JPH11107541A - Method for reinforcing skeleton of existing concrete building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reinforcing a skeleton at low noise and preferably at low vibration. SOLUTION: To reinforce a skeleton, first a plurality of openings that open to the surface of a mortar layer 14 covering the surface of the skeleton 12 are provided through the mortar layer 14 and are filled with an expanding agent, and the mortar layer 14 is separated from the skeleton 12 by the cubic expansion of the expanding agent. Next, a plurality of holes that open to the surface of the skeleton 12 are bored, and anchors 24 are inserted into the holes and secured to the skeleton 12. Next, a reinforcement assembly 26 opposite to the surface of the skeleton 12 is placed, forms 28 surrounding the reinforcement assembly 26 are placed, and then concrete is placed between the forms 28 and the skeleton 12. Preferably, ultrasonic cutting is employed in the formation of the openings and the holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing columns, beams, walls, etc., which are the bodies of existing or existing concrete buildings.

[0002]

2. Description of the Related Art In order to reinforce the frame of an existing concrete building, the thickness of the frame has been increased.

[0003] Conventionally, the reinforcement of the skeleton is performed through the following steps. That is, when a mortar layer is applied to the surface of the skeleton for the purpose of adjusting unevenness of the surface of the skeleton and finishing, etc., the mortar layer is peeled off, and then a plurality of holes that are opened in the surface of the skeleton are formed in the skeleton. The anchor member is implanted in each hole, and furthermore, a reinforcing bar assembly intersecting with the anchor member is arranged in front of the skeleton surface, and a formwork surrounding the reinforcing member assembly is arranged. This is done by placing concrete in the space specified by

[0004]

By the way, the mortar layer is peeled off by crushing the mortar layer with a breaker, for example, and the drilling of the skeleton is performed by using a drill, for example. However, the operation of peeling the mortar layer involves generation of loud noise or vibration. For this reason,
Residents and occupants of an in-service building may be physically and mentally distressed and may have a significant adverse effect on the operation or operation of equipment or equipment within the building. In particular, this is remarkable in buildings such as hotels and hospitals. From this, the working time is restricted in the conventional reinforcing method,
Alternatively, there have been cases where it is practically impossible to perform a reinforcing work on the skeleton.

It is an object of the present invention to provide a method for reinforcing a skeleton with low noise, preferably with low vibration.

[0006]

In order to reinforce the skeleton, first, a plurality of openings are formed in the mortar layer covering the surface of the skeleton, and each opening is filled with a swelling agent. The mortar layer is peeled off from the skeleton by the volume expansion of the mortar. Next, a plurality of holes are formed on the surface of the frame, and anchors are implanted in the holes. Next, a rebar assembly facing the surface of the skeleton is arranged, a formwork surrounding the rebar assembly is arranged, and then concrete is cast between the formwork and the skeleton. Preferably,
The opening is formed by subjecting the mortar layer to ultrasonic cutting, and the hole is formed by subjecting the skeleton to ultrasonic cutting. When the skeleton is not covered with the mortar layer, a plurality of holes that are opened in the surface of the skeleton are formed by ultrasonic cutting, and thereafter, an anchor member is implanted into each hole, and the surface of the skeleton is formed. The arrangement of the reinforcing bar assembly, the positioning of the formwork surrounding the reinforcing bar assembly, and the casting of concrete between the formwork and the frame are performed.

[0007]

In the present invention, the mortar layer on the surface of the skeleton is peeled off by filling the opening provided in the mortar layer with an expanding agent. The swelling agent gently expands in volume over time, during which time the inflation pressure extends in a direction perpendicular to the peripheral wall of the opening, thereby lifting the mortar layer between the openings and cracking the mortar layer. (Cracks) occur. As a result, the mortar layer peels off from the skeleton. Thus, the entire mortar layer can be peeled from the skeleton with almost no noise and vibration. When forming the openings and the holes for implanting the anchors by ultrasonic cutting, they can be performed with almost no noise and vibration. As a result, it is possible to further reinforce the frame under low noise and low vibration. Further, when the skeleton is made of exposed concrete, the holes for anchor implantation are formed by ultrasonic cutting, whereby the reinforcement of the skeleton can be performed quietly and almost without vibration. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a wall 12 is shown as an example of a frame of an existing or existing concrete building 10 to which the reinforcing method according to the present invention is applied. The frame to which the present invention is applied includes, in addition to the wall 12, columns, beams, and the like.

The wall of the concrete building or concrete wall 12 is covered on its surface 14 and on the other opposite surface 16 with mortar layers 18, 20 respectively applied to it. In the example shown, the invention is applied to one surface 14 of wall 12.

Each mortar layer 18, 20 has an average thickness of about 30 mm. In addition, one mortar layer 18
Covers not only one surface 14 of the wall 12 but also the surface of the beam 22 connected to the wall 12.

In order to reinforce the wall 12, that is, to increase (increase) the thickness of the wall 12, first, the mortar layer 18 is removed from the wall 12.
Peel off.

In order to peel off the mortar layer 18, first, a plurality of openings (not shown) are formed in the mortar layer 18 and open to the surface 14 thereof. The opening has a form such as a through-hole penetrating the mortar layer 18, a hole extending through the mortar layer 18 over most of its thickness, a groove extending vertically and horizontally. The arrangement of the through holes and the arrangement of the holes may be regular or irregular, respectively. Further, the through holes and the holes may be mixed, or through holes or holes having different diameters may be mixed. Further, the through-hole and the hole may be in any direction regardless of the extension direction. That is, these axes may be horizontal and non-horizontal, or these axes may be
May be orthogonal or non-orthogonal.

The opening can be formed by subjecting the wall 12 to ultrasonic cutting or the like. That is, a spindle having a tip provided with a grindstone or a wheel having a peripheral surface provided with a grindstone is rotated around each axis to apply the cutting force of the grindstone to the wall 14, and the spindle And by ultrasonically vibrating the wheels respectively.

The direction in which the ultrasonic vibration is applied is the axial direction of the spindle, and the emission direction of the wheel. The frequency and amplitude of the ultrasonic wave at this time are, for example, 20 kHz and 55 kHz, respectively.
Set to μm. By applying the ultrasonic vibration, the cutting resistance of the whetstone is significantly reduced. For this reason, the noise level and the vibration generated at the time of forming the opening can be significantly reduced, and more specifically, the noise or the cutting noise can be inaudible and almost non-vibration at a distance of several meters.

As a specific device for forming the opening, for example, a "hand-held rotary tool" described in Utility Model Registration No. 3019063 can be used. In this tool, a horn is attached to the tip of an ultrasonic vibrator that is rotatably supported in an outer case,
Further, a grindstone is attached to the tip of the horn. When the ultrasonic vibrator is driven to rotate around its axis, the horn and the grindstone rotate around these axes. By operating the ultrasonic vibrator, ultrasonic vibration can be generated in the axial direction of the horn. By pressing the grindstone against the surface 14 of the wall 12 to rotate the grindstone and apply ultrasonic vibration to the grindstone, the opening can be formed with almost no noise and vibration.

With respect to the openings, the shape, direction, and mutual distance of the openings are considered in consideration of the range or distance limit over which the inflation pressure of the inflating agent is effective, that is, the range or distance limit at which cracks may occur. The interval, size, depth, etc. can be set.

The opening can be formed by cutting with a drill, for example, on which ultrasonic vibration is not superimposed. However, the level of generated noise and vibration is higher in the case of cutting with the drill than in the case of ultrasonic cutting.

Next, each of the formed openings is filled with an expanding agent. The swelling agent is preferably made by kneading a drug mainly composed of an inorganic compound mainly composed of quick lime and silicate (for example, "Blystar" manufactured by Onoda Co., Ltd.) with water and kneading the mixture. Reacts with water (hydration reaction) so that its volume expands with time.

Other examples of the expanding agent include calcined dolomite, magnesia, ordinary Portland cement-blast furnace slag-bauxite-gypsum, alumina cement-lime-gypsum, and the like.

Due to the volume expansion of the expanding agent in each opening, the peripheral wall surface of each opening receives an expanding pressure in a direction perpendicular to the opening (in the radial direction of the through hole or hole).
Due to the inflation pressure, a portion between the openings of the mortar layer 18 rises and cracks occur in the portion. As a result, the mortar layer 18 peels off from the surface 14 of the wall.

The portion where the crack has occurred falls off the wall surface 14 as a large number of fragments, naturally or by applying a relatively small external force. Since the peeling of the mortar layer 18 is due to the static expansion effect of the expanding agent over time,
Almost no noise and vibration.

After the mortar layer 18 has been peeled off, the position of the reinforcing bars in the wall 12 is checked using a reinforcing bar (not shown). Next, a plurality of holes 23 are formed at a plurality of places on the wall 12 where the reinforcing bars are not arranged, and an anchor member 24 is implanted in each hole (FIG. 2). That is, the anchor member 24 is provided in each hole.
Are partially inserted, and each anchor member 24 is fixed to the wall 12 using, for example, an adhesive made of a synthetic resin. As a result, the plurality of anchor members 24 protrude from the surface 14 of the wall 12. It is desirable that the plurality of holes 23 be regularly arranged.

The holes 23 can be formed by the same method as that for forming the openings in the mortar layer 14, that is, by using the ultrasonic cutting method. Thereby, the formation of the holes 23 can be performed with little noise and little vibration. As in the formation of the opening, the hole 23 can be formed by cutting the drill without ultrasonic vibration. However,
Also in this case, the level of generated noise and vibration is higher than in the case of the ultrasonic cutting.

Next, in front of the surface 14 of the wall, a reinforcing bar assembly 26 composed of a plurality of reinforcing bars extending vertically and horizontally is attached to the anchor member 2.
4 (FIG. 3). Then, in the illustrated example, the surface 1 of the wall is surrounded by the rebar assembly 26.
4 and at a slight distance from the rebar assembly 26 (FIG. 4).

The illustrated formwork 28 includes a weir plate 30 facing the reinforcing bar assembly 26, a plurality of pairs of lateral ends 32 arranged at intervals in the vertical direction and in contact with the weir plate 30, One end fixed to the end 32 and the weir plate 30 extend toward the wall surface 14 and are screwed to some of the anchor members 24 (the symbols are omitted for simplicity of the drawing). And a plurality of form ties 34 connected with each other.

Thereafter, concrete (see solidified concrete indicated by reference numeral 36 in FIG. 5) is cast between the formwork 28 and the surface 14 of the wall. In the illustrated example, the top of the weir plate 30 is formed so as to diverge upward and upward in order to define a concrete input space. Reference numeral 38 denotes a hose for supplying concrete between the formwork 28 and the wall surface 14 from the concrete input space.

After the cast concrete has solidified, the formwork 28 is removed, and mortar 40 is poured into the space remaining between the solidified concrete 36 and the beam 22. Close with.

As a result, the thickness of the wall 12, which is one of the frames, is increased, and the wall 12 is reinforced. In the example shown,
The thickness of the wall 12 has been increased to the same thickness as the beam 22.

In the illustrated example, the finish to be applied later,
In consideration of renewal, etc., the side surface 44 of the beam 22 is further added.
And a mortar layer 48 covering the lower surface 46 thereof is peeled off from these surfaces 44 and 46 of the beam 22. Mortar layer 4
8 can be performed under low noise and low vibration in the same manner as in the mortar layer 18.

The skeleton may be made of exposed concrete which is not covered with the mortar layer. In this case, the reinforcement of the skeleton by adding concrete is the same as the step after peeling the mortar layer, except that the formation of the implantation hole of the anchor member is performed only by ultrasonic cutting. Perform by performing. By forming a hole in the frame, which is a noise source in reinforcing the frame made of exposed concrete, by the ultrasonic cutting, the reinforcement can also be performed quietly and almost without vibration.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a wall and a beam that are part of a skeleton of a concrete building.

FIG. 2 is a partial cross-sectional view of a wall during implantation of an anchor.

FIG. 3 is a schematic longitudinal sectional view of a wall and a beam in a state where a reinforcing bar assembly is arranged.

FIG. 4 is a schematic longitudinal sectional view of a wall and a beam in a state where a formwork is arranged.

FIG. 5 is a partial vertical cross-sectional view showing a part of a wall in which concrete is added and a part of a beam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Concrete building 12 Wall 14 Wall surface 18 Mortar layer 24 Anchor member 26 Reinforcement assembly 28 Formwork 36 Concrete

Claims (4)

[Claims] 1. A method of reinforcing a skeleton of an existing concrete building, comprising: forming a plurality of openings in a mortar layer covering a surface of the skeleton, the openings being open to the surface; Separating the mortar layer from the skeleton by volume expansion of the expanding agent, forming a plurality of holes opened in the surface of the skeleton, implanting an anchor member in each hole, facing the surface of the skeleton. A method of reinforcing a skeleton, comprising: arranging a rebar assembly; arranging a formwork surrounding the rebar assembly; and placing concrete between the formwork and the skeleton. 2. The method according to claim 1, wherein the opening is formed by subjecting the mortar layer to ultrasonic cutting. 3. The method according to claim 1, wherein the hole is formed by subjecting the body to ultrasonic cutting. 4. A method for reinforcing a skeleton of an existing concrete building, wherein a plurality of holes are formed in the skeleton by ultrasonic cutting, and an anchor member is implanted in each hole. Arranging a reinforcing bar assembly facing the surface of the skeleton, arranging a formwork surrounding the reinforcing bar assembly, and placing concrete between the formwork and the skeleton, reinforcing the skeleton Method.