JP2002097797A - Repairing method of existing floor and surface layer removal method of existing floor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a floor which has an excellent uniformity between repaired areas and not repaired areas and is highly durable. SOLUTION: The repairing method of an existing floor whereby the existing floor is repaired by removing the surface layer of an existing floor 1 formed by a solidifying material and forming a new surface layer 1N over the removed area. The new surface layer 1N is formed by placing a fiber reinforced solidifying material C over the removed area, in particular after recessed grooves 1g, 1g for forming reinforcement beam has been formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes a surface layer of an existing floor formed of a solidified material such as concrete or mortar, and renovates the existing floor by forming a new surface layer on the removed portion. The present invention relates to a method of repairing an existing floor and a method of removing a surface layer of the existing floor suitable for the method.

[0002]

2. Description of the Related Art Recently, aging has become a serious problem particularly on floors formed of a solidified material such as concrete or mortar (hereinafter also simply referred to as floors), especially on concrete floors of industrial factories. . In general, the degree of aging of the floor can be determined using the shape and density of cracks (cracks) as indices.

When the process of aging of the floor is viewed on the basis of a normal crack progressing process, it is as follows. That is, a one-way crack occurs due to drying shrinkage of the floor material (concrete) and external force applied by a traveling vehicle such as a forklift or a truck. This is the initial stage. Next, the one-way crack grows and the crack density increases. This is the middle stage. Then, at a later stage, cracks penetrate the floor slab, that is, so-called penetrating cracks occur, and water leakage and free lime occur. Then, in the final stage, the floor slab is collapsed and broken by permeated water or the like at the penetrating crack site.

[0004] Although the cause of the occurrence of cracks cannot be unconditionally determined, in a factory where vehicles such as forklifts travel, bending shear stress and torsional shear stress applied to the floor by the wheels of the vehicles are one of the main factors. It is considered to be one. For example, when the bending strength applied to the floor by the front wheels in a 2.5-ton forklift (air tire) is evaluated, it is about 2.04 MPa.
General design standard compressive strength of Japanese industrial floor is 18MP
Since the bending strength is usually 1/5 to 1/8 of the compressive strength, if the bending strength is set to, for example, 1/8, the bending strength of a general industrial floor is 2.25 MPa. From the above, the safety factor is calculated as 2.25 / 2.04 = 1.10. Thus, it can be seen that the general industrial floor in Japan has a remarkably low safety factor in the first place and cannot be used for a long period of time for vehicles such as forklifts.

Needless to say, the aging of the floor proceeds without stopping until it collapses, and the aging floor to a certain extent needs to be repaired for safety and the like. Therefore, conventionally, the existing floor has been repaired by a method of removing the repaired portion by cutting or the like and joining a solidifying material such as concrete to the removed portion, or completely re-stripping the entire floor.

[0006]

However, even if the repair is performed by the conventional method, there is a problem that the durability is fundamentally low as described above, and cracks may recur. In addition, particularly in the method of passing over the solidified material, there was a problem that the integrity of the repaired portion and the unrepaired portion was weak.

[0007] Accordingly, a main object of the present invention is to provide a method of constructing a highly durable floor with high integration between a repaired portion and an unrepaired portion.

[0008]

The present invention which has solved the above-mentioned problems is as follows. <Claim 1> A method of repairing an existing floor, in which a surface layer of an existing floor formed of a solidified material is removed and a new surface layer is formed on the removed portion to repair the existing floor. A method for repairing an existing floor, comprising forming a concave groove for forming a reinforcing beam in a portion and then pouring a fiber-reinforced solidifying material to form the new surface layer.

<Function and effect> In the floor thus renovated, a new surface layer is formed on the remaining part of the existing floor,
The reinforcing fibers are satisfactorily dispersed throughout the newly cast portion, and the reinforcing beam is formed as a part of the new surface layer by the solidified material filled in the groove formed in the remaining portion of the existing floor. In such renovated floors, the reinforcing beams are firmly bite into the remaining portion of the existing floor, significantly increasing the integration between the new surface layer and the existing floor, and the reinforcing fibers are embedded in the new surface layer in a uniformly dispersed state. As a result, the strength (especially on the surface) of the new surface layer itself is significantly increased, and the durability is also significantly increased. Further, the section modulus and the second moment of area of the new surface layer are increased by the reinforcing beam portion, and the bending strength is significantly increased. Therefore, it is not necessary to cut the existing floor more deeply than necessary, so that the cost can be reduced and the construction period can be shortened.

[0010] In a second aspect of the present invention, at least a plurality of grooves are formed in a target portion of the existing floor, and a convex portion between the grooves is applied with an external force to break off the surface of the existing floor. The method for repairing an existing floor according to claim 1, wherein the removing treatment and the surface finishing treatment by shot blasting are performed in this order.

<Effect> By such a main removal process, the surface layer can be removed from the existing floor while reducing the damage to the remaining portion. In addition, by performing the shot blasting process, a large number of fine irregularities are formed on the main removal processing surface, and the adhesiveness of the fiber reinforced solidifying material to be cast later is increased, thereby improving the integration between the new part and the existing part. .

<Claim 3> The method for repairing an existing floor according to claim 2, wherein, after the main removal treatment, a roughing treatment of hitting a reciprocally driven piston member against a surface to be treated is performed prior to the surface finishing treatment. .

<Effects> Particularly when the existing floor is deteriorated, a relatively fragile portion may be exposed on the main removal processing surface. Further, the concrete floor contains coarse aggregate having a particle size of 5 mm or more, and the coarse aggregate having a large particle size remains in a floating state without being cut in the above-described main removal processing. Therefore, in order to remove these fragile portions and floating aggregates, it is preferable to perform the rough cutting process according to the third aspect of the present invention following the main removal process.

<Claim 4> As the fiber-reinforced solidified material,
The method for repairing an existing floor according to any one of claims 1 to 3, wherein a steel fiber reinforced concrete containing at least steel fiber is used as the fiber.

<Effects> By using such steel fiber reinforced concrete, the strength of the new surface layer portion is remarkably increased, and the integrity with the remaining portion of the existing floor is also improved.

<Claim 5> As the fiber-reinforced solidified material,
Using a fiber reinforced solidifying material having a slump value of 13 cm or less,
The method for repairing an existing floor according to any one of claims 1 to 4.

<Effects> By setting such a very low slump value, the drying shrinkage of the new surface layer can be reduced. Also, at the time of casting, the steel fibers can be held in a form well dispersed in the solidified material.

<6> The method according to any one of <1> to <5>, wherein vibration is applied to the cast unsolidified fiber-reinforced solidified material from a surface side thereof through a vibration applying member. Renovation of existing floor.

<Function and effect> By this, the cast solidified material is compacted and densely filled in the surface layer removed portion (including the groove for forming the reinforcing beam), and the reinforcing fibers contained in the solidified material are reduced. The fibers slightly settle down due to the vibration, and especially the reinforcing fibers exposed on the surface are surely embedded in the solidified material. In particular, when the slump value of the fiber-reinforced solidified material is lowered, the consistency is large, so it is difficult to densely fill the solidified material by ordinary casting. Can be made, and the integration with the existing floor can be improved.

<Claim 7> A method for removing a surface layer of an existing floor formed of a solidified material, wherein at least a plurality of grooves are formed at a target portion of the existing floor, and a projection between the grooves is formed. A method for removing a surface layer of an existing floor, comprising applying an external force to the part to break it off.

<Effects> According to this method, the surface layer can be removed from the existing floor while reducing the damage to the remaining portion.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail below for each step with reference to the accompanying drawings. <Preliminary survey> When renovating an existing floor, it is desirable to first conduct a preliminary survey on the necessity of renovation. In determining whether or not the repair is necessary, for example, the existing floor is roughly checked to which of the damage ranks in Table 1 corresponds, and then a remedy is selected according to the selection table of FIG.

[0023]

[Table 1]

As a result, if it is necessary to renovate,
For example, the following detailed survey is conducted. B) In the following, for example, an existing floor 1 as shown in FIG. 2 is assumed. In this case, relatively normal locations, cracks 2, 2,...
Are roughly divided into three categories of locations where corrosion occurs and locations where corrosion is severe, core specimens 3, 3, ... are extracted from each location,
Investigation of painted floor material, upholstered floor material, oil, chemicals, paint, tar, adhesive, rust, etc. of the existing floor 1, and measurement of crack depth, length, density, etc. B) Further, at appropriate intervals, height level measurement points 4,
It is desirable to set 4 and measure the height level of each part. For example, as shown in FIG. 3, the floor of a warehouse or the like is most frequently used in the vicinity of the center, so that the height level is often the lowest in that part. C) In addition, joints are provided on ordinary concrete floors to prevent concrete cracks caused by environmental changes such as temperature and humidity. This is also grasped through a preliminary survey and used as an index in the joint formation of the new surface layer. D) In addition, the objects buried in the existing floor 1 are also grasped from architectural drawings.

<Design> Based on the preliminary investigation, the removal thickness of the existing floor 1, the thickness of the new surface layer 11, the mixing of the solidified material, and the like are determined.

In the case of a floor, there are problems such as opening and closing of a door.
It is preferable that the removal thickness and the new surface layer be the same, and the thickness is determined by the thickness up to a sound part of the existing floor, but cannot be determined unconditionally. And particularly preferably 30 to 50 mm. In particular, when the height level of the existing floor is not uniform as shown in FIG. 3, the removal thicknesses d1 and d2 are accordingly adjusted.
Is desirably determined so that the surface of the new surface layer 1N is horizontal.

In the present invention, a fiber-reinforced solidifying material (concrete, mortar, etc.) is used as a solidifying material to enhance the new surface layer 1N itself and improve durability. In particular, at least steel fiber as the fiber, for example (a) as shown in FIG.
Steel fiber including corrugated plate, (b) plate having spatula-shaped portions at both ends, (c) plate having corrugated irregularities on one surface, and (d) rod-shaped short fiber having disc-shaped protrusions at both ends Preferably, reinforced concrete is used. This strengthens the new surface layer and increases resistance to bending, twisting and shear forces. In addition, since the fibers are embedded in the reinforcing beam portion described below and other portions, there is an advantage that the integrity of the existing floor and the new surface layer is improved.

Further, in the present invention, it is preferable to use a polymer fiber in combination. Thereby, generation of hair-like cracks due to drying shrinkage on the surface of the new surface layer is prevented.

Table 2 shows examples of concrete mixing. The composition shown in the table is for compressive strength 27MP at 3 days of age.
This is a formulation example for achieving a bending strength of at least a, a bending strength of at least 6.0 MPa, a compressive strength at the age of 28 days of at least 38 MPa, a bending strength of at least 8.4 MPa, and a slump value (target value) of 8 ± 2.5 cm. The slump value is 0 to 1
It is preferably 3 cm, more preferably 5.5 to 10.5 cm, whereby the adhesion strength increases and the drying shrinkage becomes good. In particular, in the case of an industrial factory floor, in order to shorten the construction period and shorten the period during which the factory operation is stopped, use early-strength cement or ultra-high-strength cement.

[0030]

[Table 2]

<Construction> (Surface Removal Step) In the present invention, first, the surface layer of the portion to be repaired (or the entire surface) of the existing floor is roughly removed by the designed thickness. For this reason, for example, a well-known vibrating concrete removing device (sharpening device) may be used, but if the existing floor is aged to a certain extent, it is excessively removed to a healthy portion below the surface layer as the surface layer is removed. There is a possibility that it may give a strong shock and deteriorate. Therefore, the surface layer is preferably removed according to the invention of claim 2.

First, as shown in FIG. 5, a diamond cutter blade 10 having a width of 2 mm to 5 mm is coaxially arranged in parallel with 10 to 20 sheets at an interval of 10 mm to 20 mm. Using a grooving device that cuts the target object by rotating it around the axis while pressing against the target object, a number of grooves 20 having a predetermined depth and being parallel to each other are formed in the target part on the existing floor. Next, as shown in FIG. 6, the spatula-shaped front end contact member 31 of the chisel breaker 30 is pressed against the convex streaks 21 between the concave grooves 20 against the side surfaces thereof, particularly against the roots in the concave grooves 20. And vibrate while applying an external force to the convex streak portion 21 from the side to break it off. In this way, the effect on the existing floor 1 can be minimized. In the illustrated example, the groove 2
Although a plurality of 0s are formed in parallel and spaced apart from each other, the present invention is not limited to this example. For example, they may be formed in a grid pattern.

In particular, when the existing floor 1 is deteriorated, a relatively vulnerable portion may be exposed on the main removal processing surface. On concrete floors, the particle size is 5 mm.
The coarse aggregate described above is also included, and the coarse aggregate having such a large particle diameter remains in a floating state without being cut in the main removal process described above. Therefore, in order to remove these fragile portions and suspended aggregates, it is preferable to perform a roughing process following the main removal process. An apparatus for this is shown in FIG. This device 40 is generally referred to as a scabber, and is provided with a single or a plurality of piston members 41 having a bit at a lower end in a parallel arrangement, and reciprocatingly drives the piston members 41 in a vertical direction to strike a surface to be processed, thereby performing rough cutting. It is. When the deterioration of the existing floor is at a low level, the rough cutting process can be omitted.

Thereafter, in order to clean and roughen the surface of the surface layer removed portion, a surface treatment by so-called shot blast is performed. Steel particles, dust and fine particles generated by blasting are removed by a shot blasting device,
Collected. As a result, a large number of minute irregularities are uniformly formed on the surface of the removed portion, and the adhesion between the removed portion surface and the solidifying material to be subsequently cast thereon becomes very good, and the existing floor and the new surface layer portion The joint at the joint surface is increased.

(Step of Forming Reinforcement Beam-Forming Groove) In the present invention, as shown in FIGS. 8 and 9, the reinforcing beam-forming grooves 50, 50 are formed on the main removal surface 1S.
The concave grooves 50, 50 can be provided in plural rows in parallel at intervals of, for example, about 1000 to 2000 mm as shown in the figure, depending on the condition of the floor area to be repaired.
In particular, it is also preferable to form them in a lattice or the like to increase the strength in a plurality of directions (not shown). Further, as shown in the figure, the concave grooves 51, 51 can be formed along cracks, particularly deep portions such as penetrating. The depth of the concave grooves 50 and 51 is 20 to 40 mm, and the width is 30 to 50 mm.
mm is preferable.

The groove 50, 51 for forming the reinforcing beam has a reduced number of cutter blades (approximately 5 when a groove having a width of 50 mm is formed), and the aforementioned grooving device in which the distance between the processing cutter blades is reduced. It can be formed by using an apparatus (not shown) having the same configuration as the above.

(New Surface Layer Forming Step) After the above processing is completed, the above-mentioned fiber-reinforced solidified material is preferably produced on site, and then punched into the surface layer-removed portion (including the groove for forming the reinforcing beam). Set up. That is, especially steel fiber reinforced concrete contains steel fiber, and in order to disperse the steel fiber in the solidified material well, it is desirable to knead the material on site using a powerful mixer and to immediately pour it. Also, by lowering the slump value, the dispersibility of the steel fibers becomes better. As a specific example of the production procedure, first, a biaxial forced kneading mixer is used, and the whole amount is charged in this order in the order of sand, cement, aggregate, and fiber, and the mixture is kneaded (water is not added) for about 30 seconds. After that, the majority of the design amount (about 90%) of the water to which the additive was added was added and kneaded for about 60 seconds, and then kneaded while adding water to the gradual place within the range of the remaining amount. Adjust to slump value.

In the case of casting, if the steel fiber is contained or the slump value is low, it becomes difficult to perform pumping by pumping. Therefore, a cat wheel, a crawler-type carrier, a belt conveyor, or the like is used. It is desirable to do. As described above, it is preferable that the casting thickness is the same as the surface removal thickness.

If the fiber reinforced solidified material is cast,
As shown in (5), the cast solidified material C is roughly stretched using the register marks 60 and the like, and then spread evenly using the screed 70 and the like. In the case of the present invention, after the spread, it is preferable to apply vibration to the unsolidified fiber reinforced solidified material C from the surface side via a vibration applying member. It is particularly preferable to use a vibration screed device 70 as shown. The vibrating screed device 70 includes a screed main body 71 having a triangular longitudinal section having a pair of equalizing angles 71A at a lower end, and vibration generating means attached to the screed main body 71. . The vibration generating means 72 in the illustrated example is the air supply pump 7.
Although the air vibrator includes the 2A and the air-driven vibration generator 72B, a vibration generator driven by a rotary drive source such as an engine can be used.

For leveling, rails 73 are laid on both sides of the target area, and a screed device 70 is placed across the rails.
Is operated, and the traveling handle 74 is appropriately rotated to cause the screed device 70 to travel on the rail 73. As a result, at the same time as the spread of the surface of the solidified material C, the solidified material C is compacted, and is densely filled in the surface layer removed portion (including the groove for forming the reinforcing beam) and solidified. The reinforcing fibers contained in the material C slightly settle down due to the vibration, and particularly the reinforcing fibers exposed on the surface are surely embedded in the solidified material C. In particular, when the slump value of the fiber-reinforced solidified material C is lowered, the consistency is large. Therefore, it is difficult to densely fill the solidified material by ordinary casting. It is possible to improve the integration with the existing floor.

Further, as a final surface finish, the surface is leveled by a trowel (rotating disk spread leveling device) so that the surface is sufficiently pressed, and the corners and details are finished using a gold iron.

Also, after completion of the above-mentioned casting work, 1-2
After an hour (in the case of early-strength cement), cut off joints if necessary. At this time, it is preferable that the joints provided on the new surface layer are basically formed at the same places as the joints of the existing floor 1 which have been surveyed in advance. When the joint of the existing floor 1 is complicated, an appropriate joint, for example, a square joint having a side of about 3 m may be used.

Thereafter, it is preferable to perform the wet curing for at least about seven consecutive days for a predetermined period, for example, in the case of the above-mentioned example of the early-strength cement. In the usual case, the surface after curing is finished by applying a resin, a paint or the like. Further, it is desirable that the joint is filled with a filler such as an epoxy resin after curing is completely completed, for example, after curing for at least about 28 days in the case of the above-described example of the early-strength cement.

In the floor thus renovated, FIG.
As shown in FIG. 12 and FIG.
N is formed, the reinforcing fibers are satisfactorily dispersed throughout the newly cast portion 1N, and the reinforcing beam is formed as a part of the new surface layer 1N by the solidified material filled in the groove formed in the existing floor remaining portion 1. 1 g and 1 g are formed. In such a renovated floor, the reinforcing beams 1g and 1g firmly bite into the existing remaining floor portion 1 to remarkably increase the integration between the new surface layer 1N and the existing floor 1, and also enhance the reinforcing fibers 1 in the new surface layer 1N.
Are embedded in a state of being uniformly dispersed, the strength (especially of the surface) of the new surface layer 1N is remarkably increased, the durability is remarkably increased, and the reinforcing beam portion 1 is further increased.
g and 1g increase the section modulus and the second moment of area, and significantly increase the bending strength. Therefore, it is not necessary to cut the existing floor 1 deeper than necessary, so that cost reduction and shortening of the construction period can be realized.

[0045]

EXAMPLE After renovation of a concrete floor (3.2 m ² ) using steel fiber reinforced concrete manufactured with the composition shown in Table 3 by the method described in the embodiment (including vibration screed processing and trowel final finishing). Then, cores were removed at arbitrarily selected locations to obtain three specimens. And the bending strength of these specimens was measured. Table 4 shows the compression strength (= bending strength × 4.5) estimated from the bending strength measurement results.

[0046]

[Table 3]

[0047]

[Table 4]

From these results, the renovated floor according to the present invention has a remarkably high strength about 3.4 times that of the conventional general concrete floor (bending strength: 2.25 MPa, compressive strength: 18 MPa). Was found to be expressed.

[0049]

As described above, according to the present invention, only the surface layer of the existing floor can be repaired, low-cost and short-term construction can be performed, and the repaired portion and the unrepaired portion have high integration and durability. High floors can be built.

[Brief description of the drawings]

FIG. 1 is a countermeasure selection table for an existing floor.

FIG. 2 is a plan view of an existing floor.

FIG. 3 is a longitudinal sectional view of an existing floor.

FIG. 4 is a perspective view showing a steel reinforcing fiber.

FIG. 5 is a perspective view showing a grooving step of the main removing step.

FIG. 6 is a perspective view showing a convex portion removing step of the main removing step.

FIG. 7 is a perspective view of an apparatus used for a rough cutting process.

FIG. 8 shows a floor in a state in which a groove for forming a reinforcing beam is formed.
It is a top view.

FIG. 9 shows a floor in a state where a groove for forming a reinforcing beam is formed;
It is a longitudinal cross-sectional view.

FIG. 10 is a perspective view showing a fiber-reinforced concrete placing / laying / vibration applying step.

FIG. 11 is a plan view showing a floor after completion of construction.

FIG. 12 is a longitudinal sectional view showing a floor after completion of construction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Existing floor, 1N ... New surface layer, 1G ... Reinforcement beam part, 2 ... Crack, 3 ... Core extraction part, 4 ... Height level measurement point,
10 grooving device, 20 groove, 21 convex part, 3
0 ... Chisel breaker, 31 ... Spatial tip contact member, 4
0: rough cutting device, 50, 51: concave groove for forming a reinforcing beam, 60
... register mark, 70 ... vibrating screed device, C ... fiber reinforced solidified material

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Nobuo Saito Inventor No. 909 Kamiyasumatsu, Tokorozawa-shi, Saitama F-term in CRT World Co., Ltd. 2E176 AA03 BB01 BB27 BB36

Claims (7)

[Claims] 1. A method of repairing an existing floor by removing a surface layer of the existing floor formed of a solidified material and forming a new surface layer at the removed portion, thereby repairing the existing floor. A method of repairing an existing floor, comprising forming a groove for forming a reinforcing beam in a portion and then casting a fiber-reinforced solidifying material to form the new surface layer. 2. A main removal process of forming at least a plurality of concave grooves in a target portion of the existing floor, and applying an external force to bend a convex portion between the concave grooves, as the surface layer removing process of the existing floor, The method for repairing an existing floor according to claim 1, wherein the surface finishing treatment by shot blasting is performed in this order. 3. The method of repairing an existing floor according to claim 2, wherein after the main removal treatment, prior to the surface finishing treatment, a roughing treatment of hitting a reciprocally driven piston member against a surface to be treated is performed. 4. The method for repairing an existing floor according to claim 1, wherein a steel fiber reinforced concrete containing at least steel fiber as a fiber is used as the fiber reinforced solidifying material. 5. A fiber-reinforced solidified material having a slump value of 13 cm or less as said fiber-reinforced solidified material.
Repair method for existing floors according to any one of the above. 6. The existing floor according to claim 1, wherein vibration is applied to the cast unsolidified fiber-reinforced solidified material from a surface side thereof via a vibration applying member. Renovation method. 7. A method for removing a surface layer of an existing floor formed of a solidifying material, wherein at least a plurality of grooves are formed in a target portion of the existing floor, and a convex portion between the grooves is subjected to an external force. And removing the surface of the existing floor.