A non-supporting disassembling process for reinforced concrete buildings

Abstract

The application discloses a reinforced concrete building disassembling process without support, floor is sawed into strips and blocks according to specific support structure conditions, an angle grinder is used for straight seam cutting, a beam is sawed without support by adopting an end "H" shaped section, and a column is sawed along a horizontal plane from a column foot; the application does not need any support, all cutting surfaces are flat, reduces construction waste, saves secondary steel bar bundling and high-grade concrete pouring during later assembling, and saves processes and cost.

Description

Technical Field

[0001] This invention relates to concrete buildings, and more particularly to the field of dismantling and recycling of concrete frame structures. Background Technology

[0002] According to incomplete statistics, my country currently has over 50 billion square meters of multi-story and high-rise reinforced concrete residential buildings. The vast majority of modern buildings utilize cast-in-place monolithic reinforced concrete structures, constructed using formwork, rebar tying, and cast-in-place methods, with interconnected column, beam, and slab reinforcement, hardened into a solid whole by concrete pouring. A smaller portion uses prefabricated assembly methods, essentially "equivalent to cast-in-place," to create monolithic structures. When a building structure is damaged or needs to be demolished for other reasons, it must be dismantled. Current demolition methods mainly include blasting or demolition. However, due to the already dense urban construction, the blasting, demolition, or natural collapse of a building can have significant adverse impacts on neighboring buildings and other facilities outside the building's boundary line, causing serious social problems. Therefore, it is necessary to develop demolition methods within the building's boundary line that are harmless to the surrounding area. Furthermore, the recycling of construction waste is too costly, has low utilization rates, and produces high-strength concrete with poor mechanical and durability properties.

[0003] Chinese patent CN109797971A discloses a method for disassembling and assembling cast-in-place reinforced concrete frame structure building components. The frame structure is decomposed into transverse frames, longitudinal connecting beams, secondary beams, and floor slabs, which are the main load-bearing components. Disassembly is performed layer by layer from top to bottom, with the disassembly sequence for each structural layer being floor slabs, secondary beams, longitudinal connecting beams, and transverse frames. For floor slab removal, a disassembly zone is marked around the perimeter of the floor slab. The concrete within the disassembly zone is broken and removed, and the reinforcing bars are cut in the middle of the disassembly zone, leaving burrs around the perimeter of the floor slab and surrounding beams for reassembly. The drawbacks of this method are: firstly, it requires supports for the disassembled components, consuming time and a large number of support components; secondly, the need to leave burrs around the edges of the disassembled components necessitates secondary reinforcement binding during reuse and splicing, and the need to pour concrete with a strength grade higher than the original structural components at the splicing points, significantly increasing construction costs. Summary of the Invention

[0004] The purpose of this invention is to provide a process for dismantling reinforced concrete buildings by dismantling reinforced concrete floor slabs, beams, and columns into recyclable components without the need for supports.

[0005] To achieve the above objectives, this invention provides a non-supporting dismantling process for existing reinforced concrete buildings, which involves dismantling the building layer by layer from top to bottom in the order of slabs, beams, and columns, wherein:

[0006] 1) The floor slabs are cut into strips according to the specific support structure conditions. A straight cut is made using an angle grinder. Temporary hanging supports are provided throughout the cutting process, and the cut slabs are transported out of the building at any time.

[0007] 2) When dismantling the beam, retain the beam head that is shorter at the top and longer at the bottom at both ends of the columns. Corresponding to the beam head, the two ends of the beam are longer at the top and shorter at the bottom. First, drill holes at both ends of the horizontal section of the beam head and beam end, and then cut a horizontal seam with a wire saw. Then cut the vertical seams on the top and bottom sides. The cut beam will still be stably supported in its original position, and then it will be lifted and transported out of the building.

[0008] 3) The column is cut along the horizontal plane from the column base to become a floor column segment. Temporary support should be provided when cutting the column to prevent collapse. The removed column should be hoisted out of the building in a timely manner.

[0009] 4) Inspect and repair the dismantled building components for recycling.

[0010] After cutting a horizontal joint in the beam, insert steel strips of the same thickness as the joint width to fill and support the joint.

[0011] During the cutting process, steel strips of the same thickness are continuously inserted into the horizontal saw kerf to ensure that the cut column remains upright.

[0012] This invention involves disassembling from top to bottom. Since the floor slabs and columns are straight cuts, only simple temporary supports are needed for hoisting them out of the building, reducing a significant amount of support procedures and costs. The beams are cut using a method that requires no support. Furthermore, all the cut surfaces in this invention are straight, reducing the construction waste generated by leaving burrs on the reinforcing bars as in the prior art. This invention allows the components to be assembled like a steel structure building by welding steel plates with screw holes onto the straight cut surfaces, eliminating the need for secondary reinforcing bar binding and high-grade concrete pouring during later assembly, thus saving on procedures and costs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the disassembly of the floor slab, beam, and column of the present invention;

[0014] Figure 2 This is a schematic diagram of the floor slab cutting process according to the present invention;

[0015] Figure 3 This is a schematic diagram of the cutting of the cantilever slab of the present invention;

[0016] Figure 4 This is a schematic diagram of beam cutting according to the present invention;

[0017] Figure 5 This is a schematic diagram of the beam component of the present invention.

[0018] Label Explanation:

[0019] 1. Column; 2. Beam; 21. Beam cut; 211. Beam drilled hole; 212. Horizontal joint; 213. Upper vertical joint; 214. Lower vertical joint; 3. Floor slab; 31. Floor slab cut joint; 32. Cantilever slab cut joint. Detailed Implementation

[0020] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0021] Please see Figure 1 This invention employs 1) disassembly from top to bottom, layer by layer; 2) the floor slab is cut into strips according to the specific supporting structural conditions, such as... Figure 2 , 3 As shown, temporary hanging supports (not shown in the figure) are provided throughout the cutting process of floor slab 3. The vertical cutting seam 31 on the edge of the slab is located 100mm to 200mm inside the inner skin of the beam around the floor slab; for cantilever slabs, the vertical cutting seam is located at the top of the beam to which it is rooted. The cut slabs are transported out of the building at any time. The floor slabs are cut with a straight seam using an angle grinder. Figure 4 , 5 Beam 2 employs an end-cut "U"-shaped cross-section without support. First, a hole 211 is drilled in the waist section of the pre-cut beam end, then a horizontal slit 212 is cut using a wire saw. A steel strip of the same thickness and width as the slit is inserted and filled in. Then, vertical slits 213 and 214 are cut on the upper and lower sides. The cut beam remains stably supported in its original position, allowing for hoisting and transport out of the building. The upper vertical cut surface of the frame beam is 600–1000 mm outside the column skin; the lower vertical cut surface is 800–1400 mm outside the column skin; the horizontal simply supported surface at the beam end is 200–400 mm long, located at or near the center of the beam section height (half the beam height). Columns are cut horizontally from the column base to form floor column segments. During the cutting process, steel strips of the same thickness are continuously filled into the horizontal slits to ensure the cut columns remain upright. Temporary supports should be provided during column cutting to prevent collapse. Removed columns should be hoisted out of the building promptly. 3) The cut components, after necessary repair, can be recycled as finished concrete components or stored for reuse (see the applicant's application No. 202410227339.9 filed on February 29, 2024, concerning prefabricated reinforced concrete columns, beams, and slabs (publication date June 18, 2024)). 4) This invention generates very little construction waste, minimizing solid waste emissions.

[0022] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for dismantling existing reinforced concrete buildings without supports, wherein the building is dismantled layer by layer from top to bottom in the order of slabs, beams, and columns, characterized in that: 1) The floor slabs are cut into strips according to the specific support structure conditions. A straight cut is made using an angle grinder. Temporary hanging supports are provided throughout the cutting process, and the cut slabs are transported out of the building at any time. 2) When dismantling the beam, retain the beam head that is shorter at the top and longer at the bottom at both ends of the columns. Corresponding to the beam head, the two ends of the beam are longer at the top and shorter at the bottom. First, drill holes at both ends of the horizontal section of the beam head and beam end, and then cut a horizontal seam with a wire saw. Then cut the vertical seams on the top and bottom sides. The cut beam will still be stably supported in its original position, and then it will be lifted and transported out of the building. 3) The column is cut along the horizontal plane from the column base to become a floor column segment. Temporary support should be provided when cutting the column to prevent collapse. The removed column should be hoisted out of the building in a timely manner. 4) Inspect and repair the dismantled building components for recycling.

2. The unsupported dismantling process for existing reinforced concrete buildings as described in claim 1, characterized in that: After cutting a horizontal joint in the beam, insert steel strips of the same thickness as the joint width to fill and support the joint.

3. The unsupported dismantling process for existing reinforced concrete buildings as described in claim 1, characterized in that: During the cutting process, steel strips of the same thickness are continuously inserted into the horizontal saw kerf to ensure that the cut column remains upright.

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