High-performance mass concrete mix proportion set intersection design method

Abstract

The invention discloses a design method for a mix proportion set intersection of high-performance mass concrete. The design method comprises the following steps: raw material preparation and quality inspection; performing trial mixing on multiple groups of trial mixing concrete with different water-binder ratios and detecting; according to a detection result, drawing a relation curve between each performance index of the test-mixed concrete and a water-binder ratio by adopting conventional software, establishing a polynomial fitting curve model, and evaluating; according to the current standard specification requirements of various performance indexes of the concrete and the corresponding polynomial fitting curve model, multiple groups of concrete optimized mix proportions are obtained; and calculating the concrete adiabatic temperature rise value of each group of concrete optimized mix proportion so as to determine the optimal mix proportion of the concrete. According to the design method, scientificity, accuracy and reliability of concrete mix proportion design can be ensured; a complex mathematical model does not need to be established, conventional analysis software is adopted for analysis and modeling, operation is easy and easy to master, a large amount of time, manpower and material resources do not need to be consumed, and influences of experimental conditions and operator levels are small.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular, to a method for designing the intersection of high-performance mass concrete mix proportions. Background Art

[0002] In a cable-stayed bridge project in Shantou City, Guangdong Province, which is in a medium-high temperature area and near the ocean, the 7# main pier cap of the bridge is a dumbbell-shaped pier cap. The plane size of the pier cap is 63.0 m × 20.5 m, and the height is 5.0 m. The total pouring quantity of the pier cap concrete is 5377 m 3 , belonging to an ultra-thick and super-large pier cap structure. Due to the large number of designed reinforcement layers in the pier cap, the small spacing between adjacent reinforcements, and the area of the dumbbell-shaped pier cap being 1075 m 2 , the pouring time of each layer of concrete is long. It is required that the initial setting time of the concrete is 15 - 20 h to ensure that the upper layer of concrete in the pier cap can bond and join before the lower layer of concrete starts to set, without cold joints occurring. Also, due to the proximity to the ocean, the concrete project has strict requirements for the early cracking resistance, electric flux, and carbonation depth of the concrete. For example, the requirement for the early cracking resistance C of the concrete is 100 ≤ C < 400 (mm 2 / m 2 ), the requirement for the electric flux QS of the concrete is 500 ≤ QS < 1000 (C), and the requirement for the carbonation depth d of the concrete is 0.1 ≤ d < 10 (mm).

[0003] Currently, common concrete mix proportion design methods include: trial mixing method, orthogonal experiment method, response surface design method, artificial intelligence algorithm, empirical formula method, and chart design method. Each method has its own advantages, disadvantages, and applicable scenarios, as follows:

[0004] (1) Trial mixing method: A traditional concrete mix proportion design method. Its basic principle is to repeatedly adjust the proportions of each component through experimental means according to engineering requirements and raw material properties until a concrete mix proportion that meets the performance requirements is obtained. This method is simple and easy to implement, but it is relatively cumbersome and requires a large amount of time, manpower, and material resources. At the same time, since the trial mixing method is greatly affected by experimental conditions and operation levels, the accuracy and reliability of its results are often difficult to guarantee.

[0005] (2) Orthogonal experiment method: A concrete mix proportion design method based on the principle of mathematical statistics. This method designs experimental schemes through orthogonal tables to obtain more information with fewer experimental times, thereby optimizing the concrete mix proportion. This method has the characteristics of high efficiency and high precision and can obtain a better mix proportion scheme in a relatively short time. However, the results of the orthogonal experiment method are greatly affected by experimental conditions.

[0006] (3) Response Surface Methodology: Response Surface Methodology is also used for experimental studies with multiple factors and multiple levels. Compared with the orthogonal experimental method, Response Surface Methodology is to establish a prediction model and optimize the experimental combinations. By performing regression analysis on the relationship between various factors and the index values within the entire surface and establishing a prediction model, the optimal combination of target values can be obtained. Its basic principle is to use Design-Expert software to set the number of factors and the level intervals, obtain the experimental ratio table for experiments, and then input the experimental results into the software. Through regression analysis, the optimal experimental plan and the predicted result values can be predicted. Compared with the full factorial experiment, Response Surface Methodology also obtains the optimal factor and level combination method with a smaller number of experiments. However, it is necessary to establish a relatively complex mathematical model, which requires a high level of mathematical and statistical knowledge of the researchers; when performing response surface analysis, a large number of experiments and calculations are required to obtain sufficient data points to fit the model; there may be differences between the actual experimental conditions and the ideal conditions, which may affect the accuracy and reliability of the model.

[0007] (4) Artificial Intelligence Algorithms: The application of artificial intelligence algorithms in the field of concrete mix design is also becoming increasingly widespread. This method uses technologies such as machine learning and deep learning to process and analyze a large amount of data, thereby obtaining an optimized concrete mix. This method has the characteristics of automation and intelligence, and can greatly improve the efficiency and accuracy of mix design; however, due to the complexity of the algorithm and the limitations of the data, the application of artificial intelligence algorithms in concrete mix design still faces certain challenges.

[0008] (5) Empirical Formula Method: Based on the experience accumulated through long-term practice, it is easy to operate, the design process is relatively fast, and it can quickly meet the emergency engineering needs. It does not require complex calculations and equipment, and is suitable for on-site rapid design; however, due to the lack of systematic scientific verification and theoretical support, the empirical formula may not be able to comprehensively consider all influencing factors, resulting in the design results may not be accurate enough; the concrete performance varies greatly in different regions and under different engineering conditions, and the empirical formula may be difficult to adapt to all situations; the design process depends on the personal experience and judgment of the designer, and different designers may obtain different results, affecting the unity and reliability of the design; due to the lack of unified standards and specifications, the replicability and comparability of the empirical formula between different projects are poor.

[0009] (6) Chart design method: It provides an intuitive and simple way to design and adjust the concrete mix ratio, enabling beginners and inexperienced designers to get started quickly. Through chart design, the standardization of the concrete mix ratio can be ensured, which helps improve construction efficiency and project quality; reasonable mix ratio design can save costs as much as possible and improve economic efficiency on the premise of ensuring quality; however, due to the differences in the variety, quality, form, and even origin of concrete raw materials, as well as changes in the engineering environment, the chart design method may not cover all situations, resulting in certain limitations in actual applications; since the chart design method relies on empirical formulas and standards, it is difficult to accurately predict and adjust the performance changes of concrete under different conditions.

[0010] For the C40 high-performance mass concrete used in the above project, due to the influence of multiple factors such as sand ratio, slump flow, setting time, compressive strength, early crack resistance, electric flux, and carbonation depth, the above concrete mix ratio design method cannot be replicated, and it is difficult to ensure the scientificity, accuracy, and reliability of the mix ratio design of high-performance mass concrete. Summary of the Invention

[0011] The present invention provides a method for designing the intersection of high-performance mass concrete mix ratios to solve the technical problems existing in the existing design methods, such as the need to consume a large amount of time, manpower, and material resources, the accuracy and reliability of the results are often difficult to guarantee because the trial mixing method is greatly affected by experimental conditions and operation levels, the need to establish relatively complex mathematical models, and the high requirements for the mathematical and statistical knowledge of researchers.

[0012] The technical solution adopted by the present invention is as follows:

[0013] A method for designing the intersection of high-performance mass concrete mix ratios includes the following steps: preparation of raw materials and quality inspection; trial mixing of multiple groups of trial-mixed concrete with different water-binder ratios and detection; according to the detection results, using conventional software to draw the relationship curves between the performance indexes of the trial-mixed concrete and the water-binder ratio, establishing a polynomial fitting curve model and evaluating; according to the current standard specifications of the performance indexes of the concrete and the corresponding polynomial fitting curve model, obtaining multiple groups of optimized concrete mix ratios; calculating the adiabatic temperature rise of the concrete for each group of optimized concrete mix ratios to determine the best concrete mix ratio.

[0014] Further, the step of "trial mixing multiple groups of trial-mixed concrete with different water-binder ratios and detection" specifically includes the following steps: formulating the initial mix ratios of multiple groups of concrete with different water-binder ratios; using raw materials to trial mix the trial-mixed concrete corresponding to each group of initial mix ratios; conducting experimental detection on the performance indexes of each group of trial-mixed concrete.

[0015] Further, the "performance indicators" in the step of "testing and detecting the performance indicators of each group of trial-mixed concrete" include sand ratio, slump, spread, initial setting time and final setting time, compressive strength of concrete, early cracking resistance, electric flux, and carbonation depth.

[0016] Further, the step of "drawing the relationship curves between the performance indicators of the trial-mixed concrete and the water-binder ratio using conventional software, establishing a polynomial fitting curve model, and evaluating" specifically includes the following steps: drawing the relationship curves between the performance indicators of the trial-mixed concrete and the water-binder ratio; establishing a polynomial fitting curve model between the performance indicators of the trial-mixed concrete and the water-binder ratio to obtain the goodness of fit R 2 ; evaluating the obtained goodness of fit R 2 for evaluation.

[0017] Further, the specific operation of the step of "drawing the relationship curves between the performance indicators of the trial-mixed concrete and the water-binder ratio" is as follows: taking the water-binder ratio as the X-axis and the performance indicators of the concrete as the Y-axis, drawing the relationship curves between the sand ratio and the water-binder ratio, the spread and the water-binder ratio, the setting time and the water-binder ratio, the compressive strength of the concrete and the water-binder ratio, the early cracking resistance and the water-binder ratio, the electric flux and the water-binder ratio, and the carbonation depth and the water-binder ratio.

[0018] Further, the step of "obtaining multiple groups of optimized concrete mix proportions according to the current standard specification requirements of the performance indicators of the concrete and the corresponding polynomial fitting curve model" specifically includes the following steps: establishing a water-binder ratio set for each performance indicator according to the current standard specification requirements of the performance indicators of the concrete and the corresponding polynomial fitting curve model; fitting the water-binder ratio sets of all performance indicators to obtain multiple groups of optimized water-binder ratios for the concrete; calculating the corresponding optimized concrete mix proportions according to each group of optimized water-binder ratios for the concrete.

[0019] Further, according to the step of "establishing a water-binder ratio set for each performance indicator according to the current standard specification requirements of the performance indicators of the concrete and the corresponding polynomial fitting curve model", a water-binder ratio set A based on the early cracking resistance index, a water-binder ratio set B based on the electric flux index, a water-binder ratio set C based on the carbonation depth index, a water-binder ratio set D based on the trial mix strength index of the 28-day compressive strength of the concrete, a water-binder ratio set E based on the initial setting time index, a water-binder ratio set F based on the spread index, and a water-binder ratio set G based on the water-binder ratio index of mass concrete are obtained respectively.

[0020] Further, the step of "calculating the adiabatic temperature rise of the concrete for each group of optimized concrete mix proportions to determine the best concrete mix proportion" specifically includes the following steps: calculating the adiabatic temperature rise of the concrete for each group of optimized concrete mix proportions; determining the best concrete mix proportion according to the current standard specification requirements and the actual working requirements of the concrete.

[0021] Further, after the step of "calculating the adiabatic temperature rise of the concrete with optimized mix proportion for each group to determine the best mix proportion of the concrete", the following steps are further included: casting of the pile cap concrete, inspection of some indexes and specimen making, which specifically include the following steps: preparation work before casting; layered casting of the concrete, while conducting concrete inspection and specimen making; segmented casting of the concrete; vibration of the concrete; curing of the concrete.

[0022] Further, after the step of "casting of the pile cap concrete, inspection of some indexes and specimen making", the following step is further included: quality inspection of the pile cap concrete, which specifically includes the following steps: test detection of various performance indexes of the specimens; on-site entity crack detection of the pile cap.

[0023] The present invention has the following beneficial effects:

[0024] Compared with the traditional concrete mix proportion design method, the design method of the present invention not only follows the scientific principles and methods of concrete mix proportion design, but also analyzes and experimentally verifies from multiple influencing factors such as various performance indexes (including sand ratio, slump flow, setting time, compressive strength, early cracking resistance, electric flux, carbonation depth) of the trial-mixed concrete, ensuring the scientificity, accuracy and reliability of the mix proportion design of high-performance mass concrete; at the same time, the design method of the present invention does not need to establish a complex mathematical model, and only needs to analyze and model by using conventional analysis software, with simple operation and easy to master, without consuming a large amount of time, manpower and material resources, and being less affected by experimental conditions and operator levels, and having strong replicability and comparability in the mix proportion design of other types and various strength grades of concrete.

[0025] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0027] Figure 1 is a flowchart of the design method for the intersection of high-performance mass concrete mix proportions in the preferred embodiment of the present invention;

[0028] Figure 2 is a curve graph of the relationship between sand ratio and water-binder ratio;

[0029] Figure 3 is a curve graph of the relationship between slump flow and water-binder ratio;

[0030] Figure 4It is a curve graph showing the relationship between setting time and water-binder ratio;

[0031] Figure 5 It is a curve graph showing the relationship between concrete compressive strength and water-binder ratio;

[0032] Figure 6 It is a curve graph showing the relationship between early anti-cracking and water-binder ratio;

[0033] Figure 7 It is a curve graph showing the relationship between electric flux and water-binder ratio;

[0034] Figure 8 It is a curve graph showing the relationship between carbonation depth and water-binder ratio. Specific implementation manners

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0036] Refer to Figure 1 , a preferred embodiment of the present invention provides a method for designing the intersection of high-performance mass concrete mix proportions, including the following steps:

[0037] S1: Preparation of raw materials and quality inspection;

[0038] S2: Trial-mix multiple groups of trial-mix concrete with different water-binder ratios and conduct tests;

[0039] S3: According to the test results, use conventional software to draw the relationship curves between various performance indexes of the trial-mix concrete and the water-binder ratio, establish a polynomial fitting curve model, and evaluate;

[0040] S4: According to the current standard specifications of various performance indexes of concrete and the corresponding polynomial fitting curve model, obtain multiple groups of optimized concrete mix proportions;

[0041] S5: Calculate the adiabatic temperature rise of the concrete for each group of optimized concrete mix proportions to determine the best concrete mix proportion.

[0042] Compared with the traditional concrete mix design method, the design method of the present invention not only follows the scientific principles and methods of concrete mix design, but also analyzes and experimentally verifies various performance indicators of the trial-mixed concrete (including sand ratio, slump flow, setting time, compressive strength, early cracking resistance, electric flux, carbonation depth) and other influencing factors to ensure the scientificity, accuracy and reliability of the mix design of high-performance mass concrete. At the same time, the design method of the present invention does not require the establishment of complex mathematical models, and can be analyzed and modeled using conventional analysis software. It is simple and easy to master, does not require a large amount of time, manpower and material resources, and is less affected by experimental conditions and operator levels. In the mix design of other types and various strength grades of concrete, the replicability and comparability are relatively strong.

[0043] This application takes the mix design and construction of C40 high-performance mass concrete for the cap of a cable-stayed bridge in Shantou City, Guangdong Province, which is in a medium-high temperature area and near the ocean, as an example, and details a method for designing the intersection of high-performance mass concrete mix proportions.

[0044] Optionally, step S1: Preparation of raw materials and quality inspection, specifically as follows:

[0045] High-performance mass concrete refers to a mixture made of cement, fly ash, slag powder, manufactured sand, crushed stone, retarder and mixing water in a certain proportion. According to the types and specifications of the constituent materials of the determined high-performance mass concrete, the preparation of each constituent material is carried out on site at the mixing plant, and they are stacked separately in bins according to categories and specifications, and marked and managed to prevent rain. Before the component raw materials of high-performance mass concrete enter the site, relevant quality index inspections are carried out. All inspection results must meet the requirements of relevant national and industrial construction technical specifications, product standards or technical documents before they can be used. Specifically as follows:

[0046] 1. Cement: Huaren P.O42.5 ordinary Portland cement is used; the test results are as follows: the density is 3.05 g / cm 3 , the specific surface area is 346 m 2 / kg, the initial setting time is 242 min, the final setting time is 320 min, the soundness is qualified, the 28-day compressive strength is 51.4 MPa, and the 28-day flexural strength is 7.3 MPa. All inspection indicators meet the technical requirements of P.O42.5 in the "General Portland Cement" (GB175) standard. The 3-day hydration heat of Huaren P.O42.5 ordinary Portland cement is 240 kJ / kg, and the 7-day hydration heat is 270 kJ / kg.

[0047] 2. Fly ash: Datang Power Plant class F grade I fly ash with stable quality and uniform incoming materials is used, and its dosage is 15% of the total mass of the cementitious materials. The test results are as follows: the density is 2.52 g / cm 3, fineness is 8.3%, water demand ratio is 91%, moisture content is 0.1%, loss on ignition is 4.4%, strength activity index is 84%, and its quality meets the technical requirements of Class I fly ash in the standard of Fly Ash Used in Cement and Concrete (GB / T 1596).

[0048] 3. Ground granulated blast-furnace slag powder: S95 grade powdered ground granulated blast-furnace slag powder is adopted, and its dosage is 20% of the total mass of cementitious materials. The test results are as follows: density is 2.93 g / cm 3 , specific surface area is 422 m 2 / kg, fluidity ratio is 96%, moisture content is 0.6%, 7-day activity index is 89%, and its quality meets the technical requirements of S95 grade slag powder in the standard of Ground Granulated Blast-Furnace Slag Powder Used in Cement, Mortar and Concrete (GB / T 18046).

[0049] 4. Manufactured sand: Manufactured sand made from acid granite with hard, dense texture and high strength through multiple crushing processes is adopted. The test results are as follows: fineness modulus is 2.83, belonging to medium sand, apparent density is 2530 kg / m 3 , bulk density is 1630 kg / m 3 , mud content is 0%, methylene blue MB value test is qualified, mud lump content is 0.2%, single-stage maximum crushing value is 16.8%, and all test indexes meet the technical requirements of Class II manufactured sand in Zone 2 medium sand in the standard of Sand for Construction (GB / T 14684).

[0050] 5. Crushed stone: Continuously graded crushed stone with nominal particle size of 5 - 25 mm made from acid granite with hard, dense texture and high strength through multiple crushing processes is adopted. The test results are as follows: particle size distribution is good, mud content is 0.2%, mud lump content is 0%, content of needle-like and flaky particles is 6.8%, crushing value is 8.6%, apparent density is 2610 kg / m 3 , bulk density is 1550 kg / m 3 , and its saturated water compressive strength of rock is 93.5 MPa. All test indexes meet the technical requirements of Class II crushed stone in the standard of Crushed Stones and Pebbles for Construction (GB / T 14685).

[0051] 6. Retarding agent: HPWR-R retarding type high-performance water reducer is adopted. It is a water-based agent with a water reduction rate of 25%, and its dosage is 3.0% of the total mass of cementitious materials. Its quality meets the technical requirements of retarding type high-performance water reducer in the standard of Concrete Admixtures (GB8076).

[0052] 7. Mixing water: Drinking water is adopted. After inspection, its quality meets the requirements of mixing water for concrete in the standard of Standard for Water Used in Concrete (JGJ63).

[0053] Optionally, step "S2: Mix and test multiple groups of trial-mixed concrete with different water-binder ratios" specifically includes the following steps:

[0054] S201: Determine the initial mix proportions of multiple groups of concrete with different water-binder ratios. The specific operations are as follows:

[0055] According to the provisions of Clause 6.15.9 in the "Technical Specification for Highway Bridge and Culvert Construction" (JTG / T 3650-2020), the unit water consumption of high-performance concrete is controlled within 130 - 160 kg / m 3 and according to the provisions of Clause 7.5.3 in the "Code for Design of Mix Proportions of Ordinary Concrete" (JGJ 55-2011), the water-binder ratio shall not be greater than 0.55 and the water consumption shall not be greater than 175 kg / m 3 . Considering the water reduction rate of 25% of the HPWR-R retarder type high-performance water reducer and other factors, the unit water consumption of the concrete in this application is taken as 160 kg / m 3 . It is planned to use 7 groups of initial mix proportions of C40 concrete with a water-binder ratio difference of 0.03 for testing. See Table 1 for details:

[0056] Table 1 Initial mix proportions of 7 groups of C40 concrete with different water-binder ratios (unit: kg / m 3 )

[0057] Number Water-cement ratio Sand ratio (%) Cement Fly ash Ground granulated blast-furnace slag Manufactured sand Crushed stone Retarding type high-range water reducer Mixing water 1 0.31 38 336 77 103 645 1054 15.48 160 2 0.34 39 306 70 94 680 1065 14.10 160 3 0.37 40 281 65 86 714 1071 12.96 160 4 0.40 41 260 60 80 745 1073 12.00 160 5 0.43 42 242 56 74 776 1071 11.16 160 6 0.46 43 226 52 70 805 1067 10.44 160 7 0.49 44 213 49 65 833 1060 9.81 160

[0058] S202: Use the raw materials to mix the trial-mixed concrete corresponding to each group of initial mix proportions of concrete;

[0059] S203: Test and detect the performance indicators of each group of trial-mixed concrete. The specific operations are as follows:

[0060] For the 7 groups of C40 trial-mixed concrete with different water-binder ratios in Table 1, according to the determination methods in the "Code for Design of Mix Proportions of Ordinary Concrete" (JGJ 55-2011), "Standard Test Method for Performance of Ordinary Concrete Mixtures" (GB / T 50080), "Standard Test Method for Physical and Mechanical Properties of Concrete" (GB / T 50081), and "Standard Test Method for Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082), conduct performance index tests and detections on sand ratio, slump, spread, setting time (initial setting time and final setting time), compressive strength of concrete, early anti-cracking, electric flux, and carbonation depth. The test and detection results are shown in Table 2 for details.

[0061] Table 2 Test and detection results of performance indicators of 7 groups of C40 trial-mixed concrete with different water-binder ratios

[0062]

[0063] Optionally, step "S3: According to the test results, use conventional software to draw the relationship curves between the performance indexes of the trial-mixed concrete and the water-binder ratio, establish a polynomial fitting curve model, and evaluate" specifically includes the following steps:

[0064] S301: Draw the relationship curves between the performance indexes of the trial-mixed concrete and the water-binder ratio. The specific operation is as follows: Take the water-binder ratio as the X-axis and the performance indexes of the concrete as the Y-axis, and draw the relationship curves between the sand ratio and the water-binder ratio, the slump flow and the water-binder ratio, the setting time and the water-binder ratio, the compressive strength of the concrete and the water-binder ratio, the early anti-cracking and the water-binder ratio, the electric flux and the water-binder ratio, and the carbonation depth and the water-binder ratio, as Figure 2-8 shown.

[0065] S302: Establish a polynomial fitting curve model for the performance indexes of the trial-mixed concrete and the water-binder ratio to obtain the goodness of fit R 2 , and the specific operation is as follows:

[0066] According to the test results in Table 2, take the water-binder ratio as the X-axis and the performance indexes of the concrete as the Y-axis, and establish polynomial fitting curve models for the sand ratio and the water-binder ratio, the slump flow and the water-binder ratio, the setting time and the water-binder ratio, the compressive strength of the concrete and the water-binder ratio, the early anti-cracking and the water-binder ratio, the electric flux and the water-binder ratio, the carbonation depth and the water-binder ratio, etc., and obtain the goodness of fit R 2 , as Figures 2 to 8 shown. Specifically as follows:

[0067] (1) Modeling steps of the polynomial fitting curve model: According to the data of the water-binder ratio and its corresponding sand ratio, slump flow, setting time (initial setting time, final setting time), compressive strength of the concrete (7-day compressive strength of the concrete, 28-day compressive strength of the concrete, 60-day compressive strength of the concrete), early anti-cracking, electric flux, carbonation depth, etc. in Table 2, use the conventional WPS Office office software XLSX worksheet to draw the relationship curves between the performance indexes of the trial-mixed concrete and the water-binder ratio and establish a polynomial fitting curve model to obtain the goodness of fit R 2 .

[0068] The specific operation is as follows:

[0069] ① On the computer desktop, create a new XLSX file, double-click to open the newly created XLSX file, and input the X-axis data and Y-axis data that you need to statistically make into a curve. Among them: Input the water-binder ratio data in Table 2 in the X-axis column, and input the sand ratio data in Table 2 in the Y-axis column.

[0070] ② Switch the upper menu bar to the "Insert" option, click on the small triangle below "Scatter Chart", and select the curve type with a smooth line among them, and a smooth line scatter chart will pop up on the interface.

[0071] ③ In the area of the smooth line scatter plot, right-click and select the "Select Data" option. The "Edit Data Source" window will be displayed on the interface. Select "Series 1" and click "Edit", and the "Edit Data Series" window will be shown. In the "Series Name (N)", select the data name, which is "Sand Ratio" for this graph; in the "X-axis Series Values (X)", select the "Water-Binder Ratio" data in the X-axis column, and in the "Y-axis Series Values (Y)", select the "Sand Ratio" data in the Y-axis column. After clicking "OK", the "Sand Ratio" series curve can be successfully generated on the interface;

[0072] ④ Click on the X-axis at the bottom within the area of the smooth line scatter plot, and enter the minimum value 0.30 and the maximum value 0.50 of the X-axis in the "Axis Options" boundary; click on the Y-axis on the left within the area of the smooth line scatter plot, and enter the minimum value 37 and the maximum value 45 of the Y-axis in the "Axis Options" boundary;

[0073] ⑤ In the area of the smooth line scatter plot, click the left mouse button and then click the "Chart Elements" icon. In the "Chart Elements" options, select "Axis", "Axis Title", and "Chart Title" to complete the X-axis name, Y-axis name, and the name of the smooth line scatter plot;

[0074] ⑥ In the "Trendline" option of the chart elements, select "Polynomial (P)", "Display Equation (E)", and "Display R-Squared Value (R)", and the "Polynomial Equation" and "Goodness of Fit R 2 value" will be displayed on the smooth line scatter plot interface.

[0075] ⑦ In the "Chart Elements", select "Legend", and then select the "Right" option, and the legends of the "Sand Ratio Series Name" and the "Polynomial Series Name" will be shown on the right side interface of the smooth line scatter plot. That is, the polynomial fitting curve model of the sand ratio and the water-binder ratio is completed.

[0076] ⑧ Follow the above steps to complete in sequence: the polynomial fitting curve models of the slump flow and the water-binder ratio, the setting time and the water-binder ratio, the concrete compressive strength and the water-binder ratio, the early anti-cracking and the water-binder ratio, the electric flux and the water-binder ratio, the carbonation depth and the water-binder ratio, etc.

[0077] ⑨ In the polynomial fitting curve models of setting time vs. water-binder ratio and concrete compressive strength vs. water-binder ratio, when there are two or three series of curves on one graph, the steps for modeling the polynomial fitting curve model are as follows: When plotting the polynomial fitting curve models of setting time vs. water-binder ratio and concrete compressive strength vs. water-binder ratio, after determining the selection of "Series Name (N)", "X-axis Series Value (X)", and "Y-axis Series Value (Y)" for "Initial Setting Time or Concrete 7-day Compressive Strength", click "Add (+)" in the "Edit Data Source" window. The "Edit Data Series" window will be displayed. In the "Series Name (N)", continue to select the data name of "Final Setting Time or Concrete 28-day Compressive Strength or Concrete 60-day Compressive Strength". In the "X-axis Series Value (X)", continue to select the data of "Water-binder Ratio". In the "Y-axis Series Value (Y)", continue to select the data of "Final Setting Time or Concrete 28-day Compressive Strength or Concrete 60-day Compressive Strength" in the Y-axis column. After clicking "OK", the series curve of "Final Setting Time or Concrete 28-day Compressive Strength or Concrete 60-day Compressive Strength" can be successfully generated in the interface, which means the polynomial fitting curve model with two or three series of curves is completed on one graph.

[0078] (2) According to the above modeling steps of the polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of sand ratio vs. water-binder ratio: The polynomial formula is Y = -3E -12 x 2 + 33.333x + 27.667, and the goodness of fit R 2 = 1; where: E refers to the base of the natural logarithm function, which is a natural constant. The natural constant E is an infinite non-repeating decimal, and its value is approximately 2.718281828459045;

[0079] (3) According to the above modeling steps of the polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of slump flow vs. water-binder ratio: The polynomial formula is Y = -1865.1X 2 + 2502.8X - 184.7, and the goodness of fit R 2 = 0.9953;

[0080] (4) According to the above modeling steps of the polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of initial setting time vs. water-binder ratio: The polynomial formula is Y = 476.19X 2 + 1476.2X + 437.19, and the goodness of fit R 2 = 0.9947; The polynomial fitting curve model of final setting time vs. water-binder ratio: The polynomial formula is Y = -1058.2X 2 + 2846.6X + 312.35, and the goodness of fit R 2 = 0.9974;

[0081] (5) According to the modeling steps of the above polynomial fitting curve model, the following are obtained: The polynomial fitting curve model of the 7-day compressive strength of concrete and the water-binder ratio: The polynomial formula is Y = 137.57X 2 - 230.53X + 114.12, and the goodness of fit R 2 = 0.9998; The polynomial fitting curve model of the 28-day compressive strength of concrete and the water-binder ratio: The polynomial formula is Y = - 23.81X 2 - 92.619X + 91.857, and the goodness of fit R 2 = 0.9991; The polynomial fitting curve model of the 60-day compressive strength of concrete and the water-binder ratio: The polynomial formula is Y = - 70.106X 2 - 57.844X + 90.007, and the goodness of fit R 2 = 0.9974;

[0082] (6) According to the modeling steps of the above polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of early anti-cracking and the water-binder ratio: The polynomial formula is Y = - 1375.7X 2 + 2229.1X - 314.87, and the goodness of fit R 2 = 0.9921;

[0083] (7) According to the modeling steps of the above polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of electric flux and the water-binder ratio: The polynomial formula is Y = - 1719.6X 2 + 3123.3X - 38.275, and the goodness of fit R 2 = 0.9974;

[0084] (8) According to the modeling steps of the above polynomial fitting curve model, the following is obtained: The polynomial fitting curve model of carbonation depth and the water-binder ratio: The polynomial formula is Y = 39.683X 2 + 0.873X + 1.4159, and the goodness of fit R 2 = 0.9979.

[0085] S303: Evaluate the obtained goodness of fit R 2 ; Specifically, according to the trend line goodness of fit R 2 values of the above polynomial fitting curve models of sand ratio and water-binder ratio, slump flow and water-binder ratio, setting time and water-binder ratio, concrete compressive strength and water-binder ratio, early anti-cracking and water-binder ratio, electric flux and water-binder ratio, carbonation depth and water-binder ratio, etc., it shows that: all are greater than 0.99, and the closer the goodness of fit R 2 value is to 1, the better the model fitting effect, the higher the trend line fitting degree, and the higher the credibility. According to the above evaluation of the goodness of fit R 2 , it shows that: the credibility of the initial mix design of 7 groups of C40 concrete with different water-binder ratios is high.

[0086] Optionally, step "S4: According to the current standard specification requirements of various performance indicators of concrete and the corresponding polynomial fitting curve model, obtain multiple groups of optimized concrete mix ratios" specifically includes the following steps:

[0087] S401: According to the current standard specification requirements of various performance indicators of concrete and the corresponding polynomial fitting curve model, establish the water-binder ratio set for each performance indicator; that is, according to the performance indicators such as early anti-cracking, electric flux, carbonation depth, trial mix strength of concrete 28-day compressive strength, initial setting time, slump flow, etc. in the current relevant standard specifications, the technical requirements for the water-binder ratio of mass concrete, and the polynomial fitting curve model of relevant performance indicators, and calculate respectively to obtain the water-binder ratio set A based on the early anti-cracking index, the water-binder ratio set B based on the electric flux index, the water-binder ratio set C based on the carbonation depth index, the water-binder ratio set D based on the trial mix strength of concrete 28-day compressive strength index, the water-binder ratio set E based on the initial setting time index, the water-binder ratio set F based on the slump flow index, and the water-binder ratio set G based on the water-binder ratio index of mass concrete. Specifically as follows:

[0088] 1. According to the technical requirement in the "Concrete Quality Control Standard" (GB 50164-2011) that the early anti-cracking L-IV level is 100 ≤ C < 400 (mm 2 / m 2 ), and the polynomial formula in the polynomial fitting curve model of early anti-cracking and water-binder ratio, it is calculated that: the water-binder ratio (X value) is 0.215 to 0.440, and the water-binder ratio set A is established, then A = {0.215, 0.216,..., 0.440}.

[0089] 2. According to the technical requirements in the "Concrete Quality Control Standard" (GB 50164-2011) that the electric flux Q-IV level is 500 ≤ Q S <1000 (C), the technical requirement in the "Technical Specification for Construction of Highway Bridges and Culverts" (JTG / T 3650-2020) that the electric flux ≤ 1000 (C), and the polynomial formula in the polynomial fitting curve model of electric flux and water-binder ratio, it is calculated that: the water-binder ratio (X value) is 0.193 to 0.438, and the water-binder ratio set B is established, then B = {0.193, 0.194,..., 0.438}.

[0090] 3. According to the technical requirement in the "Standard for Quality Control of Concrete" (GB 50164-2011) that the carbonation depth of T-IV grade is 0.1≤d<10 (mm), and the polynomial formula in the polynomial fitting curve model of carbonation depth and water-binder ratio, it is calculated that the water-binder ratio (X value) is 0 to 0.454, and a water-binder ratio set C is established, then C = {0, 0.001,..., 0.454}.

[0091] 4. According to the technical requirement in the "Code for Mix Proportion Design of Ordinary Concrete" (JGJ 55-2011) that the trial mix strength of the 28-day compressive strength of concrete is ≥48.2 (MPa), and the polynomial formula in the polynomial fitting curve model of the 28-day compressive strength of concrete and water-binder ratio, it is calculated that the water-binder ratio (X value) is 0 to 0.424, and a water-binder ratio set D is established, then D = {0, 0.001,..., 0.424}.

[0092] 5. According to the technical requirement that the initial setting time required for the mass concrete construction of this bridge pier cap is 900 to 1200 (min), and the polynomial formula in the polynomial fitting curve model of the initial setting time and water-binder ratio, it is calculated that the water-binder ratio (X value) is 0.287 to 0.451, and a water-binder ratio set E is established, then E = {0.287, 0.288,..., 0.451}.

[0093] 6. According to the technical requirement in the "Evaluation Standard for High Performance Concrete" (JGJ / T385-2015) that the slump flow is 450 to 550 (mm), and the polynomial formula in the polynomial fitting curve model of the slump flow and water-binder ratio, it is calculated that the water-binder ratio (X value) is 0.340 to 0.433, and a water-binder ratio set F is established, then F = {0.340, 0.341,..., 0.433}.

[0094] 7. According to the requirement in Clause 7.5.3 of the "Code for Mix Proportion Design of Ordinary Concrete" (JGJ 55-2011) that the water-binder ratio of mass concrete shall not be greater than 0.550, and a water-binder ratio set G is established, then G = {0, 0.001,..., 0.550}.

[0095] S402: Fit the water-binder ratio sets of all performance indicators to obtain multiple groups of optimized water-binder ratios for concrete; the specific operation is as follows: For the water-binder ratio set A, water-binder ratio set B, water-binder ratio set C, water-binder ratio set D, water-binder ratio set E, water-binder ratio set F, and water-binder ratio set G, using the principle of set intersection, integrate the data to obtain the water-binder ratio set H = {0.340, 0.341,..., 0.424}, and finally fit it into the optimized water-binder ratio for concrete, with the values being 0.34, 0.36, 0.38, 0.40, 0.42.

[0096] S403: Optimize the water-binder ratio according to each group of concrete, and calculate the corresponding optimized concrete mix proportion. The specific operations are as follows:

[0097] According to the 5 groups of optimized water-binder ratios of concrete fitted above, combined with the polynomial formula in the polynomial fitting curve model of sand ratio and water-binder ratio, calculate that the sand ratios are 39.00%, 39.67%, 40.33%, 41.00%, 41.67% respectively, and the values are 39%, 40%, 40%, 41%, 42%, which meet the requirements of the sand ratio of 38% - 42% in Clause 7.5.3 of the "Code for Design of Ordinary Concrete Mix Proportions" (JGJ 55 - 2011) standard. Also, based on the unit water consumption of 160 kg / m³ of concrete 3 , the fly ash content is 15% of the total mass of the binder, the slag powder content is 20% of the total mass of the binder, and the retarder content is 3.0% of the total mass of the binder. The optimized mix proportions of 5 groups of C40 concrete with different water-binder ratios can be calculated, as shown in Table 3:

[0098] Table 3 Optimized mix proportions of 5 groups of C40 concrete with different water-binder ratios (unit: kg / m³) 3 )

[0099]

[0100] Optionally, the step "S5: Calculate the adiabatic temperature rise of the concrete for each group of optimized concrete mix proportions to determine the best concrete mix proportion" specifically includes the following steps:

[0101] S501: Calculate the adiabatic temperature rise of the concrete for each group of optimized concrete mix proportions; the control value for the maximum temperature inside the concrete placement is: the temperature rise of the concrete placement based on the initial temperature ≤ 50°C and the maximum internal temperature ≤ 75°C.

[0102] The specific process is as follows:

[0103] 1. Known conditions: The specific heat capacity C of the concrete is taken as 0.94 kJ / (kg·°C); the measured mass density ρ of the concrete is 2390 kg / m³ 3 ; according to the 3-day hydration heat of Huarun P.O42.5 ordinary Portland cement being 240 kJ / kg, the 7-day hydration heat being 270 kJ / kg, the fly ash content being 15% of the total mass of the binder, the slag powder content being 20% of the total mass of the binder, the cement being ordinary Portland cement with λ being 0.88, the initial temperature of the concrete is calculated according to the target control value of 28°C, and the total hydration heat Q of the binder is calculated according to the standard calculation methods in Clauses B.1.1, B.1.2, and B.1.3 of Appendix B.1 "Adiabatic Temperature Rise of Concrete" in the "Standard for Mass Concrete Construction" (GB 50496 - 2018) standard; the concrete age is 60 days;

[0104] 2. Calculation method: According to the standard calculation methods in Clauses B.1.1, B.1.2, B.1.3, B.1.4, and B.1.5 of Appendix B.1 - Adiabatic Temperature Rise of Concrete in the "Standard for Mass Concrete Construction" (GB 50496 - 2018), calculate the adiabatic temperature rise value T(t) of the concrete at the age of 60 days, and calculate according to formula (1):

[0105]

[0106] In the formula: T(t) - Adiabatic temperature rise value (℃) when the concrete age is t;

[0107] W - Cementitious material dosage per cubic meter of concrete (kg / m 3 );

[0108] C - Specific heat capacity of concrete [kJ / (kg·℃)];

[0109] ρ - Mass density of concrete (kg / m 3 );

[0110] Q - Total heat of hydration of cementitious materials (kJ / kg);

[0111] t - Concrete age (d);

[0112] m - Unit mass coefficient of cementitious materials related to cement type, dosage, and initial temperature of concrete entering the formwork, etc.

[0113] 3. Calculation results: After calculation, the adiabatic temperature rise values of the concrete at the age of 60 days for the optimized mix proportions of 5 groups of C40 concrete with different water - binder ratios are 55.3℃, 52.2℃, 49.5℃, 47.0℃, and 44.8℃ respectively, as shown in Table 3.

[0114] 4. In summary, the adiabatic temperature rise values of the concrete at the age of 60 days for the optimized mix proportions of C40 concrete with water - binder ratios of 0.38, 0.40, and 0.42 are 49.5℃, 47.0℃, and 44.8℃ respectively, all of which meet the requirement in the "Code for Design of Ordinary Concrete Mix Proportions" (JGJ55 - 2011) and the "Standard for Mass Concrete Construction" (GB 50496 - 2018) that the adiabatic temperature rise of concrete should not be greater than 50℃.

[0115] S502: Determine the optimal mix proportion of concrete according to the requirements of current standards and specifications and the actual working requirements of concrete. That is, according to Tables 1 to 3 and the provisions of Clause 6.15.9 in the "Technical Specification for Highway Bridge and Culvert Construction" (JTG / T 3650-2020) standard, "For the concrete of general components exposed to air, the dosage of fly ash should preferably not exceed 20%, and the dosage of Portland cement in the cementitious materials per cubic meter of concrete should preferably not be less than 240 kg", and considering the workability, strength, durability and economy of concrete comprehensively, the optimal mix proportion of C40 high-performance mass concrete is determined as follows: Cement: Fly ash: Ground granulated blast-furnace slag: Manufactured sand: Crushed stone: Retarding high-performance water reducer: Mixing water = 260: 60: 80: 745: 1073: 12.00: 160 (unit: kg / m 3 )

[0116] Optionally, after step "S5: Calculate the adiabatic temperature rise of the concrete with the optimized mix proportion for each group of concrete to determine the optimal mix proportion of concrete", step S6: Casting of pile cap concrete, inspection of some indicators and specimen production is also included, which specifically includes the following steps:

[0117] S601: Preparation work before casting. After the installation quality of the steel bars of the 7# main pier pile cap, the steel bars of the tower base and tower column, the embedded parts, the formwork, etc. have been inspected and accepted as qualified, the C40 high-performance mass concrete of the 7# main pier pile cap can be cast.

[0118] S602: The concrete is poured in layers while conducting concrete inspection and specimen fabrication. Specifically, the specific operation of the step "pouring the concrete in layers" is as follows: When pouring the bearing platform concrete on the top surface of the blinding concrete, the mass concrete is divided into 17 layers for continuous pouring, with a layer thickness of 0.3 m. Before pouring, thoroughly clean the sundries within the scope of the bearing platform, and sprinkle water to moisten the top surface of the blinding concrete, the steel bars of the bearing platform, the steel bars of the tower base and tower column, the embedded parts, and the formwork, to prevent the moisture in the bearing platform concrete from being absorbed by the overly dry formwork and blinding concrete during the pouring process, reduce the moisture loss of the concrete, and avoid the appearance of dry shrinkage cracks on the concrete surface. During pouring, the measured concrete has a slump of 160 - 180 mm, an expansion degree of 450 - 530 mm, an in-mold temperature of 20.8 - 27.8 °C, and a free fall height of 1.6 m - 1.8 m. The upper layer of concrete is poured before the initial setting of the lower layer of concrete, and so on. Before the initial setting of the 17th layer of concrete, trowel and finish the top surface, and chisel the top surface of the concrete at the tower base and tower column to make the concrete surface rough and uneven, increasing the surface roughness of the concrete, which is beneficial to the bonding of the tower base concrete and the bearing platform concrete interface and increasing the bonding strength between the tower base concrete and the bearing platform concrete. Specifically, the specific operation of the step "concrete inspection and specimen fabrication" is as follows: When pouring the bearing platform concrete, a certain amount of concrete mixture is respectively sampled at the on-site pouring location for slump, expansion degree, and setting time detection, and compressive strength, early anti-cracking, electric flux, and carbonation depth specimens of the concrete are fabricated according to the specified frequencies in the "Concrete Quality Control Standard" (GB50164), "Technical Specification for Construction of Highway Bridges and Culverts" (JTG / T3650), and "Standard for Mass Concrete Construction" (GB50496), and are cured under standard conditions until the specified age.

[0119] S603: The concrete is poured in sections; specifically, on the cross-bridge direction plane of the bearing platform, the mass concrete is divided into 3 sections for pouring, and 3 concrete pump trucks are used at the construction site to pump the concrete to the pouring location in sections. The pouring sequence of the bearing platform concrete is as follows: advancing from the middle to both sides and from the upstream to the downstream, strictly controlling the layer thickness, which is 0.3 m.

[0120] S604: Concrete vibration; specifically, for each layer of concrete placement in the front, a vibrating rod is used to follow up and vibrate in the back. The vibration spacing is controlled at 60 - 70 cm. When vibrating, the vibrating rod should be inserted into the concrete. When vibrating the upper and lower layers of concrete, the vibrating rod is inserted 5 - 10 cm into the lower layer of concrete. Each vibration must be fast inserted and slow pulled out until the concrete at that place no longer subsides, the bubbles no longer emerge, and the surface shows bleeding. In particular, strengthen the vibration of the concrete at the dense steel bar areas of the tower base and tower column to prevent the concrete from being under-vibrated, resulting in loose and non-compact concrete and low strength at the tower base and tower column.

[0121] S605: Concrete curing; specifically, before the initial setting of the concrete on the 17th floor, while finishing the surface and covering it with plastic film, after the strength reaches 2.5 MPa, water storage curing is carried out with the formwork, and the water storage depth is not less than 0.1 m. The water storage curing period with the formwork is not less than 5 days. After the removal of the bearing platform formwork, in the cavity between the bearing platform concrete and the foundation pit, it is backfilled with cohesive soil in layers, with each layer having a thickness of 300 mm and a compactness ≥ 90%, which is beneficial to the side insulation of the bearing platform concrete.

[0122] Optionally, after step "S6: Pouring of bearing platform concrete, inspection of partial indicators and specimen production", it further includes step S7: Quality inspection of bearing platform concrete, which specifically includes the following steps:

[0123] S701: Test detection of various performance indicators of specimens; specifically, for the concrete compressive strength, early anti-cracking, electric flux and carbonation depth specimens cured under standard conditions to the specified age, relevant project test detections are carried out according to the determination methods in the "Standard for Test Methods of Performance of Ordinary Concrete Mixtures" (GB / T 50080), "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GB / T 50081), and "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete" (GB / T 50082). The test detection results of various performance indicators of C40 high-performance mass concrete are shown in Table 4.

[0124] Table 4 Test detection results of various performance indicators of C40 high-performance mass concrete

[0125]

[0126] The comparison between the test detection results in Table 2 and those in Table 4 shows that there is little difference between the test detection results of various performance indicators of the C40 trial-mixed concrete during the concrete mix design and those of the C40 high-performance mass concrete during the verification of the bearing platform concrete pouring construction, verifying the scientificity, accuracy and reliability of the C40 high-performance mass concrete mix design.

[0127] S702: On-site entity crack detection of the bearing platform; optionally, after the removal of the bearing platform formwork, on-site entity inspections are carried out on the top and side surfaces of the bearing platform, and no quality defects of temperature cracks occur.

[0128] The present invention is a method for designing the intersection of high-performance mass concrete mix ratios. For the mix ratio design of other types and various strength grades of concrete, the same method for designing the intersection of concrete mix ratios can be adopted to realize the optimization of concrete mix ratio design, and the concrete mix ratio design results are scientific, accurate and reliable.

[0129] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A design method for the intersection of high-performance large-volume concrete mix proportions, characterized in that It includes the following steps: Raw material preparation and quality inspection; Mix trial batches of concrete with different water-binder ratios and conduct tests; According to the test results, use conventional software to plot the relationship curves between various performance indexes of the trial-batch concrete and the water-binder ratio, establish a polynomial fitting curve model and evaluate it; Based on the current standard specifications for various performance indexes of concrete and the corresponding polynomial fitting curve model, obtain multiple groups of optimized concrete mix ratios; Calculate the adiabatic temperature rise of the concrete for each group of optimized concrete mix ratios to determine the best concrete mix ratio.

2. The design method of the intersection of high-performance large-volume concrete mix ratios according to claim 1, characterized in that The step "Mix trial batches of concrete with different water-binder ratios and conduct tests" specifically includes the following steps: Propose initial mix ratios for multiple groups of concrete with different water-binder ratios; Use the raw materials to mix trial batches of concrete corresponding to the initial mix ratio of each group; Conduct test inspections on various performance indexes of each group of trial-batch concrete.

3. According to the method for designing the intersection of high-performance mass concrete mix ratios described in claim 2, it is characterized in that The "performance indexes" in the step "Conduct test inspections on various performance indexes of each group of trial-batch concrete" include sand ratio, slump, spread, initial setting time and final setting time, compressive strength of concrete, early anti-cracking, electric flux and carbonation depth.

4. The design method of the intersection of high-performance large-volume concrete mix ratios according to claim 1, characterized in that The step "According to the test results, use conventional software to plot the relationship curves between various performance indexes of the trial-batch concrete and the water-binder ratio, establish a polynomial fitting curve model and evaluate it" specifically includes the following steps: Plot the relationship curves between various performance indexes of the trial-batch concrete and the water-binder ratio; Establish a polynomial fitting curve model for various performance indexes of trial - mixed concrete and the water - binder ratio to obtain the goodness of fit R 2 ; Evaluate the obtained goodness of fit R 2 for evaluation.

5. According to the method for designing the intersection of high-performance mass concrete mix ratios described in claim 4, it is characterized in that The specific operation of the step "Plot the relationship curves between various performance indexes of the trial-batch concrete and the water-binder ratio" is: take the water-binder ratio as the X-axis and various performance indexes of the concrete as the Y-axis, and plot the relationship curves between sand ratio and water-binder ratio, spread and water-binder ratio, setting time and water-binder ratio, compressive strength of concrete and water-binder ratio, early anti-cracking and water-binder ratio, electric flux and water-binder ratio, and carbonation depth and water-binder ratio.

6. The design method for the intersection of high-performance large-volume concrete mix ratios according to claim 1, characterized in that, The step "Based on the current standard specifications for various performance indexes of concrete and the corresponding polynomial fitting curve model, obtain multiple groups of optimized concrete mix ratios" specifically includes the following steps: Based on the current standard specifications for various performance indexes of concrete and the corresponding polynomial fitting curve model, establish a water-binder ratio set for each performance index; Fit the water-binder ratio sets of all performance indexes to obtain multiple groups of optimized water-binder ratios for concrete; According to each group of optimized water-binder ratios for concrete, calculate and obtain the corresponding optimized concrete mix ratios.

7. According to the method for designing the intersection of high-performance mass concrete mix ratios described in claim 6, it is characterized in that According to the step of "establishing the water-binder ratio set for each performance index based on the current standard specifications for various performance indexes of concrete and the corresponding polynomial fitting curve model", the water-binder ratio set A based on the early anti-cracking index, the water-binder ratio set B based on the electric flux index, the water-binder ratio set C based on the carbonation depth index, the water-binder ratio set D based on the trial mix strength index of the 28-day compressive strength of concrete, the water-binder ratio set E based on the initial setting time index, the water-binder ratio set F based on the slump flow index, and the water-binder ratio set G based on the water-binder ratio index of mass concrete are obtained respectively.

8. The design method for the intersection of high-performance large-volume concrete mix ratios according to claim 1, characterized in that, The step of "calculating the adiabatic temperature rise of the optimized mix proportion of each group of concrete to determine the best mix proportion of concrete" specifically includes the following steps: Calculating the adiabatic temperature rise of the optimized mix proportion of each group of concrete; Determining the best mix proportion of concrete according to the requirements of the current standard specifications and the actual working requirements of concrete.

9. The design method for the intersection of high-performance large-volume concrete mix ratios according to claim 1, characterized in that, After the step of "calculating the adiabatic temperature rise of the optimized mix proportion of each group of concrete to determine the best mix proportion of concrete", it also includes the steps: casting of pile cap concrete, inspection of some indexes and specimen making, which specifically include the following steps: Preparatory work before casting; Layering casting of concrete, while conducting inspection of concrete and specimen making; Segmental casting of concrete; Vibrating of concrete; Curing of concrete.

10. The design method of the intersection of high-performance large-volume concrete mix ratios according to claim 9, characterized in that, After the step of "casting of pile cap concrete, inspection of some indexes and specimen making", it also includes the step: quality inspection of pile cap concrete, which specifically includes the following steps: Testing and detecting of various performance indexes of specimens; On-site entity crack detection of pile cap.

Images