Cutting device

Abstract

When mechanical cutting equipment is used to chip concrete structures, cracks appear on the chipped surface, so in the past, water chipping was performed after mechanical cutting and chipping.In order to prevent the effects of cracks caused by mechanical cutting and chipping from appearing, it was necessary to make the cutting depth of the water chipping large. [Solution] We discovered that cracks on the chipping surface can be suppressed when the bits on the drum that make up the cutting device are smaller than those of general-purpose ones and are arranged densely. Here, when the drum width is 350 mm, the number of lines formed by the bits is 40 to 60 lines. The chipped surface formed using the cutting device of this bit only develops small cracks similar to those produced by water chipping, and when additional concrete is poured onto the chipped surface, sufficient tensile strength is achieved between the main concrete and the additional concrete.

Description

[Technical Field]

[0001] The present invention relates to a cutting device, which is used, for example, to chip the surface of concrete framework of a concrete building or the like. [Background technology]

[0002] Generally, surface chipping of concrete structures has been carried out manually by workers using breakers. A cutting device for chipping the surface of a concrete structure is introduced in Patent Document 1. With this cutting device, even an unskilled person can easily chip the surface of a concrete structure flatly and to a uniform depth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7419614 [Patent Document 2] Special Publication No. 11-504689 [Non-patent literature]

[0004] [Non-Patent Document 1] High-precision, low-noise cutting method TS Fine Milling Method, TS Fine Milling Method Study Group "Web Archive of the Political World, National Diet Library Internet Materials Collection Project, online, text, December 5, 2023" Summary of the Invention [Problem to be solved by the invention]

[0005] The purpose of chipping away the surface of the concrete structure and making it flat is to pour more concrete onto this surface to repair or reinforce the concrete structure. Therefore, if cracks or the like occur on the formed flat chipped surface and its mechanical strength is reduced, there is a risk that the adhesive strength between the additional concrete and the chipped surface will be reduced. Generally, fine cracks (hereinafter simply referred to as "cracks") appear on the chipped surface formed mechanically using a breaker or cutting device. The reason for this is thought to be that when chipping concrete structures, the breaker's chisel or the cutting device's bit interferes with the aggregate that appears on the chipped surface, causing fine cracks in the concrete behind the aggregate.

[0006] To prevent such cracks, the previously mentioned breaker or cutting device has been used to chip the surface of the concrete structure to a first depth, and then a water jet method has been used to chip it to the target depth. Chilling using the water jet method reduces the impact force on the concrete structure, which can prevent cracks on the chipped surface, but the chipping efficiency is low. Therefore, chipping to the first depth hastily has been performed using a breaker or similar device, and then finishing chipping has been performed using the water jet method, which has a smaller impact force. However, using the water jet method in addition to mechanical chipping was time-consuming and slowed down the progress of the construction work. [Means for solving the problem]

[0007] Therefore, the present inventors have conducted extensive research into how to prevent cracks from appearing on the chipped surface when chipping concrete structural members using a mechanical cutting device. As a result, they found that when the drum bits that make up the cutting device are smaller than those of general-purpose ones and are arranged densely, cracks on the chipping surface can be suppressed. An example of a cutting device to which the drum of the present invention is attached is shown in FIG. 1A. Figure 1B shows a standard drum-mounted cutting device. Comparing Figures 1A and 1B, it can be seen that the bits in the former are smaller and more closely spaced than those in the latter. Figure 2 shows a construction machine with the cutting device of Figure 1A attached to the end of its arm. The cutting device of Figure 1B is also attached to the arm of the construction machine in the same way.

[0008] Figure 3 shows the chipping work to form vertical chipping surfaces in the concrete structure 21N. The vertical chipping surfaces on the left and in the center were formed using the cutting device of this invention shown in Figure 1A, while the chipping surfaces on the right were formed by a worker using a breaker. Similarly, Figure 4 shows the chipping work to form a vertical chipping surface on the concrete structure 40N. In the figure, the vertical chipping surfaces on the left and center were formed using the cutting device of this invention shown in Figure 1A, while the chipping surfaces on the right were formed by a worker using a breaker.

[0009] A cylindrical core specimen was extracted from the chipped surface of the concrete structure 21N in Figure 3, and the state of cracks on the cut surface was observed as follows. The cut surface of the core specimen was immersed in epoxy resin with a fluorescent paint that fluoresces under ultraviolet light, and then vacuum degassed. Images were taken under visible and ultraviolet light. The obtained images were visually observed to determine the length of the deepest crack.

[0010] FIG. 5A is a photograph under visible light of the side of a core specimen extracted from the cutting surface of a concrete structure 21N formed using the cutting device of this invention shown in FIG. 1A, and FIG. 5B is a photograph of the same core specimen under ultraviolet light. The maximum depth of the crack on the chipped surface was 7.0 mm. Similarly, Figure 5C is a photograph taken under visible light of the side of a core specimen extracted from the chipped surface of the concrete structure 21N formed using a breaker, and Figure 5D is a photograph of the same core specimen under ultraviolet light. The maximum depth of the crack on the chipped surface was 23.0 mm.

[0011] FIG. 6A is a photograph under visible light of the side of a core specimen extracted from the cutting surface of a concrete structure 40N formed using the cutting device of this invention shown in FIG. 1A, and FIG. 6B is a photograph of the same core specimen under ultraviolet light. The maximum depth of the crack on the cutting surface was 13.0 mm. Similarly, Figure 6C is a photograph taken under visible light of the side of a core specimen extracted from the chipped surface of a 40N concrete structure formed using a breaker, and Figure 6D is a photograph of the same core specimen under ultraviolet light. The maximum depth of the crack on the chipped surface was 20.0 mm.

[0012] The results in FIGS. 5 and 6 show that the chipped surface formed using the cutting device of FIG. 1A has only minute cracks compared to the chipped surface formed using a breaker.

[0013] Figure 7 shows a side view of the drum applied to the cutting device of the embodiment that obtained the results of Figures 5 and 6. Figure 8 is a development view of the outer circumferential surface of this drum. In the examples of Figures 7 and 8, the bits are arranged on the outer periphery of the drum as follows: That is, on a 350 mm wide drum outer periphery, the tips of the bits form a 51-line locus within this width in the direction of drum rotation. These loci are spaced evenly across the width of the drum outer periphery and are parallel to the direction of drum rotation (circumferential direction). Furthermore, on the outer peripheral surface of the drum, each bit is arranged at equal intervals in the circumferential direction and in the same row in the width direction (on an imaginary straight line in the width direction). For example, when the length of the outer peripheral surface is 1381.6 mm, the bits are arranged in 29 rows from row A to row X, with the distance between the centers of each bit being 57.56 mm. In this example, 106 bits are arranged on the outer surface of the drum, and the length is 100 mm. 2 This means that 2.19 bits are allocated per block.

[0014] Figure 9 shows a side view of the general-purpose drum shown in Figure 1B, and Figure 10 is a development of the outer circumferential surface of this drum. In the examples of Figures 9 and 10, the bits are arranged on the outer periphery of the drum as follows: That is, on a 350 mm wide drum outer periphery, the tips of the bits form a 29-line locus within this width in the direction of drum rotation. These loci are spaced evenly across the width of the drum outer periphery and are parallel to the direction of drum rotation (circumferential direction). Furthermore, on the outer peripheral surface of the drum, each bit is arranged at equal intervals in the circumferential direction and in the same row in the width direction (on an imaginary straight line in the width direction). For example, when the length of the outer peripheral surface is 1256.0 mm, the bits are arranged in 12 rows from row A to row L with the distance between the centers of each bit being 104.7 mm. In this example, 58 bits are arranged on the outer surface of the drum, and the length is 100 mm. 2 This means that 1.27 bits are allocated per block. According to the experience of the present inventors, cracks similar to those observed in chipping using a breaker were observed on the surface chipped using the cutting device shown in FIG. 1B.

[0015] Based on the above, and based on the study by the inventors, assuming that the width of the drum is 350 mm and the length of the drum outer circumferential surface is 1380 mm, the number of lines formed by the bits should be 40 to 60, more preferably 44 to 55. Furthermore, assuming that each bit is arranged in the same row in the width direction, the number of rows of bits arranged in the outer circumferential direction of the drum should be 25 to 33, more preferably 27 to 31. The number of bits arranged in a 100 mm square is preferably 1.50 to 2.50, and more preferably 1.90 to 2.30.

[0016] Based on the above findings, the first aspect of the present invention can be defined as follows. drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: Assuming that the width of the drum is 350 mm, the cutting device is such that the tip of the bit forms a locus of 40 to 60 lines, preferably 45 to 55 lines, within this width in the direction of rotation of the drum.

[0017] The second phase can be defined as follows: In the cutting device of the first aspect, when the length of the outer peripheral surface of the drum is assumed to be approximately 1380 mm, the number of bits arranged in the rotation direction is 25 to 33, preferably 27 to 31.

[0018] The third phase can also be defined as follows: In the cutting device of the first aspect, four to five bits are arranged in the width direction of the drum, and the tips of adjacent bits in the width direction are aligned on an imaginary straight line in the width direction of the drum.

[0019] The fourth phase can be defined as follows: In the cutting device of the third aspect, the tip of the bit arranged in the first width direction of the drum intersects, in the radial direction of the drum, with the base of the bit arranged in the second width direction preceding the rotation direction of the drum.

[0020] Furthermore, from the observation of FIGS. 7 and 8, the fifth aspect of the present invention can be defined as follows. In the cutting device of the fourth aspect, the distance between the tip of the bit arranged in the first width direction and the tip of the bit arranged in the second width direction is 55 to 60 mm.

[0021] Furthermore, it can also be defined as in the sixth to eighth aspects. That is, in the sixth aspect, in the cutting device specified in the first aspect, there is a bit whose tip faces in the direction of rotation of the drum, and this bit is positioned on the center line of the trajectory formed by the tip.

[0022] The seventh phase is drums, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for a construction machine; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: A cutting device in which 1.50 to 2.50 bits, preferably 1.90 to 2.30 bits, are arranged per 100 mm square on the outer peripheral surface of the drum. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1A is a front view of a cutting device according to an embodiment of the present invention, and FIG. 1B is a front view of a general-purpose cutting device. [Figure 2] FIG. 2 shows a construction machine equipped with a cutting device according to an embodiment. [Figure 3] FIG. 3 shows the cutting work for forming a vertical cutting surface on a vertically fixed flat concrete body 21N. [Figure 4] Figure 4 shows the cutting work to form a vertical cutting surface on a vertically fixed flat concrete body 40N. [Figure 5] Figure 5A is a photograph under visible light of the side of a core specimen extracted from the cutting surface of the concrete structure 21N formed using the cutting device of this embodiment shown in Figure 1A, and Figure 5B is a photograph of the same core specimen under ultraviolet light. [Figure 6] FIG. 6A is a photograph under visible light of the side of a core specimen extracted from the cutting surface of a concrete structure 40N formed using the cutting device of this invention shown in FIG. 1A, and FIG. 6B is a photograph of the same core specimen under ultraviolet light. [Figure 7] FIG. 7 shows a side view of the drum (FIG. 1A) to which the cutting device of the embodiment that produced the results of FIGS. 5 and 6 is applied. [Figure 8] FIG. 8 is a development view of the outer peripheral surface of the drum. [Figure 9] FIG. 9 is a side view of a drum applied to the cutting device of FIG. 1B. [Figure 10] FIG. 10 is a development view of the outer peripheral surface of the drum. [Figure 11] FIG. 11 shows a cutting device to which the present invention is applied, with FIG. 11A being a left side view, FIG. 11B being a front view, and FIG. 11C being a right side view. [Figure 12] FIG. 12 is a front view showing the state in which the cutting device is oscillated. [Figure 13] FIG. 13 is a left side view showing the structure of the reference guide 40. As shown in FIG. [Figure 14] FIG. 14 is a right side view showing the structure of the level guide 50. [Figure 15] FIG. 15 is a cross-sectional view showing the structure of the guide roller. [Figure 16] FIG. 16 shows the cutting operation by the cutting device. [Figure 17] FIG. 17 is a side view of the drum of the embodiment. [Figure 18] FIG. 18 is a development view of the outer peripheral surface of the drum of the same embodiment. [Figure 19] FIG. 19 is a schematic diagram of the test piece. DETAILED DESCRIPTION OF THE INVENTION

[0024] First, we will explain a cutting device 1 (hereinafter simply referred to as the "cutting device") according to an embodiment of the present invention. This cutting device 1 is an improved version of the rotating drum of the cutting device disclosed in Japanese Patent No. 7419614. The other structures of the cutting device are the same as those disclosed in Japanese Patent No. 7499614, and the disclosure of Japanese Patent No. 7499614 is incorporated herein by reference. The drum, which is the key feature of the present invention, can be applied to cutting devices other than cutting devices.

[0025] As shown in FIG. 11, the cutting device 1 of the embodiment is composed of an upper structure 10, a lower structure 20, and a power tilt unit 90 that connects the upper structure 10 and the lower structure 20. The upper structure 10 is made up of a pair of plate-like members 13 erected on the upper surface of a base plate 11 and a rod 15 attached to the pair. The base plate 11 and the plate-like members 13 form an upper bracket. The tip of an arm for construction machinery is fixed to the rod 15.

[0026] An attachment portion 17 is provided on the lower surface of the substrate 11. A housing 93 of a helical spline mechanism that constitutes the power tilt portion 90 and serves as a pressure adjusting portion is fixed to this attachment portion 17.

[0027] The lower structure 20 is U-shaped when viewed from the side (see FIG. 11A) and has a lower bracket 21 that is inverted L-shaped when viewed from the front (see FIG. 11B). The drum 30, reference guide 40, and level guide 50 are supported on this lower bracket 21. The lower bracket 21 is provided with a first partition plate 25 in the vertical direction, which protects the hydraulic motor (not shown) of the drum 30. Furthermore, the lower bracket 21 is provided with a second partition plate 27 in the horizontal direction, on which a hydraulic control unit (not shown), etc., are disposed.

[0028] This hydraulic control unit controls the hydraulic pressure to the helical spline mechanism that constitutes the power tilt unit 90, the hydraulic pressure to the motor, the hydraulic pressure to the cylinder 55 of the level guide 50, and the like. The drum 30 is generally used in cutting devices, and has a bit 31 attached to its periphery.

[0029] 13, the reference guide 40 comprises a substantially U-shaped frame portion 41 and a guide plate 43. The frame portion 41 is fixed to the lower bracket 21, and the outer edge (the lower edge in the figure) of the guide plate 43 is formed in an arc shape and follows the circular path described by the tip of the bit 31 of the drum 30. The structure of this reference guide 40 is the same as that of a reference guide for a general-purpose cutting device. In this example, guide plates 43 are a pair of plate-like members, with guide roller 45 disposed between them. As shown in FIG. 16, this guide roller 45 maintains its position so that it is perpendicular to the contact surface. In this example, a spherical guide 46 is used as a position maintaining section for maintaining the position of guide roller 45 (see FIG. 15). This spherical guide 46 is composed of a ball portion 46a formed on a shaft section that is mounted on the pair of guide plates 43, and a socket portion 46b that slides on this ball portion 46a.

[0030] As shown in Figure 14, the level guide 50 includes a plate portion 51 and a guide plate 53. A rod 56 of a cylinder 55 is connected to the plate portion 51, allowing the plate 51 to be fixed at any position in the vertical direction as shown in the figure. The rod 56 is disposed so as to intersect with the axis of the drum 30. The cylinder 55 is fixed to the lower bracket 21 via a frame 57. The reference guide 40 can also be replaced with this level guide 50.

[0031] A guide plate 53 is attached to the lower end of the plate portion 51. The guide plate 53 has the same shape as the guide plate 43 of the reference guide 40, but the shape is not particularly limited. A guide roller 55 is disposed between a pair of plate-like members, that is, guide plates 53. This guide roller 55 has the same structure as the guide roller 45 of the reference guide 40, and is maintained in a position perpendicular to the surface to be cut. The amount of protrusion of the rod 56 can be set as desired by controlling the hydraulic pressure of the cylinder 55. As a result, the outer edge of the guide plate 53, i.e., the position of the circumferential surface of the guide roller 55 (the distance from the drum axis) can be set as desired.

[0032] The power tilt unit 90 allows the upper structure 10 and the lower structure 20 to swing in the axial direction of the drum 30. In this example, as shown in Figure 2, they can swing 90 degrees to the left and right. Here, the power tilt unit 90 employs a mechanism in which an external gear having a helical spline is fitted with an internal gear having a helical spline that meshes with the external gear having a helical spline. The upper edge of the lower bracket 21 is fixed to a shaft 91 having an external gear, and as the shaft 91 rotates, the lower bracket 21 swings in the axial direction of the drum 30 . A housing 93 having an internal gear that meshes with the external gear of the shaft 91 is fixed to the mounting portion 17 on the underside of the base plate 11 of the upper structure 10.

[0033] The basic operation of the helical spline mechanism is to adjust the angle of the shaft 91 by adjusting the amount of engagement between the external gear and the internal gear. Therefore, by controlling the amount of oil supplied to the helical spline mechanism with the hydraulic control unit, the angle of the lower bracket 21 can be adjusted and fixed at that position. That is, the hydraulic control unit and the helical spline mechanism constitute an angle fixing unit.

[0034] By varying the hydraulic pressure supplied to the helical spline mechanism from the hydraulic control unit and maintaining a predetermined hydraulic pressure, the helical spline mechanism changes the degree of engagement between the external gear and the internal gear in response to external force, i.e., force from the lower structure 20, and the angle of oscillation of the lower structure 20 changes. The oscillation angle of the lower structure 20 is most stable when both the reference guide 40 and the level guide 50 abut against each other. Therefore, an equal force is applied to the reference guide 40 and the level guide 50. In other words, when an external force is applied, the oscillation angle of the lower structure 20 is maintained so that a predetermined hydraulic pressure is maintained, and the circumferential surface of the drum 30 oscillates to follow the unevenness of the cutting surface, even if it exists. As a result, the impact force applied to the surface to be cut by the rotation of the drum 30 is maintained uniform.

[0035] Next, the operation of this cutting device 1 will be described with reference to FIG. The arrows in the figure indicate the direction of the force applied from the arm of the construction machine. In FIG. 16A, it is assumed that a reference surface S2 is formed in advance on a surface S1 to be cut made of concrete.

[0036] As with a general-purpose cutting device, the reference guide 40 is placed opposite the reference surface S2. In this state, when pressed in the direction of the arrow (downward on the paper), the reference guide 40 comes into contact with the reference surface S2, and the end of the drum 30 on the reference guide 40 side comes into contact with the surface S1 to be cut, causing the lower structure 20 to swing counterclockwise relative to the upper structure 10 (FIG. 16A). In Figure 16A, the level guide 50 is in a floating state. If further force is applied in the direction of the arrow from this state, the lower structure 20 will swing clockwise as shown in Figures 16B and 16C. Ultimately, as shown in Figure 16D, the reference guide 40 will abut against the reference surface S2 and the level guide 50 will abut against the surface S1 to be cut. In this state, equal forces are applied to the reference guide 40 and the level guide 50. Therefore, the drum 30 forms a plane (cutting surface S3) that is an extension of the reference surface S2.

[0037] 16, the cutting depth of the surface to be cut by this cutting device 1 is determined by the distance between the tip of the reference guide 40 and the tip of the level guide 50. In other words, by adjusting the position of the tip of the level guide 50, the cutting depth can be freely and easily controlled. Since the cutting depth can be easily controlled, cutting to a desired depth can be performed in multiple stages.

[0038] Fig. 17 is a side view of the drum 30 applied to the cutting device of Fig. 11. Fig. 18 is a development view of the outer circumferential surface of the drum 30. The details of the bits 31 in the drum 30 are shown in FIGS.

[0039] Examples of the present invention and comparative examples will be described below. Three pieces of each of two types of concrete structures (first and second) were prepared, each consisting of ready-mixed concrete, which was to be used for the cutting device. The average compressive strength of the first concrete structure (21N) was 26.6 (N / mm 2 ) and the average compressive strength of the second concrete structure of 40N is 49.2N / mm 2 The compressive strength was measured according to the JIS A 1108 compressive strength test.

[0040] Each concrete structure was chipped as follows: Chip surface No. 1: Chip using the cutting device shown in Figure 1A (hereinafter referred to as cutting chipping) Chisel surface No. 2: Chisel using a #10 breaker (hereinafter referred to as breaker chipping). Chipping surface No. 3: Chipping using the cutting device shown in Figure 1A + Chipping using the water jet method (impact head type) (hereinafter referred to as water chipping) The area of ​​chipping surface No. 1 was width: 350 mm, height: 1900 mm, and depth: 30 mm. The area of ​​chipping surface No. 3 was 280 mm wide, 1730 mm high, and 45 mm deep. Here, chipping surface No. 3 was created by first forming chipping surface No. 1, and then using a water chipping device (impact head type) from Aqua Jet Systems, water chipping was performed to a depth of 15 mm to create chipping surface No. 3. The collision head type is a type of head used in the water jet method that can limit the chipping depth by spraying and colliding water jets from two nozzles. The chipping area of ​​chipping surface No. 2 was width: 200 mm, height: 1900 mm, and depth: 30 mm. Each chipping surface is formed in a vertical strip shape on the same surface of the concrete structure.

[0041] Three core specimens were taken at approximately equal intervals from each chipping surface (No. 1 to No. 3) using a wet concrete cutter. The core specimens were then prepared into cylindrical shapes with a diameter of 150 mm and lengths of 110 to 220 mm using a specimen end grinder.

[0042] (Crack observation test) The crack condition on the chipped surface of each core specimen was observed as follows. The core specimen was immersed in epoxy resin with a fluorescent dye that fluoresces under ultraviolet light, from each exposed chipped surface, and vacuum degassing was performed before the epoxy resin hardened, forcing the epoxy resin into the cracks. After 24 hours had passed and the epoxy resin had hardened, a 75mm cubic test piece was cut out from the core specimen so that the chipped surface was exposed.

[0043] The cut surfaces of the obtained test pieces were photographed under visible light and ultraviolet light, and the obtained images were visually observed to measure the maximum crack depth in each test piece. The results are shown in Table 1.

[0044] [Table 1]

[0045] Surface No. 1, which was chipped using cutting chipping, was generally flat, but surface No. 2, which was chipped using breaker chipping, had some unevenness. Surface No. 3, which was a hybrid of cutting chipping and water chipping, had some unevenness due to the exposure of coarse aggregate. From the above, it can be seen that cutting chipping is more effective in preventing cracks on the chipped surface than breaker chipping. When comparing cutting chipping with cutting + water chipping, it is clear that the crack depth in the latter is smaller, but according to the inventor's observations, the fluorescent area in the latter was larger than that of the former when observed under ultraviolet light.

[0046] (Additional concrete test) On chipping surfaces No. 1 to No. 3, additional concrete (new concrete) was poured into the areas of the core specimen where no holes had been cut, and the integrity of each chipping surface was tested. Furthermore, as a hybrid method, chipping surface No. 4 was created in the same way as chipping surface No. 3. The area of ​​chipping surface No. 4 was 280 mm wide, 1730 mm high, and 45 mm deep. Here, chipping surface No. 4 was created by first forming chipping surface No. 1, and then using a water treatment device (rotary lance type) from Aqua Jet Systems, Inc., to perform surface treatment on chipping surface No. 1. The rotary lance type is a method in which high-pressure water is sprayed from each of a rotating head equipped with multiple nozzles. Each chipped surface is washed with water to prevent drying out, and after the chipped surface has dried, a standard amount (100-200g / m) of acrylic resin primer (product name Refretreat) is applied to it. 2 ) was applied.

[0047] For the additional concrete, 24N concrete was used for the 21N structural concrete, and 42N concrete was used for the 40N structural concrete. This was to ensure that the additional concrete did not have a lower compressive strength than the structural concrete. The curing period for the additional concrete was 55 days. After curing, five core specimens were taken from the additionally poured areas on each chipped surface using a wet concrete cutter. The core specimens were cut to a diameter of 100 mm and a length of 100 mm using a specimen edge grinder. The width of the core specimens was adjusted so that the width of the main concrete and the additionally poured concrete was 50 mm:50 mm. A schematic diagram of such a test piece is shown in FIG.

[0048] To check the adhesion between the concrete structure and the additional concrete, NEXCO Test Method 422 "Adhesion Performance Test Method" (Tensile adhesive strength standard value: 1.50 N / mm 2 ) and the loading rate is 0.06±0.04N / mm per second. 2 The tensile adhesion test was carried out under the following conditions. The results are shown in Table 2.

[0049] [Table 2] The results in Table 2 show that the adhesion of the additional concrete to the hybrid cutting-water chipping surfaces No. 3 and No. 4 was high, with the highest adhesion being on the water-treated chipping surface No. 4, followed by the cutting-water chipping surface No. 1 and the breaker chipping surface No. 2.

[0050] Furthermore, the chipped surface No. 1 formed using the cutting device of this invention also met the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method": 1.50 N / mm 2 Compared to the previous example, it has a high adhesive strength. It is believed that by performing surface treatment on the chipped surface using a water treatment device with a rotary lance-type head, weak parts on the chipped surface can be efficiently removed.

[0051] (Noise test) The concrete structure was placed flat and the noise levels were measured when chipping was performed using the cutting device of the embodiment shown in Figure 1A, the general-purpose cutting device shown in Figure 1B, and a #10 breaker. The measurement method was in accordance with JIS A 8317-1 "Earth-moving machinery - Determination of sound power levels - Dynamic test conditions." The results are shown in Table 3.

[0052] [Table 3] The results in Table 3 show that the noise level of cutting chipping is lower than that of breaker chipping, and when the cutting device of this embodiment shown in Figure 1A is used, the noise level is lower than that of the general-purpose cutting device shown in Figure 1B.

[0053] (A) The tensile strength of the repaired concrete structure obtained by the repair method of concrete structure specified in any of claims 20 to 24 is greater than the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." Here, the repaired concrete structure refers to a joint of two types of concrete formed by pouring additional concrete on the chipped surface of the concrete structure. (B) The tensile strength of the repaired concrete structure obtained by the method for repairing concrete structure specified in original claim 20 is 120 to 145% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." (C) The tensile strength of the repaired concrete structure obtained by the method for repairing concrete structure specified in original claim 22 is 130 to 180% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." (D) The tensile strength of the repaired concrete structure obtained by the method for repairing concrete structure originally specified in claim 23 is 190 to 260% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." (E) Repaired concrete structure having a tensile strength of 120 to 145% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." (F) Repaired concrete structure with a tensile strength of 130 to 180% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method." (G) Repaired concrete structure with a tensile strength of 190 to 260% of the standard value of NEXCO Test Method 422 "Adhesion Performance Test Method."

[0054] The present invention is not limited to the above-described embodiments and examples, and various modifications within the scope of the claims and within the scope that can be easily conceived by a person skilled in the art are also included in the present invention.

[0055] (1) drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for a construction machine; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: Assuming that the width of the drum is 350 mm, the cutting device is such that the tip of the bit forms a locus of 40 to 60 lines, preferably 45 to 55 lines, within this width in the direction of rotation of the drum. (2) The cutting device according to (1), wherein, assuming that the length of the outer peripheral surface of the drum is approximately 1380 mm, the number of bits arranged in the rotation direction is 25 to 33, preferably 27 to 31. (3) The cutting device described in (1), wherein four to five of the bits are arranged in the width direction of the drum, and the tips of adjacent bits in the width direction are aligned on an imaginary straight line in the width direction of the drum. (4) The cutting device described in (3), wherein the tip of the bit arranged in a first width direction of the drum intersects, in the radial direction of the drum, with the base of the bit arranged in a second width direction preceding the rotation direction of the drum. (5) The cutting device according to (5), wherein the distance between the tip of the bit arranged in the first width direction and the tip of the bit arranged in the second width direction is 55 to 60 mm. (6) The cutting device according to (1), wherein there is a bit with its tip facing in the direction of rotation of the drum, and the bit is positioned on the center line of the trajectory formed by the tip. (7) drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: A cutting device in which 1.50 to 2.50 bits, preferably 1.90 to 2.30 bits, are arranged per 100 mm square on the outer peripheral surface of the drum. (8) The cutting device described in (1), wherein the pressure adjustment unit includes a tilt mechanism that connects the lower bracket and the upper bracket, and the tilt mechanism causes the lower bracket to swing relative to the upper bracket in the axial direction of the drum. (9) The tilt mechanism is configured by engaging an external gear having a helical spline with an internal gear having a helical spline that meshes with the external gear, and the amount of engagement between the external gear and the internal gear changes in response to an external force. (8) A cutting device according to the above. (10) The cutting device according to (8), wherein the distance between the tip of the reference guide and / or the level guide and the axis of the drum is variable. (11) The cutting device according to (8), wherein the pressure adjusting unit further includes an angle fixing unit that fixes the angle of the lower bracket relative to the upper bracket. (12) A cutting device as described in (8), wherein a roller is attached to the reference guide and / or the level guide, and the roller is attached to the reference guide and / or the level guide via an attitude maintaining unit, so that the roller is perpendicular to the contact surface. (13) The cutting device according to (12), wherein the attitude maintaining unit is a spherical guide. (14) A construction machine having an arm to which the cutting device according to any one of (1) to (13) is attached. (15) A method for forming a flat surface, which uses the cutting device according to any one of (1) to (13) to cut a concrete structure to be cut to a target depth to form a chipped surface. (16) A first step of cutting the concrete structure to a first depth using a general-purpose cutting device; A method for forming a chipped surface, comprising cutting the surface exposed in the first step to a target depth using the cutting device according to any one of (1) to (13) to form a chipped surface. (17) A first step of cutting a concrete structure to be cut to a second depth using the cutting device according to any one of (1) to (13); A method for forming a chipped surface, in which the surface exposed in the first step is cut to the target depth using a water jet method (impact head type) to form a chipped surface. (18) A first step of cutting a concrete structure to be cut to a target depth using the cutting device according to any one of (1) to (13); A method for forming a chipped surface, in which the surface exposed in the first step is surface treated using a water jet method (rotary lance type) to form a chipped surface. (19) A method of forming a chipped surface in which the final process of the chipped surface is surface treatment using a water jet method (rotary lance type). (20) A method for repairing concrete structure, comprising pouring additional concrete onto the chipped surface formed by the chipped surface forming method described in (15). (twenty one) A method for repairing concrete structure, comprising pouring additional concrete onto the chipped surface formed by the chipped surface forming method described in (16). (twenty two) A method for repairing concrete structure, comprising pouring additional concrete onto the chipped surface formed by the chipped surface forming method described in (17). (twenty three) A method for repairing concrete structure, comprising pouring additional concrete onto the chipped surface formed by the chipped surface forming method described in (18). (twenty four) A method for repairing concrete structure, comprising pouring additional concrete onto the chipped surface formed by the chipped surface forming method described in (19). (twenty five) drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A drum used in a cutting device, comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; When the width of the drum is 350 mm, the tip of the bit forms a locus of 40 to 60 lines, preferably 45 to 55 lines, in the direction of rotation of the drum within this width. (26) The drum described in (25) has four to five bits arranged in the width direction of the drum, and the tips of adjacent bits in the width direction are aligned on an imaginary straight line in the width direction of the drum. (27) The drum according to (25), wherein the tip of the bit arranged in a first width direction of the drum intersects, in the radial direction of the drum, the base of the bit arranged in a second width direction preceding the rotation direction of the drum. (28) The drum according to (27), wherein the distance between the tip of the bit arranged in the first width direction and the tip of the bit arranged in the second width direction is 55 to 60 mm. (29) The drum according to (25), wherein a bit is present with its tip pointing in the direction of rotation of the drum, and the bit is positioned on the center line of the trajectory generated by the tip. [Explanation of symbols]

[0056] 1 Cutting equipment 10 Superstructure 20 Undercarriage 21 Lower bracket 30 drums 31-bit 40 Reference Guide 50 Level Guide 90 Power tilt section 91 axes 100 Construction Machinery 101 Arm

Claims

1. A method for pouring additional concrete into a concrete structure, A method for applying additional concrete to a concrete structure, the method comprising a cutting and chipping step and an additional application step, and providing a tensile strength equal to or greater than the standard value of the tensile adhesive strength of NEXCO Test Method 422 "Adhesion Performance Test Method" between the concrete structure and the additional application step, The cutting and chipping step uses the following cutting device to cut the concrete structure to a target depth to form a chipping surface, In the additional pouring method, the additional pouring step pours additional concrete onto the chipping surface, The cutting device is drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: When the width of the drum is 350 mm, the tip of the bit forms a 40 to 60 line locus in the direction of rotation of the drum.

2. The method further includes a step of performing a water surface treatment using a rotary head on the chipped surface formed in the cutting and chipping step, 2. The method for pouring concrete according to claim 1, wherein the step of pouring concrete comprises pouring the poured concrete onto the chipped surface that has been subjected to water surface treatment.

3. A chipping method for forming a chipping surface by cutting the surface of a concrete structure before adding additional concrete to the concrete structure, A chipping method in which the average crack depth of the chipped surface is 7.2 mm or less, The chipping method includes cutting the concrete structure to a target depth using the following cutting device to form the chipping surface. The cutting device is drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: A chipping method in which, when the width of the drum is 350 mm, the tip of the bit forms a 40 to 60 line locus within this width in the direction of rotation of the drum.

4. 4. The chipping method according to claim 3, further comprising the step of subjecting the chipped surface to a water surface treatment using a rotary head.

5. A method for manufacturing a chipped surface formed by cutting the surface of a concrete structure before adding additional concrete to the concrete structure, In a method for manufacturing a chipped surface, the concrete structure is cut to a target depth using the following cutting device, and the average crack depth is 7.2 mm or less. The cutting device is drum, a reference guide and a level guide arranged to sandwich the drum in its axial direction, the reference guide and the level guide arranged perpendicular to the axis of the drum, wherein the tip of the reference guide is at the same level as the tip of the drum bit, and the tip of the level guide is located closer to the axis of the drum than the drum bit; a lower bracket for holding the drum, the reference guide, and the level guide; An upper bracket attached to an arm for construction machinery; A cutting device comprising: a pressure adjusting unit that connects the lower bracket and the upper bracket and applies a force from the arm of the construction machine evenly to the reference guide and the level guide; The bits are arranged on the drum as follows: When the width of the drum is 350 mm, the tip of the bit forms 40 to 60 line loci within this width in the direction of rotation of the drum.

6. The method for manufacturing a chipped surface according to claim 5, further comprising the step of: subjecting the chipped surface formed by the cutting device to a water surface treatment using a rotary head.

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