Machine-made sand concrete mix proportion design and preparation method

Abstract

The invention discloses a mix proportion design and preparation method of machine-made sand concrete, and relates to the technical field of building material preparation, the total amount of a cementing material and a glue ratio are calculated according to a compressive strength linear regression linear equation of different machine-made sand substitution rates; calculating the use amount of coarse and fine aggregates with a set sand ratio; calculating the use amounts of the fly ash, the mineral powder and the cement according to the mixing amounts of the fly ash and the mineral powder to obtain a recommended mix proportion meeting the strength requirement and a recommended mix proportion meeting the durability requirement; calculating the concrete 28d chloride ion diffusion coefficient meeting the engineering durability requirement; performing normalization processing on the 28d chloride ion diffusion coefficient of the concrete; calculating the total amount of the cementing material and the glue ratio in combination with a chloride ion diffusion coefficient equation; and combining the recommended mix proportion meeting the strength requirement and the recommended mix proportion meeting the durability requirement to obtain the optimal recommended mix proportion of the machine-made sand concrete of each strength grade. The optimal machine-made sand concrete mix proportion meeting various performance indexes at the same time can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of building material preparation, and in particular to a mix ratio design and preparation method of machine-made sand concrete. Background Art

[0002] At present, the design of the mix ratio of machine-made sand concrete is mainly realized by referring to the mix ratio design of ordinary concrete in the "Ordinary Concrete Mix Ratio Design Code" JGJ55-2011, including: preliminary calculation of mix ratio, determination of benchmark mix ratio, determination of laboratory mix ratio and determination of construction mix ratio. However, the presence of stone powder in machine-made sand will affect the strength and durability of concrete, and thus affect the calculation of mix ratio. Studies have shown that the integrated design of stone-sand-powder from the perspective of controlling the performance of machine-made sand high-performance concrete with dual constraints of glue ratio and water-powder ratio can effectively solve the influence of parameters such as machine-made sand on the workability and strength of concrete. However, this method mainly uses strength as the control index to design the mix ratio of machine-made sand concrete, and the calculation process is relatively complicated. It is also not specified for the mix ratio design with impermeability requirements, that is, this method cannot use quantitative durability indicators as the basis for the design of the mix ratio of machine-made sand concrete. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for designing and preparing the mix ratio of machine-made sand concrete with simple calculation. Based on the strength and durability requirements of machine-made sand concrete, the mix ratio design process of machine-made sand concrete is optimized, and the optimal mix ratio of machine-made sand concrete that meets various performance indicators can be obtained.

[0004] In order to achieve the above object, the present invention is implemented through the following technical solutions: In a first aspect, an embodiment of the present invention provides a method for designing a mix ratio of machine-made sand concrete, comprising: According to the linear regression equation of concrete mix strength and compressive strength with different machine-made sand replacement rates, the total amount of cementitious materials and the glue-water ratio were calculated; The amount of coarse and fine aggregates for setting the sand ratio is calculated based on the sum of coarse and fine aggregates; the amount of fly ash, mineral powder and cement is calculated based on the amount of fly ash and mineral powder added to obtain the recommended mix ratio that meets the strength requirements and the recommended mix ratio that meets the durability requirements; Calculate the 28d chloride diffusion coefficient of concrete that meets the engineering durability requirements; normalize the 28d chloride diffusion coefficient of concrete by the normalized limit value of chloride diffusion coefficient of concrete of each strength grade; and calculate the total amount of cementitious materials and glue-water ratio by combining the chloride diffusion coefficient equation; According to the specified values ​​of glue-water ratio and cementitious material dosage of concrete of different strength grades, combined with the recommended mix ratio that meets the strength requirements and the recommended mix ratio that meets the durability requirements, the optimal recommended mix ratio of machine-made sand concrete of each strength grade is obtained.

[0005] As a further implementation, when the design strength grade is less than C60, ; in, f cu,o To prepare the strength of concrete, f cu,k is the standard value of concrete cube compressive strength, σ is the standard deviation of concrete strength.

[0006] As a further implementation method, the amount of coarse and fine aggregate is calculated based on the sand ratio range of 38%-42%, among which the optimal sand ratio is 40%.

[0007] As a further implementation method, the amount of each material is calculated according to the proportion of mineral admixtures required in the actual project, wherein the optimal amount of fly ash and mineral powder in the calculation designed by this method is 30% and 15%.

[0008] As a further implementation method, the method for normalizing the 28d chloride ion diffusion coefficient that meets the requirements is: ; in, D 28 is the normalized chloride ion diffusion coefficient of concrete at 28 days, D m is the normalized value of chloride ion diffusion coefficient of concrete, D To meet the requirements of concrete 28d chloride ion diffusion coefficient.

[0009] As a further implementation, for different concrete strength grades, the value range of the chloride ion diffusion coefficient of concrete 28d is different.

[0010] As a further implementation method, the linear relationship equation between the chloride ion diffusion coefficient of concrete 28 days, the machine-made sand replacement rate, and W / B is: ①When the machine-made sand replacement rate is 0: ; ②When the machine-made sand replacement rate is not 0: ; Among them: the value range of a is 0.4038-0.4464, the value range of b is 0.7025-0.7766, the value range of c is 0.0027-0.0031, the value range of d is 0.3066-0.3389, and the value range of e is 0.5597-0.6186; r 1 is the replacement rate of machine-made sand, W / B is the glue-to-water ratio, B The total amount of rubber material.

[0011] The linear relationship equation between the chloride ion diffusion coefficient of concrete at 28 days, the replacement rate of machine-made sand, and the amount of adhesive is: ①When the machine-made sand replacement rate is 0: ; ②When the machine-made sand replacement rate is not 0: ; Among them, the value range of f is 0.0003-0.0004, the value range of g is 1.0027-1.1083, the value range of m is 0.0026-0.0029, the value range of n is 0.0003-0.0004, and the value range of s is 0.8267-0.9138.

[0012] As a further implementation method, the machine-made sand replacement rate is 0-100%, the glue-water ratio is 0.33-0.5, and the total amount of glue is 300kg / m 3 -500kg / m 3 .

[0013] In a second aspect, an embodiment of the present invention further provides a method for preparing machine-made sand concrete, wherein the optimal recommended mix ratio of machine-made sand concrete is obtained according to the design method, and the machine-made sand concrete is obtained after mixing the raw materials.

[0014] As a further implementation, the strength grade of the machine-made sand concrete is C30-C50.

[0015] The beneficial effects of the present invention are as follows: (1) Different from the cumbersome design method of traditional concrete mix ratio, the present invention can calculate the mix ratio of manufactured sand concrete that meets the strength and durability requirements based on the compressive strength of manufactured sand concrete and the 28-day chloride ion diffusion coefficient that meet the engineering requirements. Finally, the optimal mix ratio of manufactured sand concrete that meets various performance indicators is obtained in combination with the requirements of the specification.

[0016] (2) The present invention provides the linear relationship between the chloride ion diffusion coefficient of concrete at 28 days and the replacement rate of artificial sand and W / B under different conditions, as well as the linear relationship between the chloride ion diffusion coefficient of concrete at 28 days and the replacement rate of artificial sand and the amount of adhesive, so as to obtain an accurate mix ratio of artificial sand concrete and optimize the mix ratio design process of artificial sand concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0018] Figure 1 is a linear regression analysis diagram of the compressive strength data of machine-made sand concrete at different machine-made sand replacement rates according to one or more embodiments of the present invention; Figure 1 (a) is the relationship between the 28-day strength of 0%M in Table 1 and the total amount of adhesive, (b) is the relationship between the 28-day strength of 0%M in Table 1 and the adhesive ratio, (c) is the relationship between the 28-day strength of 25%M in Table 1 and the total amount of adhesive, (d) is the relationship between the 28-day strength of 25%M in Table 1 and the adhesive ratio, (e) is the relationship between the 28-day strength of 50%M in Table 1 and the total amount of adhesive, (f) is the relationship between the 28-day strength of 50%M in Table 1 and the adhesive ratio; Figure 2 It is a different concrete D according to one or more embodiments of the present invention. 28 Relationship diagram with machine-made sand replacement rate and W / B; Figure 3 4 is a graph showing the relationship between different concrete D28, machine-made sand replacement rate and total amount of adhesive according to one or more embodiments of the present invention. DETAILED DESCRIPTION It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0019] Embodiment 1: This embodiment provides a method for designing a mix ratio of machine-made sand concrete, comprising the following steps: 1) According to the provisions of "Ordinary Concrete Mix Design Code" JGJ55-2011, calculate the concrete strength that meets the project requirements f cu,o , when the design strength grade is less than C60, the specific calculation method is as follows: (1) Where: f cu,oPrepare strength of concrete in MPa; f cu,k is the standard value of concrete cube compressive strength, here we take the design strength grade of concrete, MPa; σ is the standard deviation of concrete strength, MPa.

[0020] 2) Replace the f cu,o Substitute Figure 1 The total amount of cementitious materials and the ratio of cement to water were calculated from the linear regression equation of the compressive strength of different machine-made sand replacement rates, as shown in Table 1: Table 1 Compressive strength data of machine-made sand concrete at different machine-made sand replacement rates

[0021] 3) Calculate the total amount of coarse and fine aggregates according to the mass method, and then calculate the amount of coarse and fine aggregates according to the sand ratio of 40%. In addition, the amount of fly ash, mineral powder and cement can be calculated based on the fly ash and mineral powder content of 30% and 15%, thus obtaining the recommended mix ratio that meets the strength requirements.

[0022] Among them, the mass method is a method of calculating the amount of coarse and fine aggregates based on the assumption that the mass of each cubic meter of concrete mixture is a fixed value.

[0023] 4) According to the provisions of the "Concrete Structure Durability Design Standard" GBT 50476-2019, the 28-day chloride ion diffusion coefficient of concrete that meets the engineering durability requirements can be obtained ( D ), however, there are limitations on the glue-water ratio and the amount of cementitious material in the linear relationship equation of this embodiment, so D The value range of is limited, and the specific value range is shown in Table 2: Table 2 Value range of chloride ion diffusion coefficient of concrete with different strength grades at 28 days

[0024] 5) The 28d chloride ion diffusion coefficient that meets the requirements in step 4) is normalized by the limit value of the normalized chloride ion diffusion coefficient of concrete of each strength grade. The specific calculation method is as shown in formula (2): (2) In formula (2): D 28 is the normalized chloride ion diffusion coefficient of concrete at 28 days (10 -12 m 2 / s); D m is the normalized value of the chloride ion diffusion coefficient of concrete (see Table 3, 10 for details). -12 m2 / s); D In order to meet the requirements of concrete 28d chloride ion diffusion coefficient (10 -12 m 2 / s), the 28d chloride ion diffusion coefficient of concrete is an important indicator for evaluating the concrete's ability to resist chloride ion penetration.

[0025] Table 3 Normalized limit values ​​of chloride ion diffusion coefficient of concrete at different strength grades

[0026] 6) If Figure 2 and Figure 3 As shown, replace step 5) D 28 The chloride ion diffusion coefficient after 28 days of concrete substitution and the replacement rate of machine-made sand and W / B (or the amount of adhesive material) in the linear relationship equation (chloride ion diffusion coefficient equation), the total amount of cementitious material and the glue-water ratio are calculated. The specific calculation methods are as follows: (3) (4) (5) (6) Wherein: the value range of a is 0.4038-0.4464, the value range of b is 0.7025-0.7766, the value range of c is 0.0027-0.0031, the value range of d is 0.3066-0.3389, the value range of e is 0.5597-0.6186, the value range of f is 0.0003-0.0004, the value range of g is 1.0027-1.1083, the value range of m is 0.0026-0.0029, the value range of n is 0.0003-0.0004, and the value range of s is 0.8267-0.9138; D 28 is the normalized chloride ion diffusion coefficient of concrete at 28 days (10 -12 m 2 / s); r 1 is the replacement rate of manufactured sand (0-100%); W / B is the glue-water ratio (0.33-0.53); B The total amount of rubber material (300kg / m 3 -500kg / m 3 ).

[0027] 7) Calculate the amount of each material according to the method in step 3) to obtain the recommended mix ratio that meets the durability requirements.

[0028] 8) According to the requirements of Highway Concrete Durability Design Code JTG / T3310, concrete of different strength grades should meet the specified values ​​of glue-water ratio and cementitious material dosage (as shown in Table 4). Combined with the mix ratios in steps 3) and 7), the optimal recommended mix ratio of machine-made sand concrete of each strength grade is obtained.

[0029] Table 4 Maximum glue-water ratio and cementitious material dosage of concrete with different strength grades (kg / m 3 )

[0030] In this embodiment, the fine aggregate used is machine-made sand with a fineness modulus of 3.13 and a stone powder content of 5%; the cement used is P·O42.5 cement; and the mineral admixtures used are S95 grade mineral powder and F class one fly ash.

[0031] This embodiment is different from the cumbersome design method of traditional concrete mix ratio. It can calculate the recommended mix ratio of machine-made sand concrete by obtaining the compressive strength that meets the engineering requirements, and can also calculate the recommended mix ratio of machine-made sand concrete by obtaining the 28d chloride ion diffusion coefficient that meets the requirements, thereby optimizing the mix ratio design process of machine-made sand concrete.

[0032] Embodiment 2: This embodiment provides a method for preparing machine-made sand concrete. The optimal recommended mix ratio of machine-made sand concrete is obtained according to the design method described in Example 1, and the machine-made sand concrete is obtained by mixing the raw materials.

[0033] Among them, the strength grade of machine-made sand concrete is C30-C50.

[0034] Embodiment 3: Based on the design method described in Example 1, this example assumes that the mix ratio of C40 machine-made sand concrete is designed according to the compressive strength. The specific calculation method is as follows: (1) Calculate according to formula 1 f cu,o =48.225MPa; (2) f cu,o =48.225MPaSubstitute into Figure 1 The total amount of cementitious materials and the ratio of cement to water were calculated from the linear regression equation of the compressive strength of different machine-made sand replacement rates, as shown in Table 1: ① The total amount of cementitious materials with a replacement rate of 0% is 452.44 kg / m 3 , glue-to-water ratio is 2.75; ② The total amount of cementitious materials with a replacement rate of 25% is 408.47 kg / m 3 , glue-to-water ratio is 2.45; ③ The total amount of cementitious materials with a replacement rate of 50% is 343.43 kg / m 3 , glue-to-water ratio is 2.15; ④ The total amount of cementitious materials with a replacement rate of 75% is 364.7 kg / m 3 , glue-to-water ratio is 2.26; ⑤ The total amount of cementitious materials with a replacement rate of 100% is 423.17 kg / m 3 , the glue ratio is 2.52.

[0035] (3) Assume that the apparent density of concrete is 2400 kg / m 3 , the sand ratio is 40%, the fly ash and mineral powder content is 30% and 15%, respectively. Using the mass method in the "Ordinary Concrete Mix Design Code" JGJ55-2011, the amount of each material is calculated as follows: ① The cement usage with a replacement rate of 0% is 248.84 kg / m 3 The fly ash dosage is 135.73 kg / m 3 The amount of mineral powder is 67.87 kg / m 3 The amount of fine aggregate is 713.46 kg / m 3 The amount of coarse aggregate is 1069.74 kg / m 3 The water consumption is 164.36 kg / m 3 ; ② The cement consumption with a replacement rate of 25% is 224.66 kg / m 3 The fly ash dosage is 122.54 kg / m 3 The amount of mineral powder is 61.27 kg / m 3 The amount of fine aggregate is 729.92 kg / m 3 The amount of coarse aggregate is 1094.89 kg / m 3 , the water consumption is 166.72 kg / m 3 ; ③ The cement consumption with a replacement rate of 50% is 188.89 kg / m 3 The fly ash dosage is 103.03 kg / m 3 The amount of mineral powder is 51.51 kg / m 3 The amount of fine aggregate is 758.74 kg / m 3 The amount of coarse aggregate is 1138.1 kg / m 3 The water consumption is 159.73 kg / m 3 ; ④ The cement consumption with a replacement rate of 75% is 200.58 kg / m 3 The fly ash dosage is 109.41 kg / m 3 The amount of mineral powder is 54.71 kg / m 3 The amount of fine aggregate is 749.57 kg / m 3 The amount of coarse aggregate is 1124.36 kg / m 3 The water consumption is 161.37 kg / m 3 ; ⑤ The cement consumption with a replacement rate of 100% is 232.74 kg / m 3 The fly ash dosage is 126.95 kg / m 3 The amount of mineral powder is 63.48 kg / m 3 The amount of fine aggregate is 723.56 kg / m 3 The amount of coarse aggregate is 1085.35 kg / m 3 , water consumption is 167.92 kg / m 3 .

[0036] (4) According to the provisions of GBT 50476-2019, the design service life of concrete is 100 years, and the chloride ion diffusion coefficient of concrete in service environment III-D at 28 days should be 7×10 -12 m 2 / s. Assume that a project requires that the chloride ion diffusion coefficient of C40 concrete in 28 days is 2.5×10 -12 m 2 / s, and the normalized chloride ion diffusion coefficient of concrete at 28 days was calculated according to formula (2): D 28 =0.85×10 -12 m 2 / s; (5) D 28 The chloride ion diffusion coefficient after 28 days of concrete substitution and the replacement rate of machine-made sand and W / B (or the amount of adhesive material) in the linear relationship equation, calculate: ① The total amount of cementitious materials with a replacement rate of 0% is 394 kg / m 3 , glue-water ratio is 0.44; ② The total amount of cementitious materials with a replacement rate of 25% is 395 kg / m 3 , glue-water ratio is 0.44; ③ The total amount of cementitious materials with a replacement rate of 50% is 396 kg / m 3 , glue-water ratio is 0.44; ④ The total amount of cementitious materials with a replacement rate of 75% is 397 kg / m 3 , glue-water ratio is 0.44; ⑤ The total amount of cementitious materials with a replacement rate of 100% is 398 kg / m 3 , the glue ratio is 0.44.

[0037] (6) Assume that the apparent density of concrete is 2400 kg / m 3 , the sand ratio is 40%, the fly ash and mineral powder content is 30% and 15%, respectively. Using the mass method in the "Ordinary Concrete Mix Design Code" JGJ55-2011, the amount of each material is calculated as follows: ① The cement usage with a replacement rate of 0% is 217 kg / m 3 The fly ash dosage is 118 kg / m 3 , the amount of mineral powder is 59kg / m 3 The amount of fine aggregate is 733 kg / m 3 The amount of coarse aggregate is 1099.5 kg / m 3 The water consumption is 173.5 kg / m 3 ; ② The cement consumption with a replacement rate of 25% is 217 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 59kg / m 3 The amount of fine aggregate is 732.57 kg / m 3 The amount of coarse aggregate is 1098.87 kg / m 3 , water consumption is 173.56kg / m 3 ; ③ The cement dosage for a replacement rate of 50% is 218 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 59kg / m 3 The amount of fine aggregate is 732.16 kg / m 3 The amount of coarse aggregate is 1098.24 kg / m 3 , water consumption is 173.63kg / m 3 ; ④ The cement consumption with a replacement rate of 75% is 218 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 60kg / m 3 The amount of fine aggregate is 731.73 kg / m 3 The amount of coarse aggregate is 1097.6 kg / m 3, water consumption is 173.69kg / m 3 ; ⑤ The cement consumption for a replacement rate of 100% is 219 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 60kg / m 3 The amount of fine aggregate is 731.32 kg / m 3 The amount of coarse aggregate is 1096.68 kg / m 3 , water consumption is 173.76kg / m 3 .

[0038] (7) According to the requirements of Highway Concrete Durability Design Code JTG / T3310, concrete of different strength grades should meet the specified values ​​of cement-water ratio and cementitious material dosage (see Table 4 for details). Combined with the above mix ratio and the economic cost of the mixing station, the optimal recommended mix ratio of C40 machine-made sand concrete is: ① The cement usage with a replacement rate of 0% is 217 kg / m 3 The fly ash dosage is 118 kg / m 3 , the amount of mineral powder is 59kg / m 3 The amount of fine aggregate is 733 kg / m 3 The amount of coarse aggregate is 1099.5 kg / m 3 The water consumption is 173.5 kg / m 3 ; ② The cement consumption with a replacement rate of 25% is 217 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 59kg / m 3 The amount of fine aggregate is 732.57 kg / m 3 The amount of coarse aggregate is 1098.87 kg / m 3 , water consumption is 173.56kg / m 3 ; ③ The cement consumption with a replacement rate of 50% is 188.89 kg / m 3 The fly ash dosage is 103.03 kg / m 3 The amount of mineral powder is 51.51 kg / m 3 The amount of fine aggregate is 758.74 kg / m 3 The amount of coarse aggregate is 1138.1 kg / m 3 The water consumption is 159.73 kg / m 3 ; ④ The cement consumption with a replacement rate of 75% is 218 kg / m 3The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 60kg / m 3 The amount of fine aggregate is 731.73 kg / m 3 The amount of coarse aggregate is 1097.6 kg / m 3 , water consumption is 173.69kg / m 3 ; ⑤ The cement consumption for a replacement rate of 100% is 219 kg / m 3 The fly ash dosage is 119 kg / m 3 , the amount of mineral powder is 60kg / m 3 The amount of fine aggregate is 731.32 kg / m 3 The amount of coarse aggregate is 1096.68 kg / m 3 , water consumption is 173.76kg / m 3 .

[0039] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for designing mix proportion of machine-made sand concrete, characterized in that: include: According to the linear regression equation of concrete mix strength and compressive strength with different machine-made sand replacement rates, the total amount of cementitious materials and the glue-water ratio were calculated; The amount of coarse and fine aggregates for setting the sand ratio is calculated based on the sum of coarse and fine aggregates; the amount of fly ash, mineral powder and cement is calculated based on the amount of fly ash and mineral powder added to obtain the recommended mix ratio that meets the strength requirements and the recommended mix ratio that meets the durability requirements; Calculate the 28d chloride ion diffusion coefficient of concrete that meets engineering durability requirements; The 28d chloride diffusion coefficient of concrete is normalized by the limit value of chloride diffusion coefficient of concrete of each strength grade; and the total amount of cementitious materials and the glue-water ratio are calculated by combining the chloride diffusion coefficient equation. According to the specified values ​​of glue-water ratio and cementitious material dosage of concrete of different strength grades, combined with the recommended mix ratio that meets the strength requirements and the recommended mix ratio that meets the durability requirements, the optimal recommended mix ratio of machine-made sand concrete of each strength grade is obtained.

2. The method for designing mix ratio of machine-made sand concrete according to claim 1, characterized in that: When the design strength grade is less than C60, ； in, f cu,o To prepare the strength of concrete, f cu,k is the standard value of concrete cube compressive strength, σ is the standard deviation of concrete strength.

3. The method for designing mix ratio of machine-made sand concrete according to claim 1, characterized in that: The amount of coarse and fine aggregate is calculated based on the sand ratio of 38%-42%.

4. The method for designing mix ratio of machine-made sand concrete according to claim 1, characterized in that: The method for normalizing the 28d chloride ion diffusion coefficient that meets the requirements is: ； in, D 28 is the normalized chloride ion diffusion coefficient of concrete at 28 days, D m is the normalized value of chloride ion diffusion coefficient of concrete, D To meet the requirements of concrete 28d chloride ion diffusion coefficient.

5. A method for designing mix ratio of machine-made sand concrete according to claim 1 or 4, characterized in that: For different concrete strength grades, the value range of the chloride ion diffusion coefficient of concrete at 28 days is different.

6. The method for designing mix ratio of machine-made sand concrete according to claim 1, characterized in that: The linear relationship equation between the chloride ion diffusion coefficient of concrete at 28 days, the machine-made sand replacement rate, and W / B is: When the machine-made sand replacement rate is 0: ; When the machine-made sand replacement rate is not 0: ; Among them, a, b, c, d, and e are constants within the set range. r 1 is the replacement rate of machine-made sand, W / B is the glue-to-water ratio, B The total amount of rubber material.

7. A method for designing mix ratio of machine-made sand concrete according to claim 6, characterized in that: The linear relationship equation between the chloride ion diffusion coefficient of concrete at 28 days, the replacement rate of machine-made sand, and the amount of adhesive is: When the machine-made sand replacement rate is 0: ; When the machine-made sand replacement rate is not 0: ; Among them, f, g, m, n, and s are constants with values ​​within a set range.

8. A method for designing mix ratio of machine-made sand concrete according to claim 6 or 7, characterized in that: The machine-made sand replacement rate is 0-100%, the glue-water ratio is 0.33-0.5, and the total amount of glue is 300kg / m 3 -500kg / m 3 .

9. A method for preparing machine-made sand concrete, characterized in that: According to the design method described in any one of claims 1 to 8, the optimal recommended mix ratio of machine-made sand concrete is obtained, and the machine-made sand concrete is obtained after mixing the raw materials.

10. The method for preparing machine-made sand concrete according to claim 9, characterized in that: The strength grade of the machine-made sand concrete is C30-C50.

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