Building solid waste-based cement mortar strength prediction method based on multivariate factor fitting

Abstract

The invention relates to the technical field of engineering construction, in particular to a building solid waste-based cement mortar strength prediction method based on multi-element factor fitting. According to the method, the relation between the cement component proportion, the gelation and porosity ratio and the strength of the set cement is measured through a formulating method, and a mathematical model of the relation between factor variables such as the strength of the set cement, the crushing value of the solid waste fine aggregate, the content of solid waste fine powder, the bad grain shape of the solid waste fine aggregate, the volume ratio of the fine aggregate, the surface area of the fine aggregate, the slurry bone interface and the gas content and the strength is established; therefore, the mortar strength is measured and calculated, solid waste-based cement mortar mix proportion optimization design and preparation are achieved, strength quality prediction evaluation and preparation adjustment are achieved according to tailings of different qualities and multi-factor diversified fluctuation in actual production, solid waste is reasonably utilized, and the solid waste-based cement mortar engineering quality is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering construction, and in particular to a method for predicting the strength of solid waste-based cement mortar for construction based on multivariate factor fitting. Background Art

[0002] Cement mortar is a material for masonry and plastering in construction projects, and fine aggregate is one of the necessary components of mortar. Fine aggregate is usually natural river sand, mountain sand, and machine-made sand. In recent years, the country has further increased its efforts to manage the environment for solid waste emissions. How to improve the scientific utilization rate of solid waste, reduce waste emissions, and protect the environment has become an urgent problem to be solved today. The solid waste generated by mining and mineral processing of various industrial raw materials, and the development of solid waste-based engineering materials have become a new trend in energy conservation and emission reduction. However, the sources of mining solid waste are complex and diverse. Due to their different mineral rock qualities, particle shapes, and porosities, the performance of solid waste-based cement mortar and the corresponding preparation methods are also quite different.

[0003] At present, the current industry standard "Specifications for Design of Mortar Mix Ratios for Masonry" (JGJ 98-2010) establishes a calculation formula by combining mortar mix strength, cement measured strength, mortar characteristic coefficient and cement dosage. Correspondingly, the relationship between cement measured strength, cement dosage and mortar mix strength is also given. However, the influencing factors involved are relatively few and are suitable for situations where the material is single and stable. It is not suitable for the current complex situation where the sources of tailings solid waste-based mixtures are diversified and the corresponding performance indicators vary greatly, which have a greater impact on mortar strength. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for predicting the strength of solid waste-based cement mortar for construction based on multivariate factor fitting. The present invention formulates a mortar strength prediction method by establishing a mathematical model relationship between multi-factor variables and mortar strength.

[0005] To achieve the above object, the present invention provides the following technical solutions: A method for predicting the strength of solid waste-based cement mortar for construction based on multivariate factor fitting. The process is shown in Figure 1 , Given the mix ratio of solid waste-based cement mortar, the compressive strength (age 28d) of solid waste-based cement mortar is calculated according to the following steps: 1. Solid waste-based cement mortar preparation strength f b Calculate according to formula 1: f b = λ s •f c (Formula 1) Where: f b——Solid waste-based cement mortar preparation strength (hereinafter referred to as mortar preparation strength), MPa; f c ——Strength of cement paste of mixed cementitious material (hereinafter referred to as cement paste strength), MPa; λ s ——Mortar interface coefficient.

[0006] 2. Cement stone strength f c Calculate according to formula 2: f c = λ c •f c0 (Formula 2) Where: f c ——Cement stone strength f c , MPa; f c0 ——Strength of pure cement paste f c0 , MPa; λ c ——Activity coefficient of adhesive material.

[0007] 3. Mortar interface coefficient λ s Calculate according to formula 3: λ s =λ jg •λ m •λ L •λ x (Formula 3) Where: s ——Mortar interface coefficient; λ jg ——Skeleton coefficient; λ m ——sand surface coefficient; λ L ——sand grain shape coefficient; λ x ——Fine powder influence coefficient.

[0008] Steps 4 to 18 below are the strength of cement paste f c The calculation process: 4. According to the pure cement paste strength f in formula 2 in step 2 c0 Calculate according to formula 2-1: f c0 = A0•φ B / K + B0 (Formula 2-1) Where: φ B / K ——The hydration gelation and pore volume ratio of cement stone mixed with cementitious material in solid waste-based cement mortar (hereinafter referred to as cement-pore ratio); A0, B0——Glue hole ratio constant, can be φ B / K is the independent variable, fc0 is the dependent variable and is calculated statistically through linear regression test.

[0009] 5. According to step 4, formula 2-1, the glue hole ratio φ B / K Calculate according to formula 2-1-1: φ B / K = V jn / V k (Formula 2-1-1) Where: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 ; V jn ——cementitious volume per cubic meter of solid waste-based cement mortar (hereinafter referred to as cementitious volume), m 3 ; 6. According to step 5, the total pore volume V in formula 2-1-1 k Calculate according to formula 2-1-1-1: V k = V wk + V q (Formula 2-1-1-1) Where: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 ; V wk ——The pore volume generated by the loss of free water in each cubic meter of solid waste-based cement mortar (hereinafter referred to as free water pore volume), m 3 ; V q ——The air entrained volume in each cubic meter of solid waste-based cement mortar is the product of the air entrained amount and 1 cubic meter of volume, m 3 ; 7. According to step 6, the free water pore volume V in formula 2-1-1-1 wk Calculate according to formula 2-1-1-1-1: V wk = (m w - (m cw + m kzw + m fw + m xw )) / ρ w (Formula 2-1-1-1-1) Where: m w ——Amount of mixing water in each cubic meter of solid waste-based cement mortar mix, kg; m cw ——Estimated cement hydration reaction water content in each cubic meter of solid waste-based cement mortar (hereinafter referred to as cement hydration water consumption), kg; mkzw ——The estimated amount of water for hydration reaction of active admixtures in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water consumption of active admixtures), kg; m fw ——Estimated amount of water for hydration reaction of common admixtures in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water consumption of common admixtures), kg; m xw ——The estimated amount of water for hydration reaction of tailings solid waste fine powder in each cubic meter of solid waste-based cement mortar (hereinafter referred to as water consumption for hydration of tailings solid waste fine powder), kg.

[0010] 8. According to step 5, the gel volume V in formula 2-1-1 jn Calculate according to formula 2-1-1-2: V jn = V c +V kz +V f +V x +V bw (Formula 2-1-1-2) Where: V jn ——cementitious volume per cubic meter of solid waste-based cement mortar, m 3 ; V c ——Mix ratio of cement per cubic meter of solid waste-based cement mortar, m 3 ; V kz ——The volume of active admixtures (such as granulated blast furnace slag powder and silica fume) per cubic meter of solid waste-based cement mortar mix, m 3 ; V f ——Volume of common admixtures (such as fly ash) per cubic meter of solid waste-based cement mortar mix, m 3 ; V x ——Volume of solid waste tailings fine powder (such as graphite tailings solid waste powder) per cubic meter of solid waste-based cement mortar mix, m 3 ; V bw ——Estimated volume of water used for hydration of cementitious materials in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water volume), m 3 .

[0011] 9. According to step 8, formula 2-1-1-2, V c 、V kz、 V f 、V x Calculate according to formula 2-1-1-2-1: V i = m i / ρi (Formula 2-1-1-2-1) Where: V i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, m 3 , when i is c\kz\f\x, V i They are the volume of cement, active admixture, common admixture and solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix; m i ——The amount of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, kg, when i is c\kz\f\x, m i They are respectively the amount of cement, the amount of active admixture, the amount of common admixture, and the amount of solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix, which provide known conditions for the solid waste-based cement mortar mix; ρ i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar, kg / m 3 , when i is c\kz\f\x, V i They are the cement apparent density, active admixture apparent density, common admixture apparent density, and solid waste tailings fine powder apparent density per cubic meter of solid waste-based cement mortar mix ratio, all of which are known conditions provided by the solid waste-based cement mortar mix ratio; 10. According to step 8, the volume of water V used for hydration of cementitious materials in formula 2-1-1-2 bw Calculate according to formula 2-1-1-2-2: V bw =(m cw + m kzw + m fw + m xw )• C w / ρ w (Formula 2-1-1-2-2) Where: C w ——The volume reduction coefficient of free water after hydration reaction is chemical water. Usually, the density of free water converted into hydrated structural water is usually 0.73~0.75kg / m 3 , C w Take 0.73; According to relevant research: the water in cement paste is evaporable water and non-evaporable water. All cement pastes that have been dried at 105°C or whose surrounding water vapor pressure is reduced to D- (6.67×10 -2 The water that can be removed under the condition of 1.5 Pa is called evaporable water, which is mainly capillary water, free water and gel water, as well as calcium sulphoaluminate hydrate, calcium aluminate hydrate and partially loosely bound crystal water in CS-H gel. The specific volume of these waters is basically 1cm 3 / g. Any water that cannot be removed by 105℃ or D-drying is called non-evaporable water. Some people call this part of water "chemically bound water". In fact, it is not real chemically bound water, but only an approximate value of chemically bound water. Since they have become part of the crystal structure, their specific volume is smaller than that of free water. It is believed that for fully hydrated cement, the mass of chemically bound water is about 23% of the mass of cement, while the specific volume of this water is only 0.73cm 3 / g, the specific volume of chemically bound water is smaller than that of free water, which is the main reason for the volume reduction during cement hydration.

[0012] ρ w ——Water density, kg / m 3 .

[0013] 11. According to the formula 2-1-1-1-1 in step 7 and the formula 2-1-1-2-2 in step 10, the cement hydration water consumption m cw , kg, calculated according to formula 2-1-1-2-2-1: m cw = m c •β ch •(W0 / B) (Formula 2-1-1-2-2-1) Where: β ch ——Cement hydration reaction rate coefficient, %, which can be 0.9~1. Usually, the mass percentage of 28d cement participating in hydration reaction is 0.9~1, which is the conventional technical experience value; W0 / B——water-binder ratio of hydration reaction, which can be taken as 0.24, is the conventional technical experience value.

[0014] 12. According to formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10, the water consumption of active admixture hydration m kzw , kg, calculated according to formula 2-1-1-2-2-2: m kzw = m kz •β kzh •(W0 / B) (Formula 2-1-1-2-2-2) Where: β kzh ——Hydration reaction rate coefficient of active admixture, %, usually the mass percentage of active admixture participating in hydration reaction in 28 days is 0.75~0.85, β kzh It can be taken as 0.75~0.85, which is the conventional technical experience value.

[0015] 13. According to the formula 2-1-1-1-1 in step 7 and the formula 2-1-1-2-2 in step 10, the water consumption of common admixture for hydration m fw , kg, calculated according to formula 2-1-1-2-2-3: m fw = m f •β fh •(W0 / B) (Formula 2-1-1-2-2-3) Where: β fh ——Common admixture hydration reaction rate coefficient, %, usually the mass percentage of common admixture participating in hydration reaction in 28 days is 0.25~0.35, β fh It can be taken as 0.25~0.35, which is the conventional technical experience value.

[0016] 14. According to step 7 formula 2-1-1-1-1 and step 10 formula 2-1-1-2-2, the water consumption for hydration of tailings solid waste fine powder is m xw , kg, calculated according to formula 2-1-1-2-2-4: m xw = m x •β xh •(W0 / B) (Formula 2-1-1-2-2-4) Where: β xh ——Hydration reaction rate coefficient of tailings solid waste fine powder, %, usually the mass percentage of tailings solid waste fine powder participating in the hydration reaction is 0~0.2 in 28 days, β xh It can be taken as 0~0.2, which is the conventional technical experience value.

[0017] 15. According to step 2, the activity coefficient of the rubber material in formula 2 is λ c Calculate according to formula 2-2: λc =η kz •η f •η x (Formula 2-2) Where: c ——Activity coefficient of adhesive material; η kz ——activity coefficient of active admixture; η f ——activity coefficient of common admixtures; η x ——Activity coefficient of fine powder of tailings solid waste.

[0018] 16. According to step 15, the activity coefficient η of the active admixture in formula 2-2 kz Calculate according to formula 2-2-1: η kz = A1•β kz +B1 (Formula 2-2-1) Where: A1, B1——Active admixture activity coefficient constant, can be active admixture dosage β kz (percentage of total powder) is the independent variable, ηkz is the dependent variable and is calculated statistically through linear regression test.

[0019] 17. According to step 15, the activity coefficient η of common admixture in formula 2-2 f , calculated according to formula 2-2-2: η f = A2•β f + B2 (Formula 2-2-2) Where: A2, B2——Ordinary admixture activity coefficient constant, which can be expressed as the ordinary admixture dosage β f (percentage of total powder) is the independent variable, η f is the dependent variable and is calculated statistically through linear regression test.

[0020] 18. According to step 15, the activity coefficient η of the tailings solid waste fine powder in formula 2-2 x , calculated according to formula 2-2-3: η x = A3•β x + B3 (Formula 2-2-3) Where: A3, B3——Activity coefficient constants of tailings solid waste sand fine powder, which can be used to calculate the tailings solid waste sand fine powder dosage β x (percentage of total powder) is the independent variable, η x is the dependent variable and is calculated statistically through linear regression test.

[0021] The following steps 19 to 30 are the mortar interface coefficient λ s The calculation process: 19. According to step 3, the synovial coefficient λ in formula 3 jg Calculate according to formula 3-1: λ jg = (1+0.3•φ1) / (1+φ1•δ s ) (Formula 3-1) Where: φ1——volume ratio of sand to slurry; δ s ——Crushing value of tailings solid waste sand, %, is test data, obtained by referring to the test method specified in "Sand for Construction" GB / T 14684-2022.

[0022] 20. According to step 19, formula 3-1, the volume ratio φ1 of sand to slurry is calculated according to formula 3-1-1: φ1 = V s1 / V j1 (Formula 3-1-1) Where: V s1 ——Volume of tailings solid waste sand after powder removal V s1 , m 3; V j1 ——Slurry volume per cubic meter of solid waste-based cement mortar, m 3 .

[0023] 21. According to step 20, the volume of the tailings solid waste sand V after powder removal in formula 3-1-1 s1 Calculate according to formula 3-1-1-1: V s1 = V s -V x (Formula 3-1-1-1) Where: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; V x ——Volume of fine powder in tailings solid waste sand per cubic meter of solid waste-based cement mortar, m 3 .

[0024] 22. According to step 20, the volume of slurry V in each cubic meter of solid waste-based cement mortar in formula 3-1-1 j1 , calculated according to formula 3-1-1-2: V j1 = V c + V kz + V f + V x + V w + V a + V q (Formula 3-1-1-2) Where: V c 、V kz 、 V f 、V x Calculate according to step 9; V w It is calculated by dividing the amount of water used for mixing per cubic meter of solid waste-based cement mortar by the density of water, m 3 .

[0025] 23. According to step 3, the surface coefficient of tailings solid waste sand λ in formula 3 m Calculate according to formula 3-2: λ m = 3.152 / ε s (Formula 3-2) Where: ε s ——surface area index of tailings solid waste sand; 24. According to step 23, the tailings solid waste sand surface area index ε in formula 3-2 s Calculate according to formula 3-2-1: ε s = Ss × 10 -9 (Formula 3-2-1) Where: S s ——Estimated total surface area of ​​tailings solid waste sand after sieving with a 0.16 mm square hole sieve, mm 2 .

[0026] 25. According to step 24, the total surface area S of tailings solid waste sand in formula 3-2-1 s Calculate according to formula 3-2-1-1: S s = S s1 + S s2 + S s3 + S s4 + S s5 + S s6 (Formula 3-2-1-1) Where: S s1 ——Estimated total surface area of ​​5.0mm-10.0mm particles (average particle size 7.5mm) in tailings solid waste sand, mm 2 ; S s2 ——Estimated total surface area of ​​2.5mm-5.0mm particle size (average particle size 3.75mm) in tailings solid waste sand, mm 2 ; S s3 ——Estimated total surface area of ​​1.25mm-2.5mm particle size (average particle size 1.875mm) particles in tailings solid waste sand, mm 2 ; S s4 ——Estimated total surface area of ​​0.63mm-1.25mm particle size (average particle size 0.94mm) particles in tailings solid waste sand, mm 2 ; S s5 ——Estimated total surface area of ​​0.315mm-0.63mm particle size (average particle size 0.472mm) particles in tailings solid waste sand, mm 2 ; S s6 ——Estimated total surface area of ​​0.16mm-0.315mm particle size (average particle size 0.238mm) particles in tailings solid waste sand, mm 2 .

[0027] 26. According to step 25, the total surface area S of a certain particle size of tailings solid waste sand in formula 3-2-1-1 si Calculate according to formula 3-2-1-1-1: S si = N si •S sdi(Formula 3-2-1-1-1) Where: S si ——Estimated total surface area of ​​a certain particle size of tailings solid waste sand, mm 2 , when i = 1\2\3\4\5\6, Estimated total surface area of ​​tailings solid waste sand particle size of 5.0mm-10.0mm\2.5mm-5.0mm\1.25mm-2.5mm\0.63mm-1.25mm\0.315mm-0.63mm\0.16mm-0.315mm.

[0028] N si ——The number of particles of a certain size of tailings solid waste sand. When i = 1\2\3\4\5\6, it represents the total number of particles of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm size, respectively. S sdi ——Surface area of ​​a particle of a certain particle size of tailings solid waste sand. When i = 1\2\3\4\5\6, it represents the surface area of ​​a single particle of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size, mm 2 The surface area can be calculated according to the different shapes and the average particle size of the particle size. For example, for a sphere, 4πr 2 calculate.

[0029] 27. According to step 26, the number of particles N of a certain particle size of tailings solid waste sand in formula 3-2-1-1-1 si Calculate according to formula 3-2-1-1-1-1: N si = V si / V sdi (Formula 3-2-1-1-1-1) Where: V si ——Volume of tailings solid waste sand at a certain particle size, m 3 , when i = 1\2\3\4\5\6, it represents the volume of tailings solid waste sand of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size, m 3. V sdi ——Volume of a single particle of a certain particle size of tailings solid waste sand, m 3, when i = 1\2\3\4\5\6, it represents the single particle of tailings solid waste sand with particle size of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm, mm 3 The volume can be calculated according to the different shapes and the average particle size of the particle size. For example, for a sphere, (4 / 3)πr 3 calculate.

[0030] 28. Calculate the volume V of a certain particle size of tailings solid waste sand according to formula 3-2-1-1-1-1 in step 27 si Calculate according to formula 3-2-1-1-1-1-1: V si = V s •F si (Formula 3-2-1-1-1-1) Where: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; F si ——The sieve residue of a certain particle size of tailings solid waste sand, %, when i = 1\2\3\4\5\6, it represents the sieve residue of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size of tailings solid waste sand, which is the test data, obtained by referring to the test method specified in "Sand for Construction" GB / T 14684-2022.

[0031] 29. According to step 3, the tailings solid waste sand particle shape coefficient λ in formula 3 L Calculate according to formula 3-3: λ L = 1 / (1+Q h ) (Formula 3-3) Where: L ——Sand grain shape coefficient of tailings solid waste; Q h ——The content of flaky particles in tailings solid waste sand is test data, which is obtained by referring to the test method specified in "Construction Sand" GB / T 14684-2022.

[0032] 30. According to step 3, the fine powder influence coefficient λ in formula 3 x Calculate according to formula 3-4: λ x = 1.02 / (1+1.1•X s ) (Formula 3-4) Where: x——fine powder influence coefficient; X s ——The fine powder content of tailings solid waste sand, %, is the test data, which is obtained by referring to the stone powder content test method specified in "Construction Sand" GB / T 14684-2022.

[0033] The present invention discovers and reveals the most basic mechanism of action, establishes a mathematical model relationship between multi-factor variables and mortar strength, and formulates a mortar strength prediction method, which effectively solves the difficult problems of solid waste-based cement mortar preparation and quality risk control caused by the diverse sources and large performance gaps of today's mine tailings solid waste-based mixtures.

[0034] The beneficial effects of the present invention are: 1. Through the mathematical model of mortar strength measurement, dynamic and timely risk pre-assessment of mortar strength can be achieved, providing a basis for mix design, quality control and adjustment measures, thereby ensuring the quality of solid waste-based cement mortar projects.

[0035] 2. Through the cement stone strength f c , mortar interface coefficient λ s These two influencing factors establish a mathematical model to achieve the strength of solid waste-based cement mortar f b The calculation can better respond.

[0036] 3. Through the pure cement stone strength f c0 and the activity coefficient of the adhesive material λ c Establishing a mathematical model can better characterize the strength of solid waste-based cement mortar c0 Furthermore, the strength of mortar can be more effectively calculated based on the most basic principle factors such as the strength of mixed cementitious material cement paste, the water-cementation and pore volume ratio (cement-pore ratio) of mixed cementitious material cement paste in solid waste-based cement mortar, and the mortar interface coefficient that characterizes the mortar-bone bonding performance, so as to improve the technical level of solid waste-based cement mortar preparation.

[0037] 4. Considering that the porosity of cement stone, the bonding performance of the mortar-bone interface, the distribution ratio of slurry and aggregate, and the quality of solid waste tailings sand in solid waste-based cement mortar are the main key factors affecting the strength of mortar, through the technical parameters such as the pore ratio, mortar interface coefficient, mortar-bone coefficient, sand surface coefficient, sand grain shape coefficient, fine powder interface coefficient, etc., the pores of cement stone, the amount of mineral admixtures and activity index, slurry volume, solid waste tailings sand volume rate, crushing value, surface area, poor grain shape, fine powder content and many other influencing factors are correlated with the mortar strength. In view of the complex fluctuations of tailings of different qualities and multi-factor diversity in actual production, the solid waste-based cement mortar mix design and strength calculation mathematical model are calculated by computer programming, which can realize targeted, timely, rapid and effective holographic prediction and evaluation of strength quality and adjustment of formulation, which is helpful to rationally utilize solid waste, improve utilization rate and ensure the quality of solid waste-based cement mortar projects. The correlation diagram of the influence of multiple factors on the strength of quasi-solid waste-based cement mortar is shown in Figure 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0039] Figure 1 It is the overall flow chart of the present invention.

[0040] Figure 2 This is a correlation diagram of the influence of multiple factors on the strength of solid waste-based cement mortar. DETAILED DESCRIPTION

[0041] The specific details of the present invention are further described in the following description for a full understanding of the present invention. The terms used in the specification of the present invention are only used to illustrate the advantages and features of the present invention and are not intended to limit the present invention. Unless otherwise defined, all professional and scientific terms used in the present invention have the same meanings as understood by technicians in the technical field of the present invention. The technical solution of the present invention is now further described according to specific embodiments.

[0042] A method for preparing and predicting the strength of solid waste-based cement mortar for construction based on multivariate factor fitting, the specific steps are as follows: Example 1 The iron tailings of a certain iron mine were crushed to obtain iron tailings solid waste sand. The iron tailings solid waste sand samples were extracted, dried to constant weight, and tested according to the relevant methods of the national standard "Construction Sand" (GB / T 14684-2022). The test results are shown in Table 1; the mortar mix ratio of the iron tailings solid waste sand is shown in Table 2. The solid waste sand was sieved with a 0.075 mm square hole sieve to obtain the de-powdered solid waste sand and tailings solid waste fine powder.

[0043] Table 1 Screening test results of solid waste sand from an iron tailings Table 2 Mortar mix ratio of iron tailings solid waste sand The compressive strength of solid waste-based cement mortar (age 28 days) was estimated according to the following steps: 1. Solid waste-based cement mortar preparation strength f b Calculate according to formula 1: f b = λ s •f c (Formula 1) Where: f b ——Solid waste-based cement mortar preparation strength (hereinafter referred to as mortar preparation strength), MPa; f c ——Strength of cement paste of mixed cementitious material (hereinafter referred to as cement paste strength), MPa; λ s ——Mortar interface coefficient.

[0044] 2. Cement stone strength f c Calculate according to formula 2: f c = λ c •f c0 (Formula 2) Where: f c ——Cement paste strength f c , MPa; f c0 ——Strength of pure cement paste f c0 , MPa; λ c ——Activity coefficient of adhesive material.

[0045] 3. Mortar interface coefficient λ s Calculate according to formula 3: λ s =λ jg •λ m •λ L •λ x (Formula 3) Where: s ——Mortar interface coefficient; λ jg ——Skeleton coefficient; λ m ——sand surface coefficient; λ L ——sand grain shape coefficient; λ x——Fine powder influence coefficient.

[0046] The following steps 4 to 18 are the strength of cement paste f c The calculation process: 4. According to the pure cement paste strength f in formula 2 in step 2 c0 Calculate according to formula 2-1: f c0 =A0•φ B / K +B0 (Formula 2-1) Where: φ B / K ——The hydration gelation and pore volume ratio of cement stone mixed with cementitious material in solid waste-based cement mortar (hereinafter referred to as cement-pore ratio); A0, B0——Glue pore ratio constant, can be φ B / K is the independent variable, f c0 is the dependent variable and is calculated statistically through linear regression test.

[0047] The test was conducted with reference to the molding and strength test methods specified in GB / T 17671-2021 Test Method for Strength of Cement Mortar (ISO Method), and the data are shown in Table 3. The linear regression test statistical calculation showed that A0 was 8.2, B0 was 24.8, Table 3φ B / K -f c0 Test List 5. Step 4: The glue hole ratio φ in formula 2-1 B / K Calculate according to formula 2-1-1: φ B / K = V jn / V k (Formula 2-1-1) Where: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 ; V jn ——cementitious volume per cubic meter of solid waste-based cement mortar (hereinafter referred to as cementitious volume), m 3 ; 6. Step 5: Total pore volume V in formula 2-1-1 k Calculate according to formula 2-1-1-1: V k = V wk + V q (Formula 2-1-1-1) Where: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 ; V wk——The pore volume generated by the loss of free water in each cubic meter of solid waste-based cement mortar (hereinafter referred to as free water pore volume), m 3 ; V q ——The air entrained volume in each cubic meter of solid waste-based cement mortar is the product of the air entrained amount and 1 cubic meter of volume, m 3 ; According to the test method for air content of concrete specified in the Standard for Performance Test Methods of Ordinary Concrete Mixtures GB / T 50080-2016, the mortar content is 13.1%, V q 0.131m 3 .

[0048] 7. Free water pore volume V in formula 2-1-1-1 in step 6 wk Calculate according to formula 2-1-1-1-1: V wk =(m w - (m cw + m kzw + m fw + m xw )) / ρ w (Formula 2-1-1-1-1) Where: m w ——Amount of mixing water per cubic meter of solid waste-based cement mortar mix, kg, see Table 2, m w is 266 kg.

[0049] m cw ——Estimated cement hydration reaction water content in each cubic meter of solid waste-based cement mortar (hereinafter referred to as cement hydration water consumption), kg; m kzw ——The estimated amount of water for hydration reaction of active admixtures in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water consumption of active admixtures), kg; m fw ——Estimated amount of water for hydration reaction of common admixtures in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water consumption of common admixtures), kg; m xw ——The estimated amount of water for hydration reaction of tailings solid waste fine powder in each cubic meter of solid waste-based cement mortar (hereinafter referred to as water consumption for hydration of tailings solid waste fine powder), kg.

[0050] 8. Step 5: Gel volume V in formula 2-1-1 jn Calculate according to formula 2-1-1-2: V jn = V c +V kz +V f +V x+V bw (Formula 2-1-1-2) Where: V jn ——cementitious volume per cubic meter of solid waste-based cement mortar, m 3 ; V c ——Mix ratio of cement per cubic meter of solid waste-based cement mortar, m 3 ; V kz ——The volume of active admixtures (such as granulated blast furnace slag powder and silica fume) per cubic meter of solid waste-based cement mortar mix, m 3 ; V f ——Volume of common admixtures (such as fly ash) per cubic meter of solid waste-based cement mortar mix, m 3 ; V x ——Volume of solid waste tailings fine powder (such as graphite tailings solid waste powder) per cubic meter of solid waste-based cement mortar mix, m 3 ; V bw ——Estimated volume of water used for hydration of cementitious materials in each cubic meter of solid waste-based cement mortar (hereinafter referred to as hydration water volume), m 3 .

[0051] 9. Step 8: V in formula 2-1-1-2 c 、V kz、 V f 、V x Calculate according to formula 2-1-1-2-1: V i = m i / ρ i (Formula 2-1-1-2-1) Where: V i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, m 3 , when i is c\kz\f\x, V i They are the volume of cement, active admixture, common admixture and solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix; m i ——The amount of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, kg, when i is c\kz\f\x, m i They are respectively the amount of cement, the amount of active admixture, the amount of common admixture, and the amount of solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix, which provide known conditions for the solid waste-based cement mortar mix; ρ i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar, kg / m3 , when i is c\kz\f\x, V i They are respectively the apparent density of cement per cubic meter of solid waste-based cement mortar mix, the apparent density of active admixtures, the apparent density of common admixtures, and the apparent density of solid waste tailings fine powder, all of which are known conditions provided by the solid waste-based cement mortar mix.

[0052] See Table 2, V c 0.061m 3 、V kz is 0, V f 0.046m 3 , V x 0.091m 3 .

[0053] 10. The volume of water V used for hydration of cementitious materials in formula 2-1-1-2 in step 8 bw Calculate according to formula 2-1-1-2-2: V bw =(m cw + m kzw + m fw + m xw )• C w / ρ w (Formula 2-1-1-2-2) Where: C w ——The volume reduction coefficient of free water after hydration reaction is chemical water. Usually, the density of free water converted into hydrated structural water is usually 0.73~0.75kg / m 3 , C w Take 0.73; ρ w ——Water density, kg / m 3 , take 1000kg / m 3 .

[0054] 11. Cement hydration water consumption m in formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10 cw , kg, calculated according to formula 2-1-1-2-2-1: m cw = m c •β ch •(W0 / B) (Formula 2-1-1-2-2-1) Where: β ch ——Cement hydration reaction rate coefficient, %, which can be 0.9~0.1. Usually, the mass percentage of cement participating in hydration reaction after 28 days is 0.9~1, which is the conventional technical experience value; W0 / B——water-binder ratio of hydration reaction, which can be taken as 0.24, is the conventional technical experience value.

[0055] m c 190kg, β ch Take 1, W0 / B take 0.24, after calculation, m cw is 46kg.

[0056] 12. The water consumption of active admixture hydration in formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10 is m kzw , kg, calculated according to formula 2-1-1-2-2-2: m kzw = m kz •β kzh •(W0 / B) (Formula 2-1-1-2-2-2) Where: β kzh ——Hydration reaction rate coefficient of active admixture, %, usually the mass percentage of active admixture participating in hydration reaction in 28 days is 0.75~0.85, β kzh It can be taken as 0.75~0.85, which is the conventional technical experience value.

[0057] No active admixtures are added and are not calculated.

[0058] 13. Hydration water consumption of common admixtures in formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10: m fw , kg, calculated according to formula 2-1-1-2-2-3: m fw = m f •β fh •(W0 / B) (Formula 2-1-1-2-2-3) Where: β fh ——Common admixture hydration reaction rate coefficient, %, usually the mass percentage of common admixture participating in hydration reaction in 28 days is 0.25~0.35, β fh It can be taken as 0.25~0.35, which is the conventional technical experience value.

[0059] m f is 102kg, β fh0 Take 0.3, W0 / B take 0.24, after calculation, m fw is 7kg.

[0060] 14. Water consumption for hydration of tailings solid waste fine powder in formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10 m xw , kg, calculated according to formula 2-1-1-2-2-4: m xw = m x •β xh•(W0 / B) (Formula 2-1-1-2-2-4) Where: β xh ——Hydration reaction rate coefficient of tailings solid waste fine powder, %, usually the mass percentage of tailings solid waste fine powder participating in the hydration reaction is 0~0.2 in 28 days, β xh It can be taken as 0~0.2, which is the conventional technical experience value.

[0061] m x 295kg, m x Take 0.15, W0 / B take 0.24, after calculation, m xw It is 11kg.

[0062] After calculation, the volume of water used for hydration V bw =(m cw + m kzw + m fw + m xw )• C w / ρ w = (46+7+11)• 0.73 / 1000=0.047m 3 ; Gel volume V jn = V c +V kz +V f +V x +V bw =0.061 +0+0.046 +0.091 +0.047=0.245 m 3 .

[0063] Free water pore volume V wk = (m w - (m cw + m kzw + m fw + m xw )) / ρ w =(266-(46+7+11)) / 1000=0.202m 3 ; Total pore volume V k = V wk + V q =0.202 + 0.131 =0.333m 3 .

[0064] Glue hole ratio φ B / K = V jn / V k = 0.245 / 0.333=0.736; Pure cement paste strength f c0= A0•φ B / K + B0=30.8 MPa.

[0065] The following steps 15 to 30 are the activity coefficient λ of the adhesive material. c Calculation process.

[0066] 15. According to step 2, the activity coefficient of the rubber material in formula 2 is λ c Calculate according to formula 2-2: λc =η kz •η f •η x (Formula 2-2) Where: c ——Activity coefficient of adhesive material; η kz ——activity coefficient of active admixture; η f ——activity coefficient of common admixtures; η x ——Activity coefficient of fine powder of tailings solid waste.

[0067] 16. According to step 15, the activity coefficient η of the active admixture in formula 2-2 kz Calculate according to formula 2-2-1: η kz = A1•β kz +B1 (Formula 2-2-1) Where: A1, B1——Active admixture activity coefficient constant, can be active admixture dosage β kz (percentage of total powder) is the independent variable, η kz is the dependent variable and is calculated statistically through linear regression test.

[0068] No active admixtures are added and are not calculated.

[0069] 17. According to step 15, the activity coefficient η of common admixture in formula 2-2 f , calculated according to formula 2-2-2: η f = A2•β f + B2 (Formula 2-2-2) Where: A2, B2——Ordinary admixture activity coefficient constant, which can be expressed as the ordinary admixture dosage β f (percentage of total powder) is the independent variable, η f is the dependent variable and is calculated statistically through linear regression test.

[0070] The fly ash content can be f (percentage of total powder) is the independent variable, η fAs the dependent variable, the molding and strength test methods specified in GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)" were used for the test, and the data are shown in Table 4. Through the statistical calculation of the linear regression test, it was found that A2 was -0.5, B2 was 1.1, Table 4 βf -ηf test results After calculation, the fly ash content β f =102 / (190+102+295)=17.4%, substitute into η f = -0.5•β f + 1.1, η f It is 0.83.

[0071] 18. According to step 15, the activity coefficient η of the tailings solid waste fine powder in formula 2-2 x , calculated according to formula 2-2-3: η x = A3•β x + B3 (Formula 2-2-3) Where: A3, B3——Activity coefficient constants of tailings solid waste sand fine powder, which can be used to calculate the tailings solid waste sand fine powder dosage β x (percentage of total powder) is the independent variable, η x As the dependent variable, the molding and strength test methods specified in GB / T17671-2021 "Test Method for Cement Mortar Strength (ISO Method)" were used for testing, and the data are shown in Table 5. Through linear regression test statistical calculation, it is found that A2 is -1.0, B2 is 1.0, Table 5β x -η x Test results After calculation, the amount of fine powder of tailings solid waste sand is β x =295 / (190+102+295)=50.3%, substitute into η x = -1.0•β x + 1.0, η x is 0.5.

[0072] After calculation, the activity coefficient of the rubber material λc =η kz •η f •η x =0.83*0.5=0.42, Mortar preparation strength c = λ c •f c0 =0.42•30.8=12.9.

[0073] The following steps 19 to 30 are the mortar interface coefficient λ s The calculation process: 19. According to step 3, the synovial coefficient λ in formula 3 jg Calculate according to formula 3-1: λ jg = (1+0.3•φ1) / (1+φ1•δ s ) (Formula 3-1) Where: φ1——volume ratio of sand to slurry; δ s ——Crushing value of tailings solid waste sand, %, is the test data, obtained by referring to the test method specified in "Sand for Construction" GB / T 14684-2022. The test result is 5.8%, see Table 1.

[0074] 20. According to step 19, formula 3-1, the volume ratio φ1 of sand to slurry is calculated according to formula 3-1-1: φ1 = V s1 / V j1 (Formula 3-1-1) Where: V s1 ——Volume of solid waste sand from tailings after powder removal, m 3 ; V j1 ——Slurry volume per cubic meter of solid waste-based cement mortar, m 3 .

[0075] 21. According to step 20, the volume of the tailings solid waste sand V after powder removal in formula 3-1-1 s1 Calculate according to formula 3-1-1-1: V s1 = V s -V x (Formula 3-1-1-1) Where: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; V x ——Volume of fine powder in tailings solid waste sand per cubic meter of solid waste-based cement mortar, m 3 .

[0076] 22. According to step 20, the volume of slurry V in each cubic meter of solid waste-based cement mortar in formula 3-1-1 j1 , calculated according to formula 3-1-1-2: V j1 = V c + V kz + V f + V x + V w + Va + V q (Formula 3-1-1-2) Where: V c 、V kz 、 V f 、V x Calculate according to step 9; V w It is calculated by dividing the amount of water used for mixing per cubic meter of solid waste-based cement mortar by the density of water, m 3 .

[0077] After calculation, the volume of solid waste sand V s1 =0.493-0.091=0.402m 3 Slurry volume V j1 =0.061+0+0.046+0.091+0.266+0.131+0.003=0.598 m 3 ; The volume ratio of sand to slurry is φ1 = 0.402 / 0.598 = 0.672; Bone Coefficient λ jg =(1+0.3*0.672) / (1+0.672*5.8%)=1.157.

[0078] 23. According to step 3, the surface coefficient of tailings solid waste sand λ in formula 3 m Calculate according to formula 3-2: λ m = 3.152 / ε s (Formula 3-2) Where: ε s ——surface area index of tailings solid waste sand; 24. According to step 23, the tailings solid waste sand surface area index ε in formula 3-2 s Calculate according to formula 3-2-1: ε s = S s × 10 -9 (Formula 3-2-1) Where: S s ——Estimated total surface area of ​​tailings solid waste sand after sieving with a 0.16 mm square hole sieve, mm 2 .

[0079] 25. According to step 24, the total surface area S of tailings solid waste sand in formula 3-2-1 s Calculate according to formula 3-2-1-1: S s = S s1 + S s2 + Ss3 + S s4 + S s5 + S s6 (Formula 3-2-1-1) Where: S s1 ——Estimated total surface area of ​​5.0mm-10.0mm particles (average particle size 7.5mm) in tailings solid waste sand, mm 2 ; S s2 ——Estimated total surface area of ​​2.5mm-5.0mm particle size (average particle size 3.75mm) in tailings solid waste sand, mm 2 ; S s3 ——Estimated total surface area of ​​1.25mm-2.5mm particle size (average particle size 1.875mm) particles in tailings solid waste sand, mm 2 ; S s4 ——Estimated total surface area of ​​0.63mm-1.25mm particle size (average particle size 0.94mm) particles in tailings solid waste sand, mm 2 ; S s5 ——Estimated total surface area of ​​0.315mm-0.63mm particle size (average particle size 0.472mm) particles in tailings solid waste sand, mm 2 ; S s6 ——Estimated total surface area of ​​0.16mm-0.315mm particle size (average particle size 0.238mm) particles in tailings solid waste sand, mm 2 .

[0080] 26. Step 25: The total surface area S of a certain particle size of tailings solid waste sand in formula 3-2-1-1 si Calculate according to formula 3-2-1-1-1: S si = N si •S sdi (Formula 3-2-1-1-1) Where: S si ——Estimated total surface area of ​​a certain particle size of tailings solid waste sand, mm 2 , when i = 1\2\3\4\5\6, Estimated total surface area of ​​tailings solid waste sand particle size of 5.0mm-10.0mm\2.5mm-5.0mm\1.25mm-2.5mm\0.63mm-1.25mm\0.315mm-0.63mm\0.16mm-0.315mm.

[0081] N si——The number of particles of a certain size of tailings solid waste sand. When i = 1\2\3\4\5\6, it represents the total number of particles of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm size, respectively. S sdi ——Surface area of ​​a particle of a certain particle size of tailings solid waste sand. When i = 1\2\3\4\5\6, it represents the surface area of ​​a single particle of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size, mm 2 The surface area can be calculated according to the different shapes and the average particle size of the particle size. For example, for a sphere, 4πr 2 calculate.

[0082] 27. According to step 26, the number of particles N of a certain particle size of tailings solid waste sand in formula 3-2-1-1-1 si Calculate according to formula 3-2-1-1-1-1: N si = V si / V sdi (Formula 3-2-1-1-1-1) Where: V si ——Volume of tailings solid waste sand at a certain particle size, m 3 , when i = 1\2\3\4\5\6, it represents the volume of tailings solid waste sand of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size, m 3 ; V sdi ——Volume of a single particle of a certain particle size of tailings solid waste sand, m 3 , when i = 1\2\3\4\5\6, it represents the single particle of tailings solid waste sand with particle size of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm, mm 3 The volume can be calculated according to the different shapes and the average particle size of the particle size. For example, for a sphere, (4 / 3)πr 3 calculate.

[0083] 28. Calculate the volume V of a certain particle size of tailings solid waste sand according to formula 3-2-1-1-1-1 in step 27 siCalculate according to formula 3-2-1-1-1-1-1: V si = V s •F si (Formula 3-2-1-1-1-1) Where: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; F si ——The sieve residue of a certain particle size of tailings solid waste sand, %, when i = 1\2\3\4\5\6, it represents the sieve residue of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size of tailings solid waste sand, which is the test data, obtained by referring to the test method specified in "Sand for Construction" GB / T 14684-2022, see Table 1.

[0084] After calculation, the average particle size corresponding to each nominal particle size is divided into the sieve residue F si , divided into volume V si , particle shape, single particle volume Vsdi, number of particles N si , single particle surface area Ssdi, total surface area S si See Table 6; Table 6 Statistical table of various indicators corresponding to solid waste sand with different nominal diameters After calculation, the total surface area of ​​tailings solid waste sand is S s =1246081788 mm 2 ; Tailings solid waste sand surface area index ε s is 1.246; Tailings solid waste sand surface coefficient λ m =3.152 / εs=3.152 / 1.246 =1.363.

[0085] 29. The tailings solid waste sand shape coefficient λ in formula 3 of step 3 L Calculate according to formula 3-3: λ L = 1 / (1+Q h ) (Formula 3-3) Where: L ——Sand grain shape coefficient of tailings solid waste; Q h ——The content of flake particles in tailings solid waste sand is experimental data, obtained by referring to the test method specified in GB / T 14684-2022 "Sand for Construction", see Table 1, Q hIt is 1.6%.

[0086] After calculation, λ L =1 / (1+1.6%)=0.984.

[0087] 30. Fine powder influence coefficient λ in formula 3 of step 3 x Calculate according to formula 3-4: λ x = 1.02 / (1+1.1•X s ) (Formula 3-4) Where: x ——fine powder influence coefficient; X s ——The fine powder content of tailings solid waste sand, %, is the test data, obtained by referring to the stone powder content test method specified in "Construction Sand" GB / T 14684-2022. See Table 1, which is 18.5%.

[0088] After calculation, the fine powder influence coefficient λ x =1.02 / (1+1.1*18.5%)=0.848.

[0089] According to step 3 formula 3, after calculation, the mortar interface coefficient λ s =λ jg •λ m •λ L •λ x =1.157•1.363•0.984•0.848=1.316.

[0090] According to formula 1 in step 1, after calculation, the strength of solid waste-based cement mortar is f b =λ s •f c =1.316•12.9=17.0MPa.

[0091] According to the mortar mix ratio prepared with iron tailings solid waste sand provided in Table 2, the test was carried out with reference to the compressive strength test method of "Standard for Test Methods for Physical and Mechanical Properties of Concrete" GB∕T 50081-2019, and the compressive strength of the mortar specimens after standard curing for 28 days was 17.3MPa.

[0092] Therefore, the prediction deviation of the present invention =|(17.0-17.3)*100% / 17.3|=1.7%<5%, and the prediction accuracy is relatively high.

[0093] Example 2 In Example 1, the tailings solid waste mortar mix ratio remains unchanged, but the sand is changed to graphite tailings solid waste sand. According to the method specified in the present invention, the strength prediction and evaluation are carried out on it, and corresponding improvements are made to ensure the quality, which is implemented as follows: A sample of solid waste silt from a certain graphite tailings was dried to constant weight and then tested according to the relevant methods of the national standard "Sand for Construction" (GB / T 14684-2022). The test results are shown in Table 7. A 0.075 mm square hole sieve was used to screen the solid waste sand to obtain de-powdered solid waste sand and tailings solid waste fine powder. In order to meet the construction requirements and ensure that the consistency remains unchanged, the mix ratio was adjusted accordingly as the sand became finer and the water demand increased, while the cementitious material remained unchanged, and the mortar mix ratio prepared with graphite tailings solid waste sand was obtained, as shown in Table 8.

[0094] Table 7 Screening test results of solid waste sand from a graphite tailings Table 8 Mortar mix ratio of graphite tailings solid waste sand The same steps as in Example 1 were repeated, and the compressive strength of the solid waste-based cement mortar was calculated as follows: 1. Solid waste-based cement mortar preparation strength f b Calculate according to formula 1: f b = λ s •f c (Formula 1) 2. Cement stone strength f c Calculate according to formula 2: f c = λ c •f c0 (Formula 2) 3. Mortar interface coefficient λ s Calculate according to formula 3: λ s =λ jg •λ m •λ L •λ x (Formula 3) 4. According to the pure cement paste strength f in formula 2 in step 2 c0 Calculate according to formula 2-1: f c0 = A0•φ B / K + B0 (Formula 2-1) A0 is 8.2, B0 is 24.8, 5. According to step 4, formula 2-1, the glue hole ratio φ B / K Calculate according to formula 2-1-1: φ B / K = V jn / V k (Formula 2-1-1) 6. According to step 5, the total pore volume V in formula 2-1-1 kCalculate according to formula 2-1-1-1: V k = V wk + V q (Formula 2-1-1-1) According to the test method for air content of concrete specified in the Standard for Performance Test Methods of Ordinary Concrete Mixtures GB / T 50080-2016, the mortar content is 12.2%, V q 0.122m 3 .

[0095] 7. According to step 6, the free water pore volume V in formula 2-1-1-1 wk Calculate according to formula 2-1-1-1-1: V wk = (m w - (m cw + m kzw + m fw + m xw )) / ρ w (Formula 2-1-1-1-1) 8. According to step 5, the gel volume V in formula 2-1-1 jn Calculate according to formula 2-1-1-2: V jn = V c +V kz +V f +V x +V bw (Formula 2-1-1-2) 9. According to step 8, formula 2-1-1-2, V c 、V kz、 V f 、V x Calculate according to formula 2-1-1-2-1: V i = m i / ρ i (Formula 2-1-1-2-1) See Table 8, V c 0.061m 3 、V kz is 0, V f 0.046m 3 , V x 0.093m 3 .

[0096] 10. According to step 8, the volume of water V used for hydration of cementitious materials in formula 2-1-1-2 bw Calculate according to formula 2-1-1-2-2: Vbw =(m cw + m kzw + m fw + m xw )• C w / ρ w (Formula 2-1-1-2-2) C w Take 0.73, water density ρ w Take 1000kg / m 3 .

[0097] 11. According to the formula 2-1-1-1-1 in step 7 and the formula 2-1-1-2-2 in step 10, the cement hydration water consumption m cw , kg, calculated according to formula 2-1-1-2-2-1: m cw = m c •β ch •(W0 / B) (Formula 2-1-1-2-2-1) The water-binder ratio of the hydration reaction is 0.24, m c 190kg, β ch Take 1, W0 / B take 0.24, after calculation, m cw is 46kg.

[0098] 12. According to formula 2-1-1-1-1 in step 7 and formula 2-1-1-2-2 in step 10, the water consumption of active admixture hydration m kzw , kg, calculated according to formula 2-1-1-2-2-2: m kzw = m kz •β kzh •(W0 / B) (Formula 2-1-1-2-2-2) No active admixtures are added and are not calculated.

[0099] 13. According to the formula 2-1-1-1-1 in step 7 and the formula 2-1-1-2-2 in step 10, the water consumption of common admixture for hydration m fw , kg, calculated according to formula 2-1-1-2-2-3: m fw = m f •β fh •(W0 / B) (Formula 2-1-1-2-2-3) m f is 102kg, β fh0 Take 0.3, W0 / B take 0.24, after calculation, m fw is 7kg.

[0100] 14. According to step 7 formula 2-1-1-1-1 and step 10 formula 2-1-1-2-2, the water consumption for hydration of tailings solid waste fine powder is m xw , kg, calculated according to formula 2-1-1-2-2-4: m xw = m x •β xh •(W0 / B) (Formula 2-1-1-2-2-4) m x 235kg, m x Take 0.15, W0 / B take 0.24, after calculation, m xw is 8kg.

[0101] After calculation, the volume of water used for hydration V bw =(m cw + m kzw + m fw + m xw )• C w / ρ w = (46+7+8)• 0.73 / 1000=0.045m 3 ; Gel volume V jn = V c +V kz +V f +V x +V bw =0.061 +0+0.046 +0.093 +0.045=0.245m 3 .

[0102] Free water pore volume V wk = (m w - (m cw + m kzw + m fw + m xw )) / ρ w =(273-(46+7+8)) / 1000=0.212m 3 ; Total pore volume V k = V wk + V q =0.212 + 0.122 =0.334m 3 .

[0103] Glue hole ratio φ B / K = V jn / V k = 0.245 / 0.334=0.734; Pure cement stone strengthc0 = A0•φ B / K + B0=30.8 MPa.

[0104] The following steps 15 to 30 are the activity coefficient λ of the adhesive material. c Calculation process.

[0105] 15. According to step 2, the activity coefficient of the rubber material in formula 2 is λ c Calculate according to formula 2-2: λc =η kz •η f •η x (Formula 2-2) 16. According to step 15, the activity coefficient η of the active admixture in formula 2-2 kz Calculate according to formula 2-2-1: η kz = A1•β kz +B1 (Formula 2-2-1) No active admixtures are added and are not calculated.

[0106] 17. According to step 15, the activity coefficient η of common admixture in formula 2-2 f , calculated according to formula 2-2-2: η f = A2•β f + B2 (Formula 2-2-2) A2 is -0.5, B2 is 1.1, after calculation, the fly ash content β f =102 / (190+102+235)=19.4%, substitute into η f =-0.5•β f + 1.1, η f It is 0.81.

[0107] 18. According to step 15, the activity coefficient η of the tailings solid waste fine powder in formula 2-2 x , calculated according to formula 2-2-3: η x = A3•β x + B3 (Formula 2-2-3) A2 is -1.0, B2 is 1.0, and after calculation, the tailings solid waste sand fine powder dosage β x =235 / (190+102+235)=44.6%, substitute into η x = -1.0•β x + 1.0, η x is 0.55.

[0108] After calculation, the activity coefficient of the rubber material λc =η kz •ηf •η x =0.81*0.55=0.45, Mortar preparation strength c = λ c •f c0 =0.45•30.8=13.9MPa.

[0109] The following steps 19 to 30 are the mortar interface coefficient λ s The calculation process: 19. According to step 3, the synovial coefficient λ in formula 3 jg Calculate according to formula 3-1: λ jg = (1+0.3•φ1) / (1+φ1•δ s ) (Formula 3-1) According to the test method specified in GB / T 14684-2022 "Sand for Construction", the crushing value of tailings solid waste sand δ s It is 26.8%, see Table 7.

[0110] 20. According to step 19, formula 3-1, the volume ratio φ1 of sand to slurry is calculated according to formula 3-1-1: φ1 = V s1 / V j1 (Formula 3-1-1) 21. According to step 20, the volume of the tailings solid waste sand V after powder removal in formula 3-1-1 s1 Calculate according to formula 3-1-1-1: V s1 = V s -V x (Formula 3-1-1-1) 22. According to step 20, the volume of slurry V in each cubic meter of solid waste-based cement mortar in formula 3-1-1 j1 , calculated according to formula 3-1-1-2: V j1 = V c + V kz + V f + V x + V w + V a + V q (Formula 3-1-1-2) After calculation, the volume of solid waste sand V s1 =0.493-0.093=0.40m 3 Slurry volume V j1=0.061+0.046+0.093+0.005+0.122+0.273=0.600m 3 ; The volume ratio of sand to slurry is φ1=0.40 / 0.600=0.667; Bone Coefficient λ jg =(1+0.3*0.667) / (1+0.667*26.8%)=1.018.

[0111] 23. According to step 3, the surface coefficient of tailings solid waste sand λ in formula 3 m Calculate according to formula 3-2: λ m = 3.152 / ε s (Formula 3-2) Where: ε s ——surface area index of tailings solid waste sand; 24. According to step 23, the tailings solid waste sand surface area index ε in formula 3-2 s Calculate according to formula 3-2-1: ε s = S s × 10 -9 (Formula 3-2-1) Where: S s ——Estimated total surface area of ​​tailings solid waste sand after sieving with a 0.16 mm square hole sieve, mm 2 .

[0112] 25. According to step 24, the total surface area S of tailings solid waste sand in formula 3-2-1 s Calculate according to formula 3-2-1-1: S s = S s1 + S s2 + S s3 + S s4 + S s5 + S s6 (Formula 3-2-1-1) 26. According to step 25, the total surface area S of a certain particle size of tailings solid waste sand in formula 3-2-1-1 si Calculate according to formula 3-2-1-1-1: S si = N si •S sdi (Formula 3-2-1-1-1) 27. According to step 26, the number of particles N of a certain particle size of tailings solid waste sand in formula 3-2-1-1-1 si Calculate according to formula 3-2-1-1-1-1: N si= V si / V sdi (Formula 3-2-1-1-1-1) Where: V si ——Volume of tailings solid waste sand at a certain particle size, m 3 , when i = 1\2\3\4\5\6, it represents the volume of tailings solid waste sand of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size, m 3. V sdi ——Volume of a single particle of a certain particle size of tailings solid waste sand, m 3 , when i = 1\2\3\4\5\6, it represents the single particle of tailings solid waste sand with particle size of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm, mm 3 The volume can be calculated according to the different shapes and the average particle size of the particle size.

[0113] 28. Calculate the volume V of a particle size fraction of tailings solid waste sand according to formula 3-2-1-1-1-1 in step 27 si Calculate according to formula 3-2-1-1-1-1-1: V si = V s •F si (Formula 3-2-1-1-1-1) Where: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; F si ——The sieve residue of a certain particle size of tailings solid waste sand, %, when i = 1\2\3\4\5\6, it represents the sieve residue of 5.0-10.0mm\2.5-5.0mm\1.25-2.5mm\0.63-1.25mm\0.315-0.63mm\0.16-0.315mm particle size of tailings solid waste sand respectively. It is the test data, which is obtained by referring to the test method specified in "Sand for Construction" GB / T 14684-2022, see Table 7.

[0114] After calculation, the average particle size corresponding to each nominal particle size is divided into the sieve residue F si , divided into volume V si , particle shape, single particle volume Vsdi, particle number N si , single particle surface area Ssdi, total surface area S si See Table 9; Table 9 Statistical table of various indicators corresponding to solid waste sand with different nominal diameters After calculation, the total surface area of ​​tailings solid waste sand is S s =1739119879 mm 2 ; Tailings solid waste sand surface area index ε s is 1.739; Tailings solid waste sand surface coefficient λ m =3.152 / εs=3.152 / 1.739 =1.219.

[0115] 29. According to step 3, the tailings solid waste sand shape coefficient λ in formula 3 L Calculate according to formula 3-3: λ L = 1 / (1+Q h ) (Formula 3-3) The test results were obtained by referring to the method specified in GB / T 14684-2022 "Sand for Construction", as shown in Table 7. The content of flake particles in tailings solid waste sand Q h It is 6.8%.

[0116] After calculation, λ L =1 / (1+6.8%)=0.936.

[0117] 30. According to step 3, the fine powder influence coefficient λ in formula 3 x Calculate according to formula 3-4: λ x = 1.02 / (1+1.1•X s ) (Formula 3-4) According to the test method for stone powder content specified in GB / T 14684-2022 "Sand for Construction", the fine powder content of tailings solid waste sand is X s It is 18.8%.

[0118] After calculation, the fine powder influence coefficient λ x =1.02 / (1+1.1*18.8%)=0.845.

[0119] According to step 3 formula 3, after calculation, the mortar interface coefficient λ s =λ jg •λ m •λ L •λ x =1.018•1.219•0.936•0.845=0.981.

[0120] According to formula 1 in step 1, after calculation, the strength of solid waste-based cement mortar is fb =λ s •f c =0.981•13.9=13.6MPa.

[0121] After the sand is changed from iron tailings solid waste sand to graphite tailings solid waste sand, the measured mortar compressive strength is lower than that of implementation 1. Therefore, in order to ensure the quality of the project, it should be downgraded.

[0122] According to the mortar mix ratio prepared with iron tailings solid waste sand provided in Table 8, the test was carried out with reference to the compressive strength test method of "Standard for Test Methods for Physical and Mechanical Properties of Concrete" GB∕T 50081-2019, and the compressive strength of the mortar specimens after standard curing for 28 days was 13.3MPa.

[0123] Therefore, the prediction deviation of the present invention =|(13.6-13.3)*100% / 13.3|=2.2%<5%, and the prediction accuracy is high. It can effectively predict and control the strength quality problems caused by quality fluctuations due to different sources of tailings solid waste sand, thereby ensuring the quality of the project.

[0124] The above embodiments only illustrate several implementation methods of the present invention, and should not be understood as limiting the scope of the present invention. It should be noted that other persons skilled in the art may make modifications, substitutions, and improvements without departing from the concept and scope of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of the present invention shall be based on the described claims.

Claims

1. A method for predicting the strength of solid waste-based cement mortar for construction based on multivariate factor fitting, characterized in that: The prediction method comprises the following steps: (1) Solid waste-based cement mortar preparation strength f b Calculate according to formula 1: f b = λ s •f c Formula 1; In formula 1: f b ——Preparation strength of solid waste-based cement mortar, MPa; f c ——Strength of cement paste of mixed cementitious materials, MPa; λ s ——Mortar interface coefficient; (2) Cement paste strength f c Calculate according to formula 2: f c = λ c •f c0 Formula 2; In formula 2: f c ——Cement paste strength f c , MPa; f c0 ——Strength of pure cement paste f c0 , MPa; λ c ——Activity coefficient of adhesive material; (3) Mortar interface coefficient λ s Calculate according to formula 3: λ s =λ jg •λ m •λ L •λ x Formula 3; In formula 3: s ——Mortar interface coefficient; λ jg ——Skeleton coefficient; λ m ——sand surface coefficient; λ L ——sand grain shape coefficient; λ x ——Fine powder influence coefficient.

2. The prediction method according to claim 1, characterized in that: f c0 The calculation process includes the following steps: (1) Pure cement paste strength f c0 Calculate according to formula 2-1: f c0 = A0•φ B / K + B0 formula 2-1; In formula 2-1: φ B / K ——hydration gelation and pore volume ratio of cement stone mixed with cementitious material in solid waste-based cement mortar; A0, B0 —— glue pore ratio constant; (2) Step (1) The glue hole ratio φ in formula 2-1 B / K Calculate according to formula 2-1-1: φ B / K = V jn / V k Formula 2-1-1; In formula 2-1-1: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 . V jn ——cementitious volume per cubic meter of solid waste-based cement mortar, m 3 ; (3) Step (2) Total pore volume V in formula 2-1-1 k Calculate according to formula 2-1-1-1: V k = V wk + V q Formula 2-1-1-1; In formula 2-1-1-1: V k ——Total pore volume per cubic meter of solid waste-based cement mortar, m 3 ; V wk ——The pore volume generated by the loss of free water in each cubic meter of solid waste-based cement mortar, m 3 ; V q ——Volume of air entrained in each cubic meter of solid waste-based cement mortar, m 3 ; (4) Step (3) Free water pore volume V in formula 2-1-1-1 wk Calculate according to formula 2-1-1-1-1: V wk = (m w − (m cw + m kzw + m fw + m xw )) / ρ w Formula 2-1-1-1-1; In formula 2-1-1-1-1: m w ——Amount of mixing water in each cubic meter of solid waste-based cement mortar mix, kg; m cw ——Estimated amount of cement hydration reaction water in each cubic meter of solid waste-based cement mortar, kg; m kzw ——The estimated amount of water from the hydration reaction of active admixtures in each cubic meter of solid waste-based cement mortar, kg; m fw ——Estimated amount of water from hydration reaction of common admixtures in each cubic meter of solid waste-based cement mortar, kg; m xw ——The estimated amount of water for hydration reaction of tailings solid waste fine powder in each cubic meter of solid waste-based cement mortar, kg; (5) Step (2) The gel volume V in formula 2-1-1 jn Calculate according to formula 2-1-1-2: V jn = V c +V kz +V f +V x +V bw Formula 2-1-1-2; In formula 2-1-1-2: V jn ——cementitious volume per cubic meter of solid waste-based cement mortar, m 3 ; V c ——Mix ratio of cement per cubic meter of solid waste-based cement mortar, m 3 ; V kz ——Volume of active admixture per cubic meter of solid waste-based cement mortar mix, m 3 ; V f ——Volume of common admixtures per cubic meter of solid waste-based cement mortar mix, m 3 ; V x ——Volume of solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix, m 3 ; V bw ——Estimated volume of water used for hydration of cementitious materials in each cubic meter of solid waste-based cement mortar, m 3 ; (6) Step (5) V in formula 2-1-1-2 c 、V kz、 V f 、V x Calculate according to formula 2-1-1-2-1: V i = m i / ρ i Formula 2-1-1-2-1; In formula 2-1-1-2-1: V i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, m 3 , when i is c, kz, f, x, V i They are the volume of cement, active admixture, common admixture and solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix; m i ——Amount of a certain cementitious material per cubic meter of solid waste-based cement mortar mix, kg, when i is c, kz, f, x, m i They are respectively the amount of cement, the amount of active admixture, the amount of common admixture, and the amount of solid waste tailings fine powder per cubic meter of solid waste-based cement mortar mix, which provide known conditions for the solid waste-based cement mortar mix; ρ i ——Volume of a certain cementitious material per cubic meter of solid waste-based cement mortar, kg / m 3 , when i is c, kz, f, x, V i They are the cement apparent density, active admixture apparent density, common admixture apparent density, and solid waste tailings fine powder apparent density per cubic meter of solid waste-based cement mortar mix; (7) Volume of water V used for hydration of cementitious materials in formula 2-1-1-2 in step (5) bw Calculate according to formula 2-1-1-2-2: V bw = (m cw + m kzw + m fw + m xw ) • C w / ρ w Formula 2-1-1-2-2; In formula 2-1-1-2-2: C w ——After hydration, free water becomes chemical water, and the volume reduction coefficient is 0.73~0.75kg / m 3 , C w Take 0.73; ρ w ——Water density, kg / m 3 . (8) Cement hydration water consumption m in formula 2-1-1-1-1 in step (4) and formula 2-1-1-2-2 in step (7) cw , kg, calculated according to formula 2-1-1-2-2-1: m cw = m c •β ch •(W0 / B) formula 2-1-1-2-2-1; In formula 2-1-1-2-2-1: β ch ——Cement hydration reaction rate coefficient, %, take 0.9~1; W0 / B——water-binder ratio of hydration reaction, take 0.24; (9) The water consumption of active admixture hydration in formula 2-1-1-1-1 in step (4) and formula 2-1-1-2-2 in step (7) is m kzw , kg, calculated according to formula 2-1-1-2-2-2: m kzw = m kz •β kzh •(W0 / B) formula 2-1-1-2-2-2; In formula 2-1-1-2-2-2: β kzh ——Hydration reaction rate coefficient of active admixture, %, take 0.75~0.85; (10) Hydration water consumption of common admixtures in formula 2-1-1-1-1 in step (4) and formula 2-1-1-2-2 in step (7) m fw , kg, calculated according to formula 2-1-1-2-2-3: m fw = m f •β fh •(W0 / B) formula 2-1-1-2-2-3; In formula 2-1-1-2-2-3: β fh ——Common admixture hydration reaction rate coefficient, %, take 0.25~0.35; (11) Water consumption for hydration of tailings solid waste fine powder in formula 2-1-1-1-1 in step (4) and formula 2-1-1-2-2 in step (7) m xw , kg, calculated according to formula 2-1-1-2-2-4: m xw = m x •β xh •(W0 / B) formula 2-1-1-2-2-4; In formula 2-1-1-2-2-4: β xh ——The hydration reaction rate coefficient of tailings solid waste fine powder, %, is taken as 0~0.

2.

3. The prediction method according to claim 1, characterized in that: λ c The calculation process includes the following steps: (1) The activity coefficient λ of the adhesive material in formula 2 of step (2) of claim 1 c Calculate according to formula 2-2: λc = η kz • η f • η x Formula 2-2 In formula 2-2: λ c ——Activity coefficient of adhesive material; η kz ——activity coefficient of active admixture; η f ——activity coefficient of common admixtures; η x ——Activity coefficient of fine powder of tailings solid waste; (2) The activity coefficient η of the active admixture in step (1) formula 2-2 kz Calculate according to formula 2-2-1: η kz = A1•β kz +B1 formula 2-2-1; In formula 2-2-1: A1, B1——active admixture activity coefficient constants; (3) Activity coefficient η of common admixture in step (1) formula 2-2 f , calculated according to formula 2-2-2: η f = A2•β f + B2 official 2-2-2; In formula 2-2-2: A2, B2——activity coefficient constants of common admixtures; (4) Activity coefficient η of tailings solid waste fine powder in formula 2-2 in step (1) x , calculated according to formula 2-2-3: η x = A3•β x + B3 formula 2-2-3; In formula 2-2-3: A3, B3 are the activity coefficient constants of tailings solid waste sand fine powder.

4. The prediction method according to claim 2, characterized in that: In step (5), the active admixture is granulated blast furnace slag powder or silica fume; The common admixture is fly ash.

5. The prediction method according to claim 1, characterized in that: λ s The calculation process includes the following steps: (1) The slurry-bone coefficient λ in formula 3 of step (3) of claim 1 jg Calculate according to formula 3-1: λ jg = (1+0.3•φ1) / (1+φ1•δ s )Formula 3-1; In formula 3-1: jg ——Skeleton coefficient; φ1——Volume ratio of sand to slurry; δ s ——Crushing value of tailings solid waste sand, %; (2) Step (1) The volume ratio φ1 of sand to slurry in Formula 3-1 is calculated according to Formula 3-1-1: φ1 = V s1 / V j1 Formula 3-1-1; In formula 3-1-1: V s1 ——Volume of solid waste sand after de-powdering V s1 , m 3 ; V j1 ——Slurry volume per cubic meter of solid waste-based cement mortar, m 3 ; (3) Volume V of the tailings solid waste sand removed from the powder in step (2) formula 3-1-1 s1 Calculate according to formula 3-1-1-1: V s1 = V s -V x Formula 3-1-1-1; In formula 3-1-1-1: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; V x ——Volume of fine powder in tailings solid waste sand per cubic meter of solid waste-based cement mortar, m 3 ; (4) The slurry volume V per cubic meter of solid waste-based cement mortar in formula 3-1-1 in step (3) j1 , calculated according to formula 3-1-1-2: V j1 = V c + V kz + V f + V x + V w + V a + V q Formula 3-1-1-2; In formula 3-1-1-2: V w It is calculated by dividing the amount of water used for mixing per cubic meter of solid waste-based cement mortar by the density of water, m 3 ; (5) The surface coefficient λ of the tailings solid waste sand in formula 3 of step (3) of claim 1 m Calculate according to formula 3-2: λ m = 3.152 / ε s Formula 3-2; In formula 3-2: ε s ——surface area index of tailings solid waste sand; (6) Tailings solid waste sand surface area index ε in step (5) formula 3-2 s Calculate according to formula 3-2-1: ε s = S s × 10 -9 Formula 3-2-1: In formula 3-2-1: S s ——Estimated total surface area of ​​tailings solid waste sand after sieving with a 0.16 mm square hole sieve, mm 2 ; (7) The total surface area S of the tailings solid waste sand in step (6) formula 3-2-1 s Calculate according to formula 3-2-1-1: S s = S s1 + S s2 + S s3 + S s4 + S s5 + S s6 Formula 3-2-1-1; In formula 3-2-1-1: S s1 ——Estimated total surface area of ​​5.0mm-10.0mm particles in tailings solid waste sand, mm 2 ; S s2 ——Estimated total surface area of ​​2.5mm-5.0mm particles in tailings solid waste sand, mm 2 ; S s3 ——Estimated total surface area of ​​1.25mm-2.5mm particles in tailings solid waste sand, mm 2 ; S s4 ——Estimated total surface area of ​​0.63mm-1.25mm particle size in tailings solid waste sand, mm 2 ; S s5 ——Estimated total surface area of ​​0.315mm-0.63mm particle size in tailings solid waste sand, mm 2 ; S s6 ——Estimated total surface area of ​​0.16mm-0.315mm particle size in tailings solid waste sand, mm 2 ; (8) The total surface area S of a certain particle size of tailings solid waste sand in step (7) formula 3-2-1-1 si Calculate according to formula 3-2-1-1-1: S si = N si •S sdi Formula 3-2-1-1-1; In formula 3-2-1-1-1: S si ——Estimated total surface area of ​​a certain particle size of tailings solid waste sand, mm 2 , when i = 1, 2, 3, 4, 5, and 6, they are the estimated total surface areas of the tailings solid waste sand particle sizes of 5.0mm-10.0mm, 2.5mm-5.0mm, 1.25mm-2.5mm, 0.63mm-1.25mm, 0.315mm-0.63mm, and 0.16mm-0.315mm, respectively; N si ——The number of particles of a certain size of tailings solid waste sand. When i = 1, 2, 3, 4, 5, and 6, it represents the total number of particles of 5.0-10.0mm, 2.5-5.0mm, 1.25-2.5mm, 0.63-1.25mm, 0.315-0.63mm, and 0.16-0.315mm size of tailings solid waste sand respectively; S sdi ——Surface area of ​​a particle of a certain particle size of tailings solid waste sand. When i = 1, 2, 3, 4, 5, 6, it represents the surface area of ​​a single particle of 5.0-10.0mm, 2.5-5.0mm, 1.25-2.5mm, 0.63-1.25mm, 0.315-0.63mm, 0.16-0.315mm particle size, mm 2 ; (9) The number of particles N of a certain particle size of tailings solid waste sand in step (8) formula 3-2-1-1-1 si Calculate according to formula 3-2-1-1-1-1: N si = V si / V sdi Formula 3-2-1-1-1-1; In formula 3-2-1-1-1-1: V si ——Volume of tailings solid waste sand at a certain particle size, m 3 When i = 1, 2, 3, 4, 5, and 6, it represents the volume of tailings solid waste sand of 5.0-10.0 mm, 2.5-5.0 mm, 1.25-2.5 mm, 0.63-1.25 mm, 0.315-0.63 mm, and 0.16-0.315 mm particle sizes, m 3. V sdi ——Volume of a single particle of a certain particle size of tailings solid waste sand, m 3 , when i = 1, 2, 3, 4, 5, 6, it represents the single particles of tailings solid waste sand with particle sizes of 5.0-10.0mm, 2.5-5.0mm, 1.25-2.5mm, 0.63-1.25mm, 0.315-0.63mm, and 0.16-0.315mm, respectively, mm 3 ; (10) The volume V of a particle size fraction of tailings solid waste sand in step (9) of formula 3-2-1-1-1-1 si Calculate according to formula 3-2-1-1-1-1-1: V si = V s •F si Formula 3-2-1-1-1-1; In formula 3-2-1-1-1-1: V s ——Total volume of tailings solid waste sand in each cubic meter of solid waste-based cement mortar, m 3 ; F si ——The sieve residue of a certain particle size of tailings solid waste sand, %, when i = 1, 2, 3, 4, 5, 6, it represents the sieve residue of 5.0-10.0mm, 2.5-5.0mm, 1.25-2.5mm, 0.63-1.25mm, 0.315-0.63mm, 0.16-0.315mm particle size of tailings solid waste sand respectively; (11) The tailings solid waste sand particle shape coefficient λ in formula 3 of step (3) of claim 1 L Calculate according to formula 3-3: λ L = 1 / (1+Q h ) Formula 3-3; In formula 3-3: L ——Sand grain shape coefficient of tailings solid waste; Q h ——The content of flake particles in tailings solid waste sand; (12) The fine powder influence coefficient λ in formula 3 of step (3) of claim 1 x Calculate according to formula 3-4: λ x = 1.02 / (1+1.1•X s ) Formula 3-4; In formula 3-4: x ——fine powder influence coefficient; X s ——Content of fine powder in tailings solid waste sand, %.

6. The prediction method according to any one of claims 1 to 5, characterized in that: The prediction method is used in the field of building construction.

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