Demolition method for reinforced concrete structures

Abstract

To provide a method capable of efficiently demolishing a reinforced concrete skeleton by high strength concrete by using a kinetic crushing agent.SOLUTION: A demolition method of a reinforced concrete skeleton in which a member constituting the reinforced concrete skeleton uses high strength concrete with at least 60 N / mm2 of a design reference strength includes: a step S01 of forming a plurality of charge holes in the member; a step S02 of loading a kinetic crushing agent in the charge hole; a step S06 of crushing the member by igniting the kinetic crushing agent; and a step S07 of further crushing the crushed member by a demolishing heavy machine.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for demolishing a reinforced concrete (RC) structure made of high-strength concrete. [Background technology]

[0002] In Japan, the general method of demolishing buildings is to place heavy demolition machinery on the top floor, break up and crush the building structure starting from the upper floors, and then drop and transport debris and waste materials to the lower floors. Although this may vary depending on the structural type and size of the building, demolition from the top using specialized machinery is the norm. Meanwhile, overseas, explosive blasting demolition is actively used in cities, even in relatively narrow urban areas. As is well known, the use of explosives in cities in Japan is strictly controlled, and there are only a few cases where explosives have been used to demolish basement parts of buildings, and even in such cases, strict licensing systems must be followed.

[0003] On the other hand, although the heating and crushing power is not as great as that of explosives, several types of non-explosive dynamic crushing agents that generate gas pressure close to the speed of sound and can instantly break concrete have been published in Japan in recent years and are used for pile head treatment in foundation construction.

[0004] The main demolition methods used to date are as follows: (1) Crushing method using heavy demolition machinery Demolition using heavy demolition machinery involves breaking up the concrete with a crusher and cutting the reinforcing bars with a cutter, thereby breaking the reinforced concrete structure into smaller pieces (see Patent Document 1). (2) Explosives-based crushing method Mini-blasting, a method for demolishing reinforced concrete structures, uses a small amount of high explosives. This method is used to insert small-caliber high explosives into small holes to crush specific parts of the structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-97306 A [Patent Document 2] JP 2015-129407 A Summary of the Invention [Problem to be solved by the invention]

[0006] Since the 1990s, the strength of concrete has increased dramatically, and in recent years, the actual strength of concrete has reached 200N / mm 2 Since the current demolition equipment will be more difficult to use when these buildings are renovated in the future, new demolition methods are needed.

[0007] For example, in one undisclosed case, after construction of three underground floors, a non-explosive dynamic demolition agent was used to crush the foundation beams measuring 700mm wide x 2,100mm high, and the foundation measuring 2,000mm wide x 1,200mm high, all at once, and the small pieces of the structure were dismantled using a demolition machine. In this case, the design standard strength was 60N / mm 2 The actual strength of concrete is 80N / mm 2 Since the explosives exceeded the limit, the attachments of the demolition heavy machinery could not crush the concrete structure, so a dynamic demolition agent was applied before the demolition heavy machinery was used. Since a non-explosive dynamic demolition agent was used, no notification to the relevant authorities was required.

[0008] Patent Document 2 discloses a method for crushing thin components of a structure using a dynamic crushing agent, but the objects to be crushed are thin components such as walls or floor slabs of reinforced concrete building structures, and not the main bodies such as reinforced concrete columns, foundations, and beams.

[0009] Design standard strength 36N / mm 2 High-strength concrete exceeding 60N / mm has been certified by the Minister due to the revision of the Building Standards Act in 2000. 2 Since the range of strength specified by the JIS is now less than 60N / mm, the Minister's certification targets are generally those with a design standard strength of 60N / mm2 The majority of buildings fall under this category, and for example, high-rise buildings with 35 or more floors and a height of 100 m or more are considered to fall under this category. On the other hand, the design standard strength of 60 N / mm 2 There is still some time before the buildings that use the above-mentioned high-strength concrete will reach the end of their useful life and become subject to demolition and reconstruction, but it is inevitable that such a time will come eventually.

[0010] In view of the problems of the prior art as described above, the present invention aims to provide a construction method capable of efficiently demolishing a reinforced concrete structure made of high-strength concrete by using a dynamic demolition agent. [Means for solving the problem]

[0011] The method for demolishing a reinforced concrete structure to achieve the above object is a method for demolishing a reinforced concrete structure, in which the members constituting the reinforced concrete structure are made of high-strength concrete having a design standard strength of at least 60 N / mm2, forming a plurality of charge holes in the member; loading a kinetic demolition agent into the charge holes; and igniting the kinetic demolition agent to demolition the member. So that it can be grasped and crushed by heavy demolition machinery Crushing Fragmentation and removing the crushed member. The above Further crushing by heavy demolition machinery And further fragmentation and

[0012] According to this method for dismantling reinforced concrete structures, multiple charge holes are formed in the members of the structure, dynamic demolition agents are loaded into each charge hole, and the members are crushed by ignition of the dynamic demolition agents, and then further crushed by demolition heavy machinery. 2 Even if the components made of the above-mentioned high-strength concrete cannot be crushed by the demolition heavy machinery alone, if they are crushed in advance with a dynamic crushing agent, they can be further crushed by the demolition heavy machinery, making it possible to efficiently crush and demolish reinforced concrete structures made of high-strength concrete.

[0013] In the above-mentioned method for dismantling a reinforced concrete structure, the members are a rising foundation and a beam. It is preferable that the charge holes in the beam are formed at the ends and middle parts of the beam. It is also preferable that the foundation has an enlarged portion larger than the width of the beam, and the charge holes in the foundation are formed vertically from the upper surface of the enlarged portion.

[0014] In addition, in the crushing step using the dynamic crushing agent, the member is crushed so as to be able to be grasped and crushed by the demolition heavy machinery. To fragment .

[0015] It is also preferable to connect in series the lead wires from the ignition devices of each dynamic demolition agent loaded in the end and middle parts of the beam and in each charging hole in the foundation, and to ignite and demolition each dynamic demolition agent almost simultaneously by remote control. Effect of the Invention

[0016] According to the method for demolishing a reinforced concrete structure of the present invention, a reinforced concrete structure made of high-strength concrete can be efficiently demolished by using a dynamic demolition agent. [Brief description of the drawings]

[0017] [Figure 1] 1 is a flowchart for explaining each process of a demolition method for a reinforced concrete structure using high-strength concrete according to the present embodiment. [Diagram 2] This is a top view of the main parts of the foundation and beams of a reinforced concrete structure made of high-strength concrete, which is the subject of demolition in this embodiment, and shows the planar positions of the charge holes to be formed in the foundation and beams. [Diagram 3] 3A is a view of the inside of the foundation and beam in Figure 2 as seen from the direction of the arrow A, and FIG. 3B is a view as seen from the direction of the arrow B. [Figure 4] FIG. 4 is a diagram showing specific examples of dimensions of the charge holes, foundations, and beams in FIGS. 2 and 3. [Diagram 5]4(a) to (c) show the state in which dynamic fracturing agents and the like are loaded into each of the charging holes in FIG. 2 and FIG. 3. [Figure 6] FIG. 2 is a diagram illustrating the state of gripping and crushing by the demolition heavy machinery in step S07 of FIG. 1. [Figure 7] Photograph (a) shows the foundation and beam end crushed by dynamic demolition agent in this example, and photograph (b) shows the center of the beam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart for explaining each step S01 to S07 of the demolition method of a reinforced concrete structure using high-strength concrete according to this embodiment. FIG. 2 is a top view of the main part of the foundation and beam of the reinforced concrete structure using high-strength concrete, which is the object of demolition in this embodiment, and shows the planar positions of the charge holes formed in the foundation and beam. FIG. 3 is a view (a) of the inside of the foundation and beam in FIG. 2 as seen from the direction of the arrow A, and a view (b) of the inside of the foundation and beam as seen from the direction of the arrow B. FIG. 4 is a view showing a specific example of the dimensions of the charge holes and the foundation and beam in FIG. 2 and FIG. 3. FIG. 5 is a view (a) to (c) showing the state in which the charge holes in FIG. 2 and FIG. 3 are charged with dynamic demolition agents, etc. FIG. 6 is a view showing the gripping and crushing by the demolition heavy machinery in step S07 in FIG. 1.

[0019] The method for demolishing reinforced concrete structures according to this embodiment uses a non-explosive dynamic demolition agent, and is designed to achieve a standard strength of 60 N / mm 2 This method involves first crushing the reinforced concrete structure made of the above-mentioned high-strength concrete, then using large demolition machinery to grasp and crush the structure, and finally completely dismantling the structure.

[0020] In FIG. 2, the parts to be demolished are the rising foundations F1-F4, the X-beams G11, G12, G21, and G22 in the X direction on the first basement floor, the Y-beams G31, G32, G41, and G42 in the Y direction, and the planar slabs SL between each beam. In the foundations F1-F4, the X-beams and the Y-beams intersect to form intersections 31-34. In the intersection 31, the Y-beam G31 penetrates, and as shown in FIG. 3(a), the lower part of the Y-beam G31 fits into the foundation F1. In addition, in the intersection 32, the X-beam G12 penetrates, and as shown in FIG. 3(b), the lower part of the X-beam G12 fits into the foundation F2.

[0021] First, the formation of the charging hole for loading the dynamic fracturing agent will be described with reference to Figures 2 and 3. A plurality of charging holes 51-62 and a plurality of charging holes 71-82 are formed around the bases F1 and F2, respectively. The bases F1 and F2 have enlarged portions 11a and 12a protruding from the intersections 31 and 32 of the X-beam and the Y-beam, and the charging holes 51, 54, 57, and 60 are drilled vertically from the upper surface of the enlarged portion 11a, and the charging holes 71, 74, 77, and 80 are drilled vertically from the upper surface of the enlarged portion 12a.

[0022] 2, around the foundation F1, the charging holes 52, 53 are drilled vertically at the end of the intersection 31 side of the X beam G11, and the charging holes 58, 59 are drilled vertically at the end of the intersection 31 side of the X beam G12. Also, the charging holes 61, 62 and the charging holes 55, 56 are drilled vertically at the positions corresponding to the beam ends of the intersection 31 of the Y beam G31. The charging holes 52, 53, 58, 59 at each end of the intersection 31 side of the X beams G11, G12 are formed by penetrating the slab SL at the top of the beam.

[0023] Additionally, around the periphery of the foundation F2, charging holes 81, 82 are drilled vertically at the intersection 32 side end of the Y beam G41, and charging holes 75, 76 are drilled vertically at the intersection 32 side end of the Y beam G42. Additionally, charging holes 72, 73 and similarly charging holes 78, 79 are drilled vertically at positions corresponding to the beam ends of the intersection 32 of the X beam G12. The charging holes 75, 76, 81, 82 at each end of the intersection 32 side of the Y beams G41, G42 are formed penetrating the slab SL at the top of the beams.

[0024] In addition, the charging holes 63, 64 are drilled vertically in the center of the X beam G12 between the intersections 31, 32 so as to line up in the direction Y. The charging holes 83, 84 are drilled vertically in the center of the Y beam G42 between the intersections 32, 34 so as to line up in the direction X. In addition, the charging holes 85, 86 are drilled vertically in the center of the Y beam G31 between the intersections 31, 33 so as to line up in the direction X. The charging holes 63, 64, 83, 84, 85, 86 in the center of the beam are formed by penetrating the slab SL at the top of each beam. In addition, a plurality of charging holes are formed in the foundations F3, F4 and the X beam G21 of FIG. 2 in the same manner as described above.

[0025] In addition, the interval between a pair of charge holes provided at the end and center of each beam, for example, the interval between the charge holes 52, 53 of the X beam G11 and the charge holes 58, 59 of the X beam G12, is preferably 1 / 2 the beam width (350 mm for a beam width of 700 mm, 450 mm for a beam width of 900 mm) and both charge holes are preferably arranged at equal distances from both ends of the beam width. Note that the above interval is an initial guideline, and may be changed to an appropriate position by repeatedly performing crushing.

[0026] 3(a)(b) and 4 show specific examples of the diameter and length of the charge holes, the dimensions of the foundations and beams, etc. The diameter of the charge holes 51-64, 71-86 is 40 mm, the length of the charge holes 51, 54, 57, 60, 71, 74, 77, 80 of the enlarged parts 11a and 12a of the foundations F1 and F2 is 800 mm, the length of the charge holes 52, 53, 58, 59, 72, 73, 78, 79 of the X beams G11 and G12 is 1700 mm, and the length of the charge holes 61, 62, 55, 56, 81, 82, 75, 76 of the Y beams G31, G41, and G42 is 1200 mm, but each hole length is about 2 / 3 of the height of the foundation and the beam depth. The dimensions shown in Figures 3(a)(b) and 4 are merely examples and may be changed as necessary. The diameter of the charge hole is 40 mm, which is in accordance with the cartridge diameter of the dynamic crushing agent, so the hole length is set according to the number of cartridges to be used depending on the crushing target range.

[0027] As shown in Fig. 5(a), in the 800 mm long charge hole 51, 71 in Fig. 4, a dynamic demolition agent (non-explosive demolition agent) 91 is loaded in the deepest part, clay 96 of about 30 mm thickness is filled on top of it to seal the top of the dynamic demolition agent 91, and mortar material 94 is filled using a void material as a form. In the 1200 mm long charge hole 55, 75 in Fig. 5(b), a dynamic demolition agent 91 is loaded in the deepest part, sand or other filler 95 is filled on top of it, then a dynamic demolition agent 92 is loaded, and mortar material 94 is filled on top of it via clay 96 for sealing. In the charging hole 52, 72 with a hole length of 1700 mm in Fig. 5 (c), the dynamic demolition agent 91 is loaded at the deepest part, and then the sand or other filler 95 is filled on top of it, and then the dynamic demolition agent 92 is loaded, and then the filler 95 is filled on top of that, and then the dynamic demolition agent 93 is loaded, and then the mortar material 94 is filled on top of that through the sealing clay 96. The dynamic demolition agents 91 to 93 are composed of cartridges, and the amount of demolition agent is estimated to be 1 m of the reinforced concrete structure to be crushed. 3 One cartridge (200 g) per 1000 m. Although specific examples of the lengths of the dynamic fracturing agent, the filler, the clay, and the mortar material are shown in Figs. 5(a) to (c), these are only examples and may be changed as necessary. The mortar material 94 is made of ultra-fast hardening non-shrink mortar. By using ultra-fast hardening non-shrink mortar, it is possible to develop a strength of approximately 100 N in a short time (about 1 hour), and the time required for the fracturing process can be shortened. In addition, since no shrinkage occurs during hardening, the fracturing effect of the dynamic fracturing agent can be guaranteed. In addition, ultra-fast hardening non-shrink grout material may be used instead of the mortar material.

[0028] Next, with reference to FIG. 1, steps S01 to S07 of the method for dismantling a reinforced concrete structure shown in FIGS. 2 to 5 will be described.

[0029] First, as shown in Figs. 2 and 3, a plurality of charging holes 51-64, 71-86 for loading dynamic fracturing agents are formed in the foundations F1, F2 and the beams G11, G12, G31, G41, and G42 (S01).

[0030] Next, as shown in Fig. 5(a)-(c), insert the dynamic demolition agent into each charge hole according to the hole length (S02), fix a form (for example, a void material with a diameter of 100 mm) to the top of the component, fill the mortar material 94 (S03), and check its hardening (about 1 hour). The leg wire of the ignition tool of the dynamic demolition agent is taken out to the top. In addition, the surroundings of the component to be crushed are covered with an explosion-proof sheet, etc., and cured to prevent scattering and flying of the crushed material. In addition, the dynamic demolition agent can crush multiple places almost simultaneously by connecting the leg wires in series, but since explosion-proof curing is required during crushing, the area that can be crushed at one time is limited to the area that can be covered with an explosion-proof sheet, etc.

[0031] Next, the lead wires extending from each ignition device in each dynamic crushing agent are connected in series (S04) and extended to the crushing signal. After taking measures to prevent people from entering within 30m of the crushing position, the dynamic crushing agent is ignited by remote control while counting down one minute (S05), and the dynamic crushing agent crushes the foundation and beams (S06). During this crushing, not only the beams and foundations but also the slabs SL are crushed by the dynamic crushing agent loaded into the beams. In this way, the foundations, beams and slabs of the reinforced concrete structure are crushed by the dynamic crushing agent so that they can be grasped and crushed by the grasping and crushing section AH of the demolition heavy machinery JK in Figure 6.

[0032] Next, as shown in FIG. 6, the crushed material 100, which is the foundation, beams, and slabs crushed into small pieces by the dynamic crushing agent, is grasped and crushed in the grasping and crushing section AH by a large demolition heavy machinery JK (S07), and further broken into small pieces.

[0033] According to this embodiment, a plurality of charge holes are formed in the foundation and beams of the building structure, dynamic demolition agents are loaded into each charge hole, and the foundation, beams and slabs are demolitioned by ignition of the dynamic demolition agents, and then further demolition is performed by the demolition heavy machinery. Therefore, the design standard strength is 60N / mm 2 Even if the foundations and beams made of the above-mentioned high-strength concrete cannot be crushed by the demolition heavy machinery alone, if they are crushed in advance with a dynamic crushing agent, they can be further crushed by the demolition heavy machinery, and the reinforced concrete structure made of high-strength concrete can be efficiently crushed.

[0034] In addition, high-strength concrete can be broken down using explosives, but explosives have significant restrictions on their use in the city, and require notification to the relevant government agency. Even if permission is granted, a qualified person is required, and storage and use require strict management. In contrast, the non-explosive dynamic fracturing agent used in this embodiment can be handled by anyone who has attended a course offered by the sales manufacturer, and can be used in city sites by properly managing the equipment and taking noise control measures.

[0035] In addition, at the beginning of the work, the first crushing at the multiple charge holes 51-62 around the foundation F1 in Figure 2 and the second crushing at the charge holes 63, 64 in the center of the X-beam G21 are carried out separately, and the crushing effect is confirmed for each component. When the number of cartridges of dynamic crushing agent to be used, etc. has been determined to a certain extent, it is preferable to proceed with the crushing work by appropriately combining the first and second crushing.

[0036] In addition, it is preferable to start demolition using dynamic crushing agents from the center of the building, where there is less impact on the outside, such as noise and vibration, and then proceed toward the outside of the building while gradually adjusting the amount of charge and the charge hole position.

[0037] (Example) The foundation, beams and slabs that make up the RC structure shown in Figure 2 were crushed in the same manner as in Figure 1, following the specific examples shown in Figures 3 to 5. The design strength of the concrete used in the structure was 60 N / mm 2 However, the actual strength is 69.3 to 83.7 N / mm 2 Figure 7(a)(b) shows the foundation, beam end, and beam center after crushing with the dynamic crushing agent. The foundation, beam, and slab after the preliminary crushing with the dynamic crushing agent were able to be grasped and crushed by the subsequent crushing with the demolition heavy machinery, and the structure was completely dismantled.

[0038] Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of ​​the present invention. For example, in Fig. 2, the middle part of the beam is crushed by the charge hole formed in the center of the beam, but the present invention is not limited to this, and it is also possible to form charge holes at multiple locations in the beam longitudinal direction of the middle part of the beam and crush it. [Industrial Applicability]

[0039] According to the present invention, even if a reinforced concrete structure made of high-strength concrete cannot be demolished by demolition heavy machinery alone, it can be efficiently demolished by first crushing it with a dynamic demolition agent. Furthermore, because the dynamic demolition agent is a non-explosive, it can be applied relatively easily regardless of the location of the structure to be demolished, and can also be applied in urban areas. [Explanation of symbols]

[0040] F1~F4 Basics 11a, 12a Enlarged section G11,G12,G21,G22 X beam G31,G32,G41,G42 Y beam SL Slab 31~34 Intersection 51~64 Charge hole 71~86 Charge hole 91~93 Dynamic crushing agent 94 Mortar material (ultra-fast hardening non-shrinkage mortar) 95 Filling 96 Clay 100 Crushed material JK demolition machine AH grip crushing part

Claims

1. A method for demolishing a reinforced concrete structure, The members constituting the reinforced concrete structure have a design strength of at least 60N / mm ２ The high-strength concrete used in the construction is forming a plurality of charge holes in the member; loading the charge hole with a kinetic fracturing agent; igniting the dynamic crushing agent to crush the component into small pieces that can be grasped and crushed by a demolition heavy machine; and further crushing the crushed components using the demolition heavy machinery to further reduce the size of the components.

2. 2. The method for dismantling a reinforced concrete structure according to claim 1, wherein the members are a rising foundation and a beam.

3. The method for dismantling a reinforced concrete structure according to claim 2, wherein the charge holes in the beams are formed at the ends and middle parts of the beams.

4. The foundation has an expansion greater than the width of the beam, 4. The method for dismantling a reinforced concrete structure according to claim 2 or 3, wherein the charge hole in the foundation is formed vertically from the upper surface of the enlarged portion.

5. A method for demolishing a reinforced concrete structure according to any one of claims 2 to 4, in which the lead wires from the ignition devices of each dynamic demolition agent loaded into the end and middle parts of the beam and each charge hole in the foundation are connected in series, and each dynamic demolition agent is ignited almost simultaneously by remote control to demolition.

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