Steel pipe column self-compacting concrete guide pipe pouring method
Through the method of conduit method and segmented pouring combined with insertion vibration and real-time monitoring and detection, the problem of easy separation and vibration of concrete in the ultra-long steel pipe column is solved, the uniform distribution and high density of concrete are achieved, and the steel pipe is improved Pouring quality and structural properties of columns.
Patent Information
- Application Number
- CN202411507135.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2024-12-17
AI Technical Summary
In the existing concrete pouring methods of steel pipe columns, concrete is prone to separation, especially in ultra-long steel pipe columns, which leads to uneven density, affecting load-bearing capacity and durability, and the internal space is narrow, making it difficult to vibrate, making it difficult to ensure that the density reaches the design. Require.
The conduit method is poured, sectioned pouring and vibration methods. The concrete is transported from the ground to high altitude through the conduit, and the concrete is poured in sections and vibrated with insertion vibrating rods and external mallets. The concrete performance indicators are monitored in real time and through The knocking method and ultrasonic method detect the density, adjust the mix ratio and construction technology, and ensure the high flowability, self-condensity and segregation resistance of concrete.
The concrete separation phenomenon is effectively avoided, the density and overall performance of the steel pipe column are improved, the uniform distribution and dense filling of concrete in the ultra-long steel pipe column is ensured, and the casting quality and structural stability are improved.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of building construction, and in particular relates to a method for pouring a self-compacting concrete conduit of a steel pipe column. Background Art
[0002] In the field of construction engineering, steel pipe columns are widely used as an important structural component. However, there are many problems with the existing concrete pouring methods for steel pipe columns. During the pouring process of the traditional method, concrete is prone to segregation, especially in the pouring of ultra-long steel pipe columns. Since the free fall height of the concrete is too high, the segregation problem is more serious, which leads to uneven density of the concrete, affecting the bearing capacity and durability of the steel pipe column. At the same time, the internal space of the steel pipe column is narrow and difficult to vibrate, making it difficult to ensure that the concrete reaches the density required by the design.
[0003] Therefore, based on the above technical problems, it is necessary to design a self-compacting concrete conduit casting method for steel pipe columns. By reasonably designing the concrete mix ratio, using the conduit method for casting, segmented casting and vibration, and strict quality control and testing, the problems of concrete segregation, vibration difficulty, and difficulty in ensuring density can be effectively solved, thereby improving the casting quality and overall performance of steel pipe columns. Summary of the invention
[0004] The purpose of the present invention is to provide a method for pouring self-compacting concrete conduit for steel pipe columns, aiming to solve the problems in the prior art that concrete is easy to segregate (especially in extra-long steel pipe columns due to the high height of free fall), the compactness is uneven, which affects the performance of the steel pipe columns, and the space inside the steel pipe columns is narrow and difficult to vibrate, making it difficult to ensure that the concrete density meets the design requirements.
[0005] To achieve the above object, the present invention provides the following technical solutions:
[0006] A method for pouring a steel pipe column self-compacting concrete conduit, characterized in that it comprises the following steps:
[0007] Concrete performance requirements determination and mix ratio design steps: According to the specific requirements of the steel pipe column and construction conditions, in conjunction with the design institute and commercial concrete mixing station, determine the performance requirements of the concrete, such as high fluidity, self-compactness, large slump and slump expansion, good anti-segregation ability and micro-expansion, and determine the mix ratio including cement, water, aggregate, admixture, expansion agent material selection and proportion adjustment through trial mixing tests;
[0008] The steps of conduit casting are as follows: a conduit is installed on the top of the steel pipe column to transport the concrete from the ground to the high altitude, and then poured into the steel pipe through the conduit. The installation of the conduit must ensure that the concrete flows smoothly in the conduit and is evenly distributed when poured into the steel pipe column;
[0009] Sectional pouring and vibration steps: For super-long steel pipe columns, the section pouring method is adopted. The pouring height of each section is determined according to the size of the steel pipe column and the design requirements. After each section is poured, an inserted vibrating rod is inserted from the reserved vibration hole of the steel pipe column to vibrate the inside, and a wooden hammer is used to knock on the surface of the steel pipe column to vibrate the outside;
[0010] Quality control and testing steps: During the pouring process, the slump and expansion performance indicators of the concrete are monitored in real time, the mix ratio and construction process are adjusted in time, the density of the steel pipe column is tested by tapping and ultrasonic methods, and remedial measures are taken for parts where the density does not meet the requirements.
[0011] As a preferred solution of the present invention, in the steps of determining the concrete performance requirements and designing the mix ratio, the determination of the mix ratio needs to comprehensively consider the structural characteristics and construction conditions of the steel pipe column to ensure that the concrete performance meets the casting requirements of the steel pipe column.
[0012] As a preferred solution of the present invention, in the conduit casting step, the length, diameter and installation angle of the conduit are reasonably designed according to the height and diameter of the steel pipe column and the performance of concrete.
[0013] As a preferred solution of the present invention, in the segmented pouring and vibrating steps, the determination of the pouring height of each segment must meet the design bearing capacity of the steel pipe column and the overall structural stability requirements, and the vibration time of the inserted vibrator and the knocking frequency of the external wooden hammer are adjusted according to the compaction of the concrete.
[0014] As a preferred solution of the present invention, in the quality control and testing steps, the monitoring frequency of concrete performance indicators and the testing frequency of steel pipe column density are determined according to the actual project conditions, including factors such as project scale, construction progress and quality requirements.
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] 1. In this scheme, by adopting the conduit method casting step, a conduit is installed on the top of the steel pipe column to transport concrete from the ground to the high altitude, and then poured into the steel pipe through the conduit. The installation of the conduit ensures that the concrete flows smoothly in the conduit and is evenly distributed when poured into the steel pipe column. For example, in a high-rise building project, according to the height (50 meters) and diameter (1.2 meters) of the steel pipe column and the performance of concrete (slump of 260mm, expansion of 700mm, etc.), the length of the conduit is designed to be 48 meters, the diameter is 0.25 meters, and the installation angle is 15 degrees, which effectively avoids the segregation phenomenon caused by the free fall of concrete;
[0017] In the steps of determining the performance requirements of concrete and designing the mix ratio, the design institute and the commercial concrete mixing station are jointly used to determine the performance requirements of concrete, such as high fluidity, self-compactness, large slump and slump expansion, good anti-segregation ability and micro-expansion. The appropriate mix ratio is determined through trial mixing tests. For example, in a high-rise building project, it is finally determined that the cement is P.O42.5 cement with a water-cement ratio of 0.38, 5-20mm continuously graded crushed stone and medium sand are used as aggregates, polycarboxylic acid high-performance water-reducing agent (dosage is 1.2% of the mass of the cementitious material) and hydroxypropyl methylcellulose water-retaining agent (dosage is 0.05% of the mass of the cementitious material) are used as admixtures, and UEA expansive agent (dosage is 8% of the mass of the cementitious material) is used as the expansive agent, which further improves the anti-segregation ability of the concrete.
[0018] 2. In this scheme, the super-long steel pipe column is cast in sections. The casting height of each section is determined according to the size of the steel pipe column and the design requirements. For example, in a high-rise building project, a steel pipe column with a height of 50 meters and a diameter of 1.2 meters is cast in 10 sections. The casting height of each section is 5 meters. After each section is cast, an inserted vibrator is inserted into the reserved vibration hole of the steel pipe column for internal vibration. At the same time, a wooden hammer is used to knock on the surface of the steel pipe column for external vibration.
[0019] During the vibration process, the vibration time of the inserted vibrator is set to 20 seconds at the beginning based on experience, and the frequency of the external wooden hammer is set to 30 times per minute, and is adjusted according to the density of the concrete. If bubbles are still found on the surface of the concrete or the vibration sound is uneven, the vibration time is appropriately extended by 5 seconds each time. At the same time, the frequency of the external wooden hammer is adjusted to 5 times per minute until there are no obvious bubbles on the surface of the concrete and the vibration sound is uniform, ensuring that the concrete achieves a better density effect and effectively solves the problem of vibration difficulties.
[0020] 3. In this scheme, in the quality control and testing steps, the slump and expansion performance indicators of concrete are monitored in real time during the pouring process, and the mix ratio and construction process are adjusted in time. For example, in a high-rise building project, the monitoring frequency of concrete performance indicators is determined to be once every 15 minutes to test the slump and expansion. In the early stage of pouring, since the concrete performance may fluctuate greatly, the testing frequency is appropriately increased to once every 10 minutes, and the testing is continued for the first 2 hours to ensure that the concrete performance always meets the design requirements;
[0021] The density of steel pipe columns is tested by tapping and ultrasonic methods, and remedial measures are taken for parts where the density does not meet the requirements. For example, in a certain high-rise building project, the density of steel pipe columns is tested by tapping once after every two sections are cast, and by ultrasonic method once after every three sections are cast. At key locations (such as the bottom and top of the steel pipe column and near the annular stiffening ribs), tapping tests are carried out after each section is cast, ensuring that the overall casting quality of the steel pipe column meets the design requirements. DETAILED DESCRIPTION
[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] Example 1
[0024] The present invention provides the following technical solutions:
[0025] A method for pouring a steel pipe column self-compacting concrete conduit, characterized in that it comprises the following steps:
[0026] Concrete performance requirements determination and mix ratio design steps: According to the specific requirements of the steel pipe column and construction conditions, in conjunction with the design institute and commercial concrete mixing station, determine the performance requirements of the concrete, such as high fluidity, self-compactness, large slump and slump expansion, good anti-segregation ability and micro-expansion, and determine the mix ratio including cement, water, aggregate, admixture, expansion agent material selection and proportion adjustment through trial mixing tests;
[0027] The steps of conduit casting are as follows: a conduit is installed on the top of the steel pipe column to transport the concrete from the ground to the high altitude, and then poured into the steel pipe through the conduit. The installation of the conduit must ensure that the concrete flows smoothly in the conduit and is evenly distributed when poured into the steel pipe column;
[0028] Sectional pouring and vibration steps: For super-long steel pipe columns, the section pouring method is adopted. The pouring height of each section is determined according to the size of the steel pipe column and the design requirements. After each section is poured, an inserted vibrating rod is inserted from the reserved vibration hole of the steel pipe column to vibrate the inside, and a wooden hammer is used to knock on the surface of the steel pipe column to vibrate the outside;
[0029] Quality control and testing steps: During the pouring process, the slump and expansion performance indicators of the concrete are monitored in real time, the mix ratio and construction process are adjusted in time, the density of the steel pipe column is tested by tapping and ultrasonic methods, and remedial measures are taken for parts where the density does not meet the requirements.
[0030] In a specific embodiment of the present invention, the concrete performance requirements are determined and the mix ratio design steps are analyzed:
[0031] Basis: When pouring self-compacting concrete for steel pipe columns, the concrete inside must meet specific requirements, so the concrete performance requirements must be determined based on the structural characteristics of the steel pipe column, construction conditions, and the overall requirements of the project (such as construction period, quality objectives, etc.). For example, in the Xinzhou Urban and Rural Construction Development Co., Ltd. Xinshi Primary and Middle School Attached Project, due to the large scale of the project, tight construction period, and the fact that it is an excellent project, the quality requirements for the concrete inside the steel pipe column are higher, which prompts more stringent requirements when determining the performance requirements.
[0032] Process: In conjunction with relevant units (design institutes and commercial concrete mixing plants), the performance of concrete is determined by comprehensively considering multiple factors. The design institute considers the stress conditions and bearing capacity of steel pipe columns from the perspective of structural design, while the commercial concrete mixing plant provides professional advice from the perspective of material supply and production process. The mix ratio is determined through trial mixing tests. In this process, various combinations and proportions of cement, water, aggregates, admixtures, expansion agents and other materials are adjusted to test the various performance indicators of concrete under different mix ratios, such as slump, expansion, strength, etc., and finally determine the best mix ratio that meets the requirements.
[0033] Analysis of the steps of conduit casting: The purpose of conduit installation: To solve the problem of segregation caused by free fall of concrete in traditional casting methods, and to ensure that the concrete is evenly distributed and densely filled in the steel pipe column. For example, in the casting of ultra-long steel pipe columns, the free fall height of concrete is too high, which is prone to segregation. The conduit method can effectively avoid this situation.
[0034] Conduit design requirements: The length of the conduit should be determined according to the height of the steel pipe column to ensure that the concrete can be smoothly transported from the ground to the top of the steel pipe column; the diameter should take into account the fluidity and pouring speed of the concrete to ensure that the concrete can pass through the conduit smoothly; the installation angle should be appropriate so that the concrete can be evenly distributed in the column when poured into the steel pipe column to avoid local accumulation or poor flow.
[0035] Analysis of segmented pouring and vibration steps:
[0036] Reasons for segmented pouring: For super-long steel pipe columns, segmented pouring is used to better control the pouring quality of concrete. Since the steel pipe column is too long, it is difficult to ensure the density and uniformity of the concrete in the entire column if it is poured at one time. The pouring height of each section is determined according to the size of the steel pipe column (such as diameter, wall thickness, etc.) and design requirements (such as bearing capacity, structural stability, etc.), so that each section of concrete can achieve a better density effect within a reasonable range.
[0037] Vibration method and principle: After each section is poured, an inserted vibrator is inserted into the reserved vibration hole to vibrate the concrete and knock it with a wooden hammer. The inserted vibrator uses high-frequency vibration to expel the air and voids inside the concrete to achieve a compacting effect; the external wooden hammer knocks on the surface of the steel pipe column, which can assist in internal vibration to make the concrete more compact, and on the other hand, it can check whether the concrete has been filled and compacted, and judge the internal situation by the knocking sound.
[0038] Analysis of quality control and testing steps:
[0039] Purpose of performance index monitoring: Real-time monitoring of concrete slump and expansion performance indexes during the pouring process is to ensure that the performance of concrete always meets the design requirements. Because the performance of concrete is affected by many factors, such as changes in raw materials, temperature and humidity of the construction environment, etc. Through real-time monitoring, once abnormal performance indicators are found, the mix ratio and construction process can be adjusted in time to ensure the stability of concrete quality.
[0040] Density detection method and function: The density of steel pipe columns is detected by percussion and ultrasonic methods. The percussion method is to judge the density of the internal concrete based on the sound made by percussion on the steel pipe column. A crisp sound indicates good density, while a dull sound may indicate the presence of voids. The ultrasonic method uses the propagation characteristics of ultrasonic waves in concrete to detect density. Remedial measures are taken for parts where the density does not meet the requirements, such as secondary pouring of local voids, to ensure that the overall casting quality of the steel pipe column meets the design requirements.
[0041] Specifically in this scheme, in the steps of determining the concrete performance requirements and designing the mix ratio, the determination of the mix ratio needs to comprehensively consider the structural characteristics and construction conditions of the steel pipe column to ensure that the concrete performance meets the casting requirements of the steel pipe column.
[0042] In this embodiment: First, the method of comprehensively considering the structural characteristics of the steel pipe column in determining the mix ratio can make the concrete better adapt to the specific shape and size of the steel pipe column. For example, the steel pipe column may have different diameters, heights and wall thicknesses. Concrete with a proper mix ratio can fully fill the internal space of the steel pipe, ensure close integration with the steel pipe, and improve the integrity and stability of the structure. At the same time, adjusting the mix ratio according to the structural characteristics of the steel pipe column can better deal with possible stress concentration problems and prevent cracks or damage during use.
[0043] Secondly, it is also necessary to consider the construction conditions when determining the mix ratio. Construction conditions include factors such as construction environment temperature, humidity, and construction methods. If the construction environment temperature is high, the mix ratio needs to be adjusted to ensure that the concrete does not harden too quickly during the pouring process and affect the construction quality; if the construction method is pumping, the mix ratio needs to meet the requirements of pumping to ensure the fluidity and pumpability of the concrete. This can ensure the smooth progress of the construction process, improve construction efficiency, and reduce problems and risks in construction.
[0044] Specifically in this solution, in the conduit casting step, the length, diameter and installation angle of the conduit are reasonably designed according to the height and diameter of the steel pipe column and the performance of concrete.
[0045] In this embodiment: for the steel pipe column of the above-mentioned high-rise building project, its height is 50 meters and its diameter is 1.2 meters.
[0046] According to the height and diameter of the steel pipe column and the performance of concrete (such as slump of 260mm, expansion of 700mm, etc.), the length of the conduit is designed to be 48 meters to ensure that the concrete can be transported from the ground to the top of the steel pipe column. The diameter of the conduit is 0.25 meters. Considering the fluidity and pouring speed of concrete, this diameter can ensure that the concrete passes through the conduit smoothly without blockage or slow flow.
[0047] The installation angle of the conduit is 15 degrees, which is determined through simulation and field tests. It enables the concrete to be evenly distributed inside the column when poured into the steel pipe column.
[0048] Specifically in this scheme, in the segmented pouring and vibrating steps, the determination of the pouring height of each segment must meet the design bearing capacity of the steel pipe column and the overall structural stability requirements, and the vibration time of the inserted vibrator and the knocking frequency of the external wooden hammer are adjusted according to the density of the concrete.
[0049] In this embodiment: for the steel pipe column with a height of 50 meters and a diameter of 1.2 meters in the above-mentioned high-rise building project, considering its design bearing capacity and overall structural stability requirements, the steel pipe column is divided into 10 sections for casting, and the casting height of each section is 5 meters.
[0050] After each section is poured, insert the vibrator into the reserved vibration hole for vibration. At the beginning, the vibration time is set to 20 seconds based on experience, and the external mallet hits the surface of the steel pipe column at a frequency of 30 times per minute. During the vibration process, the compaction of the concrete is judged by observing the changes on the concrete surface and listening to the vibration sound. If bubbles are still found on the concrete surface or the vibration sound is uneven, extend the vibration time appropriately, increase it by 5 seconds each time, and adjust the knocking frequency of the external mallet by 5 times per minute, until there are no obvious bubbles on the concrete surface and the vibration sound is uniform, indicating that the concrete has achieved a good compaction effect.
[0051] Specifically in this solution, in the quality control and testing steps, the monitoring frequency of concrete performance indicators and the testing frequency of steel pipe column density are determined according to the actual project conditions, including factors such as project scale, construction progress and quality requirements.
[0052] In this embodiment: In this high-rise building project, due to the large scale of the project, the construction schedule requires the casting of steel pipe columns to be completed within 3 months, and the quality requirements are high, and it is necessary to ensure that the density of the steel pipe columns and the concrete performance meet the design standards.
[0053] The monitoring frequency of concrete performance indicators is determined to be once every 15 minutes for slump and expansion. In the early stage of pouring, since the concrete performance may fluctuate greatly, the testing frequency is appropriately increased to once every 10 minutes, and the testing lasts for the first 2 hours.
[0054] The frequency of testing the density of the steel pipe column is to conduct a tapping test after every 2 sections are poured, and an ultrasonic test after every 3 sections are poured. At key locations (such as the bottom and top of the steel pipe column and near the annular stiffening ribs), a tapping test is conducted after each section is poured to ensure that the density of these locations meets the requirements. If it is found during the test that the density does not meet the requirements, the pouring is stopped immediately, the problem areas are analyzed and processed, and appropriate remedial measures are taken, such as secondary pouring of local gaps or re-pouring after adjusting the construction process.
[0055] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned 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 by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for pouring a self-compacting concrete conduit for a steel pipe column, characterized in that: The following steps are involved: Concrete performance requirements determination and mix ratio design steps: According to the specific requirements of the steel pipe column and construction conditions, in conjunction with the design institute and commercial concrete mixing station, determine the performance requirements of the concrete, such as high fluidity, self-compactness, large slump and slump expansion, good anti-segregation ability and micro-expansion, and determine the mix ratio including cement, water, aggregate, admixture, expansion agent material selection and proportion adjustment through trial mixing tests; The steps of conduit casting are as follows: a conduit is installed on the top of the steel pipe column to transport the concrete from the ground to the high altitude, and then poured into the steel pipe through the conduit. The installation of the conduit must ensure that the concrete flows smoothly in the conduit and is evenly distributed when poured into the steel pipe column; Sectional pouring and vibration steps: For super-long steel pipe columns, the section pouring method is adopted. The pouring height of each section is determined according to the size of the steel pipe column and the design requirements. After each section is poured, an inserted vibrating rod is inserted from the reserved vibration hole of the steel pipe column to vibrate the inside, and a wooden hammer is used to knock on the surface of the steel pipe column to vibrate the outside; Quality control and testing steps: During the pouring process, the slump and expansion performance indicators of the concrete are monitored in real time, the mix ratio and construction process are adjusted in time, the density of the steel pipe column is tested by tapping and ultrasonic methods, and remedial measures are taken for parts where the density does not meet the requirements.
2. A method for pouring a steel pipe column self-compacting concrete conduit according to claim 1, characterized in that: In the steps of determining the concrete performance requirements and designing the mix ratio, the determination of the mix ratio needs to comprehensively consider the structural characteristics and construction conditions of the steel pipe column to ensure that the concrete performance meets the casting requirements of the steel pipe column.
3. A method for pouring a steel pipe column self-compacting concrete conduit according to claim 2, characterized in that: In the conduit casting step, the length, diameter and installation angle of the conduit are reasonably designed according to the height and diameter of the steel pipe column and the performance of concrete.
4. A method for pouring a steel pipe column self-compacting concrete conduit according to claim 3, characterized in that: In the segmented pouring and vibrating steps, the pouring height of each segment must meet the design bearing capacity of the steel pipe column and the overall structural stability requirements, and the vibration time of the inserted vibrator and the knocking frequency of the external mallet are adjusted according to the compaction of the concrete.
5. A method for pouring a steel pipe column self-compacting concrete conduit according to claim 4, characterized in that: In the quality control and testing steps, the monitoring frequency of concrete performance indicators and the testing frequency of steel pipe column density are determined according to the actual project conditions, including factors such as project scale, construction progress and quality requirements.