reinforced concrete floor slab 2 is aging and When a crack 4 occurs in the reinforced concrete floor slab 2, a steel plate 5 extending in the bridge axis direction is bonded to the lower surface of the reinforced concrete floor slab 2 by using an epoxy resin adhesive or the like, or an anchor bolt 6 is further attached. It is embedded in the reinforced concrete floor slab 2 using an epoxy resin adhesive or the like.

By adhering the steel plate 5 to the lower surface in this manner, the reinforced concrete floor slab 2 is reinforced.

FIG. 4 shows that, instead of the steel plate 5, an I type steel 7 is arranged at an intermediate position of the main girder 1 and in the bridge axial direction to partially support and reinforce the reinforced concrete floor slab 2 from the lower surface. A support member 8 extending in the direction perpendicular to the bridge axis direction is welded between the girders 1 or fixed to the bracket 9 attached to the I-shaped steel 7 and the main girder 1 with bolts 10 to connect and fix the I-shaped steel 7. FIG.

In this way, the reinforced concrete floor slab 2 is reinforced by partially supporting the intermediate position of the main girder 1 from the lower surface with the I-shaped steel 7.

[Problems to be Solved by the Invention] However, in the above-described conventional method for reinforcing a bridge reinforced concrete floor slab, since the strength after reinforcement depends on the strength of the reinforced concrete floor slab 2 itself, deterioration of the bridge may occur. Further progressing, for example, in the steel plate bonding method shown in FIG. 3, the steel plate 5 is peeled off along with the weakening of the reinforced concrete floor slab 2, or a crack (a crack a in the drawing a in the figure) inside the reinforced concrete floor slab 2 at the side end portion of the steel plate 5. ) Occurs, and there is a fear that the reinforced concrete floor slab 2 falls off for each steel plate 5, and in the longitudinal girder reinforcement method of FIG. 4, a crack (crack b in the figure) occurs in the intermediate portion between the main girder 1 and the I-type steel 7, There is a fear that the part of the reinforced concrete floor slab 2 will be depressed.

Therefore, the steel plate bonding or the longitudinal girder reinforcement method is not a fundamental reinforcement means, and when the reinforced concrete floor slab 2 is further deteriorated after the above reinforcement method is applied, the reinforced concrete floor slab 2 must be replaced. Also, since the replacement work needs to be performed with the traffic blocked, it becomes an important issue when considering recent traffic conditions.

In view of the above situation, the present invention is to reinforce the bridge reinforced concrete floor slab so that it is not necessary to replace the reinforced concrete floor slab by attaching a steel floor slab capable of supporting the entire surface of the reinforced concrete floor slab to the main girder. It is intended to provide a method.

[Means for Solving the Problems] The present invention provides high bending by supporting and reinforcing a reinforcing steel plate having a shape capable of covering almost the entire lower surface of a reinforced concrete floor slab with reinforcing strong steel and vertical reinforcing ribs assembled in a grid pattern. While forming a steel deck with steel properties, in the main girder supporting the reinforced concrete floor slab, by connecting the upper ends of adjacent main girders with the steel deck having the high bending rigidity, each main girder is A reinforcing method of a bridge reinforced concrete floor slab is characterized in that almost the entire lower surface of the reinforced concrete floor slab is supported directly from below by the reinforcing steel plate constituting the upper surface of the steel floor slab.

[Operation] Therefore, in the present invention, the reinforced concrete floor slab is directly supported by the steel floor plate having a high rigidity that is disposed so as to abut so as to substantially cover the entire lower surface of the reinforced concrete floor slab, and the main girder space between the steel floor slabs is set. Since they are connected, even if the reinforced concrete floor slab is deteriorated, the reinforced concrete floor slab is prevented from falling off.

[Examples] Examples of the present invention will be described below with reference to the drawings.

1 and 2 are explanatory views of an embodiment of the present invention.

In the present invention, the entire exposed concrete portion of the lower surface of the reinforced concrete floor slab 2 is covered with a blocked steel floor slab 11,
The steel deck slab 11 is joined to the main girder 1.

 The steel floor slab 11 is configured as follows.

That is, each main girder is formed by using a reinforcing steel plate 13 which is formed in the same shape as the exposed concrete portion on the lower surface of the reinforced concrete floor slab 2 and in which a plurality of vertical reinforcing ribs 12 extending in the bridge lateral direction are attached at required intervals. Reinforced concrete floor slab between 1 and 1 2
Cover the exposed concrete part of the lower surface across the entire bridge axis direction.

An inverted T-shape having an upper end 14 that extends in the direction orthogonal to the bridge axis direction and that abuts the lower surface of the reinforcing steel plate 13 and that fits into the vertical reinforcing ribs 12, and that has both ends 15 that form a joint with the main girder 1. A plurality of horizontal reinforcing steels 16 having the above-mentioned structure are provided at required intervals in the bridge axis direction to integrally support the lower surface of the reinforcing steel plate 13, and both ends 15 of the horizontal reinforcing steel 16 are directly welded to the main girder 1 or to the main girder 1. It is fixed by fixing it to the provided bracket 17 with bolts 18.

In this way, under the reinforced concrete floor slab 2, a reinforcing steel plate
A steel floor slab 11 having a high bending rigidity is formed by supporting 13 with vertical reinforcing ribs 12 and lateral reinforcing steel 16 assembled in a grid pattern.
By attaching each horizontal reinforcing steel 16 of 11 to the main girder 1, the reinforced concrete floor slab 2 is stacked on the steel floor slab 11, and even if the reinforced concrete floor slab 2 itself does not have strength, the reinforced concrete floor slab 2 is supported by steel deck 11 and main girder 1.

Therefore, since the reinforced concrete floor slab 2 does not fall off even when it is deteriorated, it is not necessary to re-cover it, and repairing can be performed only by filling the gap created by the crack.

Further, when a load acts on the reinforced concrete floor slab 2, the steel floor slab 11 resists the load due to its high bending rigidity, and the load is distributed to each main girder 1 through each lateral reinforcing steel 16. Therefore, it is possible to prevent stress from concentrating on the specific main girder 1.

Note that the present invention is not limited to the above-described embodiment,
When a gap occurs between the concrete floor slab and the steel floor slab, the gap may be filled with cement grout or epoxy grout, and other various changes are made within the scope not departing from the gist of the present invention. Of course you can get it.

[Effect of the Invention] As described above, according to the method for reinforcing a bridge reinforced concrete floor slab of the present invention, a reinforcing steel plate having a shape capable of covering almost the entire lower surface of the reinforced concrete floor slab is reinforced with a grid-like reinforcing steel. A steel deck having a high bending rigidity is formed by supporting and reinforcing the longitudinal reinforcing ribs to form a steel deck having a high bending rigidity, and between the upper ends of adjacent main girders in the main girder supporting the reinforced concrete deck. By connecting, each main girder is integrated, and since almost the entire lower surface of the reinforced concrete floor slab is directly supported from below by the reinforcing steel plate that constitutes the upper surface of the steel floor slab, the load is applied to the reinforced concrete floor slab. When it acts, the steel deck will resist the load due to the high bending rigidity due to the grid-shaped reinforcing member, etc. The load on the reinforced concrete floor slab can be greatly reduced by 1/6 and the load is distributed to each main girder through each steel floor slab. It is possible to prevent stress concentration on the girder, and at the same time, by supporting the reinforced concrete floor slab directly with the steel floor slab, the reinforced concrete floor slab will not be damaged or fallen even when it is deteriorated, and therefore, the transportation It is possible to achieve various excellent effects, such as eliminating the need to cut off the floor to replace the floor slab.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, and FIG. 2 is a view of FIG.
II-II arrow view, FIG. 3 is an explanatory view of a conventional example, and FIG. 4 is an explanatory view of another conventional example. In the figure, 1 is a main girder, 2 is a reinforced concrete slab, and 11 is a steel slab.

Claims (1)

(57) [Claims] 1. A steel floor slab having high bending rigidity is obtained by supporting and reinforcing a reinforcing steel plate having a shape capable of covering substantially the entire lower surface of a reinforced concrete floor slab with reinforcing strong steel and vertical reinforcing ribs assembled in a grid pattern. In addition, in the main girder supporting the reinforced concrete floor slab, by connecting the upper ends of adjacent main girders with the steel deck having the above-mentioned high bending rigidity, the respective main girders are integrated and the upper surface of the steel deck A reinforcing method for a bridge reinforced concrete floor slab, wherein almost the entire lower surface of the reinforced concrete floor slab is directly supported from below by the reinforcing steel plate constituting the above.