Efficient high belite cement concrete construction process
By adopting double-stage mixing, layered casting, vibration compaction and wet curing methods in the construction process of high Belite cement concrete, the problems of uneven mixing, uncompromising casting and improper early curing are solved, and the molding quality and durability of concrete are significantly improved.
Patent Information
- Application Number
- CN202411983309.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-03-07
AI Technical Summary
The existing high-Belite cement concrete construction process has problems such as uneven mixing, unsolid pouring and improper early curing, resulting in the failure of the concrete forming quality and durability to reach the ideal level.
The double-stage stirring method is adopted, and the aggregate and water are pre-stirred, and then the high-belitt cement and polycarboxylic acid water reducing agent are added for main stirring; layered casting and mechanical vibration and compaction are carried out; wet curing method is used to control the initial and long-term temperature and humidity environment.
The double-step stirring method ensures full mixing of cement, aggregate and water, layered casting and vibration are dense to prevent internal voids, and wet maintenance methods prevent early drying and cracking, which significantly improves the molding quality and long-term durability of concrete.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of concrete construction and relates to an efficient high-belite cement concrete construction process. Background Art
[0002] In current construction projects, high-belite cement concrete is gradually being used in various large-scale infrastructure and construction projects due to its low clinker consumption, low carbon emissions and excellent mechanical properties. However, the existing high-belite cement concrete construction process still has many problems in actual use and cannot give full play to the advantages of high-belite cement. Specifically, traditional construction processes usually rely on experience-based operations and lack systematic and standardized process control, resulting in concrete molding quality and durability failing to reach ideal levels. For example, (1) uneven mixing leads to a decrease in material properties: the traditional single-stage mixing process makes it difficult to ensure that cement, aggregate and water are fully mixed. Especially in high-belite cement concrete, uneven mixing will directly affect its molding quality and later strength. (2) Uneven stratification during pouring easily forms weak layers: the existing process lacks precise control of the thickness of layered pouring. Too thick pouring layers have poor effects when vibrating and compacting, and are prone to forming internal voids or stratification, affecting the overall strength and durability of concrete. (3) The curing process is not standardized, leading to early cracking of concrete: in the existing construction process, the curing method of concrete is often simple and extensive, lacking precise control of humidity and temperature. Excessive water loss at an early stage causes cracking on the concrete surface, affecting the subsequent strength development and thus shortening the service life of concrete.
[0003] Based on this, it is necessary to study an efficient high-belite cement concrete construction process. Summary of the invention
[0004] The invention proposes an efficient high-belite cement concrete construction process, which solves the problems of uneven mixing, loose pouring and inadequate early curing in the existing process, and significantly improves the molding quality and long-term durability of concrete.
[0005] The technical solution of the present invention is achieved in this way: An efficient high-belite cement concrete construction process comprises the following steps: A. Prepare materials; B. Double-stage stirring: Pre-mix the aggregate and water, the mixing time is controlled at 1-2 minutes, the pre-mixing temperature is controlled at 10-25°C, and the amount of water used is 70-80% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 3-5 minutes; wherein the mass ratio of high belite cement to aggregate is 1:2.5-3.5; the amount of polycarboxylate water reducer is 0.8%-1.2% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.35-0.45; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 30-40 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 30-60 seconds and the vibration frequency at 4000-6000 times / minute; D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 15-25℃, the humidity should be above 80%, and the initial curing should be 12-24h. Then, the ambient temperature should be maintained at 15-35℃, the humidity should be above 80%, and the curing should be carried out for 7-14 days.
[0006] Preferably, step B comprises the following steps: Pre-mix the aggregate and water, the mixing time is controlled at 1-2 minutes, the pre-mixing temperature is controlled at 10-25°C, and the amount of water used is 70-80% of the total water weight; After the pre-mixing is completed, the water reducer and the remaining water are mixed to obtain a water reducer mixed solution, and then the water reducer mixed solution and high belite cement are added to the mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 3-5 minutes; wherein the mass ratio of high belite cement to aggregate is 1:2.5-3.5; and the amount of polycarboxylate water reducer is 0.8%-1.2% of the mass of high belite cement.
[0007] Preferably, the dicalcium silicate content in the high-belite cement accounts for more than 50% of the clinker, and it is required to contain 5-10% calcium aluminate and 7-12% calcium ferrite to ensure that its early strength reaches more than 10MPa. The cement should comply with the requirements of the national standard GB / T17671-2021 "Test Method for Strength of Cement Mortar" to ensure that the 28-day compressive strength reaches ≥45MPa.
[0008] Preferably, the aggregate includes crushed stone with a particle size range of 5-31.5 mm and a mud content of no more than 1%. The aggregate should be crushed stone with uniform particle size and comply with GB / T 14685-2022 "Pebbles and crushed stone for construction". The aggregate should be washed to avoid surface dust and impurities to ensure full combination with the cement paste.
[0009] Preferably, the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 15-20%, 65-75% and 10-15% of 5mm~10mm, 10mm~20mm and 16mm~31.5mm respectively; the fineness modulus of the sand is between 2.6 and 3.0, and the particle size distribution of the sand is 0.075mm-4.75mm.
[0010] Preferably, the aggregate comprises 58wt% crushed stone and 42wt% sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% of 5mm~10mm, 10mm~20mm and 16mm~31.5mm respectively.
[0011] Preferably, the stirring rates of the pre-stirring and the main stirring are both 20-30 rpm.
[0012] Preferably, the mass ratio of the high-belite cement to aggregate is 1:3.
[0013] Preferably, the polycarboxylate water-reducing agent is used in an amount of 1.0% of the mass of the high belite cement.
[0014] Preferably, in step C, the thickness is controlled at 35 cm, the vibration time is controlled at 50 s, and the vibration frequency is 5000 times / minute.
[0015] Preferably, an early strength agent may also be added to ensure the early compressive strength of the concrete within 3 days.
[0016] The working principle and beneficial effects of the present invention are: 1. The present invention provides an efficient high-belite cement concrete construction process, which aims to solve the problems of uneven mixing, loose pouring and improper early maintenance in the prior art, so as to significantly improve the molding quality, construction efficiency and durability of concrete.
[0017] 2. The present invention adopts a two-stage mixing method to ensure that cement, aggregate and water are fully mixed, avoid the segregation problem common in traditional processes, ensure that the concrete has better fluidity and uniformity, and thus improve its overall molding quality; At the same time, the combination of layered pouring and mechanical vibration compaction technology effectively prevents the generation of internal voids during the pouring process, ensuring the density and strength of each layer of concrete, thereby further improving the overall stability of the concrete structure; Furthermore, in order to improve the long-term durability of concrete, the present invention adopts a wet curing method to prevent the cracking problem caused by rapid water loss in the early stage of concrete, and through precise control of temperature and humidity, ensures the strength development of concrete in the early hardening stage, significantly improving its compressive resistance and durability.
[0018] 3. The present invention improves construction efficiency by optimizing the construction process. With the cooperation of high-efficiency processes such as double-stage mixing, layered pouring and mechanical vibration, the rework and repair work during construction is reduced, and the construction period is significantly shortened; At the same time, due to the reasonable design of the construction process of the present invention, it can effectively reduce the waste of materials, and give full play to the environmental protection advantages of high belite cement, such as low clinker consumption and low carbon emissions, which helps to reduce the impact on the environment and meets the requirements of modern green buildings; On the whole, the present invention not only improves the quality and durability of concrete, but also reduces resource waste, improves construction efficiency, and meets the demand for high-performance concrete in current construction projects. DETAILED DESCRIPTION
[0019] 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.
[0020] In the following examples and comparative examples, the high belite cement used was purchased from Jinyu High Belite Cement, in which the content of dicalcium silicate accounts for more than 50% of the clinker, and it is required to contain 5-10% calcium aluminate and 7-12% calcium ferrite; the polycarboxylate water reducer was purchased from polycarboxylate high performance water reducer (HS-2 standard type), manufacturer: Tangshan Hongshi. The fineness modulus of the sand is between 2.6 and 3.0, and the particle size distribution of the sand is 0.075mm-4.75mm.
[0021] Example 1 An efficient high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; before construction, high belite cement, aggregate, polycarboxylate water reducer and other raw materials need to be accurately weighed and pre-treated. Due to its unique chemical composition, high belite cement requires a more uniform mixing with aggregate and water. Therefore, the selection and preparation of raw materials are very important; The mud content of aggregate shall not exceed 1%, and the aggregate includes 58wt% crushed stone and 42wt% sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% respectively, with sizes of 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed at a stirring rate of 25 rpm, a stirring time of 1.5 min, and a pre-mixing temperature of 20°C, wherein the amount of water used was 75% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 4 minutes and the mixing rate is 25 rpm; wherein the mass ratio of high belite cement to aggregate is 1:3; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; One of the keys of the present invention is to adopt a two-stage mixing method to ensure the uniformity of concrete. The traditional single-stage mixing method easily leads to uneven mixing of cement, aggregate and water, especially in high-belite cement, which has a high requirement for uniformity. The uneven mixing will affect its mechanical properties and durability. In the pre-mixing stage, the aggregate and water are pre-mixed to ensure that the surface of the aggregate is completely wetted. The purpose of this stage is to reduce dust on the surface of the aggregate and promote full contact between water and aggregate to ensure that subsequent cement can be evenly wrapped on the surface of the aggregate. The pre-mixing temperature of the aggregate and water should be controlled at 10-25°C to avoid adverse effects of excessively high or low temperatures on cement hydration. In the main mixing stage, cement, remaining water and polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to ensure that the cement slurry completely wraps the aggregate and improves the working performance of the concrete. The mixing process in this stage should be uniform to avoid segregation. The polycarboxylate water reducer is added during the mixing process to ensure that the polycarboxylate water reducer is evenly integrated with the concrete. C. Layered pouring: Pour the concrete into the formwork in layers, with the thickness of each layer controlled at 35 cm. After each layer of concrete is poured, vibrate and compact it immediately, with the vibration time controlled at 40 seconds and the vibration frequency at 5,000 times per minute. Pour the concrete into the formwork in layers, with the thickness of each layer controlled at 30-40 cm. This step avoids uneven stratification or unstable structure caused by pouring too thick at one time. At the same time, a mechanical vibrator is used to vibrate and compact each layer of concrete, ensuring that there are no bubbles or voids inside the concrete. By accurately controlling the vibration time, segregation caused by excessive vibration and loose concrete caused by insufficient vibration can be prevented. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film to prevent the surface moisture from evaporating too quickly. The initial curing environment temperature should be 20℃ and the humidity should be above 80%. The initial curing should be 20h to ensure that the concrete surface remains moist. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80%. Curing should be carried out for 10 days to ensure that the compressive strength and crack resistance of the concrete are effectively improved.
[0022] Example 2 An efficient high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; before construction, high belite cement, aggregate, polycarboxylate water reducer and other raw materials need to be accurately weighed and pre-treated. Due to its unique chemical composition, high belite cement requires a more uniform mixing with aggregate and water. Therefore, the selection and preparation of raw materials are very important; the aggregate includes 58wt% crushed stone and 42wt% sand, among which the crushed stone is composed of three-grade crushed stone with mass proportions of 15%, 75% and 10% respectively, with 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed, the mixing time was controlled at 1 min, the mixing rate was 30 rpm, the pre-mixing temperature was controlled at 25 °C, and the amount of water was 70% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 5 minutes and the mixing rate is 20 rpm; wherein the mass ratio of high belite cement to aggregate is 1:3.5; the amount of polycarboxylate water reducer is 0.8% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.45; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 30 cm. After each layer of concrete is poured, vibrate and compact it immediately, with the vibration time controlled at 60 s and the vibration frequency at 4,000 times / minute. Pour the concrete into the formwork in layers, with each layer thickness controlled at 30-40 cm. This step avoids uneven stratification or unstable structure caused by pouring too thick at one time. At the same time, a mechanical vibrator is used to vibrate and compact each layer of concrete, ensuring that there are no bubbles or voids inside the concrete. By accurately controlling the vibration time, segregation caused by excessive vibration and loose concrete caused by insufficient vibration can be prevented. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film to prevent the surface moisture from evaporating too quickly. The initial curing environment temperature should be 25℃ and the humidity should be above 80%. The initial curing should be 12 hours to ensure that the concrete surface remains moist. Then, the ambient temperature should be maintained at 35℃ and the humidity should be above 80%. The curing should be carried out for 7 days to ensure that the compressive strength and crack resistance of the concrete are effectively improved.
[0023] Example 3 An efficient high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; before construction, high belite cement, aggregate, polycarboxylate water reducer and other raw materials need to be accurately weighed and pre-treated. Due to its unique chemical composition, high belite cement requires a more uniform mixing with aggregate and water. Therefore, the selection and preparation of raw materials are very important; the aggregate includes 58wt% of crushed stone and 42wt% of sand, among which the crushed stone is composed of three-grade crushed stone with mass proportions of 20%, 65% and 15% of 5mm~10mm, 10mm~20mm and 16mm~31.5mm respectively; B. Double-stage stirring: Aggregates and water were pre-mixed, the mixing time was controlled at 2 min, the mixing rate was 20 rpm, the pre-mixing temperature was controlled at 10 °C, and the amount of water was 80% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 3 minutes and the mixing rate is 30 rpm; wherein the mass ratio of high belite cement to aggregate is 1:2.5; the amount of polycarboxylate water reducer is 1.2% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.35; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 40 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 30 s and the vibration frequency at 6,000 times / minute. Pour the concrete into the formwork in layers, with each layer thickness controlled at 30-40 cm. This step avoids uneven stratification or unstable structure caused by pouring too thick at one time. At the same time, a mechanical vibrator is used to vibrate and compact each layer of concrete, ensuring that there are no bubbles or voids inside the concrete. By accurately controlling the vibration time, segregation caused by excessive vibration and loose concrete caused by insufficient vibration can be prevented. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film to prevent the surface moisture from evaporating too quickly. The initial curing environment temperature should be 15℃ and the humidity should be above 80%. The initial curing should be 24 hours to ensure that the concrete surface remains moist. Then, the ambient temperature should be maintained at 15℃ and the humidity should be above 80%. The concrete should be cured for 14 days to ensure that the compressive strength and crack resistance of the concrete are effectively improved.
[0024] Example 4 An efficient high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; wherein the mud content of aggregate shall not exceed 1%, and the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% respectively, with sizes of 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed at a stirring rate of 25 rpm, a stirring time of 1.5 min, and a pre-mixing temperature of 20°C, wherein the amount of water used was 75% of the total water weight; After the pre-mixing is completed, the water reducer and the remaining water are mixed to obtain a water reducer mixed solution, and then the water reducer mixed solution and high belite cement are added to the mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 4 minutes and the mixing rate is 25 rpm; wherein the mass ratio of high belite cement to aggregate is 1:3; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 35 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 40 seconds and the vibration frequency at 5000 times / minute. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film to prevent the surface moisture from evaporating too quickly. The initial curing environment temperature should be 20℃ and the humidity should be above 80%. The initial curing should be 20h to ensure that the concrete surface remains moist. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80%. Curing should be carried out for 10 days to ensure that the compressive strength and crack resistance of the concrete are effectively improved.
[0025] Comparative Example 1 A high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; wherein the mud content of aggregate shall not exceed 1%, and the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% respectively, with sizes of 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed at a stirring rate of 25 rpm, a stirring time of 1.5 min, and a pre-mixing temperature of 20°C, wherein the amount of water used was 75% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 4 minutes and the mixing rate is 25 rpm; wherein the mass ratio of high belite cement to aggregate is 1:2; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 35 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 40 seconds and the vibration frequency at 5000 times / minute. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 20℃ and the humidity should be above 80% for 20 hours. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80% for 10 days.
[0026] Comparative Example 2 A high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; wherein the mud content of aggregate shall not exceed 1%, and the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% respectively, with sizes of 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed at a stirring rate of 25 rpm, a stirring time of 1.5 min, and a pre-mixing temperature of 20°C, wherein the amount of water used was 75% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 4 minutes and the mixing rate is 25 rpm; wherein the mass ratio of high belite cement to aggregate is 1:4; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 35 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 40 seconds and the vibration frequency at 5000 times / minute. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 20℃ and the humidity should be above 80% for 20 hours. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80% for 10 days.
[0027] Comparative Example 3 A high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; wherein the mud content of aggregate shall not exceed 1%, and the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 17%, 70% and 13% respectively, with sizes of 5mm~10mm, 10mm~20mm and 16mm~31.5mm; B. Stirring: Aggregate, water, high belite cement and polycarboxylate water reducer are mixed and stirred to obtain concrete, wherein the stirring rate is 25 rpm and the stirring time is 5.5 min; wherein the mass ratio of high belite cement to aggregate is 1:3; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 35 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 40 seconds and the vibration frequency at 5000 times / minute. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 20℃ and the humidity should be above 80% for 20 hours. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80% for 10 days.
[0028] Comparative Example 4 A high-belite cement concrete construction process comprises the following steps: A. Preparation: Prepare high belite cement, aggregate, water and polycarboxylate water reducer; wherein the mud content of aggregate shall not exceed 1%, and the aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 30%, 45% and 25% respectively, with diameters of 5mm-10mm, 10mm-20mm and 16mm-31.5mm; B. Double-stage stirring: Aggregates and water were pre-mixed at a stirring rate of 25 rpm, a stirring time of 1.5 min, and a pre-mixing temperature of 20°C, wherein the amount of water used was 75% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 4 minutes and the mixing rate is 25 rpm; wherein the mass ratio of high belite cement to aggregate is 1:3; the amount of polycarboxylate water reducer is 1.0% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.4; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 35 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 40 seconds and the vibration frequency at 5000 times / minute. D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 20℃ and the humidity should be above 80% for 20 hours. Then, the ambient temperature should be maintained at 20℃ and the humidity should be above 80% for 10 days.
[0029] Performance Testing The concrete in the embodiments and comparative examples were cast to form 150mm*150mm*150mm standard compression test blocks, 150mm*150mm*550mm standard flexural test blocks, and 150mm*150mm*150mm standard tensile test blocks. The tests were carried out after the curing was completed. The mechanical properties of the above embodiments and comparative examples were tested according to GB50081-2019 Standard for Test Methods for Physical and Mechanical Properties of Concrete. The results are shown in Table 1.
[0030] Table 1 The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. An efficient high-belite cement concrete construction process, characterized in that: The following steps are involved: A. Prepare materials; B. Double-stage stirring: Pre-mix the aggregate and water, the mixing time is controlled at 1-2 minutes, the pre-mixing temperature is controlled at 10-25°C, and the amount of water used is 70-80% of the total water weight; After the pre-mixing is completed, high belite cement, the remaining water and the polycarboxylate water reducer are added to the pre-mixed mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 3-5 minutes; wherein the mass ratio of high belite cement to aggregate is 1:2.5-3.5; the amount of polycarboxylate water reducer is 0.8%-1.2% of the mass of high belite cement; wherein the total water consumption is a water-cement ratio of 0.35-0.45; C. Layered pouring: Pour the concrete into the formwork in layers, with each layer thickness controlled at 30-40 cm. Immediately after pouring each layer of concrete, vibrate and compact it, with the vibration time controlled at 30-60 seconds and the vibration frequency at 4000-6000 times / minute; D. Wet curing: After pouring, the concrete surface should be immediately covered with wet straw mat or plastic film. The initial curing environment temperature should be 15-25℃, the humidity should be above 80%, and the initial curing should be 12-24h. Then, the ambient temperature should be maintained at 15-35℃, the humidity should be above 80%, and the curing should be carried out for 7-14 days.
2. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The step B comprises the following steps: Pre-mix the aggregate and water, the mixing time is controlled at 1-2 minutes, the pre-mixing temperature is controlled at 10-25°C, and the amount of water used is 70-80% of the total water weight; After the pre-mixing is completed, the water reducer and the remaining water are mixed to obtain a water reducer mixed solution, and then the water reducer mixed solution and high belite cement are added to the mixture for main mixing to obtain concrete, wherein the main mixing time is controlled at 3-5 minutes; wherein the mass ratio of high belite cement to aggregate is 1:2.5-3.5; and the amount of polycarboxylate water reducer is 0.8%-1.2% of the mass of high belite cement.
3. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The dicalcium silicate content in the high belite cement accounts for more than 50% of the clinker, and is required to contain 5-10% calcium aluminate and 7-12% calcium ferrite.
4. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The aggregate includes crushed stone with a particle size range of 5-31.5 mm and a mud content not exceeding 1%.
5. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with mass proportions of 15-20%, 65-75%, and 10-15% of 5mm~10mm, 10mm~20mm, and 16mm~31.5mm respectively; the fineness modulus of the sand is between 2.6 and 3.0, and the particle size distribution of the sand is 0.075mm-4.75mm.
6. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The aggregate comprises 58wt% of crushed stone and 42wt% of sand, wherein the crushed stone is composed of three-grade crushed stone with a mass proportion of 17%, 70% and 13% respectively, with a size of 5mm-10mm, 10mm-20mm and 16mm-31.5mm.
7. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The stirring speeds of the pre-stirring and the main stirring are both 20-30 rpm.
8. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The mass ratio of the high-belite cement to the aggregate is 1:
3.
9. An efficient high-belite cement concrete construction process according to claim 1, characterized in that: The dosage of the polycarboxylate water reducer is 1.0% of the mass of the high belite cement.
10. The efficient high-belite cement concrete construction process according to claim 1, characterized in that: In step C, the thickness is controlled at 35 cm, the vibration time is controlled at 50 s, and the vibration frequency is 5000 times / minute.