WO2023206692A1 - Method for rapidly optimizing mix proportion of precast concrete components - Google Patents

Method for rapidly optimizing mix proportion of precast concrete components Download PDF

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WO2023206692A1
WO2023206692A1 PCT/CN2022/095592 CN2022095592W WO2023206692A1 WO 2023206692 A1 WO2023206692 A1 WO 2023206692A1 CN 2022095592 W CN2022095592 W CN 2022095592W WO 2023206692 A1 WO2023206692 A1 WO 2023206692A1
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concrete
curing
precast
rapid
strength
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PCT/CN2022/095592
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French (fr)
Chinese (zh)
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高原
冯良平
任京华
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中交公路长大桥建设国家工程研究中心有限公司
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Publication of WO2023206692A1 publication Critical patent/WO2023206692A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
    • B28B11/24—Apparatus or processes for treating or working the shaped or preshaped articles for curing, setting or hardening
    • B28B11/245—Curing concrete articles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/91—Use of waste materials as fillers for mortars or concrete

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  • the present disclosure relates to the technical field of precast concrete, and in particular to a method for quickly optimizing the mix ratio of precast concrete components.
  • Precast concrete technology is one of the important technologies for practicing green and low-carbon concepts and realizing bridge industrialization. Rapid curing processes such as steam curing are the core means of precast concrete technology. Rapid maintenance is conducive to increasing the turnover rate of molds, improving the utilization rate of major process equipment and labor productivity, shortening the production cycle, and reducing product costs.
  • the 28-day compressive strength of concrete standard curing is still the key quality parameter and acceptance basis for assessing the qualification of concrete components.
  • the concrete mix ratio cannot be designed and adjusted in a timely manner, nor can the quality status of precast components be predicted in a timely manner.
  • the main purpose of the present disclosure is to provide a method for quickly optimizing the mix ratio of precast concrete components to solve the problem of long optimization cycle of traditional precast concrete component mix ratios and at the same time reduce the dependence of concrete mix ratio adjustment on engineering experience.
  • the present disclosure provides a method for quickly optimizing the mix ratio of precast concrete components, which method includes:
  • the other group of the two groups of concrete specimens was cured using the constant temperature rapid curing method, and the actual strength of the concrete at 28 days ⁇ ′ 28 was measured;
  • the determined concrete 28d design strength ⁇ 28 that the concrete precast components need to reach and the concrete design strength ⁇ t2 at the end of the rapid precast curing are determined based on the design index requirements of the concrete precast components.
  • the determined concrete standard curing is completed after 28 d.
  • the maturity degree S 28 of concrete is determined under the conditions of curing temperature 20°C and relative humidity greater than 95%.
  • the predetermined concrete mix ratio is determined according to the relevant design regulations for concrete mix ratio.
  • the actual rapid precast curing method is used to maintain one of the two groups of concrete specimens, and the actual strength of the concrete ⁇ ′ t2 at the end of the rapid precast curing is measured, including:
  • the actual rapid precast curing system in China requires that one of the two sets of concrete specimens be cured.
  • the standard test method is used to measure the strength of the specimens.
  • the measured strength is the actual strength of the concrete at the end of the rapid precast curing ⁇ ′ t2 .
  • the actual rapid prefabricated curing system is determined by the curing process of prefabricated component production and preparation.
  • the curing parameters at least include the static stop time t 1 , the static stop temperature T 1 , the heating rate v 1 , the constant temperature duration t 2 , and the constant temperature temperature. T 2 , cooling rate v 2 and total rapid curing time t 3 .
  • the other group of the two sets of concrete specimens was cured using the constant temperature rapid curing method, and the actual 28d concrete strength ⁇ ′ 28 was measured, including: the two groups were cured according to the constant temperature rapid curing method. Another group of concrete specimens were cured. After the curing was completed, the strength of the specimens was measured using standard test methods. The measured strength was the actual strength of the concrete at 28 days ⁇ ′ 28 .
  • the required curing temperature is selected based on laboratory conditions, and the required curing age t q is inferred based on the maturity degree S 28 of the concrete at the end of the standard curing 28 days. owned.
  • the selection range of the required curing temperature in the constant temperature rapid curing method is 40-75°C.
  • the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
  • R is the gas constant, which is 8.314J/mol ⁇ K
  • U ar is the activation energy of the cement hydration reaction at the standard curing temperature
  • U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
  • the mix ratio of concrete is adjusted by selecting cement with a high grade, reducing the water-cement ratio, improving the particle gradation of coarse and fine aggregates, adding high-efficiency active mineral ingredients or adding high-efficiency water-reducing agents. at least one of the groups.
  • the method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure, compared with the traditional precast concrete component mix ratio optimization design method, can significantly reduce the number of trial mixes of concrete mix ratios and speed up the precast component mix proportions. production progress, greatly shortening the concrete trial mixing cycle, solving the problem of long optimization cycle of the mix ratio of traditional precast concrete components, saving time and cost, reducing the dependence of concrete mix ratio adjustment on engineering experience, and has better Scientific guidance and promotion value.
  • Figure 1 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure.
  • Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure.
  • Figure 3 is a schematic diagram of curing one of the two groups of concrete specimens using an actual rapid prefabricated curing method according to an embodiment of the present disclosure.
  • Figure 4 is a comparison diagram between a method for quickly optimizing the mix ratio of precast concrete components and a traditional mix ratio optimization method using an embodiment of the present disclosure.
  • Figure 1 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure. It should be noted that Figure 1 is only an example of application scenarios in which embodiments of the present disclosure can be applied, to help those skilled in the art understand the technical content of the present disclosure, but does not mean that the embodiments of the present disclosure cannot be used in other applications. environment or scene.
  • the method provided by this disclosure to quickly optimize the mix ratio of precast concrete components includes the following steps:
  • Step S1 Determine the concrete 28d design strength ⁇ 28 that the concrete precast components need to achieve and the concrete design strength ⁇ t2 at the end of rapid precast curing, and determine the maturity degree of concrete S 28 at the end of 28 d standard curing;
  • Step S2 Predetermine the mix ratio of concrete, and prepare two sets of concrete specimens according to the mix ratio
  • the mix ratio of concrete is first determined, and then two sets of concrete specimens are prepared according to the mix ratio.
  • Step S3 Use the actual rapid precast curing method to cure one of the two groups of concrete specimens, and measure the actual concrete strength ⁇ ′ t2 at the end of the rapid precast curing;
  • one of the two sets of concrete specimens is cured according to the actual rapid precast curing system requirements in the production process of concrete precast components.
  • the strength of the specimens is measured using standard test methods.
  • the measured strength is Actual concrete strength ⁇ ′ t2 at the end of rapid precast curing.
  • the actual rapid prefabricated curing system is determined by the curing process of prefabricated component production and preparation, and at least includes the static stop time t 1 , the static stop temperature T 1 , the heating rate v 1 , the constant temperature duration t 2 , the constant temperature temperature T 2 , and the cooling rate. Curing parameters such as rate v 2 and total rapid curing time t 3 .
  • Step S4 Use the constant temperature rapid curing method to cure the other group of concrete specimens in the two groups, and measure the actual strength ⁇ ′ 28 of the concrete in 28 days;
  • the other group of the two sets of concrete specimens is cured according to the constant temperature rapid curing method.
  • the standard test method is used to measure the strength of the specimens. The measured strength is the actual strength of the concrete at 28 days ⁇ ' 28 .
  • the required curing temperature is selected according to laboratory conditions, and the selection range of the required curing temperature is generally 40-75°C.
  • the required curing age ta is inversely derived based on the maturity degree S 28 of the concrete at the end of the standard curing 28d in step S1.
  • the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
  • R is the gas constant, which is 8.314J/mol ⁇ K
  • U ar is the activation energy of the cement hydration reaction at the standard curing temperature
  • U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
  • Step S5 Determine whether the actual strength of concrete ⁇ ′ t2 at the end of rapid precast curing is greater than the design strength of concrete at the end of rapid precast curing ⁇ t2 and the actual strength of concrete 28d ⁇ ′ 28 is greater than the design strength of concrete 28d ⁇ 28 simultaneously. If both are true, then If the requirements are met, end this process; otherwise, return to step S2 to adjust the mix ratio of concrete, prepare two sets of concrete specimens again according to the adjusted mix ratio, and then perform steps S3 to S5 to maintain and maintain the two sets of newly prepared concrete specimens.
  • the adjustment of the mix ratio of concrete consists of selecting cement with a high grade, reducing the water-cement ratio, improving the particle gradation of coarse and fine aggregates, adding high-efficiency active mineral ingredients, or adding high-efficiency water-reducing agents. At least one of the groups.
  • Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure, which includes the following steps:
  • One of the two sets of concrete specimens prepared in step 3 is cured according to the actual rapid precast curing method in the production process of concrete precast components. After the curing is completed, the standard test method is used to measure the strength of the specimens. The measured strength is rapid precast The actual strength of concrete at the end of curing ⁇ ′ t2 .
  • the actual rapid prefabricated maintenance method is determined by the maintenance process of precast component production and preparation, including static stop time t 1 , static stop temperature T 1 , heating rate v 1 , constant temperature duration t 2 , constant temperature temperature T 2 , and cooling rate v 2 and the total rapid curing time t 2 and other curing parameters.
  • the determination method of the constant temperature rapid curing method includes: firstly selecting the temperature of the constant temperature rapid curing system according to laboratory conditions, and the selection range of the temperature of the constant temperature rapid curing system is 40-75°C; and then according to the maturity of the concrete in step 2 Level S 28 is deduced to obtain the required curing age t q under constant temperature rapid curing conditions.
  • step 2 the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
  • R is the gas constant, which is 8.314J/mol ⁇ K
  • U ar is the activation energy of the cement hydration reaction at the standard curing temperature
  • U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
  • the specific debugging method of the concrete mix ratio includes one or any combination of the following methods: (1) Select cement with a high grade; (2) Reduce the water-cement ratio; (3) Improve Particle gradation of coarse and fine aggregates; (4) Incorporation of high-efficiency active mineral ingredients; (5) Incorporation of high-efficiency water-reducing agents.
  • Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure, which includes the following steps:
  • Step 1 A certain project produces C50 concrete precast box beams.
  • the 28d design strength ⁇ 28 is 50MPa
  • the required strength ⁇ t2 at the end of rapid precast curing is 37.5MPa.
  • Step 3 Determine the concrete mix proportion according to the "Design Regulations for Ordinary Concrete Mix Proportion" (JGJ 55-2011), and prepare two sets of test specimens in accordance with the "Standard for Test Methods of Physical and Mechanical Properties of Concrete” GB/T 50081-2019.
  • the concrete mix is as follows: The following table:
  • Step 4 Obtain the actual rapid prefabricated curing system based on the maintenance process of precast component production and preparation.
  • the actual rapid prefabricated curing system is shown in Figure 3, in which the static stop time is 12h, the static stop temperature is 20°C, the heating rate is 10°C/h, and the constant temperature The temperature is 50°C, the constant temperature duration is 24h, the cooling rate is 5°C/h, and the total rapid curing duration is 45h.
  • Step 6 The actual strength of concrete at the end of rapid precast curing ⁇ ′ t2 and the actual strength at 28d ⁇ ′ 28 are both greater than the design required strength at the end of rapid precast curing ⁇ t2 and the design strength at 28d ⁇ 28 , indicating that the mix ratio in step three meets the requirement of precast components. According to the design requirements, the mix ratio determined in step three is the final mix ratio.
  • Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure. It is basically the same as the method in Embodiment 2, except that the rapid precast curing is completed in step six.
  • the actual strength of concrete ⁇ ′ t2 and the actual strength of concrete at 28d ⁇ ′ 28 are not simultaneously greater than the design strength of concrete at the end of rapid precast curing ⁇ t2 and the design strength of concrete at 28d ⁇ 28 , indicating that the concrete mix ratio in step three does not meet the design requirements of precast components. , the concrete mix ratio needs to be adjusted.
  • the concrete mix ratio when adjusting the concrete mix ratio, it includes one or any combination of the following methods: (1) Select cement with a high grade; (2) Reduce the water-cement ratio; (3) ) Improve the particle gradation of coarse and fine aggregates; (4) incorporate high-efficiency active mineral ingredients; (5) incorporate high-efficiency water-reducing agents.
  • Step 1 A certain project produces C50 concrete precast box beams.
  • the 28d design strength ⁇ 28 is 50MPa
  • the required strength ⁇ t2 at the end of rapid precast curing is 37.5MPa.
  • Step 3 Determine the concrete mix proportion according to the "Design Regulations for Ordinary Concrete Mix Proportion" (JGJ 55-2011), and prepare two sets of test specimens in accordance with the "Standard for Test Methods of Physical and Mechanical Properties of Concrete” GB/T 50081-2019.
  • the concrete mix is as follows: The following table:
  • Step 4 Obtain the actual rapid prefabricated curing system based on the maintenance process of precast component production and preparation.
  • the actual rapid prefabricated curing system is shown in Figure 3, in which the static stop time is 12h, the static stop temperature is 20°C, the heating rate is 10°C/h, and the constant temperature The temperature is 50°C, the constant temperature duration is 24h, the cooling rate is 5°C/h, and the total rapid curing duration is 45h.
  • Step 6 At the end of rapid precast curing, the actual concrete strength ⁇ ′ t2 is greater than the design required strength ⁇ t2 , and the actual strength ⁇ ′ 28 at 28 days is less than the design strength ⁇ 28 at 28 days, indicating that the mix ratio in step three needs to be adjusted and optimized.
  • step three reduce the water-cement ratio by appropriately reducing the water consumption per unit of concrete, and optimize the first concrete mix ratio.
  • the adjusted concrete mix ratio is as follows:
  • step six The actual concrete strength ⁇ ′ t2 and 28d actual strength ⁇ ′ 28 at the end of rapid precast curing are both greater than the design required strength ⁇ t2 and 28d design strength ⁇ 28 at the end of rapid precast curing, indicating that the adjusted mix ratio meets the precast requirements.
  • the component design requires that the mix ratio after the second adjustment be used as the final mix ratio.

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Abstract

A method for rapidly optimizing the mix proportion of precast concrete components, comprising: determining a concrete 28d design strength and a concrete design strength at the conclusion of a rapid precast curing process which a precast concrete component must achieve; pre-determining a mix proportion of concrete, and preparing two groups of concrete specimens according to the mix proportion; curing the concrete specimens by means of an actual rapid precast curing method and a constant-temperature rapid curing means, measuring the strengths of the concrete specimens by means of a standard testing method after curing, and comparing the measured strengths with the required design strength, until the requirement is met. The present method may significantly reduce the number of trial mix attempts required to determine a concrete mix proportion, thereby speeding up the production progress of precast components, shortening the test mix cycle for the concrete, and reducing the reliance on engineering experience when adjusting the concrete mix proportion.

Description

一种快速优化预制混凝土构件配合比的方法A method to quickly optimize the mix ratio of precast concrete components 技术领域Technical field
本公开涉及预制混凝土技术领域，特别涉及一种快速优化预制混凝土构件配合比的方法。The present disclosure relates to the technical field of precast concrete, and in particular to a method for quickly optimizing the mix ratio of precast concrete components.
背景技术Background technique
预制混凝土技术是践行绿色低碳理念和实现桥梁工业化的重要技术之一，蒸汽养护等快速养护工艺是预制混凝土技术的核心手段。快速养护有利于提高模具的周转率，提高主要工艺设备的利用率及劳动生产率，有利于缩短生产周期，并有利于降低产品成本。Precast concrete technology is one of the important technologies for practicing green and low-carbon concepts and realizing bridge industrialization. Rapid curing processes such as steam curing are the core means of precast concrete technology. Rapid maintenance is conducive to increasing the turnover rate of molds, improving the utilization rate of major process equipment and labor productivity, shortening the production cycle, and reducing product costs.
在工厂化预制混凝土构件配合比设计和调整过程中，混凝土标准养护28d抗压强度仍是评定混凝土构件合格的关键质量参数和验收依据。但是，标准养护28d强度的试验方法，由于试验周期长，既不能据此及时设计和调整混凝土配合比，也不能及时预报预制构件生产制备中的质量状况。In the process of mix design and adjustment of factory-based precast concrete components, the 28-day compressive strength of concrete standard curing is still the key quality parameter and acceptance basis for assessing the qualification of concrete components. However, due to the long test period of the standard curing 28-day strength test method, the concrete mix ratio cannot be designed and adjusted in a timely manner, nor can the quality status of precast components be predicted in a timely manner.
此外，目前混凝土配合比优化的研究方法主要集中在传统的正交设计试验方法，该方法限制条件较多，实验搜寻范围有限，且研究耗时长，成本高，无法获得理想且贴近实际的配合比优化结果。In addition, the current research methods for concrete mix ratio optimization mainly focus on the traditional orthogonal design test method. This method has many restrictions, the experimental search range is limited, and the research is time-consuming and costly, and it is impossible to obtain an ideal and realistic mix ratio. Optimization Results.
因此，有必要研发一种科学的、快速的优化预制混凝土构件配合比的方法。Therefore, it is necessary to develop a scientific and rapid method for optimizing the mix ratio of precast concrete components.
发明内容Contents of the invention
有鉴于此，本公开的主要目的在于提供一种快速优化预制混凝土构件配合比的方法，以解决传统混凝土预制构件配合比优化周期长的问题，同时降低混凝土配合比调整对工程经验的依赖性。In view of this, the main purpose of the present disclosure is to provide a method for quickly optimizing the mix ratio of precast concrete components to solve the problem of long optimization cycle of traditional precast concrete component mix ratios and at the same time reduce the dependence of concrete mix ratio adjustment on engineering experience.
为达到上述目的，本公开提供了一种快速优化预制混凝土构件配合 比的方法，该方法包括：In order to achieve the above purpose, the present disclosure provides a method for quickly optimizing the mix ratio of precast concrete components, which method includes:
确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2，并确定混凝土标准养护28d结束时混凝土的成熟程度S 28； Determine the 28-day concrete design strength σ 28 that the concrete precast components need to achieve and the concrete design strength σ t2 at the end of rapid precast curing, and determine the maturity degree of concrete S 28 at the end of 28 days of standard concrete curing;
预确定混凝土的配合比，按照该配合比制备两组混凝土试件；Predetermine the mix ratio of concrete and prepare two sets of concrete specimens according to the mix ratio;
采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护，测定得到快速预制养护结束时混凝土实际强度σ′ t2； One of the two groups of concrete specimens was cured using the actual rapid precast curing method, and the actual concrete strength σ′ t2 at the end of the rapid precast curing was measured;
采用恒温快速养护方式对该两组混凝土试件中的另一组试件进行养护，测定得到混凝土28d实际强度σ′ 28； The other group of the two groups of concrete specimens was cured using the constant temperature rapid curing method, and the actual strength of the concrete at 28 days σ′ 28 was measured;
判断快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28是否同时成立，如果同时成立，则满足要求；否则，调整混凝土的配合比，按照调整后的配合比重新制备两组混凝土试件进行养护和测定，直至快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28同时成立。 Determine whether the actual strength of concrete at the end of rapid precast curing σ′ t2 is greater than the design strength of concrete at the end of rapid precast curing σ t2 and the actual strength of concrete at 28 days σ′ 28 is greater than the design strength of concrete at 28 days σ 28 at the same time. If it is true at the same time, the requirements are met; Otherwise, adjust the mix ratio of concrete and prepare two sets of concrete specimens again according to the adjusted mix ratio for curing and measurement until the actual strength of concrete σ′ t2 at the end of rapid precast curing is greater than the design strength of concrete at the end of rapid precast curing σ t2 and It is also true that the actual strength σ′ 28 of concrete 28d is greater than the design strength σ 28 of concrete 28d.
上述方案中，所述确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2是根据混凝土预制构件设计指标要求进行确定的，所述确定混凝土标准养护28d结束时混凝土的成熟程度S 28是在养护温度20℃且相对湿度大于95％的条件下确定混凝土的成熟程度S 28。 In the above scheme, the determined concrete 28d design strength σ 28 that the concrete precast components need to reach and the concrete design strength σ t2 at the end of the rapid precast curing are determined based on the design index requirements of the concrete precast components. The determined concrete standard curing is completed after 28 d. The maturity degree S 28 of concrete is determined under the conditions of curing temperature 20°C and relative humidity greater than 95%.
上述方案中，所述预确定混凝土的配合比是根据混凝土配合比相关设计规程进行确定的。In the above solution, the predetermined concrete mix ratio is determined according to the relevant design regulations for concrete mix ratio.
上述方案中，所述采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护，测定得到快速预制养护结束时混凝土实际强度σ′ t2，包括：按照混凝土预制构件生产过程中实际快速预制养护制度要求对该两组混凝土试件中的一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为快速预制养护结束时混凝土实际强度σ′ t2。 In the above scheme, the actual rapid precast curing method is used to maintain one of the two groups of concrete specimens, and the actual strength of the concrete σ′ t2 at the end of the rapid precast curing is measured, including: According to the production process of concrete precast components The actual rapid precast curing system in China requires that one of the two sets of concrete specimens be cured. After the curing is completed, the standard test method is used to measure the strength of the specimens. The measured strength is the actual strength of the concrete at the end of the rapid precast curing σ′ t2 .
上述方案中，所述实际快速预制养护制度由预制构件生产制备的养护工艺确定，养护参数至少包括静停时间时长t 1、静停温度T 1、升温速率v 1、恒温时长t 2、恒温温度T 2、降温速率v 2和快速养护总时长t 3。 In the above scheme, the actual rapid prefabricated curing system is determined by the curing process of prefabricated component production and preparation. The curing parameters at least include the static stop time t 1 , the static stop temperature T 1 , the heating rate v 1 , the constant temperature duration t 2 , and the constant temperature temperature. T 2 , cooling rate v 2 and total rapid curing time t 3 .
上述方案中，所述采用恒温快速养护方式对该两组混凝土试件中的另一组试件进行养护，测定得到混凝土28d实际强度σ′ 28，包括：按照恒温快速养护的方式对该两组混凝土试件中的另一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28。 In the above scheme, the other group of the two sets of concrete specimens was cured using the constant temperature rapid curing method, and the actual 28d concrete strength σ′ 28 was measured, including: the two groups were cured according to the constant temperature rapid curing method. Another group of concrete specimens were cured. After the curing was completed, the strength of the specimens was measured using standard test methods. The measured strength was the actual strength of the concrete at 28 days σ′ 28 .
上述方案中，在所述恒温快速养护方式中，所需养护的温度是根据实验室条件来选择的，所需养护的龄期t q是根据标准养护28d结束时混凝土的成熟程度S 28逆推得到的。 In the above scheme, in the constant temperature rapid curing method, the required curing temperature is selected based on laboratory conditions, and the required curing age t q is inferred based on the maturity degree S 28 of the concrete at the end of the standard curing 28 days. owned.
上述方案中，所述恒温快速养护方式中所需养护的温度的选择范围为40-75℃。In the above scheme, the selection range of the required curing temperature in the constant temperature rapid curing method is 40-75°C.
上述方案中，所述混凝土的成熟程度采用等效龄期t eq表征，所述等效龄期计算公式为： In the above scheme, the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
Figure PCTCN2022095592-appb-000001
Figure PCTCN2022095592-appb-000001
其中：in:
U aT＝(43830-43T)e (-0.0017T)t U aT = (43830-43T)e (-0.0017T)t
式中：R为气体常数，取8.314J/mol·K；U ar为标准养护温度下的水泥水化反应活化能；U aT为温度为T时反应活化能，是时间和温度的函数。 In the formula: R is the gas constant, which is 8.314J/mol·K; U ar is the activation energy of the cement hydration reaction at the standard curing temperature; U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
上述方案中，所述调整混凝土的配合比，采用选择标号高的水泥、降低水胶比、改善粗细骨料的颗粒级配、掺入高效活性矿物参料或掺入高效减水剂所组成群组中的至少一种。In the above scheme, the mix ratio of concrete is adjusted by selecting cement with a high grade, reducing the water-cement ratio, improving the particle gradation of coarse and fine aggregates, adding high-efficiency active mineral ingredients or adding high-efficiency water-reducing agents. at least one of the groups.
从上述技术方案可以看出，本公开提供的快速优化预制混凝土构件配合比的方法，相比于传统的预制混凝土构件配合比优化设计方法，能够显著减少混凝土配合比的试配次数，加快预制构件生产进度，大幅缩短混凝土的试配周期，解决了传统混凝土预制构件配合比优化周期长的 问题，节省了时间，节约了成本，降低了混凝土配合比调整对工程经验的依赖性，具有较好的科学指导性和推广价值。It can be seen from the above technical solutions that the method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure, compared with the traditional precast concrete component mix ratio optimization design method, can significantly reduce the number of trial mixes of concrete mix ratios and speed up the precast component mix proportions. production progress, greatly shortening the concrete trial mixing cycle, solving the problem of long optimization cycle of the mix ratio of traditional precast concrete components, saving time and cost, reducing the dependence of concrete mix ratio adjustment on engineering experience, and has better Scientific guidance and promotion value.
附图说明Description of the drawings
为了更进一步说明本公开的内容，以下结合附图对本公开做详细描述，其中：In order to further illustrate the content of the present disclosure, the present disclosure is described in detail below with reference to the accompanying drawings, in which:
图1是本公开提供的快速优化预制混凝土构件配合比的方法流程图。Figure 1 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure.
图2是依照本公开实施例的快速优化预制混凝土构件配合比的方法流程图。Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure.
图3是依照本公开实施例的采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护的示意图。Figure 3 is a schematic diagram of curing one of the two groups of concrete specimens using an actual rapid prefabricated curing method according to an embodiment of the present disclosure.
图4是采用本公开实施例的快速优化预制混凝土构件配合比的方法与传统配合比优化方法的对比图。Figure 4 is a comparison diagram between a method for quickly optimizing the mix ratio of precast concrete components and a traditional mix ratio optimization method using an embodiment of the present disclosure.
具体实施方式Detailed ways
以下，将参照附图来描述本公开的实施例。但是应该理解，这些描述只是示例性的，而并非要限制本公开的范围。在下面的详细描述中，为便于解释，阐述了许多具体的细节以提供对本公开实施例的全面理解。然而，明显地，一个或多个实施例在没有这些具体细节的情况下也可以被实施。此外，在以下说明中，省略了对公知结构和技术的描述，以避免不必要地混淆本公开的概念。Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for convenience of explanation, numerous specific details are set forth to provide a comprehensive understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. Furthermore, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily confusing the concepts of the present disclosure.
本公开实施例提出了一种快速优化预制混凝土构件配合比的方法。如图1所示，图1是本公开提供的快速优化预制混凝土构件配合比的方法流程图。需要注意的是，图1所示仅为可以应用本公开实施例的应用场景的示例，以帮助本领域技术人员理解本公开的技术内容，但并不意味着本公开实施例不可以用于其他环境或场景。The embodiment of the present disclosure proposes a method for quickly optimizing the mix ratio of precast concrete components. As shown in Figure 1, Figure 1 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components provided by the present disclosure. It should be noted that Figure 1 is only an example of application scenarios in which embodiments of the present disclosure can be applied, to help those skilled in the art understand the technical content of the present disclosure, but does not mean that the embodiments of the present disclosure cannot be used in other applications. environment or scene.
如图1所示，本公开提供的快速优化预制混凝土构件配合比的方法， 包括以下步骤：As shown in Figure 1, the method provided by this disclosure to quickly optimize the mix ratio of precast concrete components includes the following steps:
步骤S1：确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2，并确定混凝土标准养护28d结束时混凝土的成熟程度S 28； Step S1: Determine the concrete 28d design strength σ 28 that the concrete precast components need to achieve and the concrete design strength σ t2 at the end of rapid precast curing, and determine the maturity degree of concrete S 28 at the end of 28 d standard curing;
在本步骤中，根据混凝土预制构件设计指标要求，确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2。确定混凝土标准养护28d结束时混凝土的成熟程度S 28是在养护温度20℃且相对湿度大于95％的条件下进行确定的。 In this step, according to the design index requirements of concrete precast components, determine the concrete 28d design strength σ 28 that the concrete precast components need to achieve and the concrete design strength σ t2 at the end of rapid precast curing. Determine the maturity degree of concrete at the end of 28 days of concrete standard curing. S 28 is determined under the conditions of curing temperature 20°C and relative humidity greater than 95%.
步骤S2：预确定混凝土的配合比，按照该配合比制备两组混凝土试件；Step S2: Predetermine the mix ratio of concrete, and prepare two sets of concrete specimens according to the mix ratio;
在本步骤中，根据混凝土配合比相关设计规程，首先预确定混凝土的配合比，然后按照该配合比制备两组混凝土试件。In this step, according to the relevant design regulations of concrete mix ratio, the mix ratio of concrete is first determined, and then two sets of concrete specimens are prepared according to the mix ratio.
步骤S3：采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护，测定得到快速预制养护结束时混凝土实际强度σ′ t2； Step S3: Use the actual rapid precast curing method to cure one of the two groups of concrete specimens, and measure the actual concrete strength σ′ t2 at the end of the rapid precast curing;
在本步骤中，按照混凝土预制构件生产过程中实际快速预制养护制度要求对该两组混凝土试件中的一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为快速预制养护结束时混凝土实际强度σ′ t2。其中，所述实际快速预制养护制度由预制构件生产制备的养护工艺确定，至少包括静停时间时长t 1、静停温度T 1、升温速率v 1、恒温时长t 2、恒温温度T 2、降温速率v 2和快速养护总时长t 3等养护参数。 In this step, one of the two sets of concrete specimens is cured according to the actual rapid precast curing system requirements in the production process of concrete precast components. After the curing is completed, the strength of the specimens is measured using standard test methods. The measured strength is Actual concrete strength σ′ t2 at the end of rapid precast curing. Among them, the actual rapid prefabricated curing system is determined by the curing process of prefabricated component production and preparation, and at least includes the static stop time t 1 , the static stop temperature T 1 , the heating rate v 1 , the constant temperature duration t 2 , the constant temperature temperature T 2 , and the cooling rate. Curing parameters such as rate v 2 and total rapid curing time t 3 .
步骤S4：采用恒温快速养护方式对该两组混凝土试件中的另一组试件进行养护，测定得到混凝土28d实际强度σ′ 28； Step S4: Use the constant temperature rapid curing method to cure the other group of concrete specimens in the two groups, and measure the actual strength σ′ 28 of the concrete in 28 days;
在本步骤中，按照恒温快速养护的方式对该两组混凝土试件中的另一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28。在所述恒温快速养护方式中，所需养护的温度是根据实验室条件来选择的，所需养护的温度的选择范围一般为40-75℃。所需养护的龄期t a是根据步骤S1中标准养护28d结束时混凝土的成熟程度S 28逆推得到的。 In this step, the other group of the two sets of concrete specimens is cured according to the constant temperature rapid curing method. After the curing is completed, the standard test method is used to measure the strength of the specimens. The measured strength is the actual strength of the concrete at 28 days σ' 28 . In the constant temperature rapid curing method, the required curing temperature is selected according to laboratory conditions, and the selection range of the required curing temperature is generally 40-75°C. The required curing age ta is inversely derived based on the maturity degree S 28 of the concrete at the end of the standard curing 28d in step S1.
在本实施例中，所述混凝土的成熟程度采用等效龄期t eq表征，所述等效龄期计算公式为： In this embodiment, the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
Figure PCTCN2022095592-appb-000002
Figure PCTCN2022095592-appb-000002
在公式1中：In formula 1:
U aT＝(43830-43T)e (-0.0017T)t U aT = (43830-43T)e (-0.0017T)t
其中：R为气体常数，取8.314J/mol·K；U ar为标准养护温度下的水泥水化反应活化能；U aT为温度为T时反应活化能，是时间和温度的函数。 Among them: R is the gas constant, which is 8.314J/mol·K; U ar is the activation energy of the cement hydration reaction at the standard curing temperature; U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
步骤S5：判断快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28是否同时成立，如果同时成立，则满足要求，结束本流程；否则，返回步骤S2调整混凝土的配合比，按照调整后的配合比重新制备两组混凝土试件，接着执行步骤S3至S5对重新制备的两组混凝土试件进行养护和测定，直至快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28同时成立。 Step S5: Determine whether the actual strength of concrete σ′ t2 at the end of rapid precast curing is greater than the design strength of concrete at the end of rapid precast curing σ t2 and the actual strength of concrete 28d σ′ 28 is greater than the design strength of concrete 28d σ 28 simultaneously. If both are true, then If the requirements are met, end this process; otherwise, return to step S2 to adjust the mix ratio of concrete, prepare two sets of concrete specimens again according to the adjusted mix ratio, and then perform steps S3 to S5 to maintain and maintain the two sets of newly prepared concrete specimens. It is determined that the actual strength of concrete σ′ t2 at the end of rapid precast curing is greater than the design strength of concrete at the end of rapid precast curing σ t2 and the actual strength of concrete at 28 days σ′ 28 is greater than the design strength of concrete at 28 days σ 28 at the same time.
在本步骤中，所述调整混凝土的配合比，采用选择标号高的水泥、降低水胶比、改善粗细骨料的颗粒级配、掺入高效活性矿物参料或掺入高效减水剂所组成群组中的至少一种。In this step, the adjustment of the mix ratio of concrete consists of selecting cement with a high grade, reducing the water-cement ratio, improving the particle gradation of coarse and fine aggregates, adding high-efficiency active mineral ingredients, or adding high-efficiency water-reducing agents. At least one of the groups.
实施例1Example 1
请参照图2所示，图2是依照本公开实施例提供的快速优化预制混凝土构件配合比的方法流程图，包括以下步骤：Please refer to Figure 2. Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure, which includes the following steps:
①根据混凝土预制构件设计指标要求，确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2。 ① According to the design index requirements of precast concrete components, determine the 28d design strength of concrete σ 28 that the precast concrete components need to achieve and the design strength of concrete at the end of rapid precast curing σ t2 .
②确定混凝土标准养护(养护温度20℃，相对湿度大于95％)28d结束时混凝土的成熟程度S 28。 ② Determine the maturity degree S 28 of concrete at the end of 28 days of standard curing of concrete (curing temperature 20°C, relative humidity greater than 95%).
③根据混凝土配合比相关设计规程，预确定混凝土配合比，然后按照该配合比制备两组混凝土试件。③According to the relevant design regulations of concrete mix ratio, predetermine the concrete mix ratio, and then prepare two sets of concrete specimens according to the mix ratio.
④按照混凝土预制构件生产过程中实际快速预制养护方式对步骤③制备的两组混凝土试件中的一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为快速预制养护结束时混凝土实际强度σ′ t2。所述实际快速预制养护方式由预制构件生产制备的养护工艺确定，包括静停时间时长t 1、静停温度T 1、升温速率v 1、恒温时长t 2、恒温温度T 2、降温速率v 2和快速养护总时长t 2等养护参数。 ④ One of the two sets of concrete specimens prepared in step ③ is cured according to the actual rapid precast curing method in the production process of concrete precast components. After the curing is completed, the standard test method is used to measure the strength of the specimens. The measured strength is rapid precast The actual strength of concrete at the end of curing σ′ t2 . The actual rapid prefabricated maintenance method is determined by the maintenance process of precast component production and preparation, including static stop time t 1 , static stop temperature T 1 , heating rate v 1 , constant temperature duration t 2 , constant temperature temperature T 2 , and cooling rate v 2 and the total rapid curing time t 2 and other curing parameters.
⑤按照恒温快速养护的方式对步骤③制备的两组混凝土试件中的另一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28。所述恒温快速养护方式的确定方式包括：首先根据实验室条件选择恒温快速养护制度的温度，所述恒温快速养护制度的温度的选择范围为40-75℃；然后根据步骤②所述混凝土的成熟程度S 28逆推得到恒温快速养护条件下所需养护的龄期t q。 ⑤ Cure the other set of the two sets of concrete specimens prepared in step ③ according to the constant temperature rapid curing method. After the curing is completed, use standard test methods to measure the strength of the specimens. The measured strength is the actual strength of the concrete at 28 days σ′ 28 . The determination method of the constant temperature rapid curing method includes: firstly selecting the temperature of the constant temperature rapid curing system according to laboratory conditions, and the selection range of the temperature of the constant temperature rapid curing system is 40-75°C; and then according to the maturity of the concrete in step ② Level S 28 is deduced to obtain the required curing age t q under constant temperature rapid curing conditions.
⑥判断快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28是否同时成立，如果同时成立，则满足要求；否则，即快速预制养护结束时混凝土实际强度σ′ t2和混凝土28d实际强度σ′ 28不同时大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d设计强度σ 28，则对步骤③所述混凝土配合比进行调整，并重复步骤③-⑥，直至满足要求。 ⑥Judge whether the actual strength of concrete at the end of rapid precast curing σ′ t2 is greater than the design strength of concrete at the end of rapid precast curing σ t2 and the actual strength of concrete at 28 days σ′ 28 is greater than the design strength of concrete at 28 days σ 28 at the same time. If it is true at the same time, the requirements are met. ; Otherwise, that is, the actual strength of concrete σ′ t2 at the end of rapid precast curing and the actual strength of concrete at 28d σ′ 28 are not simultaneously greater than the design strength of concrete at the end of rapid precast curing σ t2 and the design strength of concrete at 28d σ 28 , then the steps in step ③ Adjust the concrete mix ratio and repeat steps ③-⑥ until the requirements are met.
进一步地，在步骤②中，所述混凝土的成熟程度采用等效龄期t eq表征，所述等效龄期计算公式为： Further, in step ②, the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
Figure PCTCN2022095592-appb-000003
Figure PCTCN2022095592-appb-000003
其中：in:
U aT＝(43830-43T)e (-0.0017T)t U aT = (43830-43T)e (-0.0017T)t
式中：R为气体常数，取8.314J/mol·K；U ar为标准养护温度下的水泥水化反应活化能；U aT为温度为T时反应活化能，是时间和温度的函数。 In the formula: R is the gas constant, which is 8.314J/mol·K; U ar is the activation energy of the cement hydration reaction at the standard curing temperature; U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
进一步地，在步骤⑥中，所述混凝土配合比具体的调试方法包括以下一种或任意几种方式组合使用：(1)选择标号高的水泥；(2)降低水胶比；(3)改善粗细骨料的颗粒级配；(4)掺入高效活性矿物参料；(5)掺入高效减水剂。Further, in step ⑥, the specific debugging method of the concrete mix ratio includes one or any combination of the following methods: (1) Select cement with a high grade; (2) Reduce the water-cement ratio; (3) Improve Particle gradation of coarse and fine aggregates; (4) Incorporation of high-efficiency active mineral ingredients; (5) Incorporation of high-efficiency water-reducing agents.
实施例2Example 2
请参照图2所示，图2是依照本公开实施例提供的快速优化预制混凝土构件配合比的方法流程图，包括以下步骤：Please refer to Figure 2. Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure, which includes the following steps:
步骤一：某工程生产制备C50的混凝土预制箱梁，根据混凝土预制构件设计指标要求，28d设计强度σ 28为50MPa，快速预制养护结束时需要达到的强度σ t2为37.5MPa。 Step 1: A certain project produces C50 concrete precast box beams. According to the design index requirements of concrete precast components, the 28d design strength σ 28 is 50MPa, and the required strength σ t2 at the end of rapid precast curing is 37.5MPa.
步骤二：确定标准养护(养护温度20℃，相对湿度大于95％)28d结束时混凝土的成熟程度S 28＝672h。 Step 2: Determine the maturity degree of concrete at the end of 28 days of standard curing (curing temperature 20°C, relative humidity greater than 95%) S 28 = 672 h.
步骤三：根据《普通混凝土配合比设计规程》(JGJ 55-2011)，确定混凝土配合比，并按照《混凝土物理力学性能试验方法标准》GB/T 50081-2019制备两组试件，混凝土配合比如下表：Step 3: Determine the concrete mix proportion according to the "Design Regulations for Ordinary Concrete Mix Proportion" (JGJ 55-2011), and prepare two sets of test specimens in accordance with the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" GB/T 50081-2019. The concrete mix is as follows: The following table:
Figure PCTCN2022095592-appb-000004
Figure PCTCN2022095592-appb-000004
步骤四：根据预制构件生产制备的养护工艺得到实际快速预制养护制度，实际快速预制养护制度如图3，其中，静停时间为12h，静停温度为20℃升温速率为10℃/h，恒温温度50℃，恒温时长为24h，降温速率为5℃/h，总快速养护时长为45h。按照上述养护制度要求对步骤三的第一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土实际快速预制养护结束时的实际强度σ′ t2＝50.5MPa。 Step 4: Obtain the actual rapid prefabricated curing system based on the maintenance process of precast component production and preparation. The actual rapid prefabricated curing system is shown in Figure 3, in which the static stop time is 12h, the static stop temperature is 20°C, the heating rate is 10°C/h, and the constant temperature The temperature is 50°C, the constant temperature duration is 24h, the cooling rate is 5°C/h, and the total rapid curing duration is 45h. The first group of specimens in step 3 shall be cured according to the requirements of the above curing system. After the curing is completed, the strength of the specimens shall be measured using standard test methods. The measured strength is the actual strength σ′ t2 = 50.5MPa at the end of the actual rapid precast curing of concrete.
步骤五：根据实验室条件确定恒温快速养护制度的温度为70℃，根据步骤二所述混凝土的成熟程度S 28＝672h，并采用公式(1)逆推计算 得到恒温快速养护条件下所需养护的龄期t q＝75h。按照上述恒温快速养护的方式对步骤三所述的第二组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28＝63.4MPa。 Step 5: Determine the temperature of the constant temperature rapid curing system to be 70°C based on laboratory conditions. According to the maturity level of the concrete S 28 = 672 hours as described in step 2, use formula (1) to back-calculate to obtain the required curing under constant temperature rapid curing conditions. The age t q =75h. The second group of specimens described in step 3 were cured according to the constant temperature rapid curing method mentioned above. After the curing, the strength of the specimens was measured using standard testing methods. The measured strength was the actual strength of the concrete for 28 days σ' 28 = 63.4MPa.
步骤六：快速预制养护结束时混凝土实际强度σ′ t2和28d实际强度σ′ 28同时大于快速预制养护结束时设计要求的强度σ t2和28d设计强度σ 28，说明步骤三的配合比满足预制构件设计要求，以步骤三确定的配合比为最终配合比，从图4可见，通过本公开实施例提供的快速优化预制混凝土构件配合比的方法，本实施例混凝土预制构件配合比优化周期仅为75小时，与传统配合比优化方法相比大大降低了配合比设计调整周期，进一步实现预制构件缩短工期的目标。 Step 6: The actual strength of concrete at the end of rapid precast curing σ′ t2 and the actual strength at 28d σ′ 28 are both greater than the design required strength at the end of rapid precast curing σ t2 and the design strength at 28d σ 28 , indicating that the mix ratio in step three meets the requirement of precast components. According to the design requirements, the mix ratio determined in step three is the final mix ratio. It can be seen from Figure 4 that through the method of quickly optimizing the mix ratio of precast concrete components provided by the embodiment of the present disclosure, the optimization cycle of the mix ratio of precast concrete components in this embodiment is only 75 Hours, compared with the traditional mix ratio optimization method, the mix ratio design adjustment cycle is greatly reduced, further achieving the goal of shortening the construction period of prefabricated components.
实施例3Example 3
请参照图2所示，图2是依照本公开实施例提供的快速优化预制混凝土构件配合比的方法流程图，与实施例2的方法基本相同，不同之处在于：步骤六中快速预制养护结束时混凝土实际强度σ′ t2和混凝土28d实际强度σ′ 28并非同时大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d设计强度σ 28，说明步骤三中的混凝土配合比不满足预制构件设计要求，需要对混凝土配合比进行调整，具体在对混凝土配合比进行调整时，包括以下一种或任意几种方式组合使用：(1)选择标号高的水泥；(2)降低水胶比；(3)改善粗细骨料的颗粒级配；(4)掺入高效活性矿物参料；(5)掺入高效减水剂。 Please refer to Figure 2. Figure 2 is a flow chart of a method for quickly optimizing the mix ratio of precast concrete components according to an embodiment of the present disclosure. It is basically the same as the method in Embodiment 2, except that the rapid precast curing is completed in step six. The actual strength of concrete σ′ t2 and the actual strength of concrete at 28d σ′ 28 are not simultaneously greater than the design strength of concrete at the end of rapid precast curing σ t2 and the design strength of concrete at 28d σ 28 , indicating that the concrete mix ratio in step three does not meet the design requirements of precast components. , the concrete mix ratio needs to be adjusted. Specifically, when adjusting the concrete mix ratio, it includes one or any combination of the following methods: (1) Select cement with a high grade; (2) Reduce the water-cement ratio; (3) ) Improve the particle gradation of coarse and fine aggregates; (4) incorporate high-efficiency active mineral ingredients; (5) incorporate high-efficiency water-reducing agents.
对于本实施例，具体包括以下步骤：For this embodiment, the following steps are specifically included:
步骤一：某工程生产制备C50的混凝土预制箱梁，根据混凝土预制构件设计指标要求，28d设计强度σ 28为50MPa，快速预制养护结束时需要达到的强度σ t2为37.5MPa。 Step 1: A certain project produces C50 concrete precast box beams. According to the design index requirements of concrete precast components, the 28d design strength σ 28 is 50MPa, and the required strength σ t2 at the end of rapid precast curing is 37.5MPa.
步骤二：确定标准养护(养护温度20℃，相对湿度大于95％)28d结束时混凝土的成熟程度S 28＝672h。 Step 2: Determine the maturity degree of concrete at the end of 28 days of standard curing (curing temperature 20°C, relative humidity greater than 95%) S 28 = 672 h.
步骤三：根据《普通混凝土配合比设计规程》(JGJ 55-2011)，确定混凝土配合比，并按照《混凝土物理力学性能试验方法标准》GB/T 50081-2019制备两组试件，混凝土配合比如下表：Step 3: Determine the concrete mix proportion according to the "Design Regulations for Ordinary Concrete Mix Proportion" (JGJ 55-2011), and prepare two sets of test specimens in accordance with the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" GB/T 50081-2019. The concrete mix is as follows: The following table:
Figure PCTCN2022095592-appb-000005
Figure PCTCN2022095592-appb-000005
步骤四：根据预制构件生产制备的养护工艺得到实际快速预制养护制度，实际快速预制养护制度如图3，其中，静停时间为12h，静停温度为20℃升温速率为10℃/h，恒温温度50℃，恒温时长为24h，降温速率为5℃/h，总快速养护时长为45h。按照上述养护制度要求对步骤三的第一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土实际快速预制养护结束时的实际强度σ′ t2＝38.8MPa。 Step 4: Obtain the actual rapid prefabricated curing system based on the maintenance process of precast component production and preparation. The actual rapid prefabricated curing system is shown in Figure 3, in which the static stop time is 12h, the static stop temperature is 20°C, the heating rate is 10°C/h, and the constant temperature The temperature is 50°C, the constant temperature duration is 24h, the cooling rate is 5°C/h, and the total rapid curing duration is 45h. The first group of specimens in Step 3 is cured according to the requirements of the above curing system. After the curing is completed, the strength of the specimens is measured using standard testing methods. The measured strength is the actual strength σ′ t2 = 38.8MPa at the end of the actual rapid precast curing of concrete.
步骤五：根据实验室条件确定恒温快速养护制度的温度为70℃，根据步骤二所述混凝土的成熟程度S 28＝672h，并采用公式(1)逆推计算得到恒温快速养护条件下所需养护的龄期t q＝75h。按照上述恒温快速养护的方式对步骤三所述的第二组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28＝48.3MPa。 Step 5: Determine the temperature of the constant temperature rapid curing system to be 70°C based on laboratory conditions. According to the maturity level of the concrete S 28 = 672 hours as described in step 2, use formula (1) to back-calculate to obtain the required curing under constant temperature rapid curing conditions. The age t q =75h. The second group of specimens described in step 3 were cured according to the constant temperature rapid curing method mentioned above. After the curing, the strength of the specimens was measured using standard testing methods. The measured strength was the actual strength of the concrete for 28 days σ' 28 = 48.3MPa.
步骤六：快速预制养护结束时混凝土实际强度σ′ t2大于设计要求的强度σ t2，28d实际强度σ′ 28小于28d设计强度σ 28，说明需要对步骤三的配合比进行调整优化。 Step 6: At the end of rapid precast curing, the actual concrete strength σ′ t2 is greater than the design required strength σ t2 , and the actual strength σ′ 28 at 28 days is less than the design strength σ 28 at 28 days, indicating that the mix ratio in step three needs to be adjusted and optimized.
重复步骤三，通过适当降低混凝土单位用水量方式降低水胶比，对第一次混凝土配合比进行优化调整，调整后的混凝土配合比如下表：Repeat step three, reduce the water-cement ratio by appropriately reducing the water consumption per unit of concrete, and optimize the first concrete mix ratio. The adjusted concrete mix ratio is as follows:
Figure PCTCN2022095592-appb-000006
Figure PCTCN2022095592-appb-000006
重复步骤四，测得强度为混凝土实际快速预制养护结束时的实际强度σ′ t2＝43.5MPa。 Repeat step four, and the measured strength is the actual strength σ′ t2 = 43.5MPa at the end of the actual rapid precast curing of concrete.
重复步骤五，测得强度为混凝土28d实际强度σ′ 28＝58MPa。 Repeat step five, and the measured strength is the actual strength of concrete 28d σ′ 28 =58MPa.
重复步骤六，快速预制养护结束时混凝土实际强度σ′ t2和28d实际强度σ′ 28同时大于快速预制养护结束时设计要求的强度σ t2和28d设计强 度σ 28，说明调整后的配合比满足预制构件设计要求，将第二次调整后的配合比作为最终配合比。 Repeat step six. The actual concrete strength σ′ t2 and 28d actual strength σ′ 28 at the end of rapid precast curing are both greater than the design required strength σ t2 and 28d design strength σ 28 at the end of rapid precast curing, indicating that the adjusted mix ratio meets the precast requirements. The component design requires that the mix ratio after the second adjustment be used as the final mix ratio.
以上所述的具体实施例，对本公开的目的、技术方案和有益效果进行了进一步详细说明，所应理解的是，以上所述仅为本公开的具体实施例而已，并不用于限制本公开，凡在本公开的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本公开的保护范围之内。The above-mentioned specific embodiments further describe the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above-mentioned are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this disclosure shall be included in the protection scope of this disclosure.

Claims (10)

  1. 一种快速优化预制混凝土构件配合比的方法，该方法包括：A method to quickly optimize the mix ratio of precast concrete components, which includes:
    确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2，并确定混凝土标准养护28d结束时混凝土的成熟程度S 28； Determine the 28-day concrete design strength σ 28 that the concrete precast components need to achieve and the concrete design strength σ t2 at the end of rapid precast curing, and determine the maturity degree of concrete S 28 at the end of 28 days of standard concrete curing;
    预确定混凝土的配合比，按照该配合比制备两组混凝土试件；Predetermine the mix ratio of concrete and prepare two sets of concrete specimens according to the mix ratio;
    采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护，测定得到快速预制养护结束时混凝土实际强度σ′ t2； One of the two groups of concrete specimens was cured using the actual rapid precast curing method, and the actual concrete strength σ′ t2 at the end of the rapid precast curing was measured;
    采用恒温快速养护方式对该两组混凝土试件中的另一组试件进行养护，测定得到混凝土28d实际强度σ′ 28； The other group of the two groups of concrete specimens was cured using the constant temperature rapid curing method, and the actual strength of the concrete at 28 days σ′ 28 was measured;
    判断快速预制养护结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28是否同时成立，如果同时成立，则满足要求；否则，调整混凝土的配合比，按照调整后的配合比重新制备两组混凝土试件进行养护和测定，直至快速预制养扩结束时混凝土实际强度σ′ t2大于快速预制养护结束时混凝土设计强度σ t2和混凝土28d实际强度σ′ 28大于混凝土28d设计强度σ 28同时成立。 Determine whether the actual strength of concrete at the end of rapid precast curing σ′ t2 is greater than the design strength of concrete at the end of rapid precast curing σ t2 and the actual strength of concrete at 28 days σ′ 28 is greater than the design strength of concrete at 28 days σ 28 at the same time. If it is true at the same time, the requirements are met; Otherwise, adjust the mix ratio of concrete and prepare two sets of concrete specimens again according to the adjusted mix ratio for curing and measurement until the actual concrete strength σ′ t2 at the end of rapid precast curing is greater than the concrete design strength σ t2 at the end of rapid precast curing. It is also true that the actual strength σ′ 28 of concrete 28d is greater than the design strength σ 28 of concrete 28d.
  2. 根据权利要求1所述的快速优化预制混凝土构件配合比的方法，所述确定混凝土预制构件需要达到的混凝土28d设计强度σ 28和快速预制养护结束时混凝土设计强度σ t2是根据混凝土预制构件设计指标要求进行确定的，所述确定混凝土标准养护28d结束时混凝土的成熟程度S 28是在养护温度20℃且相对湿度大于95％的条件下确定混凝土的成熟程度S 28。 According to the method of quickly optimizing the mix ratio of precast concrete components according to claim 1, the determination of the concrete 28d design strength σ 28 that the concrete precast components need to achieve and the concrete design strength σ t2 at the end of rapid precast curing are based on the concrete precast component design indicators. It is required to determine the maturity degree S 28 of concrete at the end of 28 days of concrete standard curing by determining the maturity degree S 28 of concrete under the conditions of curing temperature 20°C and relative humidity greater than 95%.
  3. 根据权利要求1所述的快速优化预制混凝土构件配合比的方法，所述预确定混凝土的配合比是根据混凝土配合比相关设计规程进行确定的。According to the method for quickly optimizing the mix ratio of precast concrete components according to claim 1, the predetermined concrete mix ratio is determined according to relevant design regulations for concrete mix ratios.
  4. 根据权利要求1所述的快速优化预制混凝土构件配合比的方法，所述采用实际快速预制养护方式对该两组混凝土试件中的一组试件进行养护，测定得到快速预制养护结束时混凝土实际强度σ′ t2，包括： According to the method for quickly optimizing the mix ratio of precast concrete components according to claim 1, the actual rapid precast curing method is used to maintain one group of the two groups of concrete specimens, and the actual concrete actual value at the end of the rapid precast curing is measured. Strength σ′ t2 , including:
    按照混凝土预制构件生产过程中实际快速预制养护制度要求对该两组混凝土试件中的一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为快速预制养护结束时混凝土实际强度σ′ t2。 One of the two sets of concrete specimens was cured in accordance with the requirements of the actual rapid precast curing system in the production process of concrete precast components. After the curing was completed, the strength of the specimens was measured using standard test methods. The measured strength was at the end of the rapid precast curing. Actual strength of concrete σ′ t2 .
  5. 根据权利要求4所述的快速优化预制混凝土构件配合比的方法，所述实际快速预制养护制度由预制构件生产制备的养护工艺确定，养护参数至少包括静停时间时长t 1、静停温度T 1、升温速率v 1、恒温时长t 2、恒温温度T 2、降温速率v 2和快速养护总时长t 3。 According to the method of quickly optimizing the mix ratio of precast concrete components according to claim 4, the actual rapid precast curing system is determined by the curing process of precast component production and preparation, and the curing parameters at least include the static stop time t 1 and the static stop temperature T 1 , heating rate v 1 , constant temperature duration t 2 , constant temperature temperature T 2 , cooling rate v 2 and total rapid curing duration t 3 .
  6. 根据权利要求1所述的快速优化预制混凝土构件配合比的方法，所述采用恒温快速养护方式对该两组混凝土试件中的另一组试件进行养护，测定得到混凝土28d实际强度σ′ 28，包括： According to the method of quickly optimizing the mix ratio of precast concrete components according to claim 1, the constant temperature rapid curing method is used to maintain the other group of concrete specimens in the two groups, and the actual strength of the concrete 28d is measured to be σ′ 28 ,include:
    按照恒温快速养护的方式对该两组混凝土试件中的另一组试件进行养护，养护结束后采用标准试验方法测定试件强度，测得强度为混凝土28d实际强度σ′ 28。 The other group of concrete specimens in the two groups was cured according to the constant temperature rapid curing method. After the curing was completed, the strength of the specimens was measured using standard test methods. The measured strength was the actual strength of the concrete at 28 days σ′ 28 .
  7. 根据权利要求6所述的快速优化预制混凝土构件配合比的方法，在所述恒温快速养护方式中，所需养护的温度是根据实验室条件来选择的，所需养护的龄期t q是根据标准养护28d结束时混凝土的成熟程度S 28逆推得到的。 The method for quickly optimizing the mix ratio of precast concrete components according to claim 6, in the constant temperature rapid curing method, the temperature required for curing is selected based on laboratory conditions, and the age t q of required curing is based on The maturity degree of concrete at the end of 28 days of standard curing is obtained by inverse calculation of S 28 .
  8. 根据权利要求7所述的快速优化预制混凝土构件配合比的方法，所述恒温快速养护方式中所需养护的温度的选择范围为40-75℃。According to the method for quickly optimizing the mix ratio of precast concrete components according to claim 7, the selection range of the temperature required for curing in the constant temperature rapid curing method is 40-75°C.
  9. 根据权利要求7所述的快速优化预制混凝土构件配合比的方法，所述混凝土的成熟程度采用等效龄期t eq表征，所述等效龄期计算公式为： According to the method for quickly optimizing the mix ratio of precast concrete components according to claim 7, the maturity of the concrete is characterized by the equivalent age t eq , and the equivalent age calculation formula is:
    Figure PCTCN2022095592-appb-100001
    Figure PCTCN2022095592-appb-100001
    其中：in:
    U aT＝(43830-43T)e (-0.0017T)t U aT = (43830-43T)e (-0.0017T)t
    式中：R为气体常数，取8.314J/mol·K；U ar为标准养护温度下的水泥水化反应活化能；U aT为温度为T时反应活化能，是时间和温度的函数。 In the formula: R is the gas constant, which is 8.314J/mol·K; U ar is the activation energy of the cement hydration reaction at the standard curing temperature; U aT is the reaction activation energy when the temperature is T, which is a function of time and temperature.
  10. 根据权利要求1所述的快速优化预制混凝土构件配合比的方法，所述调整混凝土的配合比，采用选择标号高的水泥、降低水胶比、改善粗细骨料的颗粒级配、掺入高效活性矿物参料或掺入高效减水剂所组成群组中的至少一种。The method for quickly optimizing the mix ratio of precast concrete components according to claim 1. The method for adjusting the mix ratio of concrete is to select cement with a high grade, reduce the water-cement ratio, improve the particle gradation of coarse and fine aggregates, and incorporate high-efficiency activity. At least one of the group consisting of mineral materials or high-efficiency water-reducing admixtures.
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CN110962224A (en) * 2019-12-31 2020-04-07 天津中匠建筑科技有限公司 Test method and device for acquiring steam curing parameters of prefabricated part at low temperature and steam curing method
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CN104020046A (en) * 2014-06-04 2014-09-03 王卫仑 Method for estimating compressive strength of concrete in early stage
JP2016037014A (en) * 2014-08-08 2016-03-22 株式会社竹中工務店 Method for producing concrete molding and production management method for concrete molding
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