Mix ratio of radiation-proof mass concrete wall and its preparation and construction method
By using specific mix ratios and construction methods in cold environments, the high cost and temperature stress problems of radiation-proof large volume concrete in the prior art are solved, and low-cost and efficient concrete preparation and radiation-proof performance are achieved.
Patent Information
- Application Number
- CN202510069635.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-04-08
AI Technical Summary
The prior art preparation of radiation-proof large volume concrete in cold environments has problems such as high cost and high preparation requirements. It is easy to cause temperature stress due to hydration heat during winter construction, resulting in cracks on the concrete surface.
Specific mix ratios and construction methods are adopted, including the use of Class F secondary fly ash and S95 slag powder as blends, combined with PCA-VI polycarboxylic acid water-reducing antifreeze as admixture, and a stirring transport truck and insulation facilities are used during the construction process to control the temperature and pouring speed of the concrete to ensure the uniformity and compactness of the concrete.
It realizes the low-cost and efficient preparation of radiation-proof large-volume concrete in cold environments, reduces construction costs, and avoids temperature stress problems caused by hydration heat, ensuring the integrity and radiation-proof performance of concrete.
Abstract
Description
Technical Field
[0001] The present invention relates to the field of concrete technology, and in particular to a radiation-proof large-volume concrete wall mix ratio in a cold environment (below 5° C.) and a preparation and construction method thereof. Background Art
[0002] At present, different radiation sources and instruments are widely used in various military, aerospace and research centers. At the same time, nuclear shielding technology has also received great attention from the public. The danger of these radiations mainly comes from their high penetration and ionization energy, which can damage normal human cells and cause gene mutations. Long-term exposure to nuclear radiation environment will cause people to have problems such as decreased immunity, cancer, and even immediate death. Therefore, effective radiation shielding of nuclear facilities is very important.
[0003] In the prior art, the prepared radiation-proof concrete is mostly made of raw materials mixed with metallic elements such as lead or barite, and is prepared at room temperature. The radiation-proof concrete has factors such as high cost and high preparation requirements. In addition, during winter construction, in order to prevent large-volume concrete from causing large temperature stress due to hydration heat during the solidification process in winter, which leads to cracks on the concrete surface, the large-volume concrete is required to be retarded, that is, the early strength of the large-volume concrete should be low rather than high, and the hydration heat of cement in the large-volume concrete needs to be reduced to ensure that no cracks are generated in the concrete, thereby ensuring that radiation does not penetrate out.
[0004] Therefore, it is of great practical significance to develop a low-cost radiation-proof large-volume concrete suitable for cold environments. Summary of the invention
[0005] The purpose of the present invention is to provide a radiation-proof large-volume concrete wall mix ratio and a preparation and construction method thereof, which can prepare radiation-proof large-volume concrete in a cold environment through scientific material selection and testing.
[0006] In order to achieve the above object, the present invention adopts the following technical scheme: A radiation-proof large-volume concrete wall mix ratio, wherein the amount of each component in each cubic meter of concrete mix ratio is: 240 kg of ordinary Portland cement, 886 kg of sand, 87 kg of water, 827 kg of crushed stone, 207 kg of fine stone, 90 kg of the first admixture, 75 kg of the second admixture, and 5.3 kg of admixture; and the concrete bulk density is not less than 2.4 kg / m 3 .
[0007] The first admixture is made of Class F secondary fly ash produced by Datang Xi'an Thermal Power Plant, and the temperature before mixing is not less than 10°C; The second admixture is S95 slag powder produced by Shaanxi Sai Ke Rui En Ecological Building Materials Co., Ltd., and the temperature before mixing is not less than 10°C; The admixture selected is PCA-VⅠ polycarboxylic acid water-reducing antifreeze agent produced by Jiangsu Subote New Materials Co., Ltd.
[0008] Specifically, the ordinary Portland cement is selected from Jidong Cement Tongchuan Co., Ltd., with a specification model of P·O42.5, and the temperature of the cement before mixing is not less than 45°C; The sand is selected from high-quality medium-coarse sand, and the mud content of the sand is controlled to be less than 3%. The medium-coarse sand with a fineness modulus between 2.6 and 3.0 is selected to achieve the purpose of reducing concrete shrinkage, and the temperature of the sand before mixing is not less than 8°C; The water is conventional tap water, and the temperature before mixing is not lower than 30°C and not higher than 45°C; The crushed stone is selected to be 10mm to 25mm, with a mud content of less than 3%, and the temperature of the crushed stone before mixing is not less than 8°C; The fine stone is selected to be 5mm to 10mm, with a mud content of less than 3%, and the temperature of the fine stone before mixing is not lower than 8°C. It is combined with crushed stone to form a secondary gradation to achieve the purpose of reducing concrete shrinkage.
[0009] A method for preparing and constructing a radiation-proof mass concrete wall, wherein the amount of each component in the concrete mix ratio per cubic meter is: 240 kg of ordinary Portland cement, 886 kg of sand, 87 kg of water, 827 kg of crushed stone, 207 kg of fine stone, 90 kg of the first admixture, 75 kg of the second admixture, and 5.3 kg of admixture; When mixing, first pour all the crushed stone, fine stone, sand and 75% of the water in the mix ratio into the mixer, and stir for 20 seconds to wet the fine stone and sand; then pour all the ordinary Portland cement, the first admixture and the second admixture in the mix ratio and stir for 40 seconds; then add the remaining 25% of the water and admixture in the mix ratio and stir for 30 seconds; During the transportation of concrete, the concrete mixture is transported by concrete mixer trucks, which are equipped with heat preservation facilities. The water in the tank should be drained before loading. During transportation, the mixing tank should keep a slow rotation of 3 to 6 revolutions per minute to ensure the uniformity of the quality of the concrete and prevent segregation during transportation. Before entering the mold, the concrete mixture should not be lower than 10℃ and the slump should be 180±20cm; The on-site construction process is as follows: arrange concrete ducts, arrange temperature measuring points, pour the first layer of concrete, vibrate, return to pour the second layer of concrete, vibrate again, and repeat the operation; the concrete vibration operation advances in the direction of the pipe withdrawal, the concrete surface is leveled, compacted, and smoothed for the first time, the concrete surface is leveled, compacted, and smoothed for the second time, and maintenance and concrete temperature measurement and monitoring are carried out.
[0010] In actual application, the free fall height of concrete is not more than 2m. Concrete ducts are arranged for tall walls. To avoid segregation, 200mm corrugated pipes are used for the ducts. The longitudinal spacing of the ducts is 1.6-2 meters and the lateral spacing is 0.8-0.9 meters.
[0011] In order to better monitor the temperature inside and outside the concrete, a wireless thermometer system is used for the temperature measurement point arrangement. Before pouring the concrete, the temperature measuring sleeve is fixed at the required position, and the temperature measuring components are placed at different heights of the sleeve. Through thermoelectric conversion, data collection and processing, the temperature changes of different parts of the concrete are monitored on the microcomputer. The temperature measurement time shall be no less than 14 days. The temperature shall be measured every 2 hours for the first 3 days, every 4 hours from the 4th to the 7th day, and every 8 hours from the 8th to the 14th day.
[0012] Specifically, when pouring wall concrete, it is poured in layers and symmetrically, with each pouring layer height not exceeding 0.5m; after each layer of concrete is poured symmetrically and completed, the material unloading position returns to the initial point and the previous step is repeated. The pouring height also does not exceed 0.5m, and the pouring is cyclically poured to the upper construction joint; the concrete pouring speed should not be too fast, so as to avoid deformation and instability of the formwork and bracket due to the large impact force caused by the fast pouring speed.
[0013] Furthermore, the vibration time limit for each vibration point is until the bubbles in the concrete are eliminated, the spacing between the vibration points is 1.5 times the effective radius of the vibrating rod, that is, 0.4m but not more than 0.5m, and the vibration time is 5-10 seconds and not more than 10 seconds; to prevent segregation, the vibration must be dense, without missed vibration, insufficient vibration, or over-vibration, and the vibration points must be uniform, and the vibrating rod should be inserted quickly and pulled out slowly; when pouring each upper layer, the vibrating rod should be inserted into the lower layer 0.1m to eliminate the cold joint between the two layers; each time the concrete is poured, no pause is allowed in the middle, and no construction joints should be left, and continuous operation must be required until the pouring of the pouring section is completed.
[0014] Furthermore, three vibrators are arranged in front, middle and back of each pouring position; the first one is arranged at the pouring point of concrete, and the vibrator is responsible for vibrating the concrete out of the pipe so that it flows into the bottom layer through the surface reinforcement; the second one is set in the middle part of the concrete, responsible for the compaction of the inclined concrete; the third one is set at the foot of the slope to ensure the compaction of the concrete below the bottom reinforcement.
[0015] Furthermore, under cold conditions, after the concrete is poured, the concrete is insulated by covering it with plastic film and felt for insulation and curing to prevent shrinkage cracks in the concrete and ensure smooth hydration of the cement. During the pouring process, the concrete is immediately covered and insulated after initial setting, and two layers of felt are covered on the outer wall of the formwork for curing. The material, measures and thickness of the insulation layer are adjusted at any time according to the temperature measurement to control the temperature difference between the inside and outside of the concrete to be no more than 25°C and the cooling rate to be no more than 2°C / day.
[0016] Compared with the prior art, the radiation-proof mass concrete wall mix ratio and its preparation and construction method described in the present invention have the following advantages: In the radiation-proof large-volume concrete wall mix ratio and its preparation and construction method provided by the present invention, construction factors are taken into consideration in the mix ratio design, and the concrete performance is designed and controlled more accurately, which greatly reduces the construction cost of the radiation-proof large-volume concrete. Through the mix ratio of concrete, the functional requirements of radiation protection are achieved from the traditional concrete characteristics, and good effects are achieved. DETAILED DESCRIPTION
[0017] The embodiment of the present invention provides a radiation-proof large-volume concrete wall mix ratio, wherein the amount of each component in the concrete mix ratio per cubic meter is: 240 kg of ordinary Portland cement, 886 kg of sand, 87 kg of water, 827 kg of crushed stone, 207 kg of fine stone, 90 kg of the first admixture, 75 kg of the second admixture, and 5.3 kg of admixture; and the concrete bulk density is not less than 2.4 kg / m 3 .
[0018] The embodiment of the present invention further provides a method for preparing and constructing a radiation-proof large-volume concrete wall. The amount of each component in the concrete mix ratio per cubic meter is: 240 kg of ordinary Portland cement, 886 kg of sand, 87 kg of water, 827 kg of crushed stone, 207 kg of fine stone, 90 kg of the first admixture, 75 kg of the second admixture, and 5.3 kg of admixture; When mixing, first pour all the crushed stone, fine stone, sand and 75% of the water in the mix ratio into the mixer, and stir for 20 seconds to wet the fine stone and sand; then pour all the ordinary Portland cement, the first admixture and the second admixture in the mix ratio and stir for 40 seconds; then add the remaining 25% of the water and admixture in the mix ratio and stir for 30 seconds; During the transportation of concrete, the concrete mixture is transported by concrete mixer trucks, which are equipped with heat preservation facilities. The water in the tank should be drained before loading. During transportation, the mixing tank should keep a slow rotation of 3 to 6 revolutions per minute to ensure the uniformity of the quality of the concrete and prevent segregation during transportation. Before entering the mold, the concrete mixture should not be lower than 10℃ and the slump should be 180±20cm; The on-site construction process is as follows: arrange concrete ducts, arrange temperature measuring points, pour the first layer of concrete, vibrate, return to pour the second layer of concrete, vibrate again, and repeat the operation; the concrete vibration operation advances in the direction of the pipe withdrawal, the concrete surface is leveled, compacted, and smoothed for the first time, the concrete surface is leveled, compacted, and smoothed for the second time, and maintenance and concrete temperature measurement and monitoring are carried out.
[0019] Compared with the prior art, the radiation-proof mass concrete wall mix ratio and the preparation and construction method thereof described in the embodiment of the present invention have the following advantages: In the radiation-proof large-volume concrete wall mix ratio and its preparation and construction method provided by the embodiments of the present invention, construction factors are taken into consideration in the mix ratio design, and the concrete performance is designed and controlled more accurately, which greatly reduces the construction cost of radiation-proof large-volume concrete. Through the mix ratio of concrete, the functional requirements of radiation protection are achieved from the traditional concrete characteristics, and good effects are achieved.
[0020] Among them, the first admixture can be selected from Class F secondary fly ash produced by Datang Xi'an Thermal Power Plant, and the temperature before mixing is not less than 10°C; The second admixture can be S95 slag powder produced by Shaanxi Sai Ke Rui En Ecological Building Materials Co., Ltd., and the temperature before mixing is not less than 10°C; The above-mentioned admixture can be selected from PCA-VⅠ polycarboxylic acid water-reducing antifreeze agent produced by Jiangsu Subote New Materials Co., Ltd.
[0021] Specifically, the above-mentioned ordinary Portland cement can be selected from the manufacturer Jidong Cement Tongchuan Co., Ltd. with the specification model P·O42.5, and the temperature of the cement before mixing is not less than 45°C; The above-mentioned sand can be high-quality medium-coarse sand, and the mud content of the sand is controlled to be less than 3%. Medium-coarse sand with a fineness modulus between 2.6 and 3.0 is selected to achieve the purpose of reducing concrete shrinkage, and the temperature of the sand before mixing is not less than 8°C; The water mentioned above can be regular tap water, and the temperature before mixing should not be lower than 30℃ and not higher than 45℃; The above-mentioned crushed stone can be selected from 10mm to 25mm, with a mud content of less than 3%, and the temperature of the crushed stone before mixing should not be lower than 8℃; The above-mentioned fine stone can be selected from 5mm to 10mm, with a mud content of less than 3%, and the temperature of the fine stone before mixing should not be lower than 8°C. It can be combined with crushed stone to form a secondary grading to achieve the purpose of reducing concrete shrinkage.
[0022] In actual application, the free fall height of concrete is not more than 2m. Concrete ducts are arranged for tall walls. To avoid segregation, 200mm corrugated pipes can be used for the ducts. The longitudinal spacing of the ducts can be 1.6-2 meters, and the lateral spacing can be 0.8-0.9 meters.
[0023] In order to better monitor the temperature inside and outside the concrete, a wireless thermometer system is used for the temperature measurement point arrangement. Before pouring the concrete, the temperature measuring sleeve is fixed at the required position, and the temperature measuring components are placed at different heights of the sleeve. In addition, the temperature changes of different parts of the concrete can be monitored on the microcomputer through thermoelectric conversion, data collection and processing. The temperature measurement time can be no less than 14 days. The temperature can be measured every 2 hours for the first 3 days, every 4 hours from the 4th to the 7th day, and every 8 hours from the 8th to the 14th day.
[0024] Specifically, when pouring wall concrete, it is poured in layers and symmetrically, and the height of each pouring layer may not exceed 0.5m; after each layer of concrete is poured symmetrically and completed, the material unloading position returns to the initial point, and the previous step is repeated. The pouring height also does not exceed 0.5m, and the pouring is cyclically poured to the upper construction joint; the concrete pouring speed should not be too fast, so as to avoid deformation and instability of the formwork and bracket due to the large impact force caused by the fast pouring speed.
[0025] Furthermore, the vibration time limit for each vibration point is until the bubbles in the concrete are eliminated, and the spacing between the vibration points can be 1.5 times the effective radius of the vibrating rod, that is, it can be 0.4m but not more than 0.5m, and the vibration time can be 5-10 seconds and not more than 10 seconds; to prevent segregation, the vibration must be dense, without missed vibration, insufficient vibration, or over-vibration, and the vibration points must be uniform, and the vibrating rod should be inserted quickly and pulled out slowly; when pouring each upper layer, the vibrating rod can be inserted into the lower layer 0.1m to eliminate the cold joint between the two layers; each time the concrete is poured, no pause is allowed in the middle, and no construction joints should be left, and continuous operation must be required until the pouring of the pouring section is completed.
[0026] Furthermore, three vibrators can be arranged in front, middle and back of each pouring position; the first one can be arranged at the pouring point of concrete, and the vibrator is responsible for vibrating the concrete out of the pipe so that it flows into the bottom layer through the surface reinforcement; the second one can be set in the middle part of the concrete, responsible for the compaction of the slope concrete; the third one can be set at the foot of the slope to ensure the compaction of the concrete below the bottom reinforcement.
[0027] Furthermore, under cold conditions, after the concrete is poured, the concrete can be insulated by covering it with plastic film and felt to prevent shrinkage cracks in the concrete and ensure smooth cement hydration. During the pouring process, the concrete can be covered and insulated immediately after initial setting. Two layers of felt can be used to cover the outer wall of the formwork for maintenance. The material, measures and thickness of the insulation layer can be adjusted at any time according to the temperature measurement. The temperature difference between the inside and outside of the concrete can be controlled to be no more than 25°C and the cooling rate can be no more than 2°C / day.
[0028] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A radiation-proof mass concrete wall mix ratio, characterized in that: The amount of each component in the concrete mix per cubic meter is: 240kg of ordinary Portland cement, 886kg of sand, 87kg of water, 827kg of crushed stone, 207kg of fine stone, 90kg of the first admixture, 75kg of the second admixture, and 5.3kg of admixture; and the concrete bulk density is not less than 2.4kg / m 3 .
2. The radiation-proof mass concrete wall mix ratio according to claim 1 is characterized in that: The first admixture is selected from Class F secondary fly ash produced by Datang Xi'an Thermal Power Plant, and the temperature before mixing is not less than 10°C; The second admixture is S95 slag powder produced by Shaanxi Sai Ke Rui En Ecological Building Materials Co., Ltd., and the temperature before mixing is not less than 10°C; The admixture selected is PCA-VI polycarboxylic acid water-reducing antifreeze agent produced by Jiangsu Subote New Materials Co., Ltd.
3. The radiation-proof mass concrete wall mix ratio according to claim 1 or 2 is characterized in that: The ordinary Portland cement is produced by Jidong Cement Tongchuan Co., Ltd. and has a specification of P·O42.5, and the temperature of the cement before mixing is not less than 45°C; The sand is selected from high-quality medium-coarse sand, and the mud content of the sand is controlled to be less than 3%. The medium-coarse sand with a fineness modulus between 2.6 and 3.0 is selected to achieve the purpose of reducing concrete shrinkage, and the temperature of the sand before mixing is not less than 8°C; The water is conventional tap water, and the temperature before mixing is not lower than 30°C and not higher than 45°C; The crushed stone is selected to be 10mm to 25mm, with a mud content of less than 3%, and the temperature of the crushed stone before mixing is not less than 8°C; The fine stone is selected to be 5mm to 10mm, with a mud content of less than 3%, and the temperature of the fine stone before mixing is not lower than 8°C. It is combined with crushed stone to form a secondary gradation to achieve the purpose of reducing concrete shrinkage.
4. A method for preparing and constructing a radiation-proof mass concrete wall, characterized in that: The amount of each component in the concrete mix per cubic meter is: 240kg of ordinary Portland cement, 886kg of sand, 87kg of water, 827kg of crushed stone, 207kg of fine stone, 90kg of the first admixture, 75kg of the second admixture, and 5.3kg of admixture; When mixing, first pour all the crushed stone, fine stone, sand and 75% of the water in the mix ratio into the mixer, and stir for 20 seconds to wet the fine stone and sand; then pour all the ordinary Portland cement, the first admixture and the second admixture in the mix ratio and stir for 40 seconds; then add the remaining 25% of the water and admixture in the mix ratio and stir for 30 seconds; During the transportation of concrete, the concrete mixture is transported by concrete mixer trucks, which are equipped with heat preservation facilities. The water in the tank should be drained before loading. During transportation, the mixing tank should keep a slow rotation of 3 to 6 revolutions per minute to ensure the uniformity of the quality of the concrete and prevent segregation during transportation. Before entering the mold, the concrete mixture should not be lower than 10℃ and the slump should be 180±20cm; The on-site construction process is as follows: arrange concrete ducts, arrange temperature measuring points, pour the first layer of concrete, vibrate, return to pour the second layer of concrete, vibrate again, and repeat the operation; the concrete vibration operation advances in the direction of the pipe withdrawal, the concrete surface is leveled, compacted, and smoothed for the first time, the concrete surface is leveled, compacted, and smoothed for the second time, and maintenance and concrete temperature measurement and monitoring are carried out.
5. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 4, characterized in that: The free fall height of concrete is not more than 2m. Concrete ducts are arranged for tall walls. To avoid segregation, 200mm corrugated pipes are used for the ducts. The longitudinal spacing of the ducts is 1.6-2 meters and the lateral spacing is 0.8-0.9 meters.
6. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 5, characterized in that: In order to better monitor the temperature inside and outside the concrete, the temperature measurement points are arranged using a wireless thermometer system. Before pouring the concrete, the temperature measuring sleeve is fixed at the required position, and the temperature measuring components are placed at different heights of the sleeve; through thermoelectric conversion, data collection and processing, the temperature changes of different parts of the concrete are monitored on the microcomputer; The temperature measurement time shall be no less than 14 days. The temperature shall be measured every 2 hours for the first 3 days, every 4 hours from the 4th to the 7th day, and every 8 hours from the 8th to the 14th day.
7. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 6, characterized in that: When pouring wall concrete, pour it in layers and symmetrically, with each pouring layer height not exceeding 0.5m; after each layer of concrete is poured symmetrically and completed, the material unloading position returns to the initial point and the previous step is repeated. The pouring height also does not exceed 0.5m, and the pouring is cyclically poured to the upper construction joint; the concrete pouring speed should not be too fast, so as to avoid deformation and instability of the formwork and bracket due to the large impact force caused by too fast pouring speed.
8. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 7, characterized in that: The vibration time limit for each vibration point is until the bubbles in the concrete are eliminated. The distance between the vibration points is 1.5 times the effective radius of the vibrating rod, that is, 0.4m but not more than 0.5m. The vibration time is 5-10 seconds and not more than 10 seconds. To prevent segregation, the vibration must be dense, without missed vibration, insufficient vibration, or over-vibration. At the same time, the vibration points must be uniform, and the vibrating rod should be inserted quickly and pulled out slowly. When pouring each upper layer, the vibrating rod should be inserted into the lower layer 0.1m to eliminate the cold joint between the two layers. Each time the concrete is poured, no pause is allowed and no construction joints should be left. Continuous operation is required until the pouring of the pouring section is completed.
9. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 8, characterized in that: Three vibrators are arranged in front, middle and back of each pouring position; the first one is arranged at the pouring point of concrete, and the vibrator is responsible for vibrating the concrete out of the pipe so that it can flow into the bottom layer through the surface reinforcement; the second one is set in the middle part of the concrete and is responsible for the compaction of the inclined concrete; the third one is set at the foot of the slope to ensure the compaction of the concrete below the bottom reinforcement.
10. The method for preparing and constructing a radiation-proof massive concrete wall according to claim 9, characterized in that: Under cold conditions, after the concrete is poured, the concrete is insulated by covering it with plastic film and felt to prevent shrinkage cracks in the concrete and ensure smooth cement hydration. During the pouring process, the concrete is immediately covered and insulated after initial setting. Two layers of felt are covered on the outer wall of the formwork for maintenance. The material, measures and thickness of the insulation layer are adjusted at any time according to the temperature measurement to control the temperature difference between the inside and outside of the concrete to no more than 25°C and the cooling rate to no more than 2°C / day.