Method for curing super-thick irregular concrete roof of medical linear accelerator room

Abstract

This invention provides a method for curing ultra-thick, irregular concrete roof slabs in medical linear accelerator chambers, belonging to the field of large-volume concrete structure construction technology. In this invention, as the roof slab pouring nears completion, the 1.5m thick slab is poured first, at which point the 3m thick portion of the slab is about to begin formwork pouring. The 1.5m thick slab enters the curing stage first and requires proper protection. After the 3m thick slab is poured, its sides differ from the top surface, requiring formwork curing. Curing utilizes geotextile for moisture retention and cotton cloth for insulation as basic methods, resulting in different treatment approaches for different thicknesses, the top surface, and the formwork-covered areas. This invention ensures that concrete at different development stages and under different exposure conditions can be cured in one go, preventing concrete cracking.

Description

Technical Field

[0001] This invention relates to the field of construction technology for large-volume concrete structures, specifically to a method for curing an ultra-thick, irregular concrete roof slab for a medical linear accelerator chamber. Background Technology

[0002] Medical linear accelerators are products used for routine clinical X-ray or electron beam radiotherapy, consisting of components such as a treatment head, accelerator tube, magnetron / klystron, collimator, positioning system, treatment bed, control system, modulator, and water-cooling unit.

[0003] Linear accelerators generate radiation during operation, therefore their machine rooms need to be designed with ultra-thick concrete walls. Due to varying radiation levels at different locations, the central cross-shaped protrusion of the roof slab is 3 meters thick, while the remaining areas are 1.5 meters thick (see Figure 1). Traditional ultra-thick roof slabs address uneven thickness by using large-area insulation, but lack specific curing measures for special areas with significant thickness differences and long pouring times.

[0004] Therefore, how to cure concrete slabs with huge thickness differences to ensure that the concrete is of high quality in one go and avoid radiation leakage due to defects is a problem that needs to be solved at this stage. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a method for curing ultra-thick irregular concrete roof slabs in medical linear accelerator chambers. This method not only provides targeted curing for special circumstances, but also clarifies the time nodes for each curing step, making the curing measures more specific, applicable to the curing of ultra-thick irregular roof slabs, and thus more valuable for widespread application.

[0006] Technical Solution: The present invention discloses a method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber. The concrete roof slab structure includes a 3m thick cross-shaped roof slab and a 1.5m thick roof slab located below the 3m thick roof slab. A staggered internal angle is formed between the 3m thick roof slab and the 1.5m thick roof slab. The 3m thick roof slab has an external angle and a side formwork section. The method includes the following steps:

[0007] Step 1: When constructing the side formwork of the 3m thick top slab, add a geotextile (2) between the formwork template (5) of the 3m thick top slab and the vertical secondary keel (4); Proceed to Step 2;

[0008] Step 2: When the top slab pouring is nearing completion, after the large surface of the 1.5m thick top slab is poured, the 1.5m thick top slab is finished with the first finishing grouting, covered with plastic film and sprayed with water to moisten it; at this time, the pouring of the upper half of the 3m thick top slab, which is higher than 1.5m, will begin; proceed to Step 3.

[0009] Step 3: After waiting for 1 to 1.5 hours, the 1.5m thick top slab will lose some of its fluidity. Then, start pouring the upper half of the 3m thick top slab that is higher than 1.5m. Otherwise, it is easy to cause grout leakage at the bottom of the suspended formwork. This step takes 4 hours. Proceed to Step 4.

[0010] Step 4: After the 3m thick top slab is fully poured, perform the first finishing and finishing of the 3m thick top slab, cover it with plastic film and spray it with water to moisten it; after spraying water to moisten the side hanging formwork, cover it with 2cm thick thermal insulation cotton cloth and rainproof plastic sheet until the curing is completed; proceed to step 5.

[0011] Step 5: Remove the plastic film on the 1.5m thick top slab, perform a second finishing and smoothing of the 1.5m thick top slab, and cover it with plastic film. At this time, cover the outer layer of the plastic film with geotextile, and then spray water to moisten it; proceed to step 6.

[0012] Step 6: After the first finishing of the 3m thick roof slab is completed for 6 hours, remove the plastic film covering the 3m thick roof slab, perform the second finishing of the 3m thick roof slab and cover it with plastic film. At this time, cover the outer layer of the plastic film with geotextile, and then spray water to moisten it; proceed to step 7.

[0013] Step 7: 20 hours after the 1.5m thick top slab is poured, remove the plastic film covering the 1.5m thick top slab, perform the final finishing and grouting of the 1.5m thick top slab and sprinkle water to keep it moist; cover the top surface in sequence with a moisture-retaining geotextile, a moisture-proof plastic sheet, a 2cm thick thermal insulation cotton cloth, and a rainproof plastic sheet; proceed to step 8.

[0014] Step 8: 20 hours after the 3m thick roof slab is poured, remove the plastic film covering the 3m thick roof slab, perform the third finishing and finishing of the slurry on the 3m thick roof slab and sprinkle water to keep it moist. Then cover the 3m thick roof slab in sequence with a moisture-retaining geotextile, a plastic sheet that acts as a moisture barrier, a 2cm thick thermal insulation cotton cloth and a rainproof plastic sheet; proceed to step 9.

[0015] Step 9: After 28 days from the completion of Step 8, the overall curing is complete. Remove the curing materials from each layer and dismantle the formwork.

[0016] Furthermore, the maintenance method for the misaligned corner is to lay a double-layer extruded polystyrene board 3 with a size of 200mm×60mm in a circular pattern at the corner. The top surface of the double-layer extruded polystyrene board is then covered in sequence with a moisture-retaining geotextile, a moisture-proof plastic sheet, a 2cm thick thermal insulation cotton cloth, and a rainproof plastic sheet. Each layer should be folded up and covered on top of the extruded polystyrene board strip in sequence, and the overlap width of each layer should not be less than 0.5m.

[0017] Furthermore, the maintenance method for the external corner is to hang down 0.5m around the corner with the 2cm thick insulating cotton cloth and the rainproof plastic sheet from step 8, completely wrapping the external corner, and fix the bottom edge of the rainproof plastic sheet with tape.

[0018] Furthermore, in step 1, after the 1.5m thick top slab is first finished with grout, covered with plastic film and sprayed with water to moisten it, a double layer of 15mm thick wooden formwork is laid on the top surface of the 1.5m thick top slab to prevent construction personnel and equipment from damaging the unhardened surface when pouring the 3m thick top slab.

[0019] Furthermore, in step 3, when the upper half of the 3m thick top slab is higher than 1.5m during pouring, the operating range of personnel and equipment must be strictly limited, and personnel must not step outside the area of ​​the double-layer 15mm thick wooden formwork.

[0020] Furthermore, in step 4, the exposed screw is also wrapped with a 2cm thick insulating cotton cloth and a rainproof plastic sheet. The screw must not penetrate the 2cm thick insulating cotton cloth. This step is because metal has a small specific heat capacity, and this step is to avoid the screw from exchanging heat violently with the outside environment, which would cause the heat inside the concrete to be lost through the screw more quickly, resulting in uneven local cooling and cracking.

[0021] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0022] (1) The present invention adopts different maintenance measures for special situations, such as misaligned internal corners, external corners, side hanging molds and screws;

[0023] (2) Since the corners and screws are areas where heat is more easily dissipated, the present invention takes effective measures to strengthen heat preservation;

[0024] (3) Regarding the side hanging mold, the traditional approach is to perform full curing after molding, while the present invention performs curing with the mold on throughout the process, further reducing the intense heat flow;

[0025] (4) The present invention clarifies the time nodes of each maintenance step, the maintenance measures are more specific, more applicable to the maintenance of ultra-thick irregular roof slabs, and have greater promotional value. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure mentioned in the background section;

[0027] Figure 2 This is a diagram showing the side-mounted formwork maintenance details in this invention;

[0028] Figure 3 This is a cross-sectional view showing all parts of the invention in the maintenance state;

[0029] In the diagram: 1 is a 0.5m cotton cloth and rainproof cloth overlapping downwards from the 3m thick top slab; 2 is the geotextile located between the suspended formwork and the vertical secondary joists; 3 is a double-layer 200mm×60mm extruded polystyrene strip, with the cotton cloth and rainproof cloth on top of the 1.5m thick slab turned up; 4 is the vertical secondary joists; 5 is the suspended formwork. Detailed Implementation

[0030] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0031] like Figures 2-3 The method for curing an ultra-thick, irregular concrete roof slab in a medical linear accelerator chamber is shown. The concrete roof slab structure includes a 3m thick, cross-shaped roof slab and a 1.5m thick roof slab located below the 3m thick roof slab. A staggered, concave angle is formed between the 3m thick roof slab and the 1.5m thick roof slab. The 3m thick roof slab has convex corners and side formwork sections. The method includes the following steps:

[0032] Step 1: When constructing the side formwork for the 3m thick roof slab, add a layer of geotextile 2 between the 3m thick roof slab formwork 5 and the vertical secondary keel 4; Proceed to Step 2;

[0033] Step 2: When the top slab pouring is nearing completion, after the main surface of the 1.5m thick top slab is poured, perform the first finishing touches, cover with plastic film, and spray with water to moisten the surface. At this time, the pouring of the upper half of the 3m thick top slab, which is higher than the 1.5m, will begin. After the first finishing touches, plastic film covering, and water moistening of the 1.5m thick top slab, lay a double layer of 15mm thick wooden formwork on the top surface of the 1.5m thick top slab. The length of the bolts (6) extending beyond the double nuts for the formwork should be controlled within 50mm to prevent affecting the subsequent covering with cotton cloth.

[0034] Step 3: After waiting for 1 to 1.5 hours, the 1.5m thick top slab will lose some of its fluidity. Then, start pouring the upper half of the 3m thick top slab that is higher than 1.5m. This takes 4 hours. When pouring the upper half of the 3m thick top slab that is higher than 1.5m, strictly limit the operating range of personnel and equipment. Do not step outside the area covered by the double-layer 15mm thick wooden formwork.

[0035] Step 4: After the 3m thick top slab is fully poured, perform the first finishing and finishing of the 3m thick top slab, cover it with plastic film and spray water to moisten it; after spraying water to moisten the side hanging formwork, cover it with 2cm thick thermal insulation cotton cloth and rainproof plastic sheet until the curing is completed; the 2cm thick thermal insulation cotton cloth and rainproof plastic sheet should also wrap the exposed screw 6, and the screw 6 should not penetrate the 2cm thick thermal insulation cotton cloth.

[0036] Step 5: Remove the plastic film on the 1.5m thick top slab, perform a second finishing and smoothing of the 1.5m thick top slab, and cover it with another plastic film. At this time, cover the outer layer of the plastic film with a geotextile, and then spray water to moisten it.

[0037] Step 6: Six hours after the first finishing of the 3m thick roof slab, remove the plastic film covering the 3m thick roof slab, perform the second finishing of the 3m thick roof slab, and cover it with plastic film again. At this time, cover the outer layer of the plastic film with geotextile, and then spray water to moisten it.

[0038] Step 7: 20 hours after the 1.5m thick roof slab is poured, remove the plastic film covering the 1.5m thick roof slab, perform a final finishing touch on the slurry, and sprinkle water to retain moisture. The top surface should then be covered in sequence with a moisture-retaining geotextile, a moisture-proof plastic sheet, a 2cm thick insulating cotton sheet, and a rainproof plastic sheet.

[0039] Step 8: After 20 hours of pouring the 3m thick top slab, remove the plastic film covering the 3m thick top slab, perform the third finishing and finishing of the slurry on the 3m thick top slab and sprinkle water to keep it moist. Then cover the 3m thick top slab in sequence with a moisture-retaining geotextile, a plastic sheet that provides moisture insulation, a 2cm thick thermal insulation cotton cloth and a rainproof plastic sheet.

[0040] Step 9: After 28 days from the completion of Step 8, the overall curing is complete. Remove the curing materials from each layer and dismantle the formwork.

[0041] The maintenance method for the inside corner of the misaligned platform is to lay a double-layer extruded polystyrene board 3 with a size of 200mm×60mm in a circle at the inside corner. The maintenance method for the outside corner is to hang down 0.5m around the edges of the 2cm thick thermal insulation cotton cloth and rainproof plastic cloth from step 8, completely wrapping the outside corner, and fix the bottom edge of the rainproof plastic cloth with tape.

[0042] In this embodiment, as the top slab pouring nears completion, the 1.5m thick top slab is poured first, at which point the 3m thick section of the top slab is about to begin pouring using suspended formwork. The 1.5m thick top slab enters the curing stage first and requires proper protection. After the 3m thick top slab is poured, its sides differ from the top surface and are cured with the formwork in place. Curing utilizes geotextile for moisture retention and cotton cloth for insulation as the basic methods, resulting in different treatments for different thicknesses, the top surface, and the suspended formwork area. This ensures that concrete at different development stages and under different exposure conditions can be cured properly in one go, preventing concrete cracking.

[0043] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for curing an ultra-thick, irregular concrete roof slab in a medical linear accelerator chamber, wherein the concrete roof slab comprises a 3m thick, cross-shaped roof slab and a 1.5m thick roof slab located below the 3m thick roof slab, with a staggered internal angle formed between the 3m thick roof slab and the 1.5m thick roof slab, and the 3m thick roof slab having external corners and side formwork sections, characterized in that... Includes the following steps: Step 1: When constructing the side formwork of the 3m thick top slab, add a geotextile (2) between the formwork template (5) of the 3m thick top slab and the vertical secondary keel (4); Proceed to Step 2; Step 2: When the top slab pouring is nearing completion, after the large surface of the 1.5m thick top slab is poured, the 1.5m thick top slab is finished with the first finishing grouting, covered with plastic film and sprayed with water to moisten it; at this time, the pouring of the upper half of the 3m thick top slab, which is higher than 1.5m, will begin; proceed to Step 3. Step 3: After waiting for 1 to 1.5 hours, the 1.5m thick top slab will lose some of its fluidity. Then, start pouring the upper half of the 3m thick top slab, which is higher than 1.5m. This takes 4 hours. Proceed to Step 4. Step 4: After the 3m thick top slab is fully poured, perform the first finishing and finishing of the 3m thick top slab, cover it with plastic film and spray it with water to moisten it; after spraying water to moisten the side hanging formwork, cover it with 2cm thick thermal insulation cotton cloth and rainproof plastic cloth until the curing is completed; proceed to step 5. Step 5: Remove the plastic film on the 1.5m thick top plate, perform a second grouting and finishing on the 1.5m thick top plate, and cover it with another plastic film. At this time, cover the outer layer of the plastic film with a geotextile, and then spray water to moisten it; Proceed to Step 6. Step 6: After the first finishing of the 3m thick roof slab is completed for 6 hours, remove the plastic film covering the 3m thick roof slab, perform the second finishing of the 3m thick roof slab and cover it with plastic film. At this time, cover the outer layer of the plastic film with geotextile and then spray water to moisten it; proceed to step 7. Step 7: After 20 hours of pouring the 1.5m thick top slab, remove the plastic film covering the 1.5m thick top slab, perform a final finishing and grouting on the 1.5m thick top slab, and sprinkle water to keep it moist. Cover the top surface in sequence with a moisture-retaining geotextile, a moisture-proof plastic sheet, a 2cm thick thermal insulation cotton cloth, and a rainproof plastic sheet; proceed to step 8. Step 8: After 20 hours of pouring the 3m thick roof slab, remove the plastic film covering the 3m thick roof slab, perform a third finishing and finishing of the slurry on the 3m thick roof slab and sprinkle water to keep it moist. Then cover the 3m thick roof slab in sequence with a moisture-retaining geotextile, a moisture-proof plastic sheet, a 2cm thick thermal insulation cotton cloth and a rainproof plastic sheet; proceed to step 9. Step 9: After 28 days from the completion of Step 8, the overall curing is complete. Remove the curing materials from each layer and dismantle the formwork.

2. The method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber according to claim 1, characterized in that: The maintenance method for the misaligned corner is to lay a double-layer extruded polystyrene board (3) with a size of 200mm×60mm in a loop at the misaligned corner.

3. The method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber according to claim 1, characterized in that: The maintenance method for the external corner is to use the 2cm thick thermal insulation cotton cloth and rainproof plastic cloth in step 8 to hang down 0.5m on all sides to completely wrap the external corner, and fix the bottom edge of the rainproof plastic cloth with tape.

4. The method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber according to claim 1, characterized in that: In step 2, after the 1.5m thick top slab is first finished with grout, covered with plastic film and sprayed with water to moisten it, a double layer of 15mm thick wooden template is laid on the top surface of the 1.5m thick top slab.

5. The method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber according to claim 1, characterized in that: In step 3, when the upper half of the 3m thick top slab is higher than 1.5m during pouring, the operating range of personnel and equipment must be strictly limited, and personnel must not step outside the area of ​​the double-layer 15mm thick wooden formwork.

6. The method for curing an ultra-thick irregular concrete roof slab in a medical linear accelerator chamber according to claim 1, characterized in that: In step 4, the 2cm thick thermal insulation cotton cloth and rainproof plastic cloth also wrap the exposed screw, and the screw must not penetrate the 2cm thick thermal insulation cotton cloth.

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