A clear water concrete column layered pouring process

Abstract

This invention relates to the field of building construction technology and discloses a layered pouring process for fair-faced concrete columns. The layered pouring process includes the following steps: Step 1, refined construction preparation and component prefabrication; Step 2, surveying and setting out and rebar tying; Step 3, formwork erection and acceptance; Step 4, layered pouring and coordinated vibration; Step 5, interlayer bonding control and curing. This invention, through five innovative steps—refined construction preparation and component prefabrication, surveying and setting out and rebar tying, formwork erection and acceptance, layered pouring and coordinated vibration, and interlayer bonding control and curing—achieves an extremely smooth and seamless facade effect for fair-faced concrete columns, realizes a non-porous column body, ensures the absolute precision and stability of the protective layer, eliminates corner defects and ensures uniform density, and provides inherent material quality assurance. Furthermore, the mutual support of these five improvements creates a powerful synergistic effect in this pouring process.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a layered pouring process for fair-faced concrete columns. Background Technology

[0002] In the construction field, fair-faced concrete is increasingly used due to its unique artistic expression and durability. As a green and environmentally friendly building material, fair-faced concrete columns reduce the use of decorative materials and the generation of construction waste during construction, which aligns with the concept of sustainable development. Researching key construction technologies will further promote the widespread application of fair-faced concrete columns, which will help reduce the pollution of the construction industry to the environment, promote the development of green buildings, and improve the living environment. Researching key construction technologies for fair-faced concrete columns can effectively improve construction quality, reduce rework and maintenance costs, and lower project costs. At the same time, by improving construction efficiency and shortening the construction period, the economic benefits of the project can be realized earlier. In addition, high-quality fair-faced concrete columns have good durability, which can reduce later maintenance costs and extend the service life of buildings, thus having significant economic value in the long run.

[0003] To address the quality issues of "surface bubbles," "surface roughness," and "surface contamination" that arise during the construction of clear water columns.

[0004] However, when pouring fair-faced concrete columns in layers, the following common problems are difficult to overcome: 1. The defects of the traditional formwork system result in insufficient rigidity of the traditional loosely assembled wooden formwork, which is prone to slight deformation under the lateral pressure of concrete, resulting in poor column surface flatness, numerous formwork joints, and improper treatment, which easily leads to grout leakage and rough surface quality problems; 2. The traditional reinforcement system uses wooden back ribs and tie bolts for reinforcement, which has limited rigidity. In order to resist lateral pressure, tie bolts need to be densely set, leaving a large number of bolt holes in the column body, which destroys the integrity of the concrete surface; 3. Conventional vibration methods are often operated by one worker around the column, which easily causes uneven vibration. The corner area of ​​the column is prone to air bubbles due to the dense reinforcement, which can easily form honeycomb, pitting, or dense air bubble zones; 4. Conventional mix design does not fully consider the special requirements of fair-faced concrete, resulting in poor fluidity, cohesion, and water retention, leading to surface contamination such as watermarks and sand spots.

[0005] Therefore, this application provides a layered pouring process for fair-faced concrete columns that achieves high-quality finishing by systematically optimizing formwork engineering, reinforcement system, protective layer control, vibration operation and concrete mix proportion. Summary of the Invention

[0006] The purpose of this invention is to provide a layered casting process for fair-faced concrete columns, which solves the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A layered casting process for fair-faced concrete columns, comprising the following steps:

[0009] Step 1: Refined construction preparation and component prefabrication;

[0010] Step 2: Measurement and layout, and rebar tying;

[0011] Step 3: Template erection and acceptance;

[0012] Step 4: Layered pouring and coordinated vibration;

[0013] Step 5: Interlayer bonding control and maintenance.

[0014] As a further aspect of the present invention: the refined construction preparation and component prefabrication include the following steps:

[0015] Step 1.1, Template Engineering Design Optimization:

[0016] Step 1.1.1: Template selection and prefabrication: Large-scale composite wood templates with a high-strength plastic coating are used as panels. In the factory, the vertical wooden back ribs and plastic-sealed templates are pre-fixed with automated equipment to form a unitized template system. All nail holes are sealed with plastic coating of the same material to ensure that the inner side of the template panel in contact with the concrete is smooth and gapless.

[0017] Step 1.1.2: External corner treatment: The external corners of the columns are not assembled on-site, but instead use pre-made plastic round chamfer strips, which are firmly bonded and fixed to the unit templates on both sides in the factory in advance to form a uniform, smooth and wear-resistant arc-shaped external corner;

[0018] Step 1.2, Improvement of the reinforcement system layout:

[0019] Step 1.2.1: Abandoning the traditional wooden back bracing and tie bolts, high-strength "I"-shaped steel is used as column hoops, utilizing its extremely high moment of inertia to provide bending stiffness far exceeding that of conventional systems;

[0020] Step 1.2.2: Based on accurate concrete lateral pressure calculation, the spacing of the steel column hoops is increased to ensure that the deformation of the formwork is controlled within the allowable range (e.g., ≤2mm) under the maximum lateral pressure. Since the steel column hoops have high rigidity, no tie bolts need to be installed in the middle, thus achieving no perforation in the column body.

[0021] Step 1.3, Improvement of the reinforcement protective layer setting method:

[0022] Step 1.3.1: Use prefabricated high-strength circular concrete blocks with a through hole in the center. During construction, the vertical main reinforcement bars of the column pass through the central hole of the block.

[0023] Step 1.3.2: The circular pad makes contact with the template in a ring shape, ensuring stable stress distribution. Furthermore, its strength is similar to that of the concrete column, thus preventing the formation of weak points.

[0024] Step 1.4, Improvement of concrete mix design:

[0025] Step 1.4.1: Conduct specialized mix design and testing, focusing on adjusting the proportion of mineral admixtures (mineral powder, fly ash) in the total cementitious materials. Through the complementary morphological and activity effects between the two, optimize the density and viscosity of the slurry.

[0026] Step 1.4.2: Finely adjust the dosage of high-efficiency polycarboxylate superplasticizer to impart excellent workability to concrete while ensuring extremely low water consumption (water-cement ratio ≤ 0.40);

[0027] Step 1.4.3: Through repeated experiments, evaluate the flowability (slump / spread) and cohesiveness (cohesiveness) of concrete, find the best balance between the two, ensure that the concrete has high flowability but does not segregate, and good cohesiveness but does not caking, and finally select the optimal mix proportion.

[0028] As a further aspect of the present invention, the specific steps of the measurement and layout and rebar binding are as follows: accurately measure and lay out the column position line and elevation control line according to the design drawings, bind the column rebar skeleton, and after inserting the circular concrete pads, evenly arrange and fix the pads along the height direction of the main rebar according to the design requirements (such as no less than 2 per meter) to ensure the accurate thickness of the protective layer.

[0029] As a further aspect of the present invention: the template erection and acceptance includes the following steps:

[0030] Step 3.1: Assemble the prefabricated unitized templates (including fixed external corner chamfers) on site, reinforce them with encrypted "I"-shaped steel column hoops, and install and lock them one by one from bottom to top;

[0031] Step 3.2: Check the template joints, verticality, and cross-sectional dimensions, and confirm that the chamfer lines at the external corners are straight;

[0032] Step 3.3: Complete the acceptance procedures for the formwork project.

[0033] As a further embodiment of the present invention: the layered casting and coordinated vibration include the following steps:

[0034] Step 4.1: Layering: Based on the column height, divide the pouring process into several layers, with the pouring height of each layer controlled between 1.5 and 2.0 meters, and mark the layer lines on the outside of the formwork;

[0035] Step 4.2: Concrete supply and discharge: Use the mix proportion optimized in step 1.4 to mix concrete, ensuring that the workability of the concrete delivered to the site meets the requirements, and use a chute or pipe to discharge the concrete to prevent segregation;

[0036] Step 4.3, Improvement of the vibration method:

[0037] Step 4.3.1: Simultaneous vibration at four corners: When vibrating each pouring layer, arrange four operators, holding high-frequency vibrators, to be located at the four corners of the column, ready to vibrate simultaneously.

[0038] Step 4.3.2: Standardize operating procedures: All four personnel shall follow the same instructions and strictly adhere to the "quick insertion, slow removal" operating procedure;

[0039] Step 4.3.3: Orderly movement: Starting from the four corners, the vibrator moves orderly towards the center of the column, with the insertion points distributed in a quincunx pattern and the spacing not exceeding 400mm. The vibration time is based on the concrete surface no longer significantly sinking, no more air bubbles emerging, and the appearance of slurry.

[0040] As a further aspect of the present invention, the interlayer bonding control and maintenance includes the following steps:

[0041] Step 5.1: Ensure that the next layer is poured before the initial setting of the lower layer of concrete to avoid construction cold joints;

[0042] Step 5.2: After the top layer of concrete is poured, perform fine scraping;

[0043] Step 5.3: The formwork can only be removed after the concrete strength reaches the specified value (usually 1.2MPa). After removal, the concrete should be wrapped with non-woven fabric and moisturized using an automatic spraying system.

[0044] As a further aspect of the present invention, the standard length of a single template in step 1.1.1 reaches 6 meters to reduce horizontal seams.

[0045] As a further improvement of the present invention, the arrangement of the vertical main reinforcement of the column passing through the central hole of the pad block in step 1.3.1 fundamentally eliminates the possibility of displacement or tilting of the pad block during the pouring and vibration process.

[0046] As a further aspect of the present invention: the "quick insertion" in step 4.3.2 is to prevent the surface concrete from being compacted first and thus hindering the release of air bubbles in the lower part, while the "slow withdrawal" is to allow the concrete to fully fill the voids formed when the vibrator is withdrawn.

[0047] As a further aspect of the present invention, the curing time in step 5.3 shall not be less than 14 days.

[0048] Compared with the prior art, the beneficial effects of the technical solution of this application are as follows:

[0049] 1. The large plastic-sealed unit templates prefabricated in the factory, combined with nail hole sealing technology, provide a forming surface with ultra-high flatness and smoothness. The 6-meter-long template greatly reduces horizontal seams, and the finished plastic chamfers ensure that all external corners have consistent curvature and are straight and upright, so that the fair-faced concrete columns form an extremely flat and seamless facade effect.

[0050] 2. By adopting high-rigidity "I"-shaped steel column hoops and arranging them densely, the use of tie bolts in the column body is completely eliminated, so that the formed concrete column body has no bolt holes, maintaining the absolute integrity and purity of the finish, eliminating the risk of color difference caused by sealing bolt holes, and realizing a hole-free column body for fair-faced concrete columns.

[0051] 3. The circular concrete spacer allows the main reinforcement bars to pass through the center, and it will not shift under any construction disturbance. This ensures that the thickness of the protective layer is highly uniform at any cross-section and any height, effectively preventing the reinforcement bars from being hidden and improving the structural durability. This ensures the absolute precision and stability of the protective layer for the fair-faced concrete column.

[0052] 4. The innovative method of simultaneous vibration at four corners ensures that the corner areas, where the reinforcement is most concentrated and air bubbles are most difficult to expel, can be fully and evenly vibrated. This effectively eliminates honeycomb, pitting, and weak points in the corners. Simultaneous vibration also promotes the uniform distribution of concrete slurry throughout the entire cross section, eliminating corner defects and ensuring uniform compaction of the fair-faced concrete column base.

[0053] 5. By optimizing the composition of cementitious materials and the dosage of water-reducing agent to determine the optimal mix ratio, the concrete has both good fluidity and excellent encapsulation properties. This reduces the generation of air bubbles and lowers the risk of bleeding and segregation from the material's inherent nature, forming a uniform, dense, and consistent surface, thus providing an inherent material quality guarantee for fair-faced concrete columns.

[0054] 6. Through the mutual support of five major improvements, this invention forms an organic whole, giving the casting process a powerful synergistic effect. Attached Figure Description

[0055] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0056] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] Example 1:

[0059] This invention provides a layered casting process for fair-faced concrete columns.

[0060] The layered casting process includes the following steps:

[0061] Step 1: Refined construction preparation and component prefabrication;

[0062] Step 1.1, Template Engineering Design Optimization:

[0063] Step 1.1.1: Template selection and prefabrication: Large-scale composite wood templates with a high-strength plastic coating are used as panels. In the factory, the vertical timber back ribs and plastic-sealed templates are pre-fixed with automated equipment to form a unitized template system. All nail holes are sealed with plastic coating of the same material to ensure that the inner side of the template panel in contact with the concrete is smooth and gapless. The standard length of a single template reaches 6 meters to reduce horizontal joints.

[0064] Step 1.1.2: External corner treatment: The external corners of the columns are not assembled on-site, but instead use pre-made plastic round chamfer strips, which are firmly bonded and fixed to the unit templates on both sides in the factory in advance to form a uniform, smooth and wear-resistant arc-shaped external corner;

[0065] Step 1.2, Improvement of the reinforcement system layout:

[0066] Step 1.2.1: Abandoning the traditional wooden back bracing and tie bolts, high-strength "I"-shaped steel is used as column hoops, utilizing its extremely high moment of inertia to provide bending stiffness far exceeding that of conventional systems;

[0067] Step 1.2.2: Based on accurate concrete lateral pressure calculation, the spacing of the steel column hoops is increased to ensure that the deformation of the formwork is controlled within the allowable range (e.g., ≤2mm) under the maximum lateral pressure. Since the steel column hoops have high rigidity, no tie bolts need to be installed in the middle, thus achieving no perforation in the column body.

[0068] Step 1.3, Improvement of the reinforcement protective layer setting method:

[0069] Step 1.3.1: Use prefabricated high-strength circular concrete blocks with a through hole in the center. During construction, the vertical main reinforcement of the column passes through the central hole of the block. This method of setting up fundamentally eliminates the possibility of displacement or tilting of the block during pouring and vibration.

[0070] Step 1.3.2: The circular pad makes contact with the template in a ring shape, ensuring stable stress distribution. Furthermore, its strength is similar to that of the concrete column, thus preventing the formation of weak points.

[0071] Step 1.4, Improvement of concrete mix design:

[0072] Step 1.4.1: Conduct specialized mix design and testing, focusing on adjusting the proportion of mineral admixtures (mineral powder, fly ash) in the total cementitious materials. Through the complementary morphological and activity effects between the two, optimize the density and viscosity of the slurry.

[0073] Step 1.4.2: Finely adjust the dosage of high-efficiency polycarboxylate superplasticizer to impart excellent workability to concrete while ensuring extremely low water consumption (water-cement ratio ≤ 0.40);

[0074] Step 1.4.3: Through repeated experiments, evaluate the flowability (slump / spread) and cohesiveness (cohesiveness) of concrete, find the best balance between the two, ensure that the concrete has high flowability but does not segregate, and good cohesiveness but does not caking, and finally select the optimal mix proportion.

[0075] Step 2: Measurement and layout, and rebar tying;

[0076] The specific steps for measurement, layout, and rebar tying are as follows: Accurately measure and lay out the column position lines and elevation control lines according to the design drawings, tie the column rebar cage, and after inserting the circular concrete spacers, evenly arrange and fix the spacers along the height direction of the main rebars according to the design requirements (such as no less than 2 per meter) to ensure the accurate thickness of the protective layer.

[0077] Step 3: Template erection and acceptance;

[0078] The template erection and acceptance process includes the following steps:

[0079] Step 3.1: Assemble the prefabricated unitized templates (including fixed external corner chamfers) on site, reinforce them with encrypted "I"-shaped steel column hoops, and install and lock them one by one from bottom to top;

[0080] Step 3.2: Check the template joints, verticality, and cross-sectional dimensions, and confirm that the chamfer lines at the external corners are straight;

[0081] Step 3.3: Complete the acceptance procedures for the formwork project.

[0082] Step 4: Layered pouring and coordinated vibration;

[0083] Layered pouring and coordinated vibration include the following steps:

[0084] Step 4.1: Layering: Based on the column height, divide the pouring process into several layers, with the pouring height of each layer controlled between 1.5 and 2.0 meters, and mark the layer lines on the outside of the formwork;

[0085] Step 4.2: Concrete supply and discharge: Use the mix proportion optimized in step 1.4 to mix concrete, ensuring that the workability of the concrete delivered to the site meets the requirements, and use a chute or pipe to discharge the concrete to prevent segregation;

[0086] Step 4.3, Improvement of the vibration method:

[0087] Step 4.3.1: Simultaneous vibration at four corners: When vibrating each pouring layer, arrange four operators, holding high-frequency vibrators, to be located at the four corners of the column, ready to vibrate simultaneously.

[0088] Step 4.3.2: Unified operating procedures: The four people follow the unified instructions and strictly implement the "quick insertion and slow withdrawal" operating procedure. "Quick insertion" is to prevent the surface concrete from being compacted first and thus hindering the release of air bubbles in the lower part. "Slow withdrawal" is to allow the concrete to fully fill the voids formed when the vibrator is pulled out.

[0089] Step 4.3.3: Orderly movement: Starting from the four corners, the vibrator moves orderly towards the center of the column, with the insertion points distributed in a quincunx pattern and the spacing not exceeding 400mm. The vibration time is based on the concrete surface no longer significantly sinking, no more air bubbles emerging, and the appearance of slurry.

[0090] Step 5: Interlayer bonding control and curing;

[0091] Interlayer bonding control and maintenance includes the following steps:

[0092] Step 5.1: Ensure that the next layer is poured before the initial setting of the lower layer of concrete to avoid construction cold joints;

[0093] Step 5.2: After the top layer of concrete is poured, perform fine scraping;

[0094] Step 5.3: The formwork can only be removed after the concrete strength reaches the specified value (usually 1.2MPa). Immediately after demolding, wrap the concrete with non-woven fabric and use an automatic spraying system for moisturizing and curing. The curing time shall not be less than 14 days.

[0095] Based on Embodiment 1, the present invention will be further described in detail through a non-limiting embodiment.

[0096] Example 2: In the lobby of an office building, there is an independent fair-faced concrete column with a cross-section of 800mm×800mm and a height of 10.5 meters. The design standard is fair-faced concrete.

[0097] Implementation process:

[0098] 1. Preparation stage:

[0099] Step 1.1: Template and reinforcement: Custom 21mm thick plastic-coated wooden templates are prefabricated in the factory with 50mm×100mm timber to form unit templates that are 6 meters high and 1.6 meters wide. PVC prefabricated chamfer strips are pasted on the external corners. The reinforcement uses I-beam steel column hoops with the following spacing: 500mm at the bottom, 600mm in the middle, and 700mm at the top.

[0100] Step 1.2: Protective layer spacers: Custom C40 concrete circular spacers, 50mm outer diameter, 20mm central hole diameter, one spacer is installed every 500mm of height for each main reinforcement bar;

[0101] Step 1.3: Concrete mix proportion: After trial mixing, the final material usage per m³ was determined as follows: 350 kg of P.O42.5 cement, 70 kg of fly ash (Grade I), 60 kg of mineral powder (S95), 192 kg of water, 720 kg of sand, 1050 kg of crushed stone, 8.6 kg of polycarboxylate superplasticizer, slump at discharge 220 mm, spread 600 mm, and excellent workability and coating properties.

[0102] 2. On-site construction:

[0103] Step 2.1: After the steel bars are tied, pass the 16 vertical main bars through the corresponding circular spacers and fix them according to the spacing.

[0104] Step 2.2: Hoist the four unit formwork pieces together, then install seven I-beam steel column hoops from bottom to top, lock them with special clamps, and inspect and accept them as qualified;

[0105] Step 2.3: Divide the 10.5-meter column height into 6 layers for pouring, each layer being approximately 1.75 meters high;

[0106] Step 2.4: When pouring each layer of concrete, arrange 4 experienced vibrators, each responsible for one corner, and follow the command instructions. At the same time, quickly insert the vibrator into the lower layer about 50mm, slowly pull it out, and then move it to the middle area in sequence to ensure uniform vibration without dead corners. Strictly control the interval between layers to within 60 minutes.

[0107] Step 2.5: After pouring, cover with a film to retain moisture and maintain the moisture.

[0108] 3. Effect Verification:

[0109] After demolding, the column surface is smooth as a mirror, with a uniform bluish-gray color and no color difference. The external corner lines are straight and smooth, without any damage. There are no bolt holes on the column body, and the facade is complete and pure. Upon close inspection, the corner concrete is dense and there are no clusters of air bubbles. After testing, the flatness deviation is less than 2mm, the verticality deviation is less than 5mm, and the protective layer thickness has a 100% pass rate. The appearance quality exceeds the national standard and has achieved extremely high quality.

[0110] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A process for the layered casting of a fair-faced concrete column, characterized in that: The layered casting process includes the following steps: Step 1: Refined construction preparation and component prefabrication; Step 2: Measurement, layout, and rebar tying; Step 3: Template erection and acceptance; Step 4: Layered pouring and coordinated vibration; Step 5: Interlayer bonding control and maintenance.

2. The fair-faced concrete column layered pouring process according to claim 1, characterized in that, The detailed construction preparation and component prefabrication include the following steps: Step 1.1, Template Engineering Design Optimization: Step 1.1.1: Template selection and prefabrication: Large-scale composite wood templates with a high-strength plastic coating are used as panels. In the factory, the vertical wooden back ribs and plastic-sealed templates are pre-fixed with automated equipment to form a unitized template system. All nail holes are sealed with plastic coating of the same material to ensure that the inner side of the template panel in contact with the concrete is smooth and gapless. Step 1.1.2: External corner treatment: The external corners of the columns are not assembled on-site, but instead use pre-made plastic round chamfer strips, which are firmly bonded and fixed to the unit templates on both sides in the factory in advance to form a uniform, smooth and wear-resistant arc-shaped external corner; Step 1.2, Improvement of the reinforcement system layout: Step 1.2.1: Abandoning the traditional wooden back bracing and tie bolts, high-strength "I"-shaped steel is used as column hoops, utilizing its extremely high moment of inertia to provide bending stiffness far exceeding that of conventional systems; Step 1.2.2: Based on accurate concrete lateral pressure calculation, the spacing of the steel column hoops is increased to ensure that the deformation of the formwork is controlled within the allowable range (e.g., ≤2mm) under the maximum lateral pressure. Since the steel column hoops have high rigidity, no tie bolts need to be installed in the middle, thus achieving no perforation in the column body. Step 1.3, Improvement of the reinforcement protective layer setting method: Step 1.3.1: Use prefabricated high-strength circular concrete blocks with a through hole in the center. During construction, the vertical main reinforcement bars of the column pass through the central hole of the block. Step 1.3.2: The circular pad makes contact with the template in a ring shape, ensuring stable stress distribution. Furthermore, its strength is similar to that of the concrete column, thus preventing the formation of weak points. Step 1.4, Improvement of concrete mix design: Step 1.4.1: Conduct specialized mix design and testing, focusing on adjusting the proportion of mineral admixtures (mineral powder, fly ash) in the total cementitious materials. Through the complementary morphological and activity effects between the two, optimize the density and viscosity of the slurry. Step 1.4.2: Finely adjust the dosage of high-efficiency polycarboxylate superplasticizer to impart excellent workability to concrete while ensuring extremely low water consumption (water-cement ratio ≤ 0.40); Step 1.4.3: Through repeated experiments, evaluate the flowability (slump / spread) and cohesiveness (cohesiveness) of concrete, find the best balance between the two, ensure that the concrete has high flowability but does not segregate, and good cohesiveness but does not caking, and finally select the optimal mix proportion.

3. The fair-faced concrete column layered pouring process according to claim 1, characterized in that, The specific steps for measurement, layout, and rebar binding are as follows: Accurately measure and lay out the column position lines and elevation control lines according to the design drawings, bind the column rebar cage, and after inserting the circular concrete spacers, evenly arrange and fix the spacers along the height direction of the main rebars according to the design requirements (such as no less than 2 per meter) to ensure the accurate thickness of the protective layer.

4. The fair-faced concrete column layered pouring process according to claim 1, characterized in that, The template erection and acceptance process includes the following steps: Step 3.1: Assemble the prefabricated unitized templates (including fixed external corner chamfers) on site, reinforce them with encrypted "I"-shaped steel column hoops, and install and lock them one by one from bottom to top; Step 3.2: Check the template joints, verticality, and cross-sectional dimensions, and confirm that the chamfer lines at the external corners are straight; Step 3.3: Complete the acceptance procedures for the formwork project.

5. The fair-faced concrete column layered pouring process according to claim 1, characterized in that, The layered pouring and coordinated vibration include the following steps: Step 4.1: Layering: Based on the column height, divide the pouring process into several layers, with the pouring height of each layer controlled between 1.5 and 2.0 meters, and mark the layer lines on the outside of the formwork; Step 4.2: Concrete supply and discharge: Use the mix proportion optimized in step 1.4 to mix concrete, ensuring that the workability of the concrete delivered to the site meets the requirements, and use a chute or pipe to discharge the concrete to prevent segregation; Step 4.3, Improvement of the vibration method: Step 4.3.1: Simultaneous vibration at four corners: When vibrating each pouring layer, arrange four operators, holding high-frequency vibrators, to be located at the four corners of the column, ready to vibrate simultaneously. Step 4.3.2: Standardize operating procedures: All four personnel shall follow the same instructions and strictly adhere to the "quick insertion, slow removal" operating procedure; Step 4.3.3: Orderly movement: Starting from the four corners, the vibrator moves orderly towards the center of the column, with the insertion points distributed in a quincunx pattern and the spacing not exceeding 400mm. The vibration time is based on the concrete surface no longer significantly sinking, no more air bubbles emerging, and the appearance of slurry.

6. The fair-faced concrete column layered pouring process according to claim 1, characterized in that, The interlayer bonding control and maintenance includes the following steps: Step 5.1: Ensure that the next layer is poured before the initial setting of the lower layer of concrete to avoid construction cold joints; Step 5.2: After the top layer of concrete is poured, perform fine scraping; Step 5.3: The formwork can only be removed after the concrete strength reaches the specified value (usually 1.2MPa). After removal, the concrete should be wrapped with non-woven fabric and moisturized using an automatic spraying system.

7. The fair-faced concrete column layered pouring process according to claim 2, characterized in that, In step 1.1.1, the standard length of a single template is 6 meters to reduce horizontal seams.

8. The fair-faced concrete column layered pouring process according to claim 2, characterized in that, The arrangement of the vertical main reinforcement bars of the column passing through the central hole of the pad block in step 1.3.1 fundamentally eliminates the possibility of displacement or tilting of the pad block during the pouring and vibration process.

9. The fair-faced concrete column layered pouring process according to claim 5, characterized in that, The "quick insertion" in step 4.3.2 is to prevent the surface concrete from being compacted first and thus hindering the release of air bubbles in the lower part, while the "slow withdrawal" is to allow the concrete to fully fill the voids formed when the vibrator is pulled out.

10. The fair-faced concrete column layered pouring process according to claim 6, characterized in that, The curing time in step 5.3 shall not be less than 14 days.

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