Pouring construction method of large-span spherical structure roof with crossed arc-shaped curved surface rib beams

Abstract

The invention relates to a pouring construction method for a large-span spherical structure roof with crossed arc-shaped curved surface rib beams. The pouring construction method comprises the steps that firstly, the concrete mix proportion is determined; step 2, dividing a construction area and constructing by a skip method; thirdly, a formwork is installed and covered; 4, reinforcing steel bar binding and joint waterproofing are carried out; 5, layered pouring and curing of concrete are conducted; and sixthly, the fourth step and the fifth step are repeated, and pouring of the whole roof is completed. According to the method, the construction quality and efficiency are improved, and a new thought and method are provided for concrete pouring of the large-span complex structure roof.

Description

Technical Field

[0001] The invention relates to the field of civil engineering, in particular to a pouring construction method for a spherical structure roof with a large span and a cross-arc curved rib beam. Background Art

[0002] A large concrete spherical roof with intersecting curved rib beams spans 130 meters in a certain earth-covered building. The upper portion is a thin-shell hemispherical roof, while the lower portion is composed of intersecting curved rib beams. The rib beams have a cross-sectional height of 2.4 meters, with a width that gradually decreases radially. The bottom surface is a hyperbolic surface, and a surface finish of exposed concrete is required.

[0003] According to design calculations, the roof has a total area of ​​approximately 13,000 square meters, uses 15,000 cubic meters of concrete, has a maximum slope of approximately 30°, and has a maximum Miller beam cross-section of 2.9 meters by 2.4 meters. These parameters indicate that the roof structure is not only large in size but also complex in shape, making construction difficult and impossible to complete in one go.

[0004] For conventional concrete roofs, the monolithic casting method allows for a cohesive, integrated structure with enhanced waterproofing. However, for the large-span, spherical roof structure with intersecting curved rib beams involved in this proposal, the monolithic casting method cannot be completed in one go due to its complex structure and large size. This can lead to uneven concrete vibration at densely reinforced joints and concrete flow during steep slopes. Furthermore, the densely ribbed beam area contains a large volume of concrete, resulting in excessively high concrete temperature rise, making it difficult to ensure pouring quality and construction efficiency.

[0005] The main reasons for the above problems are: 1. The building is large in size and densely packed with steel bars, making construction difficult. It is also difficult to guarantee the supply of concrete and the quality of its pouring. 2. Due to its large volume, large-volume concrete releases a large amount of heat during cement hydration, resulting in a significant temperature difference between the interior and surface of the concrete, which can cause concrete cracking. Traditionally, cooling measures have been used to address this large temperature difference between the interior and surface of large-volume concrete, such as inserting cooling water pipes within the structure. However, when the steel bars are too dense, the gaps between the bars are very small, making cooling water pipes difficult to insert.

[0006] 3. The roof slope is large, reaching about 30°, which makes the concrete easy to flow after pouring, affecting the pouring quality and molding effect. Summary of the Invention

[0007] The present invention aims to overcome the defects of the prior art and provide a casting construction method for a large-span spherical structure roof with crossed arc-shaped curved rib beams, so as to solve the problem of concrete casting of large-volume spherical structure roofs, especially for large-span spherical structure roofs with crossed arc-shaped curved rib beams.

[0008] In order to solve the above-mentioned technical problems, the present invention is achieved as follows: A pouring construction method for a large-span spherical structure roof with crossed arc-shaped curved rib beams is characterized in that it comprises the following steps: Step 1: Determine the concrete mix ratio; Step 2: Construction area division and skip-storage construction; Step 3: Template installation and covering; Step 4: Steel bar binding and node waterproofing; Step 5: Concrete layer pouring and curing; Step 6: Repeat steps 4 and 5 to complete the pouring of the entire roof.

[0009] The method for pouring a large-span spherical structure roof with cross-arc curved rib beams is characterized in that step one specifically comprises selecting concrete with low hydration heat, high expansion, good workability and anti-flowing properties.

[0010] The method for casting a large-span spherical structure roof with crossed arc-shaped curved rib beams is characterized in that step two specifically comprises: using the skip-bin method to cast the roof concrete, setting at least three construction joints circumferentially, setting several construction joints radially according to the area of ​​the plate, and dividing the construction area into multiple blocks for casting.

[0011] The method for casting a large-span spherical structure roof with a cross-arc curved rib beam is characterized in that step three specifically comprises: erecting formwork and installing templates according to the divided blocks, setting a covering template at the lowest part where the slope is the largest, the template height extends along the curved surface, and a 15×15 cm template hole is opened every 1 meter as a concrete discharge port and a vibrating rod insertion port.

[0012] The method for casting a large-span spherical structure roof with cross-arc curved rib beams is characterized in that step four specifically comprises: binding the dense-rib beams and the plate shell steel bars, and setting water-stop steel plates at the construction joints to strengthen the node waterproofing.

[0013] The method for casting a large-span spherical structure roof with a cross-arc curved rib beam is characterized in that step five specifically comprises: pouring concrete in layers, with each layer pouring thickness not exceeding 500 mm, promptly covering and curing the concrete after pouring, and performing thermal insulation curing according to temperature monitoring points.

[0014] The casting construction method of the large-span spherical structure roof with cross-arc curved rib beams is characterized in that the construction joints are chiseled out after curing is completed to remove the cement film, loose stones and weak concrete layer on the surface of the construction joints.

[0015] The casting construction method of a large-span spherical structure roof with crossed arc-shaped curved rib beams is characterized in that the construction area is divided into 23 blocks, and the construction is completed circle by circle in order from the outside to the inside and according to the principle of relative support.

[0016] The method for casting a large-span spherical structure roof with crossed arc-shaped curved rib beams is characterized in that when tying the steel bars, the main bars are densely arranged at the intersection nodes of multiple beams, the steel bars are tied according to the principle of main beams on top and secondary beams on the bottom, and fish scale nets are set at the construction joints to cut the concrete.

[0017] The method for pouring and constructing a large-span spherical structure roof with crossed arc-shaped curved rib beams is characterized in that: during the concrete layered pouring and curing steps, thermal insulation and curing are performed through temperature monitoring points arranged in advance, and the temperature difference between the inside and outside is controlled to be no more than 25°C, and the temperature difference between the surface and the ring is controlled to be no more than 20°C, so as to prevent concrete cracking.

[0018] The beneficial effects of the present invention are as follows: As can be seen from the above technical solution, the present application provides a method for casting and constructing a spherical structure roof with a large span and cross-arc curved rib beams. By selecting concrete with specific properties, such as low hydration heat, high expansion, good workability and anti-flow concrete, the present invention can adapt to the complex structure and slope requirements of the spherical structure roof with a large span and cross-arc curved rib beams, reduce the problems of concrete flow and uneven vibration, and thus improve the construction quality.

[0019] By adopting the skip-bin construction method, the construction area is divided into multiple blocks for sequential pouring, which can reduce the amount of concrete poured at the same time, making the pouring process more controllable and conducive to improving construction efficiency.

[0020] By layered pouring and timely covering and curing, as well as thermal insulation curing according to temperature monitoring points, the temperature stress inside the concrete can be effectively controlled and the problem of concrete cracking caused by excessive temperature rise can be reduced.

[0021] This application is not only applicable to large-span spherical structure roofs with cross-arc curved rib beams, but can also be adjusted and optimized according to actual conditions and is applicable to concrete pouring construction of other similar complex structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Figure 1 Schematic diagram of roof partition.

[0023] Figure 2 This is the layout diagram of construction joints for beams and slabs.

[0024] Figure 3 Schematic diagram of the roof covering template. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions of the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection requested by this application. like Figure 1-3 Shown: A pouring construction method for a large-span spherical structure roof with cross-arc curved rib beams. Specific steps: Step 1: Determine the concrete mix ratio. First, have a professional mix manufacturer conduct a concrete mix ratio test. Since it is a large volume concrete, it is preferred to use concrete with high hydration heat and high expansion, and good workability to ensure that there is no segregation during vibration. In addition, due to the large slope of the roof, the concrete also needs to have a certain anti-flow performance. Step 2: Considering the roof area reaches 13,000 square meters, the roof is divided into 23 areas for construction. Three construction joints are set in the circumferential direction, and several construction joints are set in the radial direction according to the area of ​​the panels. The construction is completed circle by circle in the order from the outside to the inside and according to the principle of relative support. Step 3: Build the formwork according to the 23 partition blocks and install the formwork; considering that the entire roof is a hemispherical surface with the largest slope at the bottom, close to 30 degrees, a surface covering formwork is set in this area. The formwork height extends 2 meters along the surface, and a 15*15 cm formwork hole is opened every 1 meter as the concrete discharge port and the vibrating rod insertion port.

[0026] Step 4: Roof reinforcement tying steps: First, tie the Miller beam reinforcement, then the plate and shell reinforcement. The main reinforcement is densely arranged at the intersection of multiple beams. The reinforcement can be tied according to the principle of main beams on top and secondary beams on the bottom. According to the zoning drawings, fish scale mesh is installed at the construction joints of the multi-ribbed beams to cut the concrete. Waterstop steel plates are installed at the construction joints of the plate and shell to strengthen the joints. Finally, after the reinforcement is tied, temperature monitoring points are arranged to measure the temperature of the large volume of concrete. Step 5: Pour concrete in layers. According to the results of the test section and the large-volume concrete construction specifications, the pouring thickness of each layer is required to be no more than 500mm. After pouring, timely cover and maintain the film. Insulate and maintain according to the temperature monitoring points arranged in advance. The temperature difference between the inside and outside should not exceed 25℃, and the temperature difference between the surface and the ring should not exceed 20℃ to prevent concrete cracking. For concrete vibration measures, use φ70 / φ50 vibrating rods. The vibration points should be increased at the corners of the construction joints, and the vibration time should be extended in areas with dense steel bars.

[0027] Step 6: After pouring a block and curing, the construction joints must be chiseled to remove the cement film, loose stones, and weak concrete layers on the surface of the construction joints. Treatment methods include sandblasting, high-pressure water flushing, pneumatic chiseling, or manual chiseling. The surface must be thoroughly moistened and rinsed clean, and no water should accumulate. During pouring, cement mortar with the same composition as the concrete should be laid on the construction joints to ensure the quality of the joints. During the pouring process, the construction joints should be carefully compacted to ensure a tight bond. Step 7: Repeat steps 4 to 6 to complete the pouring of the entire roof; This application proposes an improvement plan from three aspects: concrete mix ratio, mold, and construction area division, and proposes a casting construction plan for a large-span spherical structure roof with crossed arc-shaped curved rib beams.

[0028] First, choose concrete with low hydration heat, high expansion, and good workability. This kind of concrete is not prone to segregation during vibration. In addition, due to the steep slope of the roof, the concrete also needs to have certain anti-flow properties.

[0029] Secondly, three circumferential construction joints were set, and several radial joints were set according to the area of ​​the slabs, dividing the construction area into 23 blocks. The construction joints reduced the amount of concrete poured at any one time, making the pouring process more controllable and reducing problems such as concrete flow and uneven vibration.

[0030] Then, the formwork was erected and installed according to the 23 divided blocks. At the lowest point, where the slope was the steepest, a covering formwork was set up. The formwork height extended along the curved surface, and holes were opened in the formwork to serve as the concrete discharge port and the vibrator insertion port to ensure smooth concrete pouring.

[0031] Next, the ribbed beam reinforcement is tied first, followed by the slab and shell reinforcement, following the principle of primary beams on top and secondary beams on the bottom. Fish-scale mesh is installed at the construction joints to cut the concrete, and waterstop steel plates are installed at the slab and shell joints to strengthen waterproofing.

[0032] Finally, concrete is poured in layers from bottom to top, with each layer no thicker than 500mm to ensure quality and reduce internal thermal stress. After pouring, the concrete is promptly covered with film for curing. Insulation curing is performed according to pre-arranged temperature monitoring points to control the temperature difference between the inside and outside, as well as the temperature difference between the surface and the surrounding area, to prevent concrete cracking.

[0033] After a block is poured and cured, the construction joints must be chiseled to remove the cement film, loose stones, and weak concrete layers on the surface. During pouring, cement mortar with the same composition as the concrete should be laid on the construction joints to ensure the quality of the joints.

[0034] By implementing this specific solution, the invention effectively addresses issues encountered during the pouring process of large-span, spherical roof structures with intersecting curved rib beams, such as the inability to complete the pouring in one go, uneven concrete vibration due to dense reinforcement nodes, concrete flow during pouring on steep slopes, and excessively high temperature rise of large concrete volumes. This solution not only improves construction quality and efficiency but also provides new ideas and methods for pouring concrete for large-span, complex roof structures.

[0035] The above are only embodiments provided for this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A method for pouring a large-span spherical roof with a cross-curved curved rib beam, characterized in that It includes the following steps: Step 1: Determine the concrete mix ratio; Step 2: Construction area division and skip-storage construction; Step 3: Template installation and covering; Step 4: Steel bar binding and node waterproofing; Step 5: Concrete layer pouring and curing; Step 6: Repeat steps 4 and 5 to complete the pouring of the entire roof.

2. The pouring construction method of a large-span spherical structure roof with cross-arc curved rib beams according to claim 1 is characterized in that Step one is specifically: select concrete with low hydration heat, high expansion, good workability and anti-flow.

3. The pouring construction method of a large-span spherical structure roof with cross-arc curved rib beams according to claim 1 is characterized in that Step 2 is specifically: use the skip-bin method to pour the roof concrete, set at least three construction joints in the circumferential direction, set several construction joints in the radial direction according to the area of ​​the plate, and divide the construction area into multiple blocks for pouring.

4. The pouring construction method of a large-span spherical structure roof with cross-arc curved rib beams according to claim 1 is characterized in that Step three is as follows: erect the formwork and install the formwork according to the divided blocks, set up the covering formwork at the lowest part where the slope is the largest, extend the formwork height along the curved surface and open a 15×15 cm formwork hole every 1 meter as the concrete discharge port and vibrating rod insertion port.

5. The pouring construction method of a large-span spherical structure roof with cross-arc curved rib beams according to claim 1 is characterized in that Step 4 is specifically: tying the multi-ribbed beams and plate shell reinforcements, and setting water-stop steel plates at the construction joints to strengthen the node waterproofing.

6. The pouring construction method of a large-span spherical structure roof with cross-arc curved rib beams according to claim 1 is characterized in that Step five is as follows: concrete is poured in layers, with each layer not exceeding 500mm in thickness; after pouring, the concrete is promptly covered and maintained, and insulation maintenance is performed according to the temperature monitoring points.

7. The pouring construction method of a large-span spherical structure roof with crossed arc-shaped curved rib beams according to claim 6, characterized in that: After curing is completed, chisel the construction joints to remove the cement film, loose stones and weak concrete layer on the surface of the construction joints.

8. The method for casting a large-span spherical structure roof with crossed arc-shaped curved rib beams according to claim 3, characterized in that: The construction area is divided into 23 blocks, and the construction is completed circle by circle in the order from the outside to the inside and according to the principle of relative support.

9. The method for casting a large-span spherical structure roof with crossed arc-shaped curved rib beams according to claim 5, characterized in that: When tying the steel bars, the main bars are densely arranged at the intersection of multiple beams. The steel bars are tied according to the principle of main beams on top and secondary beams on the bottom, and fish scale nets are set at the construction joints to cut the concrete.

10. The pouring construction method of a large-span spherical structure roof with crossed arc-shaped curved rib beams according to claim 6, characterized in that: During the concrete layered pouring and curing steps, thermal insulation curing is performed through temperature monitoring points arranged in advance to control the temperature difference between the inside and outside to be no more than 25°C and the temperature difference between the surface and the ring to be no more than 20°C to prevent concrete cracking.

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