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chimney removal
1. Construction method
According to the actual situation of the demolition site, on-site survey, through multi-party research and analysis comparison, combined with previous construction experience, the chimney demolition decided to adopt the method of erecting a circular wall scaffolding, manually using the wind pickaxe to disassemble the chimney from top to bottom one by one, dismantling the construction plan of free landing in blocks, dismantling the chimney barrel body to +15m in turn, and the remaining 15m barrel body was crushed by excavator.
2. Preparation before construction
Before the construction of the demolition project, master the 80m chimney construction drawings and construction plan, and understand the division of the adjacent building. Take protective measures for pipelines and facilities that need to be retained. The specific measures are as follows:
Due to the large number of buildings and pipelines around the chimney to be demolished, the operating platform shall be closed during the demolition work, and no gravel shall be splashed outward (except dust). -
Chimney brush buoy color ring
The coating of this project is carried out by a combination of airless spraying, roller coating and brush coating, and the primer is roller coating. And the construction personnel must be trained and skilled personnel with practical experience.
2.3.1 Construction Conditions
(1) The moisture content within 20mm of the wall should be less than 15%, otherwise the overall heat treatment measures are adopted.
(2) The temperature must not be less than 5 °C, the humidity must be less than 75%, and construction is strictly prohibited in rainy and windy weather. (Including 24-hour range before and after rain)
(3) The spraying operation should be carried out in a clean environment to avoid dust pollution of the undried coating;
(4) In the working environment, smoking and other open flame operations are strictly prohibited, and contact with other high temperature heat sources is avoided;
(5) When the temperature exceeds 35 °C, the workpiece cannot be constructed under the condition of direct sunlight.
2.3.2 Preparation before spraying
(1) Between the ambient temperature of 5~38, the relative humidity is below 75% can be painted, the coating construction shall not be carried out when the surface of the component condenses, and it should be protected from rain within 4H after painting.
(2) Before the painting construction, a special coating process test should be carried out.
(3) Coating materials, process requirements should comply with the following provisions:
a. The coating should be sprayed according to the drawings, and the coating materials, processes and performance requirements should be required.
b. Before painting, the type, name, quality and construction part of the paint should be carefully confirmed, and the main performance indicators of each batch of paint should be inspected.
c. The mixing ratio of two-component coatings should be clarified, and stirred evenly and used after ripening, and those that exceed the deadline shall not be used.
d. When receiving the paint, check the batch number, production date, and tightness of the coating, and the expired paint is resolutely not used.
e. The paint that has been opened should be carefully checked before use, and it is found that agglomeration, discoloration, whitening and other deterioration phenomena cannot be used.
f. The container used should be water-free, oil-free, dust-free, free of paint residue and other impurities, and different coatings cannot be mixed with the same container.
g. According to different coatings and sprayed parts, choose different spraying nozzles.
h. Check whether the sprayer and the pipeline and the spray gun are firmly connected.
i. Test the nozzle first to check whether the spray gun, sprayer and other pipelines are normal.
j. Before painting, a brush or clean compressed air should be used to remove dust and other dirt on the surface of the workpiece. -
square chimney new
The main sub-construction scheme of the external structure of the cylinder
1. Operation platform system
1.1 The principle of hydraulic lifting mold turning process
Hydraulic formwork structure, formwork is installed in blocks, and the slope of the formwork is easy to adjust and control. Cumulative errors in construction can be avoided; After concrete pouring, because the concrete and the formwork do not run oppositely, the concrete will not cause damage when lifted on the climbing frame, and the quality of the concrete can be guaranteed; The formwork lifting is accurate in place, the tool-type support system is simple and convenient to operate, the labor intensity is low, and the ergonomics are high.
The principle of the chimney hydraulic lifting and turning construction device is to use the support rod buried in the reinforced concrete cylinder wall as the load-bearing body, and drive the operating platform system, vertical transportation system and formwork system through the hydraulic lifting system climbing.
1.2 Characteristics of hydraulic lifting mold turning process
The hydraulic lifting mold turning process is a new type of formwork system formed on the basis of absorbing the advantages of formwork system such as hydraulic sliding mold and large formwork without derrick, which has the characteristics of easy quality assurance, high safety and fast construction speed.
The hydraulic lifting and turning construction device is composed of operating platform system, vertical transportation system, formwork system, hydraulic lifting system, electrical control system and other parts. -
Concrete Chimney New Construction
Engineering overview：
In accordance with the requirements of the chimney design and construction drawings, ensure that the quality and quantity of the project are guaranteed to complete all construction projects. The content of construction by Party B: excavation of earthwork, backfilling, transport of spoil, cutting of excess foundation pile head, pile hole connection, beginning of chimney foundation with cushion layer, completion of foundation cap, foundation ring wall, inner cylinder equipment foundation , Laying of lightning protection pressure ring; the construction content of the main body above ±0.00m includes the main structure concrete, steel bars, pre-embedded iron parts, lightning protection down conductors, lightning rods, shutters, steel doors, beacon lights, beacon paint, closed construction of the top platform, chimney Internal steel knot platform, ladder production and installation, coiling, production and installation of titanium steel composite board chimney, rust removal and anticorrosion of all steel structure parts (sand blasting is required for rust removal), insulation project of steel chimney, etc. Specifically, it is carried out with design drawings, including loose water. For details, please refer to the construction drawing. This construction includes construction, completion, acceptance, and delivery.
This project is a reinforced concrete structure; it is equipped with a reinforced concrete outer cylinder and a total of 5 floors of platforms. Two titanium steel chimneys are installed inside the reinforced concrete outer cylinder, and the total height of the chimneys is 100m.
1. Foundation: The foundation of the chimney and support of this project is a slab-type pile-raft foundation. The foundation depth is 4.0 meters.
2. Outer cylinder of the chimney: the outer cylinder of the chimney adopts a reinforced concrete structure, the height of the cylinder is 97.0m, the thickness of the cylinder wall is 500mm from ±0.0m to 37.5m, 450mm from 37.5m to 50.0m, 400mm from 50.0m to 97.0m, and the concrete grade for C40.
3. Chimney inner cylinder: the diameter of two titanium steel chimneys is 4400mm, 12.0m～40.0m is 14mm+1.2mm titanium steel composite plate, 40.0m～95.5m is 12mm+1.2mm titanium steel composite plate, 95.5m～ 100.0m is 10mm+1.2mm titanium steel composite plate.
4. Paint red and white navigation marks above 67.0m of the chimney, a total of 6 lines.Construction process:
Operating platform system
1.1 The principle of hydraulic lifting and turning process
Hydraulic formwork structure, the formwork is installed in blocks, and the slope of the formwork is easy to adjust and control. It can avoid the cumulative error of construction; after the concrete is poured and tamped, because the concrete and the formwork do not move relative to each other, the concrete will not be damaged when it is lifted on the climbing frame, and the quality of the concrete can be guaranteed; the formwork is lifted and placed accurately, and the tool-type support system is operated Simple and convenient, low labor intensity and high work efficiency.
Composition of Chimney Hydraulic Lifting and Turning Construction Device The principle of the lifting and turning process is that the supporting rod buried in the reinforced concrete wall is the main load-bearing body, and the hydraulic lifting system climbs to drive the operating platform system, vertical transportation system and formwork system.
1.2 Characteristics of hydraulic lift turning process
The hydraulic lifting and turning process is a new type of formwork system formed on the basis of absorbing the advantages of formwork systems such as hydraulic sliding formwork without derrick and large formwork, which has the characteristics of easy quality assurance, high safety, and fast construction speed. .
The hydraulic lifting and turning over construction device is composed of an operating platform system, a vertical transportation system, a formwork system, a hydraulic lifting system, and an electrical control system. -
chimney landscaping painting
Construction process:
Tower wall base layer treatment→ tower wall crack repair→ polymer mortar repair, leveling → rolling pure epoxy sealing varnish the first pass→ spraying acrylic polyurethane topcoat→ spraying acrylic polyurethane topcoat, second pass→ tower wall landscaping → equipment removal→ site cleaning → final acceptance
Grassroots treatment
2.2.1 For uneven surfaces (including cornices and other parts) directly use the hanging basket for manual mechanical grinding, the formwork interface seam staggered grinding, the degree of grinding should be smooth and does not expose the steel protective layer, the formwork interface staggered grinding to achieve a smooth transition. The surface after sanding is basically flat. When there are exposed rebar heads and embedded metal components on the concrete surface, the concrete around the exposed metal should be chiseled to fully expose the exposed metal, and then the exposed metal should be cut off or cut off along the lowest point to ensure that the remaining metal is less than 30mm below the concrete surface. For metal components with a large exposed area such as steel plates, the surrounding concrete should be chiseled first, the sharp edges and corners of the metal plate should be polished into an arc above R2mm, and then the sandpaper tray should be installed with a portable grinder to polish and remove rust to St3 on the exposed part of the embedded steel plate, and the corresponding metal anti-corrosion primer and intermediate paint should be painted according to the design requirements of metal anti-corrosion. The concrete chiseled surface is treated as required, the concrete of the chiseled part is repaired with polymer mortar, and the leveling is ensured. Finally, it is coated as a whole together with the concrete surface. (Note: (1) When cutting steel bars or grinding steel plates, the strength of concrete around the steel bars and embedded steel plates shall not be damaged.) (2) Under the premise of ensuring the thickness of the concrete protective layer, the smaller the scope of concrete chiseled, the better. (3) Pay attention to the matching of metal coating and concrete coating).
2.2.2 Remove dirt and oil to ensure that the wall surface is clean and dry.
2.2.3 Dust removal treatment: the dust and debris left on the surface after grinding are treated.
2.2.4 Anti-alkali treatment of the wall to reduce the pH value of the wall to below 10, which plays an important role in protecting the durability of the coating.
2.2.5 The dryness of the wall, the moisture content within 20mm of the wall should be less than 15%, otherwise the overall heat treatment measures should be adopted.
2.2.6 Requirements for the natural environment during the construction period: the temperature must not be less than 5 °C, the humidity must be less than 75%, and construction is strictly prohibited in rainy and windy weather. (Including the 24-hour range before and after rain).
2.2.7 The base layer with thicker thickness is repaired by layered filling method after sanding and smoothing.
2.3 Painting method
The coating of this project is carried out by a combination of airless spraying, roller coating and brush coating, and the primer is roller coating. And the construction personnel must be trained and skilled personnel with practical experience.
