Mass concrete dynamic jump construction method based on coastal super high-rise building

Abstract

The invention relates to the technical field of building construction, and discloses a mass concrete dynamic skip construction method based on a coastal super high-rise building, which comprises the following steps: dividing a construction area into a plurality of skip blocks according to the structural characteristics, the size and the concrete pouring capacity of the coastal super high-rise building, the width is determined according to the structural shape and construction convenience, and a construction joint containing a fast-easy closing net or a steel plate net is reserved between every two adjacent skip blocks; a dynamic adjustment model is established in combination with coastal region meteorological data, concrete material performance parameters and construction progress requirements and used for automatically adjusting the sequence of warehouse jumping, the pouring time interval and the concrete mixing proportion; and the concrete mix proportion is optimized according to dynamic adjustment model requirements. The climate adaptability effect is as follows: the method adapts to the coastal changeable marine climate, optimizes the sequence of warehouse jumping, the pouring interval and the concrete mix proportion in real time by dynamically adjusting the model, avoids adverse weather influences such as typhoon and high temperature, and ensures continuous and stable construction.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a dynamic skip-construction method for large-volume concrete in coastal super high-rise buildings. Background Technology

[0002] In the construction of super high-rise buildings in coastal areas, large-volume concrete structures are widely used. Traditional post-cast strip construction methods have many drawbacks, such as long construction periods, difficulty in cleaning post-cast strips, susceptibility to leakage, and impact on the overall structural construction progress. Furthermore, the unique environment of coastal areas, heavily influenced by marine climate, presents higher requirements for crack prevention and waterproofing in concrete construction. While existing skip-pour construction methods have solved some problems to a certain extent, they lack a dynamic adjustment mechanism tailored to the characteristics of super high-rise buildings in coastal areas, making it difficult to fully adapt to the complex and ever-changing construction environment and structural requirements.

[0003] Therefore, developing a dynamic skip-construction method for large-volume concrete in coastal super high-rise buildings is of great practical significance. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a dynamic skip-construction method for large-volume concrete in coastal super high-rise buildings, solving the problems mentioned in the background technology.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for dynamic skip-construction of large-volume concrete for super high-rise coastal buildings, comprising:

[0008] Based on the structural characteristics, dimensions and concrete pouring capacity of the coastal super high-rise building, the construction area is divided into multiple jump-section blocks. The length of a single jump-section block does not exceed 40m, and the width is determined according to the structural shape and construction convenience. Construction joints containing quick-closing mesh or steel mesh are reserved between adjacent jump-section blocks.

[0009] A dynamic adjustment model was established by combining meteorological data of coastal areas, concrete material performance parameters and construction progress requirements to automatically adjust the skip-pour sequence, pouring time interval and concrete mix ratio.

[0010] Optimize the concrete mix proportion according to the requirements of the dynamic adjustment model, select low heat of hydration cement, add 20%-30% fly ash or mineral powder, use polycarboxylate-based high-performance water-reducing agent, control the water-cement ratio between 0.4 and 0.45, and select appropriate coarse and fine aggregates.

[0011] The pouring is carried out according to the skip-section sequence determined by the dynamic adjustment model. The odd or even number of sections are poured first. The time interval between pouring of adjacent sections is not less than 7 days. The layered pouring method is adopted, and the thickness of each layer does not exceed 500mm. An immersion vibrator is used for compaction.

[0012] Temperature sensors are placed inside and on the surface of the concrete to monitor temperature changes in real time and control the concrete pouring temperature. The temperature should not exceed 30°C in summer and not be lower than 5°C in winter. When the temperature difference between the inside and the surface exceeds 25°C, heat preservation or cooling measures are taken.

[0013] Concrete should be cured promptly after pouring, with water retention for curing in summer and plastic film and cotton felt for insulation and moisture retention in winter. During the curing period, cracks should be inspected regularly and dealt with promptly if any are found.

[0014] Preferably, the process of establishing the dynamic adjustment model includes:

[0015] Collect historical meteorological data and real-time weather forecast information for coastal areas, and analyze the impact of meteorological factors such as temperature, humidity, and wind speed on concrete construction;

[0016] Tests were conducted on concrete materials to obtain performance parameters such as cement hydration heat, shrinkage rate, and elastic modulus, and a model was established to show the relationship between concrete performance and material composition and environmental conditions.

[0017] Based on the construction schedule and structural stress characteristics of the super high-rise building, the constraints and objective function of the skip-construction method are determined.

[0018] A dynamic adjustment model was established using numerical simulation methods, combining meteorological data, concrete performance parameters, and construction constraints. The model was then verified and optimized using actual engineering data.

[0019] Preferably, the dynamic adjustment model can adjust the pouring sequence and pouring time interval in real time according to changes in real-time meteorological data, so as to adapt to the variable marine climate environment in the coastal area.

[0020] Preferably, the dynamic adjustment model can dynamically adjust the concrete mix proportion based on real-time monitoring data of concrete performance parameters to ensure that the performance of concrete under different environmental conditions meets construction requirements.

[0021] Preferably, during the concrete mix design optimization process, when the ambient temperature is high, the model is dynamically adjusted to increase the amount of retarder and extend the setting time of the concrete to avoid affecting the construction quality due to the concrete setting too quickly caused by high temperature.

[0022] Preferably, during the concrete mix design optimization process, when a significant loss in concrete slump is detected, the model is dynamically adjusted to increase the dosage of water-reducing agent, thereby improving the workability of the concrete and ensuring that the concrete can be poured and vibrated smoothly.

[0023] Preferably, during the dynamic skip-pour pouring process, an information-based construction management system is adopted to monitor parameters such as pouring progress, concrete slump, and vibration in real time through wireless transmission technology, and transmit the data to the control center to adjust the construction parameters in a timely manner according to the requirements of the dynamic adjustment model.

[0024] Preferably, the information-based construction management system can automatically issue early warning signals based on real-time monitoring data, reminding construction personnel to take corresponding measures when the pouring progress is too fast or too slow, the concrete slump does not meet the requirements, or the vibration is not dense enough.

[0025] Preferably, during the temperature control and monitoring process, the burial spacing of the cooling water pipes is 1-1.5m, and the water flow rate can be dynamically adjusted according to the changes in the internal temperature of the concrete. When the internal temperature of the concrete rises rapidly, the water flow rate is increased; when the internal temperature of the concrete approaches the design requirements, the water flow rate is decreased.

[0026] Preferably, during the maintenance and crack inspection process, for cracks with a width of less than 0.2 mm, a surface sealing method is used, in which epoxy resin putty is applied to the surface of the crack; for cracks with a width of 0.2 mm or greater, a pressure grouting method is used, in which epoxy resin grout is injected into the crack using pressure equipment to fill it.

[0027] (III) Beneficial Effects

[0028] Compared with existing technologies, this invention provides a dynamic skip-construction method for large-volume concrete in coastal super high-rise buildings, which has the following advantages:

[0029] 1. Climate adaptability: Adaptable to the changeable marine climate of the coastal area, the dynamic adjustment model optimizes the sequence of pouring, the interval between pours and the concrete mix ratio in real time, avoiding the adverse effects of typhoons, high temperatures and other weather conditions, and ensuring continuous and stable construction.

[0030] 2. Concrete quality control effect: Optimized concrete mix proportion (low heat of hydration cement, reasonable admixtures) + dynamic temperature control (temperature difference ≤25℃) + precise crack treatment, significantly reducing the temperature crack rate and ensuring that the concrete strength and impermeability meet the standards.

[0031] 3. Construction efficiency and management effectiveness: Relying on the information system for real-time monitoring and early warning (pouring progress, slump, etc.), combined with scientific skip-pouring division and curing, the construction cycle is shortened, the drawbacks of traditional processes (such as the difficulty of cleaning post-pouring strips) are reduced, and construction efficiency is improved. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] I. Implementation of the Division of Construction Area into Skip-and-Pack Blocks

[0034] Division basis: Based on the characteristics of the raft slab structure (no obvious stress concentration area, only local thickening section around the elevator shaft), concrete pouring capacity (two truck pumps are configured on site, with a pouring efficiency of 100m³ / h per unit and a total capacity of 200m³ / h), and construction convenience, the skip-concrete block division scheme was determined.

[0035] Specific division: The raft slab is divided into 3 longitudinal sections of 35m / block along the length direction (120m); and into 3 transverse sections of 20m / block along the width direction (60m), ultimately forming 9 rectangular skip blocks (numbered 1-9). The volume of a single block is approximately 35m × 20m × 2.5m = 1750m³, and the single pouring time is approximately 8-9 hours (including transportation waiting time), which meets the pouring capacity requirements.

[0036] Construction joint setting: A 200mm wide construction joint is reserved between adjacent skip blocks. Quick-closing mesh is used as an isolation component and fixed by φ12mm steel bars (500mm spacing) to ensure that the quick-closing mesh is perpendicular to the bottom surface of the raft slab, to prevent displacement during concrete pouring, and to ensure that the concrete of subsequent adjacent blocks is tightly bonded.

[0037] II. Establishment and Implementation of Dynamic Adjustment Model

[0038] Basic data collection and processing

[0039] Meteorological data: Collect historical meteorological data of the coastal area for the past 5 years (average monthly temperature 5-32℃, average monthly humidity 65%-85%, typhoon season from July to September, maximum instantaneous wind speed 15m / s), and connect to the local meteorological department's data platform in real time to obtain real-time forecasts for the next 72 hours (such as temperature, precipitation, and wind speed).

[0040] Concrete performance tests: P.O42.5 low-heat slag cement was selected. Key performance parameters were determined through laboratory tests: 3-day heat of hydration 235 kJ / kg, 28-day shrinkage rate 0.038%, and 28-day modulus of elasticity 3.2 × 10⁻⁶. 4 MPa, establish the relationship model of "cement dosage - heat of hydration - ambient temperature" and "fly ash content - shrinkage rate".

[0041] Construction constraints: Clear schedule constraints (three blocks need to be poured each month to ensure the main structure is capped on schedule) and structural constraints (construction joints should avoid stress concentration areas such as elevator shafts and shear walls, and be parallel to the structural axis).

[0042] Model Construction and Validation: Using ABAQUS numerical simulation software, meteorological data, concrete performance parameters and constraints were input to construct a dynamic adjustment model. The No. 1 block of the project was selected for trial pouring for validation. The model predicted a maximum internal temperature of 62℃ 3 days after pouring, while the actual monitored value was 60℃, with an error of ≤3%, thus validating the model's effectiveness.

[0043] Model dynamic adjustment application: 48 hours before the arrival of a typhoon, the model monitors the real-time wind speed and will reach 12m / s. It will automatically adjust the pouring sequence - prioritize the pouring of blocks No. 3 and No. 5 on the windward side (originally planned to be poured the next day), and suspend the pouring of blocks on the leeward side to avoid the typhoon causing the pouring to be interrupted; during the high temperature in summer (average daily temperature of 32℃), the model will automatically extend the pouring interval between adjacent blocks to 10 days (originally 7 days) to reduce the superposition of temperature stress.

[0044] III. Implementation of Concrete Mix Proportion Optimization

[0045] Based on the output parameters of the dynamically adjusted model, the baseline mix proportion (unit: kg / m³) was determined as follows: P.O42.5 low-heat cement 300, Grade II fly ash 75 (admixture 25%), 5-31.5mm continuously graded coarse aggregate 1100, medium sand (fineness modulus 2.6) 650, polycarboxylate superplasticizer 4.5 (admixture 1.2%), tap water 135, water-cement ratio 0.42, initial slump 180±20mm, 28d compressive strength ≥40MPa.

[0046] High-temperature environment adjustment: When the average daily temperature in summer exceeds 30℃, the model instruction increases the dosage of retarder (hydroxycarboxylic acid) from 0.05% (0.15kg / m³) to 0.08% (0.24kg / m³), and the initial setting time of concrete is extended from 12h to 18h to avoid excessively rapid setting during transportation and pouring.

[0047] Slump loss adjustment: When the concrete is transported from the batching plant to the site (40 minutes by car), the slump is monitored to drop from 180 mm to below 140 mm. The model command increases the water-reducing agent dosage to 1.4% (5.25 kg / m³). After secondary mixing, the slump recovers to 170 mm, which meets the pouring requirements.

[0048] IV. Implementation of Dynamic Skip-Pouring

[0049] Pouring sequence and interval: The odd-numbered blocks (1, 3, 5) are poured first, and the pouring sequence proceeds from the end of the block away from the construction joint towards the construction joint to avoid concrete accumulation at the construction joint; the adjacent even-numbered blocks (2, 4, 6) are poured on the 8th day after the odd-numbered blocks are poured (to meet the ≥7-day interval requirement), and the remaining blocks 7, 8, and 9 are poured on the 9th day after the even-numbered blocks are poured.

[0050] Layered pouring and vibration: The “sloping layered method” is adopted for pouring, with the thickness of each layer controlled at 450mm (≤500mm). A 500mm wide step is set at the layer interface. A φ50 immersion vibrator is used with a vibration spacing of 300mm and an insertion depth of 50mm to the lower layer of concrete. The vibration time is 20-30s until no air bubbles overflow and cement slurry appears on the concrete surface, avoiding under-vibration or over-vibration.

[0051] Information-based monitoring: Three sets of wireless monitoring devices are deployed in each block—temperature sensor (monitoring internal / surface temperature), slump meter (testing once per hour), and pouring progress counter (real-time statistics of pouring volume). The data is transmitted to the control center via 5G wireless transmission. When the pouring progress of block 1 is detected to be 40 m³ / h (lower than the planned 50 m³ / h), the control center automatically issues an alert, and one additional concrete pump truck is immediately added on site, restoring the progress to 52 m³ / h.

[0052] V. Temperature Control and Maintenance Implementation

[0053] Temperature monitoring and control: Temperature sensors are arranged in a 2m×2m grid inside each silo, and two sensors are arranged on the top and two on the sides of the surface. In summer, the temperature of the aggregate is controlled at 28℃ (≤30℃) by mixing aggregate with cold water (water temperature ≤20℃) + shading the mixing tank. In winter, it is controlled at 6℃ (≥5℃) by mixing aggregate with hot water (water temperature ≤80℃) + preheating aggregate. When the internal temperature of silo No. 3 reaches 62℃ and the temperature difference with the surface is 28℃ (over 25℃), two layers of flame-retardant insulation blankets (thermal conductivity ≤0.04W / (m・K)) are immediately covered on the surface. At the same time, the flow rate of the DN50 cooling water pipes (1.2m spacing, serpentine arrangement) pre-embedded in the silo is increased from 2m³ / h to 3m³ / h. After 4 hours, the temperature difference drops to 22℃.

[0054] Curing and Crack Treatment: In summer, within 24 hours after pouring, water should be stored on the top surface of the block for curing at a depth of 50mm for 7 days to prevent rapid evaporation. In winter, within 6 hours after pouring, first cover with a layer of plastic film (overlapping 100mm to prevent air leakage), then cover with a layer of 50mm thick cotton felt, extending the curing period to 14 days. During the curing period, a crack width meter was used for daily inspection. Two micro-cracks of 0.15mm width were found, and the surface sealing method was used—after cleaning the crack surface, a 2mm thick layer of epoxy resin putty (100mm wide) was applied. One crack of 0.25mm width was found, and the pressure grouting method was used—the epoxy resin grout was injected into the crack using a 0.3-0.5MPa pressure grouting machine. After grouting, the crack was covered with cotton felt for curing for 3 days, and the crack healed well.

[0055] VI. Implementation Results

[0056] The raft foundation of this coastal super high-rise building was constructed using this method. The average 28-day compressive strength of the concrete reached 42.5 MPa (meeting the C35 design requirements). The incidence of temperature cracks was reduced from 15% in the traditional skip-pour method to 3%. The construction period was shortened by 10 days compared to the plan. Furthermore, the impact of two typhoons on the construction was successfully avoided. This method meets the quality and safety requirements for the construction of large-volume concrete for coastal super high-rise buildings.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamic skip-construction method for large-volume concrete in coastal super high-rise buildings, characterized in that, include: Based on the structural characteristics, dimensions and concrete pouring capacity of the coastal super high-rise building, the construction area is divided into multiple jump-section blocks. The length of a single jump-section block does not exceed 40m, and the width is determined according to the structural shape and construction convenience. Construction joints containing quick-closing mesh or steel mesh are reserved between adjacent jump-section blocks. A dynamic adjustment model was established by combining meteorological data of coastal areas, concrete material performance parameters and construction progress requirements to automatically adjust the skip-pour sequence, pouring time interval and concrete mix ratio. Optimize the concrete mix proportion according to the requirements of the dynamic adjustment model, select low heat of hydration cement, add 20%-30% fly ash or mineral powder, use polycarboxylate-based high-performance water-reducing agent, control the water-cement ratio between 0.4 and 0.45, and select appropriate coarse and fine aggregates. The pouring is carried out according to the skip-section sequence determined by the dynamic adjustment model. The odd or even number of sections are poured first. The time interval between pouring of adjacent sections is not less than 7 days. The layered pouring method is adopted, and the thickness of each layer does not exceed 500mm. An immersion vibrator is used for compaction. Temperature sensors are placed inside and on the surface of the concrete to monitor temperature changes in real time and control the concrete pouring temperature. The temperature should not exceed 30°C in summer and not be lower than 5°C in winter. When the temperature difference between the inside and the surface exceeds 25°C, heat preservation or cooling measures are taken. Concrete should be cured promptly after pouring, with water retention for curing in summer and plastic film and cotton felt for insulation and moisture retention in winter. During the curing period, cracks should be inspected regularly and dealt with promptly if any are found.

2. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, The process of establishing the dynamic adjustment model includes: Collect historical meteorological data and real-time weather forecast information for coastal areas, and analyze the impact of meteorological factors such as temperature, humidity, and wind speed on concrete construction; Tests were conducted on concrete materials to obtain performance parameters such as cement hydration heat, shrinkage rate, and elastic modulus, and a model was established to show the relationship between concrete performance and material composition and environmental conditions. Based on the construction schedule and structural stress characteristics of the super high-rise building, the constraints and objective function of the skip-construction method are determined. A dynamic adjustment model was established using numerical simulation methods, combining meteorological data, concrete performance parameters, and construction constraints. The model was then verified and optimized using actual engineering data.

3. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 2, characterized in that, The dynamic adjustment model can adjust the pouring sequence and pouring time interval in real time according to changes in real-time meteorological data, so as to adapt to the variable marine climate environment in coastal areas.

4. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 2, characterized in that, The dynamic adjustment model can dynamically adjust the concrete mix proportion based on real-time monitoring data of concrete performance parameters, ensuring that the performance of concrete under different environmental conditions meets construction requirements.

5. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, During the concrete mix optimization process, when the ambient temperature is high, the model is dynamically adjusted to increase the amount of retarder and extend the setting time of the concrete to avoid affecting the construction quality due to the concrete setting too quickly caused by high temperature.

6. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, During the concrete mix optimization process, when a significant loss in concrete slump is detected, the model is dynamically adjusted to increase the dosage of water-reducing agent, thereby improving the workability of the concrete and ensuring that it can be poured and vibrated smoothly.

7. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, During the dynamic skip-pour pouring process, an information-based construction management system is used to monitor parameters such as pouring progress, concrete slump, and vibration in real time through wireless transmission technology. The data is then transmitted to the control center, and the construction parameters are adjusted in a timely manner according to the requirements of the dynamic adjustment model.

8. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 7, characterized in that, The information-based construction management system can automatically issue early warning signals based on real-time monitoring data. When the pouring progress is too fast or too slow, the concrete slump does not meet the requirements, or the compaction is not dense enough, it will remind the construction personnel to take corresponding measures.

9. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, During the temperature control and monitoring process, the spacing between the buried cooling water pipes is 1-1.5m, and the water flow rate can be dynamically adjusted according to the changes in the internal temperature of the concrete. When the internal temperature of the concrete rises rapidly, the water flow rate is increased; when the internal temperature of the concrete approaches the design requirements, the water flow rate is decreased.

10. The method for dynamic skip-construction of large-volume concrete for coastal super high-rise buildings according to claim 1, characterized in that, During the maintenance and crack inspection process, for cracks with a width of less than 0.2 mm, the surface sealing method is used, in which epoxy resin putty is applied to the surface of the crack; for cracks with a width of 0.2 mm or greater, the pressure grouting method is used, in which epoxy resin grout is injected into the crack using pressure equipment to fill it.