Concrete shrinkage prediction method and system based on hydration heat

Abstract

The invention discloses a concrete shrinkage prediction method and system based on hydration heat, and the method comprises the steps: carrying out concrete hydration heat and shrinkage tests, and measuring hydration heat and shrinkage values; constructing a hydration heat influence coefficient according to the hydration heat, and constructing a shrinkage limit value prediction function; according to the material composition proportion of the concrete cementing material, constructing a material composition coefficient, and constructing a shrinkage development function; and constructing a concrete shrinkage prediction model according to the shrinkage limit value prediction function and the shrinkage development function. According to the method, coefficients of various influence factors in a shrinkage limit value prediction function and a shrinkage development function are respectively trained by using data measured by a test, then various parameters in a concrete shrinkage prediction model are determined to form a trained model, and by using the trained model, data measurement with less time is needed, so that the concrete shrinkage prediction accuracy is improved. The self-constriction prediction method can predict self-constriction for a long time, reduces data collection difficulty, is not limited to specific cementing material composition types, and is wide in applicability and high in accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete shrinkage measurement, and in particular to a concrete shrinkage prediction method and system based on hydration heat. Background Art

[0002] Concrete shrinkage refers to the reduction in volume of concrete during and after its setting and hardening process due to internal moisture changes, chemical reactions, temperature fluctuations, and other factors. Excessive or uneven shrinkage can cause cracking in the concrete, seriously affecting the durability, impermeability, and aesthetics of the structure. Concrete shrinkage is a complex process, involving thermal expansion and contraction due to temperature fluctuations, chemical shrinkage caused by the hydration reaction of the cementitious material, and shrinkage caused by the subsequent reduction in internal humidity due to hydration. Currently, researchers at home and abroad believe that material composition is the fundamental internal factor affecting shrinkage, and that reduced internal humidity is the primary driving force for matrix shrinkage. Combined with the concrete shrinkage mechanism, both temperature-induced expansion and contraction and reduced internal humidity are related to the hydration history and degree of hydration reaction of the cementitious material.

[0003] Hydration heat, a thermal characteristic of the hydration reaction process, is closely related to concrete shrinkage. Predicting concrete shrinkage using hydration heat can reflect the concrete hydration process and the extent of the hydration reaction, while also accounting for changes in the material's thermal temperature. However, the different material compositions and ratios of cementitious materials affect the hydration process and extent of the hydration reaction, resulting in different hydration heat releases. Experimental analysis of hydration heat and shrinkage of cementitious materials with specified material components can predict the shrinkage of concrete containing these cementitious materials. However, since cementitious materials are often formulated with different materials and proportions based on actual needs, the applicability and accuracy of the prediction method decreases with changes in material type and proportion. Summary of the Invention

[0004] The embodiments of the present invention provide a concrete shrinkage prediction method and system based on hydration heat to solve the technical problem of low applicability and accuracy of concrete shrinkage prediction methods.

[0005] In a first aspect, an embodiment of the present invention provides a method for predicting concrete shrinkage based on hydration heat, comprising:

[0006] S101, conduct concrete hydration heat and shrinkage test, measure the hydration heat release and shrinkage value of concrete, and record the test environment humidity;

[0007] S102, constructing a hydration heat influence coefficient based on the hydration heat release;

[0008] S103, constructing a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant;

[0009] S104, constructing a material composition coefficient based on the material composition ratio of the cementitious material obtained from the concrete hydration heat and shrinkage test, and constructing a shrinkage development function based on the material composition coefficient;

[0010] S105, constructing a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function;

[0011] S106 , generating a predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted and using the constructed concrete shrinkage prediction model.

[0012] Furthermore, the S102 includes:

[0013] According to the hydration heat release measured in different groups and at different ages in the concrete hydration heat and shrinkage test, a linear function was used for regression fitting to construct the hydration heat influence coefficient expression at different ages.

[0014] According to the heat release fitting coefficient in the hydration heat influence coefficient expression of different ages, the logarithmic function is used for regression fitting to construct the heat release fitting coefficient expression;

[0015] The hydration heat influence coefficient is determined based on the heat release fitting coefficient expression.

[0016] Furthermore, the heat release fitting coefficient in the hydration heat influence coefficient expression at different ages is subjected to regression fitting using a logarithmic function to construct a heat release fitting coefficient expression, including:

[0017] According to the heat release fitting coefficient of each age, the heat release fitting coefficient expression is constructed using logarithmic function;

[0018] According to the heat release fitting coefficient of each age, regression fitting is performed on the heat release fitting coefficient expression to determine the fitting parameters in the heat release fitting coefficient expression;

[0019] According to the fitting parameters, the fitting coefficient expression of heat release is determined.

[0020] Furthermore, the S103 includes:

[0021] Calculate the humidity influence coefficient according to the test environment humidity;

[0022] A shrinkage limit value prediction function is constructed using the hydration heat influence coefficient, humidity influence coefficient and compressive strength constant.

[0023] Furthermore, the S104 includes:

[0024] According to the material composition coefficient, the shrinkage development function is constructed;

[0025] Based on the hydration heat release and shrinkage values ​​measured in concrete hydration heat and shrinkage tests, a nonlinear fitting is performed on the product of the shrinkage limit value prediction function and the shrinkage development function to construct an expression for the material composition coefficient in the shrinkage development function.

[0026] Determine the shrinkage development function based on the material composition coefficient expression.

[0027] Furthermore, the product of the shrinkage limit value prediction function and the shrinkage development function is subjected to nonlinear fitting based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test to construct an expression for the material composition coefficient in the shrinkage development function, including:

[0028] According to the shrinkage values ​​of different material composition ratios in concrete hydration heat and shrinkage tests, the product of shrinkage limit value prediction function and shrinkage development function is subjected to nonlinear fitting to obtain the material composition coefficients of different material composition ratios.

[0029] According to the material composition coefficients of different material composition ratios, the material composition coefficient expression is constructed using multivariate polynomials;

[0030] According to the material composition coefficient expression and the cementitious material addition ratio of the concrete hydration heat and shrinkage test, a linear function is used for fitting to determine the material fitting coefficient in the material composition coefficient expression;

[0031] According to the material fitting coefficient, the material composition coefficient expression is determined.

[0032] In a second aspect, an embodiment of the present invention provides a concrete shrinkage prediction system based on hydration heat, comprising:

[0033] Concrete hydration heat and shrinkage test module, used to conduct concrete hydration heat and shrinkage tests and measure the hydration heat release and shrinkage value of concrete, and record the test environment humidity;

[0034] A hydration heat influence coefficient construction module is used to construct the hydration heat influence coefficient according to the hydration heat release;

[0035] A shrinkage limit value prediction function construction module is used to construct a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity and the compressive strength constant;

[0036] A shrinkage development function construction module is used to construct a material composition coefficient according to the material composition ratio of the cementitious material in the concrete hydration heat and shrinkage test, and to construct a shrinkage development function according to the material composition coefficient;

[0037] A concrete shrinkage prediction model building module is used to build a concrete shrinkage prediction model based on a shrinkage limit value prediction function and a shrinkage development function;

[0038] The shrinkage prediction module is used to generate the predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted using the established concrete shrinkage prediction model.

[0039] Furthermore, the hydration heat impact coefficient construction module includes:

[0040] The hydration heat influence coefficient expression construction unit is used to construct the hydration heat influence coefficient expression of different ages by using a linear function for regression fitting based on the hydration heat release of different groups and different ages in the concrete hydration heat and shrinkage test;

[0041] A heat release fitting coefficient expression construction unit is used to construct a heat release fitting coefficient expression by using a logarithmic function for regression fitting based on the heat release fitting coefficient in the hydration heat influence coefficient expression at different ages;

[0042] The hydration heat influence coefficient generating unit is used to determine the hydration heat influence coefficient according to the heat release fitting coefficient expression.

[0043] Furthermore, the shrinkage limit value prediction function construction module includes:

[0044] Humidity influence coefficient calculation unit, used to calculate the humidity influence coefficient according to the test environment humidity;

[0045] The shrinkage limit value prediction function construction unit is used to construct the shrinkage limit value prediction function using the hydration heat influence coefficient, the humidity influence coefficient and the compressive strength constant.

[0046] Furthermore, the shrinkage-growth function building module includes:

[0047] A shrinkage development function construction unit is used to construct a shrinkage development function according to a material composition coefficient;

[0048] A material composition coefficient expression construction unit is used to perform nonlinear fitting on the product of the shrinkage limit value prediction function and the shrinkage development function based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test, and to construct the material composition coefficient expression in the shrinkage development function;

[0049] The shrinkage development function generating unit is used to determine the shrinkage development function according to the material composition coefficient expression.

[0050] Embodiments of the present invention provide a method and system for predicting concrete shrinkage based on hydration heat. The method conducts concrete hydration heat and shrinkage tests, prepares concrete with different cementitious material composition ratios, and measures the hydration heat release and autogenous shrinkage values ​​in multiple groups. The hydration heat release, ambient humidity, and compressive strength are used to construct a shrinkage limit value prediction function that represents the degree of influence of hydration heat on autogenous shrinkage. Furthermore, the composition ratio of cementitious materials during concrete preparation is used to construct a shrinkage development function that represents the influence of the cementitious material ratio on the hydration reaction process and autogenous shrinkage. The shrinkage limit value prediction function and the shrinkage development function are used to construct a concrete shrinkage prediction model. Multiple sets of data measured by concrete hydration heat and shrinkage tests are used to train the coefficients representing various influencing factors in the shrinkage limit prediction function and the shrinkage development function, respectively, to determine the calculation formulas for each influencing factor, and then to determine the various parameters in the concrete shrinkage prediction model to form a trained model. Using the trained model, the shrinkage of concrete over a longer period can be predicted based on the addition ratio of cementitious materials during concrete preparation and the heat release of concrete during 7 days of hardening. Only a short period of data measurement is required to predict the autogenous shrinkage over a longer period of time, which reduces the difficulty of data collection. It is not limited to a specific type of cementitious material composition, and has a wide applicability and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0052] Figure 1 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to the first embodiment of the present invention;

[0053] Figure 2 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to the second embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the regression fitting results of the hydration heat influence coefficient and the 7-day hydration heat according to Example 2 of the present invention;

[0055] Figure 4 This is a schematic diagram of the fitting results of the fitting coefficient expression of heat release at different ages according to the second embodiment of the present invention;

[0056] Figure 5 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to the third embodiment of the present invention;

[0057] Figure 6This is a schematic diagram of the nonlinear fitting results of the product of the shrinkage limit prediction function and the shrinkage development function and the different ages of concrete hardening according to the third embodiment of the present invention;

[0058] Figure 7 This is a schematic diagram of the fitting results of the material composition coefficient expression according to the third embodiment of the present invention;

[0059] Figure 8 This is a structural diagram of a concrete shrinkage prediction system based on hydration heat according to the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0060] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0061] Concrete shrinkage includes plastic shrinkage, drying shrinkage, carbonation shrinkage, and autogenous shrinkage. Autogenous shrinkage is a volumetric contraction caused by the hydration reaction between cementitious materials and water, which consumes internal moisture and leads to a decrease in the relative humidity within the concrete. Autogenous shrinkage primarily occurs during the early hardening stages of concrete and is closely related to the heat of hydration released during the hydration reaction. This heat of hydration causes the temperature inside the concrete to rise, which is then gradually dissipated to the external environment. This not only causes temperature fluctuations but also further exacerbates autogenous shrinkage. Therefore, the autogenous shrinkage of the prepared concrete can be predicted by the material composition and ratio of the cementitious materials, as well as the different levels of hydration heat generated, based on the inherent connection between hydration heat characteristics and autogenous shrinkage.

[0062] Example 1

[0063] Figure 1 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to a first embodiment of the present invention. This embodiment obtains training data through concrete hydration heat and shrinkage tests, constructs and trains a concrete shrinkage prediction model based on hydration heat, and enables the model to predict concrete shrinkage based on hydration heat. The method specifically includes the following steps:

[0064] S101, conduct concrete hydration heat and shrinkage tests, measure the hydration heat release and shrinkage value of the concrete, and record the test environment humidity.

[0065] To build and train a concrete shrinkage prediction model, we conducted concrete hydration heat and shrinkage tests using concrete of varying composition ratios. We measured the hydration heat and shrinkage of the concrete in different groups during the tests, while also recording the ambient humidity to collect data for model training. Concrete of varying composition ratios releases varying amounts of heat during hydration, depending on the type and proportion of the constituent materials, and exhibits varying shrinkage patterns. Therefore, by capturing the relationship between hydration heat release and shrinkage, we can predict concrete shrinkage based on this heat release.

[0066] For example, concrete with different material components and mix proportions was divided into multiple groups for concrete hydration heat and shrinkage testing. The concrete was prepared using P·Ⅱ42.5 grade cement, Class F Grade I fly ash, S95 slag powder, granite sand with a fineness modulus of 2.8, 1.0% methylene blue, and 7.5±0.2% stone powder as fine aggregate. Coarse aggregate was 5-25 mm continuously graded crushed stone with a crushing value of 5% and a flaky particle content of 3%. A polycarboxylate superplasticizer was used as a water reducer. The mix proportions are shown in Table 1 and used to collect training data for a concrete autogenous shrinkage prediction model. The specific test method can be as follows: all concrete raw materials are kept at a constant temperature for 24 hours, then stirred and mixed until uniform. The materials are then quickly placed in an adiabatic temperature rise measuring instrument, maintained in an adiabatic state, and the temperature change caused by hydration inside the instrument is measured. The hydration heat is calculated by calculating the total heat gain within the instrument.

[0067] Table 1 Concrete mix ratio (kg.m -3 )

[0068]

[0069] In order to improve the measurement accuracy of hydration heat, since hydration heat is mainly generated by the hydration reaction of cementitious materials, the hydration heat of cementitious materials can also be measured experimentally. The specific test method can be: the raw materials such as cementitious materials, admixtures and fillers are treated at a constant temperature for 24 hours, and then the materials are stirred and mixed evenly, and placed in the corresponding hydration heat device for measurement according to the corresponding method. The measurement methods include but are not limited to: isothermal conduction calorimetry, which uses an isothermal calorimeter to quickly transfer the heat released by the hydration of materials such as cement to a constant temperature radiator to keep the cement and other hydrated bodies at a constant temperature. The data collector automatically collects the voltage difference between the test sample cell and the reference sample cell, outputs the thermal power, and the integral of the thermal power over time is the total heat of hydration; the heat of solution method, which uses a heat of solution meter, and under the condition of a certain temperature around the calorimeter, unhydrated cement and cement hydrated for a certain age are dissolved in a standard acid solution of a certain concentration, and the difference in heat of solution is measured as the heat of hydration released by the cement during the age; the direct method, which uses a direct calorimeter to directly measure the temperature change caused by cement hydration in the calorimeter in a constant temperature environment, and the hydration heat is obtained by calculating the total heat accumulated and dissipated in the calorimeter.

[0070] Autogenous shrinkage can be measured according to relevant industry testing standards. For example, a 100mm diameter and 420mm long PVC pipe is used as a test mold. After the specimen is formed, it is sealed with plastic wrap and placed in a constant temperature (20°C ± 2°C) and humidity (60% ± 5%) environment. The final setting time is simultaneously measured, with readings taken from the start of final setting and shrinkage values ​​recorded. All raw materials must be kept at 20°C ± 2°C for 24 hours before testing. Using this test method, the heat of hydration and autogenous shrinkage data for different groups at critical ages are shown in Table 2.

[0071] Table 2 Concrete hydration heat and autogenous shrinkage at main ages

[0072]

[0073]

[0074] S102, constructing a hydration heat influence coefficient based on the hydration heat release amount.

[0075] The hydration heat impact coefficient is constructed based on the hydration heat release and shrinkage value of concrete measured in the concrete hydration heat and shrinkage test. First, the humidity impact coefficient is determined based on the test environment humidity during the concrete hydration heat and shrinkage test. Then, the compressive strength constant is determined based on the 28-day compressive strength of the concrete cube. Finally, the hydration heat release q is used to construct the hydration heat impact coefficient G. a (q). Using the hydration heat influence coefficient G aThe product of (q), compressive strength constant and humidity influence coefficient can be used to obtain the concrete shrinkage value measured in the concrete hydration heat and shrinkage test, so as to analyze the relationship between hydration heat and concrete autogenous shrinkage. The relationship between concrete strength grade and shrinkage is complex. For ordinary concrete, the higher the strength (the water-cement ratio decreases to a certain extent), the smaller the shrinkage. However, for high-strength or even ultra-high-strength concrete, the higher the strength, the more significant the shrinkage. Therefore, the compressive strength constant is introduced. When the 28-day cube compressive strength does not exceed 50MPa, the compressive strength constant is taken as 18. Since the autogenous shrinkage of concrete is mainly affected by the heat release of hydration heat and the environmental humidity, the heat release of hydration heat q is measured during the test, and there are relevant laws to follow with the material composition and proportion relationship of the cementitious material. The humidity influence coefficient can also be determined according to the test environment humidity, and the compressive strength constant can be determined according to the compressive strength of the concrete. Therefore, the measured concrete shrinkage value, the determined compressive strength constant and the humidity influence coefficient can be used to construct the hydration heat influence coefficient G reflecting the hydration heat influence trend based on the heat release of hydration heat q. a (q).

[0076] S103: Construct a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant.

[0077] Since the autogenous shrinkage of concrete is a process that gradually changes over time and eventually approaches a stable value, the main influencing factors of the autogenous shrinkage of concrete hydration reaction include the heat released by hydration, ambient humidity, and compressive strength. Therefore, the hydration heat influence coefficient representing the degree of influence of hydration heat, the humidity influence coefficient representing the degree of influence of ambient humidity, and the compressive strength constant can be used to construct a shrinkage limit value prediction function representing the autogenous shrinkage limit of concrete. The formula is as follows:

[0078] v sh =G a (q)·F(f cu.28 )·A(f cu.28 ,R H )

[0079] Among them, ε sh Indicates the shrinkage value of concrete, G a (q) represents the hydration heat influence coefficient, F(f cu.28 ) represents the compressive strength constant, A(f cu.28 ,R H ) represents the humidity influence coefficient, f cu.28 It represents the compressive strength of concrete cube when it hardens to the 28th day age, R H Indicates ambient humidity (%).

[0080] S104: constructing a material composition coefficient based on the material composition ratio of the cementitious material obtained from the concrete hydration heat and shrinkage test, and constructing a shrinkage development function based on the material composition coefficient.

[0081] Cementitious materials include cement, lime, fly ash, and slag. Each material has different hydration reaction rates and different properties of its hydration products. Therefore, the composition and proportion of cementitious materials are the primary factors affecting concrete autogenous shrinkage. Different materials have varying degrees of influence on autogenous shrinkage at different stages of concrete hardening. By introducing material composition coefficients to represent the influence of each cementitious material component on concrete autogenous shrinkage, a shrinkage development function is constructed to describe the temporal evolution of concrete autogenous shrinkage.

[0082] S105: Constructing a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function.

[0083] The constructed shrinkage limit prediction function can represent the limit condition when concrete autogenous shrinkage tends to stabilize, and the constructed shrinkage development function can represent the development process of concrete autogenous shrinkage. The concrete shrinkage prediction model is constructed using the shrinkage limit prediction function and the shrinkage development function. The constructed model can predict concrete shrinkage based on the different ages of concrete hardening and the heat released by the hydration reaction during the hardening process. The model formula is as follows:

[0084] ε sh (t) = ε sh β s (t)

[0085] Among them, ε sh (t) represents the concrete shrinkage at different ages, i.e., the concrete shrinkage prediction model, ε sh represents the shrinkage limit prediction function, β s (t) represents the shrinkage development function, and t represents time, that is, the age of concrete hardening.

[0086] S106 , generating a predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted and using the constructed concrete shrinkage prediction model.

[0087] In steps S102-S105, functions representing various factors influencing concrete autogenous shrinkage in the prediction model (e.g., hydration heat influence coefficient and shrinkage limit prediction function) are constructed. The hydration heat release and shrinkage values ​​measured in the concrete hydration heat and shrinkage test in step S101 are then used to train these constructed functions representing various influencing factors through fitting. Fitting coefficients within the functional expressions of these various influencing factors are then determined, and then the functional expressions for calculating these various influencing factors are determined, ultimately forming a trained concrete shrinkage prediction model. During model training, using only data from multiple sets of concrete hydration heat and shrinkage tests, over a relatively short timeframe (including 7 days of hydration heat and 42 days of shrinkage values ​​at different ages, i.e., a maximum of 42 days), it is possible to predict the autogenous shrinkage of concrete over a longer period of 60 or even 90 days. When using the prediction model to predict the shrinkage of concrete to be predicted, it is only necessary to generate the predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the proportional relationship between the two cementitious materials when the concrete is added. This is used to represent the non-self-shrinkage of the concrete to be predicted at different ages of hardening.

[0088] In this embodiment, concrete hydration heat and shrinkage tests are conducted, concrete with different cementitious material composition ratios is prepared, and the hydration heat release and autogenous shrinkage values ​​are measured in multiple groups. The hydration heat release, ambient humidity, and compressive strength are used to construct a shrinkage limit value prediction function that represents the degree of influence of hydration heat on autogenous shrinkage. The composition ratio of cementitious materials used in concrete preparation is then used to construct a shrinkage development function that represents the influence of the cementitious material ratio on the hydration reaction process and autogenous shrinkage. The shrinkage limit value prediction function and the shrinkage development function are used to construct a concrete shrinkage prediction model. Multiple sets of data measured by concrete hydration heat and shrinkage tests are used to train the coefficients representing various influencing factors in the shrinkage limit prediction function and the shrinkage development function, respectively, to determine the calculation formulas for each influencing factor, and then to determine the various parameters in the concrete shrinkage prediction model to form a trained model. Using the trained model, the shrinkage of concrete over a longer period can be predicted based on the addition ratio of cementitious materials during concrete preparation and the heat release of concrete during 7 days of hardening. Only a short period of data measurement is required to predict the autogenous shrinkage over a longer period of time, which reduces the difficulty of data collection. It is not limited to a specific type of cementitious material composition, and has a wide applicability and high accuracy.

[0089] Example 2

[0090] Figure 2 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to a second embodiment of the present invention. This embodiment is optimized based on the above embodiment. In this embodiment, S102 is specifically optimized as follows:

[0091] According to the hydration heat release measured in different groups and at different ages in the concrete hydration heat and shrinkage test, a linear function was used for regression fitting to construct the hydration heat influence coefficient expression at different ages.

[0092] According to the heat release fitting coefficient in the hydration heat influence coefficient expression of different ages, the logarithmic function is used for regression fitting to construct the heat release fitting coefficient expression;

[0093] The hydration heat influence coefficient is determined based on the heat release fitting coefficient expression.

[0094] Accordingly, the concrete shrinkage prediction method based on hydration heat provided in this embodiment specifically includes:

[0095] S201, conduct concrete hydration heat and shrinkage tests, measure the hydration heat release and shrinkage value of the concrete, and record the test environment humidity.

[0096] S202, based on the hydration heat release measured in different groups and at different ages in the concrete hydration heat and shrinkage test, a linear function is used for regression fitting to construct an expression for the hydration heat influence coefficient at different ages.

[0097] In order to reflect the influence of hydration heat on the autogenous shrinkage of concrete, the hydration heat influence coefficient expression is constructed using the hydration heat of concrete and the hydration heat release measured in the shrinkage test. The hydration heat influence coefficient expression is used to express the influence of hydration heat on autogenous shrinkage when the humidity and pressure in the test environment are constant, that is, the relationship between hydration heat and autogenous shrinkage. Since different groups of concrete are prepared using cementitious materials with different material compositions and proportions during the concrete autogenous shrinkage test, multiple groups of tests are carried out separately, and data for each group and multiple ages are measured. The 7-day hydration heat / J of each group and the shrinkage values ​​of each group at different ages (such as 3d, 7d, 14d, 28d, 42d) are used to deduce using the shrinkage limit value prediction function, and the shrinkage value is substituted into ε sh , the humidity of the test environment and the compressive strength constant are substituted into A(f cu.28 ,R H ) and F(f cu.28 ), construct the hydration heat influence coefficient G a (q) expression. During the construction process, it can be found that G a (q) is distributed as a linear function, and the expression of the hydration heat influence coefficient constructed using the linear function is as follows:

[0098] G a (q)=K1+K2q

[0099] Among them, K irepresents the heat release fitting coefficient, and i=(1,2), q represents the hydration heat release, and in this embodiment, it is the 7-day hydration heat value of each group measured.

[0100] S203, based on the heat release fitting coefficient in the hydration heat influence coefficient expression at different ages, a regression fitting is performed using a logarithmic function to construct a heat release fitting coefficient expression.

[0101] In order to capture the relationship between hydration heat release and shrinkage value, the 7-day hydration heat of different groups and the shrinkage values ​​at different ages measured in Table 2 were used to analyze the G a (q) is used to perform regression fitting on the linear function and train the functional expression of the hydration heat influence coefficient. The regression results are as follows: Figure 3 As shown in the figure, the horizontal axis is the 7-day hydration heat of different groups, and the vertical axis is the G obtained by substituting the experimental data in S202. a (q) value. The figure uses different colors and shapes of marking points to distinguish the contraction values ​​of each group at different ages. The multiple marking points of different colors and shapes on the same vertical line in each group are the contraction values ​​of the same group at different ages. At the same time, in order to ensure the accuracy, the goodness of fit R 2 It should be kept above 0.9. Through regression fitting, multiple groups of heat release fitting coefficients of different age groups were obtained, as shown in Table 3. It was found that the heat release fitting coefficient K i Logarithmic distribution.

[0102] Table 3 Linear fitting results of autogenous shrinkage heat release coefficient and heat release

[0103]

[0104] Specifically, according to the heat release fitting coefficient of each age period, the heat release fitting coefficient expression is constructed using a logarithmic function.

[0105] According to the heat release fitting coefficients at different ages in Table 3, the heat release fitting coefficient K was constructed using the logarithmic function. i The expression is as follows:

[0106] K i =a i ln(t)+b i

[0107] Among them, K i represents the heat release fitting coefficient, and i=(1,2), t represents time, a i 、b i is the fitting parameter.

[0108] According to the heat release fitting coefficients of each age in Table 3, regression fitting was performed on the heat release fitting coefficient expression to determine the fitting parameters in the heat release fitting coefficient expression.

[0109] In order to capture the changing law of the heat release fitting coefficient with different ages of concrete hardening, the heat release fitting coefficients of different ages in Table 3 obtained by regression fitting are used to train the model so that the model can meet the task requirements of predicting shrinkage value based on hydration heat. The heat release fitting coefficient expression is fitted with the heat release fitting coefficients of each age in Table 3 to determine the fitting parameter a in the heat release fitting coefficient formula. i 、b i The value of . Figure 4 As shown, the relationship between the heat release fitting coefficient K1 and the time t is K1 = -0.262×ln(t)-1.589, that is, a1 = -0.262, b1 = -1.589, and the relationship between the heat release fitting coefficient K2 and the time t is K2 = 0.00193×ln(t)+0.0071, that is, a2 = 0.00193, b2 = 0.0071.

[0110] According to the fitting parameters, the fitting coefficient expression of heat release is determined.

[0111] In K i The fitting parameter a in the expression i 、b i After fitting and determining it as a fixed value, the corresponding heat release fitting coefficient expression can be determined, which is K1 = -0.262×ln(t)-1.589, K2 = 0.00193×ln(t)+0.0071.

[0112] S204, determining the hydration heat influence coefficient according to the heat release fitting coefficient expression.

[0113] After the expressions of the two heat release fitting coefficients in the hydration heat influence coefficient expression are determined, the only variable in the two heat release fitting coefficients is time t. The specific values ​​of the two heat release fitting coefficients can be determined according to time, and then the hydration heat influence coefficient G can be determined by time (concrete shrinkage age) and hydration heat release q. a The specific value of (q) is used to predict the shrinkage limit of concrete in combination with ambient humidity and pressure.

[0114] S205: Construct a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant.

[0115] S206: constructing a material composition coefficient based on the material composition ratio of the cementitious material obtained from the concrete hydration heat and shrinkage test, and constructing a shrinkage development function based on the material composition coefficient.

[0116] S207: Construct a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function.

[0117] S208 , generating a predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted and using the constructed concrete shrinkage prediction model.

[0118] This example uses the heat of hydration and autogenous shrinkage values ​​measured in concrete hydration and shrinkage tests, combined with ambient humidity and compressive strength, to construct a shrinkage limit function. This function represents the concrete's shrinkage limit, representing the autogenous shrinkage near a steady state. The parameters of the influencing coefficients in the function are trained using actual test data to form a definitive functional expression. In practical use, the concrete shrinkage limit can be predicted by measuring only the 7-day heat of hydration, the actual ambient humidity, and the compressive strength of the concrete cube. This allows for prediction of concrete autogenous shrinkage over a longer period using only a limited amount of measured data.

[0119] In an optional implementation of this embodiment, S205 includes:

[0120] Calculate the humidity influence coefficient based on the test environment humidity.

[0121] Humidity influence coefficient A(f cu.28 ,R H ), is calculated based on the actual humidity in the environment, and the calculation formula is as follows:

[0122]

[0123] Among them, f cu.28 It represents the compressive strength of concrete cube when it hardens to the 28th day age, R H Indicates ambient humidity (%).

[0124] A shrinkage limit value prediction function is constructed using the hydration heat influence coefficient, humidity influence coefficient and compressive strength constant.

[0125] After determining the expression of the hydration heat influence coefficient, the product of the hydration heat influence coefficient and the compressive strength constant is used to construct the shrinkage limit value prediction function. The formula is as follows:

[0126] ε sh =G a (q)·F(f cu.28 )·A(f cu.28 ,R H )

[0127] Among them, the hydration heat influence coefficient G aThe value of (q) can be determined based on the different ages and the measured 7-day hydration heat release. The humidity influence coefficient can be calculated based on the ambient humidity. The compressive strength constant is determined based on the compressive strength of the concrete cube at 28 days. The limit value of the autogenous shrinkage of concrete (the stable situation) can then be predicted using the shrinkage limit value function.

[0128] Example 3

[0129] Figure 5 This is a flow chart of a method for predicting concrete shrinkage based on hydration heat according to the third embodiment of the present invention. This embodiment is optimized based on the above embodiment. In this embodiment, S104 is specifically optimized as follows:

[0130] According to the material composition coefficient, the shrinkage development function is constructed;

[0131] Based on the hydration heat release and shrinkage values ​​measured in concrete hydration heat and shrinkage tests, a nonlinear fitting is performed on the product of the shrinkage limit value prediction function and the shrinkage development function to construct an expression for the material composition coefficient in the shrinkage development function.

[0132] Determine the shrinkage development function based on the material composition coefficient expression.

[0133] Accordingly, the concrete shrinkage prediction method based on hydration heat provided in this embodiment specifically includes:

[0134] S301, conduct concrete hydration heat and shrinkage tests, measure the hydration heat release and shrinkage value of the concrete, and record the test environment humidity.

[0135] S302, constructing a hydration heat influence coefficient based on the hydration heat release amount.

[0136] S303: Construct a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant.

[0137] S304: Construct a shrinkage development function based on the material composition coefficient.

[0138] The material composition coefficient is used to represent the effect of the hydration heat released by different material components in the cementitious material during the hydration reaction on the shrinkage of concrete. The released hydration heat is related to the hydration reaction time. Therefore, it is necessary to construct the shrinkage development function β representing the concrete shrinkage process by analyzing the law of the material composition coefficient over time (hydration reaction time, which can also be regarded as the hardening time of concrete). s (t), the shrinkage development function can express the shrinkage of concrete at different ages, and the formula is as follows:

[0139]

[0140] Among them, β s (t) represents the contraction-development function, η s ,η h represents the material composition coefficient, t represents time (unit: day, d), that is, the hardening age of concrete, and h represents the size constant, which is the ratio of the cross-sectional area to the circumference of the concrete specimen.

[0141] S305, based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test, perform nonlinear fitting on the product of the shrinkage limit value prediction function and the shrinkage development function to construct an expression for the material composition coefficient in the shrinkage development function.

[0142] The product of the established shrinkage limit prediction function and the shrinkage development function is used to represent the shrinkage of concrete at different hardening ages. The hydration heat release and shrinkage values ​​measured in the concrete hydration heat and shrinkage test are substituted into the shrinkage limit prediction function and the shrinkage development function, and the product of the two is used for fitting. It is found that the product has a multivariate polynomial distribution. By deduction, an expression for the material composition coefficient in the shrinkage development function is formed. For example, the product of the shrinkage limit prediction function and the shrinkage development function can be expressed as:

[0143] ε sh (t) = ε sh β s (t)

[0144] Among them, ε sh represents the shrinkage limit prediction function, β s (t) represents the contraction-development function, ε sh (t) represents the product of the two, that is, the shrinkage of concrete at different ages of hardening. According to the hydration heat release q measured in the experiment, the concrete hardening age t (time) and the formula of the shrinkage limit value prediction function, ε is determined. sh The value of ε sh (t) value, and then derive the material composition coefficient η according to the formula of the shrinkage development function s ,η h The expression is as follows:

[0145] η s =n0+n1θ

[0146] η h =p0+p1θ

[0147] Among them, n0, n1, p0, p1 represent the material composition coefficient η s ,η h The material fitting coefficient θ represents the charging ratio of the cementitious material, which is the charging ratio of fly ash and slag in this embodiment.

[0148] Specifically, according to the shrinkage values ​​of different material composition ratios in the concrete hydration heat and shrinkage test, the product of the shrinkage limit value prediction function and the shrinkage development function is nonlinearly fitted to obtain the material composition coefficients of different material composition ratios.

[0149] Using the hydration heat release q and concrete hardening age t measured by concrete hydration heat and shrinkage test, a nonlinear fitting is performed on the product of the shrinkage limit prediction function and the shrinkage development function. The fitting results are shown in the figure below. Figure 6 As shown in Table 4, according to the fitting curves of different groups, the values ​​of the material composition coefficients corresponding to different groups are determined respectively.

[0150] Table 4 Autogenous shrinkage prediction fitting results

[0151]

[0152] According to the material composition coefficients of different material composition ratios, the material composition coefficient expression is constructed using multivariate polynomials.

[0153] According to the fitting results in Table 4, the distribution law of the material composition coefficient can be found. The material composition coefficient expression is constructed using a multivariate polynomial, and the formula is as follows:

[0154] η s =n0+n1θ

[0155] η h =p0+p1θ

[0156] Among them, n0, n1, p0, p1 represent the material composition coefficient η s ,η h The material fitting coefficient θ represents the charging ratio of the cementitious material, which is the charging ratio of fly ash and slag in this embodiment.

[0157] According to the material composition coefficient expression and the cementitious material addition ratio of the concrete hydration heat and shrinkage test, the material fitting coefficient in the material composition coefficient expression is determined by fitting using a linear function.

[0158] Since the composition and proportion of concrete cementitious materials are known when adding materials, and the hydration heat is directly related to the type and proportion of cementitious materials, the influence of different material components represented by the two material composition coefficients can be inferred based on the addition ratio of cementitious materials. According to the fitting results in Table 4, it can be found that the distribution of material composition coefficients is in the form of a linear function. Therefore, a linear function is used to fit the material composition coefficient expression. The material fitting coefficients in the material composition coefficient expression are trained using the data of concrete hydration heat and shrinkage tests. The fitting results are shown in Figure 4. Figure 7As shown, we can see that n0=0.814, n1=0.084, p0=0.00335, p1=0.00424.

[0159] According to the material fitting coefficient, the material composition coefficient expression is determined.

[0160] The material fitting coefficients obtained by training with the measured data of concrete hydration heat and shrinkage tests are used to determine the expression of the material composition coefficients:

[0161] η s =0.814+0.084θ

[0162] η h =0.00335+0.00424θ

[0163] S306, determining the shrinkage development function based on the material composition coefficient expression.

[0164] After the expression of the material composition coefficient is determined, the only variable in the formula is the addition ratio of the cementitious material θ, which can be known when the concrete is prepared. Therefore, the material composition coefficient η can be determined during the use stage of the model. s ,η h The specific value of the contraction-development function β is determined s (t), the variables in the shrinkage-development function are time t and size constant h. These two values ​​can also be known during the use of the model, so the shrinkage-development function can be determined.

[0165] S307: Construct a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function.

[0166] S308 , generating a predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted and using the established concrete shrinkage prediction model.

[0167] This example analyzes the effects of different cementitious material compositions and proportions on hydration patterns to construct a shrinkage development function. This function represents the cementitious material hydration process and its influence on concrete autogenous shrinkage. Combined with a shrinkage limit prediction function, this function can be used to predict concrete autogenous shrinkage. The shrinkage development function is trained using the heat of hydration and shrinkage values ​​at different ages measured in concrete shrinkage tests. The material composition coefficients used in the shrinkage development function to represent the influence of different cementitious materials on autogenous shrinkage are then determined. Furthermore, the shrinkage development function can be determined based on the material composition ratios of the cementitious materials. This allows the prediction model to be applied to a variety of cementitious material types, improving its applicability.

[0168] Example 4

[0169] Figure 8 This is a schematic structural diagram of a concrete shrinkage prediction system based on hydration heat according to a fourth embodiment of the present invention. In this embodiment, the concrete shrinkage prediction system based on hydration heat includes:

[0170] Concrete hydration heat and shrinkage test module 810, used to perform concrete hydration heat and shrinkage tests and measure the hydration heat release and shrinkage value of concrete, and record the test environment humidity;

[0171] A hydration heat influence coefficient construction module 820 is used to construct a hydration heat influence coefficient according to the hydration heat release amount;

[0172] The shrinkage limit value prediction function construction module 830 is used to construct the shrinkage limit value prediction function according to the hydration heat influence coefficient, the test environment humidity and the compressive strength constant;

[0173] A shrinkage development function construction module 840 is used to construct a material composition coefficient based on the material composition ratio of the cementitious material in the concrete hydration heat and shrinkage test, and to construct a shrinkage development function based on the material composition coefficient;

[0174] A concrete shrinkage prediction model building module 850 is used to build a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function;

[0175] The shrinkage prediction module 860 is used to generate the predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the cementitious material composition ratio of the concrete to be predicted using the established concrete shrinkage prediction model.

[0176] The hydration heat-based concrete shrinkage prediction system provided in this embodiment performs concrete hydration heat and shrinkage tests and measures the hydration heat release and shrinkage value of the concrete through a concrete hydration heat and shrinkage test module; constructs a hydration heat influence coefficient through a hydration heat influence coefficient construction module; constructs a shrinkage limit value prediction function using the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant through a shrinkage limit value prediction function construction module; constructs a material composition coefficient and a shrinkage development function based on the material composition ratio of the cementitious material through a shrinkage development function construction module; constructs a concrete shrinkage prediction model through a concrete shrinkage prediction model construction module; and uses the constructed concrete shrinkage prediction model through the shrinkage prediction module to predict the shrinkage of the concrete based on the measured hydration heat release and the cementitious material composition ratio. Multiple sets of data measured by concrete hydration heat and shrinkage tests are used to train the coefficients representing various influencing factors in the shrinkage limit prediction function and the shrinkage development function, respectively, to determine the calculation formulas for each influencing factor, and then to determine the various parameters in the concrete shrinkage prediction model to form a trained model. Using the trained model, the shrinkage of concrete over a longer period can be predicted based on the addition ratio of cementitious materials during concrete preparation and the heat release of concrete during 7 days of hardening. Only a short period of data measurement is required to predict the autogenous shrinkage over a longer period of time, which reduces the difficulty of data collection. It is not limited to a specific type of cementitious material composition, and has a wide applicability and high accuracy.

[0177] Based on the above embodiments, the hydration heat impact coefficient construction module includes:

[0178] The hydration heat influence coefficient expression construction unit is used to construct the hydration heat influence coefficient expression of different ages by using a linear function for regression fitting based on the hydration heat release of different groups and different ages in the concrete hydration heat and shrinkage test;

[0179] A heat release fitting coefficient expression construction unit is used to construct a heat release fitting coefficient expression by using a logarithmic function for regression fitting based on the heat release fitting coefficient in the hydration heat influence coefficient expression at different ages;

[0180] The hydration heat influence coefficient generating unit is used to determine the hydration heat influence coefficient according to the heat release fitting coefficient expression.

[0181] Based on the above embodiments, the shrinkage limit value prediction function construction module includes:

[0182] Humidity influence coefficient calculation unit, used to calculate the humidity influence coefficient according to the test environment humidity;

[0183] The shrinkage limit value prediction function construction unit is used to construct the shrinkage limit value prediction function using the hydration heat influence coefficient, the humidity influence coefficient and the compressive strength constant.

[0184] Based on the above embodiments, the shrinkage-evolution function construction module includes:

[0185] A shrinkage development function construction unit is used to construct a shrinkage development function according to a material composition coefficient;

[0186] A material composition coefficient expression construction unit is used to perform nonlinear fitting on the product of the shrinkage limit value prediction function and the shrinkage development function based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test, and to construct the material composition coefficient expression in the shrinkage development function;

[0187] The shrinkage development function generating unit is used to determine the shrinkage development function according to the material composition coefficient expression.

[0188] The concrete shrinkage prediction system based on hydration heat provided by the embodiment of the present invention can execute the concrete shrinkage prediction method based on hydration heat provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0189] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for predicting concrete shrinkage based on hydration heat, characterized in that: include: S101, conduct concrete hydration heat and shrinkage test, measure the hydration heat release and shrinkage value of concrete, and record the test environment humidity; S102, constructing a hydration heat influence coefficient based on the hydration heat release; S103, constructing a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity, and the compressive strength constant; S104, constructing a material composition coefficient based on the material composition ratio of the cementitious material obtained from the concrete hydration heat and shrinkage test, and constructing a shrinkage development function based on the material composition coefficient; S105, constructing a concrete shrinkage prediction model based on the shrinkage limit value prediction function and the shrinkage development function; S106 , generating a predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted and using the constructed concrete shrinkage prediction model.

2. The method according to claim 1, characterized in that The S102 includes: According to the hydration heat release measured in different groups and at different ages in the concrete hydration heat and shrinkage test, a linear function was used for regression fitting to construct the hydration heat influence coefficient expression at different ages. According to the heat release fitting coefficient in the hydration heat influence coefficient expression of different ages, the logarithmic function is used for regression fitting to construct the heat release fitting coefficient expression; The hydration heat influence coefficient is determined based on the heat release fitting coefficient expression.

3. The method according to claim 2, characterized in that The heat release fitting coefficient in the hydration heat influence coefficient expression at different ages is subjected to regression fitting using a logarithmic function to construct a heat release fitting coefficient expression, including: According to the heat release fitting coefficient of each age, the heat release fitting coefficient expression is constructed using logarithmic function; According to the heat release fitting coefficient of each age, regression fitting is performed on the heat release fitting coefficient expression to determine the fitting parameters in the heat release fitting coefficient expression; According to the fitting parameters, the fitting coefficient expression of heat release is determined.

4. The method according to claim 1, wherein The S103 includes: Calculate the humidity influence coefficient according to the test environment humidity; A shrinkage limit value prediction function is constructed using the hydration heat influence coefficient, humidity influence coefficient and compressive strength constant.

5. The method according to claim 1, wherein The S104 includes: According to the material composition coefficient, the shrinkage development function is constructed; Based on the hydration heat release and shrinkage values ​​measured in concrete hydration heat and shrinkage tests, a nonlinear fitting is performed on the product of the shrinkage limit value prediction function and the shrinkage development function to construct an expression for the material composition coefficient in the shrinkage development function. Determine the shrinkage development function based on the material composition coefficient expression.

6. The method according to claim 5, characterized in that The method comprises performing nonlinear fitting on the product of the shrinkage limit value prediction function and the shrinkage development function based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test, and constructing an expression for the material composition coefficient in the shrinkage development function, including: According to the shrinkage values ​​of different material composition ratios in concrete hydration heat and shrinkage tests, the product of shrinkage limit value prediction function and shrinkage development function is subjected to nonlinear fitting to obtain the material composition coefficients of different material composition ratios. According to the material composition coefficients of different material composition ratios, the material composition coefficient expression is constructed using multivariate polynomials; According to the material composition coefficient expression and the cementitious material addition ratio of the concrete hydration heat and shrinkage test, a linear function is used for fitting to determine the material fitting coefficient in the material composition coefficient expression; According to the material fitting coefficient, the material composition coefficient expression is determined.

7. A concrete shrinkage prediction system based on hydration heat, characterized in that: include: Concrete hydration heat and shrinkage test module, used to conduct concrete hydration heat and shrinkage tests and measure the hydration heat release and shrinkage value of concrete, and record the test environment humidity; A hydration heat influence coefficient construction module is used to construct the hydration heat influence coefficient according to the hydration heat release; A shrinkage limit value prediction function construction module is used to construct a shrinkage limit value prediction function based on the hydration heat influence coefficient, the test environment humidity and the compressive strength constant; A shrinkage development function construction module is used to construct a material composition coefficient according to the material composition ratio of the cementitious material in the concrete hydration heat and shrinkage test, and to construct a shrinkage development function according to the material composition coefficient; A concrete shrinkage prediction model building module is used to build a concrete shrinkage prediction model based on a shrinkage limit value prediction function and a shrinkage development function; The shrinkage prediction module is used to generate the predicted shrinkage of the concrete to be predicted based on the measured hydration heat release and the composition ratio of the cementitious materials of the concrete to be predicted using the established concrete shrinkage prediction model.

8. The system according to claim 7, characterized in that The hydration heat impact coefficient building module includes: The hydration heat influence coefficient expression construction unit is used to construct the hydration heat influence coefficient expression of different ages by using a linear function for regression fitting based on the hydration heat release of different groups and different ages in the concrete hydration heat and shrinkage test; A heat release fitting coefficient expression construction unit is used to construct a heat release fitting coefficient expression by using a logarithmic function for regression fitting based on the heat release fitting coefficient in the hydration heat influence coefficient expression at different ages; The hydration heat influence coefficient generating unit is used to determine the hydration heat influence coefficient according to the heat release fitting coefficient expression.

9. The system according to claim 7, wherein: The shrinkage limit value prediction function building module includes: Humidity influence coefficient calculation unit, used to calculate the humidity influence coefficient according to the test environment humidity; The shrinkage limit value prediction function construction unit is used to construct the shrinkage limit value prediction function using the hydration heat influence coefficient, the humidity influence coefficient and the compressive strength constant.

10. The system according to claim 7, wherein: The shrinkage-growth function building block includes: A shrinkage development function construction unit is used to construct a shrinkage development function according to a material composition coefficient; A material composition coefficient expression construction unit is used to perform nonlinear fitting on the product of the shrinkage limit value prediction function and the shrinkage development function based on the hydration heat release and shrinkage value measured by the concrete hydration heat and shrinkage test, and to construct the material composition coefficient expression in the shrinkage development function; The shrinkage development function generating unit is used to determine the shrinkage development function according to the material composition coefficient expression.

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