Cutting device

Abstract

When chipping away at structural concrete using mechanical cutting equipment, cracks appear on the chipped surface. Therefore, conventionally, water chipping was performed after mechanical chipping. To avoid the effects of cracks caused by mechanical chipping, it was necessary to increase the depth of the water chipping. [Solution] We found that cracking of the chipped surface can be suppressed by making the bits of the drum constituting the cutting device smaller than general-purpose bits and arranging them densely. Here, when the width of the drum is set to 350 mm, the number of lines formed by the bits is set to 40 to 60 lines. Using such a cutting bit, only small cracks similar to those produced by water chipping occur on the chipped surface, and when additional concrete is poured onto such a chipped surface, sufficient tensile strength is obtained between the structural concrete and the additional concrete.

Claims

1. This is a method of adding concrete to the structural concrete, A concrete pouring method comprising a cutting and chipping step and a concrete pouring step, which imparts a tensile strength between the structural concrete and the previously poured concrete equal to or greater than the standard value of tensile adhesive strength of NEXCO Test Method 422 "Adhesion Performance Test Method", The aforementioned cutting and chipping step uses the following cutting device to cut the structural concrete to the target depth and form a chipped surface. The aforementioned additional concrete pouring step is an additional concrete pouring method in which additional concrete is poured onto the chipped surface, The cutting device is drum, A reference guide and a level guide are arranged to sandwich the drum in its axial direction, wherein the reference guide and the level guide are arranged perpendicular to the axis of the drum, the tip of the reference guide is at the same level as the tip of the bit of the drum, and the tip of the level guide is located closer to the axis of the drum than the bit of the drum. The drum, the reference guide and the lower bracket that holds the level guide, Upper bracket to be attached to the arm of construction machinery, and A cutting device comprising a pressure adjustment unit that connects the lower bracket and the upper bracket, and which ensures that the force from the arm of the construction machine is applied evenly to the reference guide and the level guide, The bits are arranged on the drum as follows: A method for increasing the number of drilling strokes, wherein, when the width of the drum is set to 350 mm, the tip of the bit forms 40 to 60 line trajectories in the direction of rotation of the drum within this width.

2. The system further includes a step of performing water chipping of 7.2 mm to 15 mm using a collision head on the chipped surface formed in the aforementioned cutting and chipping step. The additional concrete pouring method according to claim 1, wherein the additional pouring step involves pouring the additional concrete onto the chipped surface formed by the water chipping.

3. The system further includes a step of performing a water surface treatment using a rotating head on the chipped surface formed in the cutting and chipping step, The method for adding concrete according to claim 1, wherein the additional concrete-adding step involves pouring the additional concrete onto the water-surface-treated chipped surface.

4. The method for adding concrete according to any one of claims 1 to 3, wherein, before the cutting and chipping step, the structural concrete is cut to a first depth with a general-purpose cutting device, and the structural concrete is cut to the target depth in the cutting step.

5. A chipping method for forming a chipped surface by cutting the surface of the structural concrete before pouring additional concrete onto the structural concrete, A chipping method that sets the average crack depth of the chipped surface to 7.2 mm or less, The chipping method involves using the following cutting device to cut the structural concrete to a target depth and form the chipped surface. The cutting device is drum, A reference guide and a level guide are arranged to sandwich the drum in its axial direction, wherein the reference guide and the level guide are arranged perpendicular to the axis of the drum, the tip of the reference guide is at the same level as the tip of the bit of the drum, and the tip of the level guide is located closer to the axis of the drum than the bit of the drum. The drum, the reference guide and the lower bracket that holds the level guide, Upper bracket to be attached to the arm of construction machinery, and A cutting device comprising a pressure adjustment unit that connects the lower bracket and the upper bracket, and which ensures that the force from the arm of the construction machine is applied 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 set to 350 mm, the tip of the bit forms 40 to 60 line trajectories in the direction of rotation of the drum within this width.

6. The chipping method according to claim 5, further comprising performing water chipping of 7.2 mm to 15 mm using a collision head on the chipped surface.

7. The chipping method according to claim 6, wherein a water surface treatment using a rotating head is performed on the chipped surface.

8. A chipping method according to any one of claims 5 to 7, wherein, before cutting with the aforementioned cutting device, the structural concrete is cut to a first depth with a general-purpose cutting device, and the structural concrete is cut to a target depth with the aforementioned cutting device.

9. A repair body for structural concrete manufactured using the concrete pouring method described in any one of claims 1 to 3.

10. A repaired structural concrete body manufactured using the additional concrete pouring method described in claim 4.

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