CN114702274A

CN114702274A - Design method for self-compacting concrete mix proportion

Info

Publication number: CN114702274A
Application number: CN202210424563.8A
Authority: CN
Inventors: 刘凌晖; 雷明锋; 段炼; 龚琛杰; 甘淑清; 伍江航; 康磊; 施成华
Original assignee: Central South University; China Railway Guangzhou Group Co Ltd
Current assignee: Central South University; China Railway Guangzhou Group Co Ltd
Priority date: 2022-04-21
Filing date: 2022-04-21
Publication date: 2022-07-05
Anticipated expiration: 2042-04-21
Also published as: CN114702274B

Abstract

The invention provides a design method of self-compacting concrete mix proportion, comprising the steps of S1, measuring and/or calculating performance parameters of raw materials; step S2, constructing an excess sand layer model and an excess slurry model, and determining a parameter t by using the excess sand layer model_sSaid t is_sThe thickness of the excessive filling sand layer on the surface of the coarse aggregate is expressed, and the excessive filling sand layer is used for reflecting the rolling effect of the solid phase material under different fine aggregate ratios and realizing the correlation between the volume ratios of the coarse aggregate and the fine aggregate; determining a parameter t using a surplus slurry model_pSaid t is_pThe thickness of the excessive slurry filling layer on the surfaces of the coarse aggregate and the fine aggregate is expressed, and the excessive slurry filling layer is used for reflecting the lubricating effect of the self-compacting concrete under different slurry material ratios and realizing the correlation among the coarse aggregate, the fine aggregate and the slurry volume ratio; and step S3, determining the mixing proportion of the self-compacting concrete. The invention can realize dynamic adjustment of the mix proportion of the self-compacting concrete, thereby being suitable for the raw materials in different regionsMaterial and construction environment change requirements.

Description

Design method for self-compacting concrete mix proportion

Technical Field

The invention relates to the technical field of building materials, in particular to a self-compacting concrete mix proportion design method based on customization of an aggregate surface filling layer.

Background

The self-compacting concrete can be formed by only depending on the self-gravity action without additionally carrying out mechanical vibration and filling the space of the template to form compact and uniform concrete. Self-compacting concrete has excellent filling properties (fluidity), gap-passing properties, and segregation resistance (stability). For the construction parts with dense reinforcing bars, narrow construction space or difficult vibration compaction, the self-compacting concrete is adopted, so that the production efficiency can be effectively improved, and the on-site pouring construction quality can be ensured.

The concept of self-compacting concrete was first proposed by the japanese scholars Okamura in 1986, which established a progressive empirical preparation: firstly, fixing the volume content of sand and stone, then gradually determining a preparation method which meets the rheological property of slurry, mortar and concrete mixture by adjusting the water-cement ratio and the additive content and combining with a test means. With the subsequent popularization of the application scene of the self-compacting concrete, domestic scholars also successively put forward some general self-compacting concrete mix proportion design methods. For example, the Yushiwu and the like provide a modified full-scale calculation method, and a mixing proportion design method of the fixed sand proportion is improved; wuhongjuan proposes a parameter design method, and combines four proportioning parameters of aggregate coefficient, sand pull-out coefficient, admixture coefficient and water-cement ratio to calculate the mixture ratio for the total calculation of sand, stone, slurry and slurry composition; longguang provides an aggregate spacing model based on a visual distance method, and a proper spacing range is given for designing the contents of coarse and fine aggregates and slurry of the self-compacting concrete; the soup and the like provide a preparation method of self-compacting concrete based on most compact stacking trial preparation and stacking compaction degree so as to meet the requirements of fluidity, economic performance and strength of the self-compacting concrete.

However, the domestic area is vast, and the properties of raw materials in all areas have large fluctuation. For the field, the general design method for the mix proportion of the self-compacting concrete has the limitations of huge test amount, large performance fluctuation, and the need of pertinently changing the mix proportion after the construction condition is changed. Therefore, in order to overcome the limitations of the prior art, it is necessary to provide a design method capable of dynamically adjusting the mix proportion of the self-compacting concrete according to the changes of raw materials and construction conditions.

Disclosure of Invention

The invention aims to provide a design method of the mix proportion of self-compacting concrete, which has the following specific technical scheme:

a design method for the mix proportion of self-compacting concrete comprises the following steps:

step S1, measuring and/or calculating the performance parameters of the raw material

The raw materials comprise a solid-phase material and a slurry material, wherein the solid-phase material comprises coarse aggregate and fine aggregate; the slurry material comprises a cementing material, an additive and water; the cementing material comprises cement, fly ash, slag and silica fume; the additive comprises a water reducing agent and a viscosity modifier; the performance parameters comprise the density of the coarse aggregate, the density of the fine aggregate, the grading parameter of the coarse aggregate, the grading parameter of the fine aggregate and the specific surface area s of the coarse aggregate_caSpecific surface area s of fine aggregate_faDensity of cementitious material, density of water ρ_wDensity of admixture rho_adAnd coarseFilling factor PD of aggregate_caThe filling ratio PD of the fine aggregate_faAnd the water reducing rate and the solid content of the water reducing agent;

step S2, constructing an aggregate surface excess filling layer model, and determining the correlation between the excess filling layer parameters and the components of the raw material

The concrete steps of constructing the excess filling layer model of the aggregate surface are constructing an excess sand layer model and an excess slurry model, and determining a parameter t by utilizing the excess sand layer model_sSaid t is_sThe thickness of the excessive filling sand layer on the surface of the coarse aggregate is expressed, and the excessive filling sand layer is used for reflecting the rolling effect of the solid phase material under different fine aggregate ratios and realizing the correlation between the volume ratios of the coarse aggregate and the fine aggregate; determining a parameter t using a surplus slurry model_pSaid t is_pThe thickness of the excessive slurry filling layer on the surfaces of the coarse aggregate and the fine aggregate is expressed, and the excessive slurry filling layer is used for reflecting the lubricating effect of the self-compacting concrete under different slurry material ratios and realizing the correlation among the coarse aggregate, the fine aggregate and the slurry volume ratio;

step S3, determining the mixing proportion of the self-compacting concrete

Firstly, according to the expected performance requirement of the self-compacting concrete, determining the W/B ratio and the P/B ratio in the slurry by using the components and the performance parameters of the slurry material in the step S1, wherein the W/B ratio is the ratio of water to the gelled material, and the P/B ratio is the ratio of the additive to the gelled material;

secondly, selecting t which simultaneously meets the filling performance and the clearance passing performance of the self-compacting concrete_sAnd t_pAnd from t_s、t_pCalculating the W/B ratio and the P/B ratio to obtain the initial mix proportion of the self-compacting concrete;

then, preparing fresh concrete according to the initial mixing proportion, and testing whether the fresh concrete meets the expected performance requirement of the self-compacting concrete; if the requirement of the expected performance is met, the initial mixing proportion is the mixing proportion of the self-compacting concrete; otherwise, adjust t_s、t_pCalculating the W/B ratio or the P/B ratio to obtain the corrected mix proportion of the self-compacting concrete until the fresh concrete prepared according to the corrected mix proportion meets the expected performance requirement, wherein the corrected mix proportion is the self-compacting concreteAnd (4) mixing proportion of soil.

Further, in step S3, the reinforcement clearance of the self-compacting concrete is 32.9-52.9mm, wherein t is_sThe value range of (a) is 0-4.0mm, t_pThe value range of (A) is 0-0.16 mm.

Further, in step S1, the density of the coarse aggregate includes an apparent density ρ of the coarse aggregate_caAnd bulk density of coarse aggregate ρ'_ca；

The density of the fine aggregate includes an apparent density ρ of the fine aggregate_faAnd bulk density of fine aggregate ρ'_fa；

The grading parameter of the coarse aggregate is 5mm-16 mm; the grading parameter of the fine aggregate is 0.075mm-5 mm;

the density of the cementing material is the apparent density of the cementing material, which comprises the apparent density rho of cement_ceApparent density of fly ash rho_flaApparent density of slag ρ_slagAnd apparent density ρ of silica fume_si；

Density rho of the admixture_adThe density of the mixed liquid of the water reducing agent and the viscosity modifier.

Further, the step S2 includes the following processes:

s2.1, constructing an excess sand layer model

The excess sand layer model is specifically constructed by a solid-phase material stack body composed of coarse aggregate and fine aggregate;

in the excess sand model:

the fine aggregate comprises an excess filling sand layer and a filling sand body, the excess filling sand layer is an excess sand layer formed on the surface of the coarse aggregate by the fine aggregate, and the thickness of the excess filling sand layer is a parameter t_s(ii) a The filling sand body is filling sand filled in gaps of the coarse aggregate framework by fine aggregates;

calculating the ratio d of the absolute volume of the fine aggregate to the absolute volume of the solid phase material by the expressions (S2.1-1) to (S2.1-6)_fa：

In the expression (S2.1-1), V_ca-solidThe absolute stacking volume of the coarse aggregate in the solid-phase material mixed stacking body is used; v_fa-solidAbsolute stacking volume of fine aggregate in the solid-phase material mixed stacking body;

calculating V by expression (S2.1-2)_ca-solid：

V_ca-solid＝U_ca·PD_ca (S2.1-2)

In the expression (S2.1-2), U_caIs the coarse aggregate bulk;

U_ca＝U_a·λ_ca (S2.1-3)

in the expression (S2.1-3), U_aIs the volume of the solid phase material stack; lambda [ alpha ]_caThe proportion of the stacking volume of the coarse aggregate in the total volume of the solid-phase material stacking body is;

calculating V by expression (S2.1-5)_fa-solid：

V_fa-solid＝PD_fa·U_fa(S2.1-5)

In the expression (S2.1-5), U_faIs the bulk of the fine aggregate;

U_fa＝U_FI-fa+U_EF-fa＝U_a·λ_ca·P_void-ca+t_s·V_ca-soild·s_ca (S2.1-6)

in the expression (S2.1-6), U_FI-faFilling the sand accumulation volume; u shape_EF-faFilling the accumulation volume of the sand layer for surplus; p_void-caIs the void fraction of coarse aggregate, and P_void-ca＝1-PD_ca；

D is established by expressions (S2.1-1) - (S2.1-6)_faAnd t_sFurther calculating the filling ratio PD of the mixed stacked body of coarse aggregate and fine aggregate_tol；

Step S2.2, constructing excess slurry model

The surplus slurry model is a concrete mixture, and is specifically constructed by a stacking body composed of coarse aggregate, fine aggregate and slurry materials;

in the excess slurry model, the absolute volume V of coarse aggregate in the concrete mixture is calculated by the expressions (S2.2-1) to (S2.2-2)_caAnd the absolute volume V of the fine aggregate_fa：

V_fa＝λ_tol·V_t·PD_tol·d_fa (S2.2-1)

V_ca＝λ_tol·V_t·PD_tol·(1-d_fa) (S2.2-2)

In the expressions (S2.2-1) and (S2.2-2), λ_tolIs the proportion of the volume of the solid phase material stacking body in the total volume of the concrete mixture; v_tIs the total volume of the concrete mixture;

calculating lambda by the expression (S2.2-3)_tol：

Further, in step S3, t satisfying both the self-compacting concrete filling performance and the clearance passing performance is selected_sAnd t_pSet V to_tIs 1m³Calculating the powder coefficient ρ per unit volume by the expressions (S3-1) to (S3-9)_lpAnd the mass of each component in the concrete mixture object to determine the mixing proportion of the self-compacting concrete:

m_b＝(V_lp-V_air)·ρ_lp (S3-2)

m_ce＝m_b·β_ce (S3-3)

m_fla＝m_b·β_fla (S3-4)

m_slag＝m_b·β_slag (S3-5)

m_si＝m_b·β_si (S3-6)

m_w＝m_b·W/B (S3-7)

m_fa＝V_fa·ρ_fa (S3-8)

m_ca＝V_ca·ρ_ca (S3-9)

in expressions (S3-1) - (S3-9), m_bIs the mass of the gelled material; m is_ceThe mass of the cement; m is_flaIs the mass of the fly ash; m is_slagThe quality of the slag; m is a unit of_siThe mass of the silica fume; m is_wIs the mass of water; m is_faThe mass of the fine aggregate; m is_caThe mass of the coarse aggregate; v_airThe air content of the concrete mixing object is measured; v_lpThe volume of slurry in the concrete mixture is measured;

v in expression (S3-2)_lpCalculated by expressions (S3-10) - (S3-12):

V_lp＝V_EF-lp+V_FI-lp (S3-10)

V_FI-lp＝λ_tol·V_t·(1-PD_tol) (S3-11)

V_EF-lp＝λ_tol·V_t·[PD_tol·d_fa·s_fa·t_p+PD_tol·(1-d_fa)·s_ca·t_p] (S3-12)

in the expressions (S3-10) - (S3-12), V_EF-lpThe volume of the surplus slurry on the surface of the solid-phase material in the concrete mixture is determined; v_FI-lpThe solid phase material voids are filled with the slurry volume.

Further, in step S3, the value range of the W/B ratio is calculated by expressions (S3-13) - (S3-16):

f_cu,0≥1.15f_cu,k (S3-15)

f_cu,0≤f_cu-low＜f_cu-up (S3-16)

in the expressions (S3-13) - (S3-16), f_cu,kThe standard value of the compressive strength of the self-compacting concrete is obtained; f. of_cu,0The average control value of the laboratory standard cube compressive strength test is that the self-compacting concrete meets the 95% strength guarantee rate; f. of_cu-lowIs f_cu,0A lower limit strength estimate of; f. of_cu-upIs f_cu,0An upper limit strength estimated value of (1); f. of_ce,gThe grade strength of the cement; k is a radical of formula₁And k₂Are all empirical constants; alpha is alpha_aAnd alpha_bAre all regression coefficients; alpha is alpha_flaIs the coefficient of the cementing material of the fly ash; alpha is alpha_slagIs the cementitious material coefficient of the slag; gamma ray_flaIs the influence coefficient of the fly ash; gamma ray_slagThe influence coefficient of the slag; gamma ray_siThe influence experience coefficient of the silica fume is used; gamma ray_ceThe cement strength surplus coefficient; beta is a_ceThe mass ratio of the cement in the cementing material is shown; beta is a_flaThe mass ratio of the fly ash in the cementing material is shown; beta is a beta_slagThe mass ratio of the slag in the cementing material is; beta is a_siThe mass ratio of the silica fume in the gelled material is shown as follows;

and after the W/B ratio is determined, determining the P/B ratio by a visual method according to the viscosity test result of the slurry.

Further, in step S2.1, the grading parameter of the coarse aggregate includes a first particle size interval and a second particle size interval, wherein the first particle size interval is 10-16mm, and the second particle size interval is 5-10 mm; grading parameters of the fine aggregate comprise a third particle size interval, wherein the third particle size interval is 0.075mm-5 mm; the PD_tolCalculated by expressions (S2.2-7) - (S2.2-14):

PD_tol＝Φ_agg (S2.2-7)

y₁＝0.6(1-d_fa) (S2.2-12)

y₂＝0.4(1-d_fa) (S2.2-13)

y₃＝d_fa (S2.2-14)

in the expressions (S2.2-7) to (S2.2-14), Φ_aggActual filling rate of the solid phase material mixed accumulation body; k is a framework compaction coefficient; y is₁The volume ratio of the coarse aggregate in the first particle size interval in the solid-phase material mixed accumulation body is shown; y is₂The volume ratio of the coarse aggregate in the second particle size interval in the solid-phase material mixed accumulation body is shown; y is₃The volume ratio of the fine aggregate in the third particle size interval in the solid-phase material mixed accumulation body is; beta is a₁The virtual filling rate of the coarse aggregate in the first particle size interval is shown; beta is a₂The virtual filling rate of the coarse aggregate in the second particle size interval is obtained; beta is a₃The virtual filling rate of the fine aggregate in the third particle size interval is obtained; gamma ray₁The virtual filling rate is the virtual filling rate when the coarse aggregate in the first particle size interval occupies the space dominance; gamma ray₂The virtual filling rate is the virtual filling rate when the coarse aggregate in the second particle size interval occupies the space dominance; gamma ray₃The virtual filling rate is the virtual filling rate when the fine aggregate in the third particle size interval occupies the space domination; alpha₁₂The loosening effect coefficient between the first particle size interval and the second particle size interval; alpha₁₃The loosening effect coefficient between the first particle size interval and the third particle size interval is obtained; alpha₂₃Is the second particle size interval and the third particleThe loosening effect coefficient between the radial intervals; b₂₁Is the wall effect coefficient between the second particle size interval and the first particle size interval; b is a mixture of₃₁Is the wall effect coefficient between the third particle size interval and the first particle size interval; b₃₂Is the wall effect coefficient between the third particle size interval and the second particle size interval.

The technical scheme of the invention at least has the following beneficial effects:

the design method of the self-compacting concrete mixing proportion provided by the invention determines the performance parameters of the raw materials, and solid phase components and slurry components in the raw materials through the step S1; the excess sand layer model and the excess slurry model are constructed through step S2, and the parameter t is determined using the excess sand layer model_sThrough t_sRealizing the correlation between the volume proportion of the coarse aggregate and the fine aggregate; determining a parameter t using a surplus slurry model_pThrough t_pRealizing the correlation among the volume proportions of coarse aggregate, fine aggregate and slurry; when the self-compacting concrete mix ratio is determined in step S3, t is used_sQuantifying the rolling effect of fine aggregate on coarse aggregate, using t_pThe filling effect of the slurry on the solid-phase material is quantified, and the W/B ratio and the P/B ratio in the slurry are combined to realize dynamic adjustment of the mix proportion of the self-compacting concrete, so that the requirements on raw materials in different regions and the change of construction environment are met. In addition, the invention adopts the W/B ratio determined by the expressions (S3-13) - (S3-16) and the P/B ratio determined by a visual method to properly control the slurry viscosity, can obtain better proportioning stability of the newly mixed concrete and effectively reduce the segregation phenomenon.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic flow chart of a design method of a self-compacting concrete mix proportion in example 1 of the present invention;

FIG. 2 is a schematic view of a model of an excess sand layer in example 1 of the present invention;

FIG. 3 is a schematic illustration of the compaction of the excess sand layer on the surface of the coarse aggregate of FIG. 2;

FIG. 4 is a schematic view of a surplus slurry model in example 1 of the present invention;

FIG. 5 is a schematic illustration of excess slurry layer compaction of the surface of coarse and fine aggregates in FIG. 4;

FIG. 6 is a combination graph of a filling performance attainment curve and a clearance passage capability curve in example 1 of the present invention;

the mortar comprises A1, coarse aggregate, A2, fine aggregate, A3, an excess filling sand layer, A4, a filling sand body, A5, a slurry material, A6, an excess slurry filling layer and A7 filling slurry.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

Example 1:

a production line is newly introduced into a certain prefabricating yard, local broken stones, river sand, powder and the like are planned to be adopted to prepare self-compacting C60 concrete prefabricated parts, and because local raw materials have great difference and the reinforcement arrangement conditions of different prefabricated parts are inconsistent, the original self-compacting concrete mix proportion in a factory cannot be directly used, so that the self-compacting concrete mix proportion is required to be adapted to the requirements of the local raw materials and the parts and is adjusted.

Example 1 provides a method of designing a mix ratio of self-compacting concrete for the above case.

Referring to fig. 1, the design method of the self-compacting concrete mix proportion comprises the following steps:

step S1, determining and/or calculating the property parameters of the raw material

The raw material bagThe method comprises the following steps of (1) preparing a solid-phase material and a slurry material, wherein the solid-phase material comprises coarse aggregate and fine aggregate; the slurry material comprises a cementing material, an additive and water; the cementing material comprises cement, fly ash, slag and silica fume; the additive comprises a water reducing agent and a viscosity modifier; the performance parameters comprise the density of the coarse aggregate, the density of the fine aggregate, the grading parameter of the coarse aggregate, the grading parameter of the fine aggregate and the specific surface area s of the coarse aggregate_caSpecific surface area s of fine aggregate_faDensity of cementitious material, density of water ρ_wDensity of admixture rho_adThe filling ratio PD of the coarse aggregate_caThe filling ratio PD of the fine aggregate_faAnd the water reducing rate and the solid content of the water reducing agent;

step S3, determining the mixing proportion of the self-compacting concrete

Firstly, according to the expected performance requirements (specifically including an expected strength value and a target viscosity value) of the self-compacting concrete, determining the W/B ratio and the P/B ratio in the slurry by using the components and the performance parameters of the slurry material in the step S1 to determine the viscosity of the slurry, wherein the W/B ratio is the ratio of water to the gelled material, and the P/B ratio is the ratio of the additive to the gelled material;

then, preparing fresh concrete according to the initial mixing proportion, and testing whether the working performance test of the fresh concrete meets the expected performance requirement of the self-compacting concrete; if the requirement of the expected performance is met, the initial mixing proportion is the mixing proportion of the self-compacting concrete; otherwise, adjust t_s、t_pAnd calculating the W/B ratio or the P/B ratio to obtain the corrected mix proportion of the self-compacting concrete until the fresh concrete prepared according to the corrected mix proportion meets the expected performance requirement, wherein the corrected mix proportion is the mix proportion of the self-compacting concrete.

In step S3, the reinforcement clearance of the self-compacting concrete is 37.9-52.9mm, wherein t is_sHas a value range of 0-4.0mm, t_pThe value range of (A) is 0-0.16 mm.

In step S1, the density of the coarse aggregate includes an apparent density ρ of the coarse aggregate_caAnd bulk density of coarse aggregate ρ'_ca；

The step S1 includes the following processes:

and S1.1, testing the apparent density of the raw material by adopting a liquid discharge method and a pycnometer method. The raw materials were labeled and apparent densities were as follows (mineral admixtures only used fly ash and silica fume):

of coarse aggregates (of basalt macadam in situ)Apparent density ρ_ca＝2680kg/m³(ii) a Apparent density ρ of fine aggregate (local river sand)_fa＝2600kg/m³(ii) a Apparent density ρ of cement (specifically 52.5R cement)_ce＝3100kg/m³(ii) a Apparent density rho of fly ash (particularly I-class fly ash)_fla＝2400kg/m³(ii) a Apparent density ρ of silica fume (specifically, S95 silica fume)_si＝2330kg/m³Density of admixture is rho_ad＝1080kg/m³(ii) a Apparent density of slag ρ_slag＝2800kg/m³。

Step S1.2, calculating the filling rate PD of the coarse aggregate_ca

The self-compacting concrete is prepared by adopting coarse aggregate with grading parameters of 5-16 mm, and comprises a first particle size interval and a second particle size interval, wherein the first particle size interval is 10-16mm, and the second particle size interval is 5-10 mm. Adopting a bulk density testing barrel to fill and test the weight of the coarse aggregate in a first particle size interval in loose packing after filling the container: w_{ca_10-16}15.571kg, the weight of the loose-packed coarse aggregate in the second particle size interval after filling the container was tested using a bulk density testing bucket: w_{ca_5-10}15.490 kg. Bulk volume Vol of bulk density test bucket used_C10L, then the corresponding bulk density can be calculated respectively:

initial filling rate alpha of first particle size interval₁And an initial filling factor alpha of the second particle size region₂Respectively adopting the following expressions to calculate:

step S1.2.1, adopting double-parameter CPM model pair of interactive correction₁And alpha₂Carrying out analysis calculation to determine the coarse aggregate collocation of the first particle size interval and the second particle size interval:

firstly, adopting a dual-parameter CPM model to perform mixing filling rate trial calculation and coarse aggregate grading optimization, and respectively solving the virtual filling rate of a coarse aggregate accumulation body in a first particle size interval and a second particle size interval by adopting the following formula:

in the formula, i' is the mark number of the particle size interval, and 1 and 2 are taken; when i' is 1, a first particle size interval is represented; when i' is 2, the second particle size interval is represented; k is the framework compaction coefficient, and K is 4.1 under the condition of loose packing.

From this, it is found that in a loosely packed state, β₁Is 0.723, beta₂Is 0.719.

Step S1.2.2, define s ═ D₂/D₁Wherein D is₁The average grain size of the first grain size interval is 13 mm; d₂The average grain diameter of the second grain diameter interval is 7.5 mm;

calculating a loosening effect coefficient alpha between the first particle size interval and the second particle size interval by the following formula₁₂：

a₁₂＝1-(1-s)^5.0-1.9·s·(1-s)^3.1＝0.9103

The wall effect coefficient b between the second particle size interval and the first particle size interval was calculated by the following formula₂₁：

b₂₁＝1-(1-s)^1.9-2.1·s·(1-s)^10.5-0.2·(1-s)^7.6＝0.8045

S1.2.3, if only the coarse aggregate is considered, the ratio of the absolute volume of the coarse aggregate in the first particle size interval and the second particle size interval in the total volume of the coarse aggregate is h₁And h₂. The volume ratio y of the coarse aggregate in the second particle size interval in the solid phase material mixed accumulation body₂＝h₂The volume ratio y of the coarse aggregate in the first particle size range in the solid-phase material mixed accumulation body₁＝h₁Then, the virtual filling rate γ after the coarse aggregates in the first particle size interval and the second particle size interval are mixed and stacked can be calculated:

γ＝Minimum(γ₁,γ₂)

the final dummy fill ratio γ is taken as γ₁And gamma₂Minimum value of (1).

Actual filling factor phi of coarse aggregate mixture_CACalculated by the following formula:

the calculation results obtained by the steps S1.2.1-S1.2.3 are shown in Table 1:

TABLE 1 CPM model with different coarse aggregate ratios of gamma and phi_CAPredicted value of (2)

y₂	0	0.1	0.2	0.3	0.4	0.5	0.6	0.7
									γ	0.723	0.729	0.735	0.742	0.745	0.741	0.736	0.732
Φ_CA	0.581	0.586	0.591	0.595	0.596	0.596	0.595	0.592

As can be seen from Table 1, h₂When the filling rate is 0.4, the virtual filling rate γ is the maximum, and the coarse aggregate is matched according to the maximum virtual filling rate γ, and the corresponding filling rate PD of the coarse aggregate_ca(i.e., the filling ratio of the coarse aggregate mixture in the first particle size interval and the second particle size interval) and phi_CAThe same applies to all the cases, 0.596, the void ratio P of the coarse aggregate deposit at this time_void-caIs 0.404.

Step S1.3, calculating the filling rate PD of the fine aggregate_faAnd grading index q

A third particle size range (corresponding to an average particle size D) in which the fine aggregate has a grading parameter of 0.075mm to 5mm₃1.8mm), the bulk density ρ 'of the fine aggregate under loose-packing was measured by filling with a bulk density measuring barrel'_faAnd a filling ratio PD_fa：

Further, obtaining the grading of fine aggregate, referring to the Specification "Sand for construction" (GB/T14684-2011), dividing the fine aggregate with the nominal diameter of 0.075mm-5mm into 6 sections by using a circular sieve mesh sieve, specifically, a third grain diameter section is 0.075mm-0.16mm, a third grain diameter section is 0.16mm-0.315mm, a third grain diameter section is 0.315mm-0.63mm, a third grain diameter section is 0.63mm-1.25mm, a fifth grain diameter section is 1.25mm-2.5mm and a sixth grain diameter section is 2.5mm-5mm, weighing and calculating the accumulated screen residue rate p of each section_i7.33%, 16.84%, 29.76%, 46.74%, 69.58% and 100% respectively, and the cumulative screen residue p of each particle size interval of the fine aggregate is characterized by a Funk-Dinger formula_i：

In the formula: i is the mark number of the particle size interval for screening the fine aggregate, and 1, 2, 3, 4, 5 and 6 are taken; when i is 1, a third particle size interval is represented; when i is 2, the third particle size interval is represented; when i is 3, a third particle size interval is represented; when i is 4, a third four-particle size interval is represented; when i is 5, a third particle size interval is represented; when i is 6, a third six-particle size interval is represented; d_i'is a mesh diameter in each particle size interval of the sieved fine aggregate, D'₁-D′₆Respectively 0.16mm, 0.315mm, 0.63mm, 1.25mm, 2.5mm, 5mm, D_minThe lower limit of the particle size interval of the fine aggregate is 0.075 mm; d_maxThe upper limit of the particle size interval of the fine aggregate is 5 mm; q is a grading index.

D'_iAnd corresponding p_iAnd forming a data set by the data, and carrying out nonlinear fitting on the data set by using a least square method and a Funk-Dinger formula to obtain a grading index q.

Step S1.4, calculating the specific surface area S of the coarse aggregate_caAnd specific surface area s of fine aggregate_fa

For coarse aggregate, 100 pieces of characteristic form crushed stones are screened, the coarse aggregate is placed on white paper according to the modes of front projection, top projection and side projection to carry out outline tracing, the projection length L, the projection width B and the projection thickness T of each outline are measured by a ruler, and 100 groups of experimental data are tested. Calculating the average value of the corresponding projection size proportionality coefficients by using the following formula:

wherein m is an average proportionality coefficient of the projection width B and the projection thickness T; n is the average proportionality coefficient of the projection length L and the projection width B.

Further, the projection magnification coefficient d of the coarse aggregate is calculated by m and n_p：

Therefore, the specific surface area of the coarse aggregate can be obtained by solving by a discrete method:

in the above formula, f is a shape area coefficient; h is_iˊThe proportion of the absolute volume of the coarse aggregate in the particle size interval i' in the total volume of the coarse aggregate is shown; k is the shape volume coefficient; d_iˊIs the average particle size of the coarse aggregate particle size interval i'.

For the fine aggregate, the roundness of the local river sand is good, the local river sand is approximately regarded as spherical, the projection size proportionality coefficients are all set to be 1, projection amplification is not needed, meanwhile, the ratio f/k of the shape area coefficient and the shape volume coefficient of the fine aggregate is 6.0, and the specific surface area of the fine aggregate can be calculated by adopting a continuous method.

In the above formula, dp_iCumulative percent screen function p for fine aggregate_iDifferentiation of (2).

The step S2 includes the following processes:

s2.1, constructing an excess sand layer model

Referring to fig. 2-3, the excess sand layer model is specifically constructed by a solid phase material stack composed of coarse aggregate and fine aggregate;

in the excess sand model:

the fine aggregate comprises an excess filling sand layer A3 and a filling sand body A4, the excess filling sand layer is an excess sand layer formed on the surface of the coarse aggregate A1 by the fine aggregate A2, and the thickness of the excess filling sand layer is a parameter t_s(ii) a The filling sand body is filling sand with fine aggregate filled in gaps of a coarse aggregate framework;

calculating V by expression (S2.1-2)_ca-solid：

V_ca-solid＝U_ca·PD_ca (S2.1-2)

In the expression (S2.1-2), U_caIs the coarse aggregate bulk;

U_ca＝U_a·λ_ca (S2.1-3)

calculating V by expression (S2.1-5)_fa-solid：

V_fa-solid＝PD_fa·U_fa (S2.1-5)

In the expression (S2.1-5), U_faIs the bulk of the fine aggregate;

U_fa＝U_FI-fa+U_EF-fa＝U_a·λ_ca·P_void-ca+t_s·V_ca-soild·s_ca (S2.1-6)

in the expression (S2.1-6), U_FI-faFilling the sand accumulation volume; u shape_EF-faFor excess packed sand layer bulk, see fig. 3; p_void-caIs the void fraction of coarse aggregate, and P_void-ca＝1-PD_ca；

Step S2.2, constructing excess slurry model

Referring to fig. 4-5, the excess slurry model is a concrete mixture, and is specifically constructed by a pile body composed of coarse aggregate a1, fine aggregate a2 and slurry material a 5; the slurry material A5 comprises a surplus slurry filling layer A6 and a filling slurry A7, wherein the surplus slurry filling layer A6 is formed on the surfaces of coarse aggregate and fine aggregate; the filler slurry a7 is formed at the voids of the solid phase material, i.e., at the voids between the coarse aggregate and the fine aggregate.

In the excess slurry model, the absolute volume V of the coarse aggregate in the concrete mixture is calculated by expressions (S2.2-1) - (S2.2-2)_caAnd the absolute volume V of the fine aggregate_fa：

V_fa＝λ_tol·V_t·PD_tol·d_fa (S2.2-1)

V_ca＝λ_tol·V_t·PD_tol·(1-d_fa) (S2.2-2)

calculating lambda by expression (S2.2-3)_tol：

In step S3, t satisfying both the self-compacting concrete filling performance and the clearance passing performance is selected_sAnd t_pSetting V_tIs 1m³Calculating the powder coefficient ρ per unit volume by the expressions (S3-1) to (S3-9)_lpAnd the mass of each component in the concrete mixture object to determine the mixing proportion of the self-compacting concrete:

m_b＝(V_lp-V_air)·ρ_lp (S3-2)

m_ce＝m_b·β_ce (S3-3)

m_fla＝m_b·β_fla (S3-4)

m_slag＝m_b·β_slag (S3-5)

m_si＝m_b·β_si (S3-6)

m_w＝m_b·W/B (S3-7)

m_fa＝V_fa·ρ_fa (S3-8)

m_ca＝V_ca·ρ_ca (S3-9)

in expressions (S3-1) to (S3-9), m_bIs the mass of the gelled material; m is_ceThe mass of the cement; m is_flaIs the mass of the fly ash; m is_slagThe quality of the slag; m is_siThe mass of the silica fume; m is_wIs the mass of water; m is a unit of_faThe mass of the fine aggregate; m is_caThe mass of the coarse aggregate; v_airThe gas content of the concrete mixing object is 2%; v_lpThe volume of slurry in the concrete mixture is measured;

v in expression (S3-2)_lpCalculated by expressions (S3-10) - (S3-12):

V_lp＝V_EF-lp+V_FI-lp (S3-10)

V_FI-lp＝λ_tol·V_t·(1-PD_tol) (S3-11)

in the expressions (S3-10) - (S3-12), V_EF-lpThe volume of the surplus slurry on the surface of the solid-phase material in the concrete mixture is determined; v_FI-lpThe solid phase material voids are filled with the slurry volume, see fig. 5.

In step S3, the value range of the W/B ratio is calculated by expressions (S3-13) - (S3-16):

f_cu,0≥1.15f_cu,k (S3-15)

f_cu,0≤f_cu-low＜f_cu-up (S3-16)

in the expressions (S3-13) - (S3-16), f_cu,kFor the standard value of compressive strength of self-compacting concrete, in example 1 f_cu,kThe self-compacting concrete is self-compacting C60 concrete, and the value of the self-compacting concrete is 60 MPa; f. of_cu,0The average control value of the laboratory standard cube compressive strength test which meets the 95% strength guarantee rate for the self-compacting concrete; f. of_cu-lowIs f_cu,0A lower limit strength estimate of; f. of_cu-upIs f_cu,0An upper limit strength estimated value of (1); f. of_ce,gThe grade strength of the cement is 52.5MPa, and the concrete adopted is 52.5 cement; k is a radical of₁And k₂Are empirical constants, in the order of 0.42 and-1.2; alpha is alpha_aAnd alpha_bAll are regression coefficients, 0.53 and 0.20 are taken respectively; alpha is alpha_flaIs the cementing material coefficient of the fly ash, and alpha is alpha for I or II grade fly ash (the mixing amount is not more than 30 percent)_flaTaking 0.4; alpha is alpha_slagAlpha is the binding material coefficient of the slag (particularly the granulated blast furnace slag), and alpha is the content of S95 and above grade slag (the content is not more than 40 percent)_slagTaking 0.9; gamma ray_flaThe influence coefficient of the fly ash is selected by referring to table 5.1.3 in JGJ55-2011 common concrete mix proportion design rule, wherein gamma is_flaThe value is 0.75; gamma ray_slagFor the influence coefficient of slag, the slag is selected by referring to table 5.1.3 in JGJ55-2011 common concrete mix proportion design rule, wherein gamma is_slagThe value is 1; gamma ray_siThe influence experience coefficient of the silica fume is used; gamma ray_ceFor the cement strength surplus coefficient, the concrete is selected by referring to table 5.1.4 in JGJ55-2011 design rule of common concrete mix proportion, and when 52.5 cement is adopted, gamma is selected_ceIs 1.10; beta is a beta_ceThe mass ratio of the cement in the cementing material is shown;β_flathe mass ratio of the fly ash in the cementing material is shown; beta is a_slagThe mass ratio of the slag in the cementing material is shown; beta is a_siIs the mass ratio of silica fume in the cementing material, wherein, when beta is_siAt 10%, γ_siIs 1.2; when beta is_siWhen 0, γ_siIs 1.0; when beta is_siWhen the content is in the range of 0 to 10%, gamma_siDetermining a value by interpolation;

In summary, the W/B ratio ranges and corresponding f are determined by the expressions (S3-13) - (S3-16)_cu-lowAnd f_cu-upSee table 2 for specific results.

TABLE 2

W/B ratio	0.33	0.34	0.35	0.36	0.37
						f_cu-low(MPa)	73.83	71.62	69.53	67.56	65.69
f_cu-up(MPa)	81.21	78.66	76.24	73.97	71.81

Determining f according to expressions (S3-15) - (S3-16)_cu-low69.53MPa, and the W/B ratio is 0.35.

The admixture is prepared by adopting a mixed solution of 98 wt% of a medium cross-linked CP-J polycarboxylic acid water reducing agent (the water reducing rate is 40%, the solid content is 50% and 2 wt% of a viscosity modifier (in particular, Basff REHOPLUS 420), and the density rho of the admixture_ad＝1080kg/m³. In order to control the viscosity of the slurry, firstly adding an additive accounting for 0.5 percent of the weight of the powder, then adding a cementing material and water according to the empirical proportion, adjusting the adding amount of the additive by a dropper, and determining the optimal value of the P/B ratio to be 0.60 percent by slurry viscosity test and a visual method. If the P/B ratio exceeds 0.60%, the viscosity of the slurry is too low, obvious water and powder layering phenomena occur, and configuration cannot be carried out.

In step S2.1, the grading parameters of the coarse aggregate include a first particle size interval and a second particle size interval, wherein the first particle size interval is 10-16mm, and the second particle size interval is 5-10 mm; grading parameters of the fine aggregate comprise a third particle size interval, wherein the third particle size interval is 0.075mm-5 mm; the PD_tolCalculated by expressions (S2.2-7) - (S2.2-14):

PD_tol＝Φ_agg (S2.2-7)

y₁＝0.6(1-d_fa) (S2.2-12)

y₂＝0.4(1-d_fa) (S2.2-13)

y₃＝d_fa (S2.2-14)

in the expressions (S2.2-7) to (S2.2-14), Φ_aggActual filling rate of the solid phase material mixed accumulation body; k is a framework compaction coefficient; y is₁The volume ratio of the coarse aggregate in the first particle size interval in the solid-phase material mixed accumulation body is shown; y is₂The volume ratio of the coarse aggregate in the second particle size interval in the solid-phase material mixed accumulation body is determined; y is₃The volume ratio of the fine aggregate in the third particle size interval in the solid-phase material mixed accumulation body is; beta is a₁The virtual filling rate of the coarse aggregate in the first particle size interval is obtained; beta is a₂The virtual filling rate of the coarse aggregate in the second particle size interval is shown; beta is a₃The virtual filling rate of the fine aggregate in the third particle size interval is shown; gamma ray₁The virtual filling rate is the virtual filling rate when the coarse aggregate in the first particle size interval occupies the space dominance; gamma ray₂The virtual filling rate is the virtual filling rate when the coarse aggregate in the second particle size interval occupies the space dominance; gamma ray₃The virtual filling rate is the virtual filling rate when the fine aggregate in the third particle size interval occupies the space dominance; alpha₁₂The loosening effect coefficient between the first particle size interval and the second particle size interval is 0.9103; alpha₁₃The loosening effect coefficient between the first particle size interval and the third particle size interval is 0.3596; alpha₂₃The loosening effect coefficient between the second particle size interval and the third particle size interval is 0.5517; b is a mixture of₂₁The wall effect coefficient between the second particle size interval and the first particle size interval is 0.8045; b₃₁The wall effect coefficient between the third particle size interval and the first particle size interval is 0.1214; b₃₂Is the third particle size regionThe wall effect coefficient between the interval of the second and third particle sizes is 0.3532.

In this embodiment 1, a step S3 is adopted to determine a mix ratio of self-compacting concrete for different steel bar clear distances, where the different steel bar clear distances are specifically (1) the steel bar clear distance is 37.9 mm; (2) the clear distance of the steel bars is 42.9 mm; (3) the clear distance between the steel bars is 52.9 mm.

In step S3, the procedure for determining the mix ratio of the self-compacting concrete at each steel bar clearance is as follows:

first, the initial mix ratio of the self-compacting C60 concrete was calculated

According to the determined W/B ratio and P/B ratio, t which simultaneously meets the self-compacting C60 concrete filling performance and the clearance passing performance is selected_sAnd t_pFrom t_s、t_pThe initial mix proportion of the self-compacting C60 concrete is calculated by the expressions (S3-1) to (S3-12), and the specific results are shown in Table 3.

TABLE 3 self-compacting C60 concrete Unit volume (V)_tIs 1m³) Initial mix ratio of

According to the initial mix proportion obtained in the table 3, self-compacting C60 concrete under different construction requirements is prepared, and working performance tests (slump flow expansion and J-ring slump flow expansion tests) are carried out by referring to the technical specification of self-compacting concrete application (JGJ/T283-2012), and the stability of fresh concrete is insufficient due to the fact that the fluidity expansion of the steel bar clear distance of 42.9mm is too large. Therefore to parameter t_sAnd t_pAdaptive fine tuning was performed to obtain the corresponding modified mix ratio, the specific results are shown in table 4.

TABLE 4 self-compacting C60 concrete Unit volume (V)_tIs 1m³) Corrected mixing ratio of

The modified mix ratios obtained according to table 4 meet the desired performance requirements, and the modified mix ratio at this time is the mix ratio of self-compacting C60 concrete.

In the design method of mix proportion of self-compacting concrete provided in this embodiment 1, the performance parameters of the raw materials, and the solid phase components and slurry components in the raw materials are determined through step S1; the excess sand layer model and the excess slurry model are constructed through step S2, and the parameter t is determined using the excess sand layer model_sThrough t_sRealizing the correlation between the volume proportion of the coarse aggregate and the fine aggregate; determining a parameter t using a surplus slurry model_pThrough t_pRealizing the correlation among the volume proportions of coarse aggregate, fine aggregate and slurry; when the self-compacting concrete mix ratio is determined in step S3, t is used_sQuantifying the rolling effect of fine aggregate on coarse aggregate, using t_pThe filling effect of the slurry on the solid-phase material is quantified, and the W/B ratio and the P/B ratio in the slurry are combined to realize dynamic adjustment of the mix proportion of the self-compacting concrete, so that the requirements on raw materials in different regions and the change of construction environment are met. In addition, in the embodiment 1, the W/B ratio determined by the expressions (S3-13) - (S3-16) and the P/B ratio determined by a visual method are adopted, so that the slurry viscosity can be properly controlled, the proportioning stability of the newly mixed concrete can be better, and the segregation phenomenon can be effectively reduced.

By adopting the design method for the mix proportion of the self-compacting concrete in the embodiment 1, the standard filling performance curve of the self-compacting concrete with different mix proportions and the clearance passing capacity curve of the self-compacting concrete with different mix proportions under the condition of determining the clear distance of the reinforcing steel bar can be obtained.

The filling performance standard curve is obtained as follows:

first, at t_sThe value range of (a) is within 0-4.0mm, and different t is set at equal intervals_sValue and for determined t_sT with different value settings_pAnd calculating to obtain the corresponding self-compacting concrete mixing ratio. Secondly, carrying out a working performance test, taking slump expansion fluidity 600mm as a filling performance standard index, and taking each t as_s、t_pClassifying the points to draw a corresponding boundary line as a filling performance standard curve, seeCurve a in fig. 6:

the acquisition procedure for the gap throughput capacity curve is as follows:

first, at t_sThe value range of (a) is within 0-4.0mm, and different t is set at equal intervals_sValue and for determined t_sT with different value settings_pAnd calculating to obtain the corresponding self-compacting concrete mixing ratio. And secondly, judging the clearance passing capacity of the self-compacting concrete under the corresponding mix proportion according to a CBI (reference book: De Schutter G, Bartos P, Domone P, Gibbs J. self-compacting concrete: Whittles Publishing Caithhness, 2008). When the ROB is less than 1, the clearance passing capacity of the self-compacting concrete under the corresponding mix proportion reaches the standard, and then corresponding clearance passing capacity curves of the self-compacting concrete under different mix proportions can be obtained for the steel bar clear distances of 37.9mm, 42.9mm and 52.9mm, specifically referring to curves b, c and d in fig. 6.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for the mix proportion of self-compacting concrete is characterized by comprising the following steps:

The raw materials comprise a solid-phase material and a slurry material, wherein the solid-phase material comprises coarse aggregate and fine aggregate; the slurry material comprises a cementing material, an additive and water; the cementing material comprises cement, fly ash, slag and silica fume; the additive comprises a water reducing agent and a viscosity modifier; the performance parameters comprise the density of the coarse aggregate, the density of the fine aggregate, the grading parameter of the coarse aggregate, the grading parameter of the fine aggregate and the specific surface area s of the coarse aggregate_caSpecific surface area s of fine aggregate_faDensity of cementitious material, density of water ρ_wDensity of admixture rho_adThe filling ratio PD of the coarse aggregate_caThe filling ratio PD of the fine aggregate_faAnd the water reducing rate and the solid content of the water reducing agent;

step S3, determining the mixing proportion of the self-compacting concrete

2. The self-compacting concrete mix proportion designing method of claim 1, wherein in step S3, the reinforcement clearance of the self-compacting concrete is 32.9-52.9mm, wherein t is_sThe value range of (a) is 0-4.0mm, t_pThe value range of (A) is 0-0.16 mm.

3. The self-compacting concrete mix proportion design method of claim 2, wherein in step S1, the density of the coarse aggregate comprises an apparent density ρ of the coarse aggregate_caAnd bulk density of coarse aggregate ρ'_ca；

the density of the cementing material is the apparent density of the cementing material, including the apparent density rho of cement_ceApparent density of fly ash rho_flaApparent density of slag ρ_slagAnd apparent density ρ of silica fume_si；

4. The self-compacting concrete mix proportion design method as claimed in claim 3, wherein said step S2 includes the following processes:

s2.1, constructing an excess sand layer model

in the excess sand model:

the fine aggregate comprises an excessive filling sand layer and a filling sand body, the excessive filling sand layer is an excessive sand layer formed on the surface of the coarse aggregate by the fine aggregate, and the thickness of the excessive filling sand layer is a parameter t_s(ii) a The filling sand body is fine aggregateFilling sand filled in gaps of the coarse aggregate framework;

calculating V by expression (S2.1-2)_ca-solid：

V_ca-solid＝U_ca·PD_ca (S2.1-2)

In the expression (S2.1-2), U_caIs the coarse aggregate bulk;

U_ca＝U_a·λ_ca (S2.1-3)

calculating V by expression (S2.1-5)_fa-solid：

V_fa-solid＝PD_fa·U_fa (S2.1-5)

In the expression (S2.1-5), U_faIs the bulk of the fine aggregate;

U_fa＝U_FI-fa+U_EF-fa＝U_a·λ_ca·P_void-ca+t_s·V_ca-soild·s_ca (S2.1-6)

in the expression (S2.1-6), U_FI-faFilling the sand accumulation volume; u shape_EF-faFor filling in excessThe accumulation volume of the sand filling layer; p_void-caIs the void fraction of coarse aggregate, and P_void-ca＝1-PD_ca；

Step S2.2, constructing excess slurry model

V_fa＝λ_tol·V_t·PD_tol·d_fa (S2.2-1)

V_ca＝λ_tol·V_t·PD_tol·(1-d_fa) (S2.2-2)

calculating lambda by expression (S2.2-3)_tol：

5. The self-compacting concrete mix proportion designing method as claimed in claim 4, wherein in step S3, t satisfying both the self-compacting concrete filling performance and the clearance passing performance is selected_sAnd t_pSetting V_tIs 1m³Calculating the powder coefficient ρ per unit volume by the expressions (S3-1) to (S3-9)_lpAnd the mass of each component in the concrete mixture object to determine the mixing proportion of the self-compacting concrete:

m_b＝(V_lp-V_air)·ρ_lp (S3-2)

m_ce＝m_b·β_ce (S3-3)

m_fla＝m_b·β_fla (S3-4)

m_slag＝m_b·β_slag (S3-5)

m_si＝m_b·β_si (S3-6)

m_w＝m_b·W/B (S3-7)

m_fa＝V_fa·ρ_fa (S3-8)

m_ca＝V_ca·ρ_ca (S3-9)

in expressions (S3-1) - (S3-9), m_bIs the mass of the gelled material; m is a unit of_ceThe mass of the cement; m is_flaThe mass of the fly ash; m is_slagThe quality of the slag; m is_siThe mass of the silica fume; m is_wIs the mass of water; m is a unit of_faThe mass of the fine aggregate; m is_caThe mass of the coarse aggregate; v_airThe air content of the concrete mixing object is measured; v_lpThe volume of slurry in the concrete mixture is measured;

v in expression (S3-2)_lpCalculated by expressions (S3-10) - (S3-12):

V_lp＝V_EF-lp+V_FI-lp (S3-10)

V_FI-lp＝λ_tol·V_t·(1-PD_tol) (S3-11)

in the expressions (S3-10) - (S3-12), V_EF-lpIs solid phase material in concrete mixing objectExcess slurry volume on the surface of the material; v_FI-lpThe solid phase material voids are filled with the slurry volume.

6. The self-compacting concrete mix proportion design method as claimed in claim 5, wherein in step S3, the value range of the W/B ratio is calculated by expressions (S3-13) - (S3-16):

f_cu,0≥1.15f_cu,k (S3-15)

f_cu,0≤f_cu-low＜f_cu-up (S3-16)

in the expressions (S3-13) - (S3-16), f_cu,kThe standard value of the compressive strength of the self-compacting concrete is obtained; f. of_cu,0The average control value of the laboratory standard cube compressive strength test is that the self-compacting concrete meets the 95% strength guarantee rate; f. of_cu-lowIs f_cu,0A lower limit strength estimate of; f. of_cu-upIs f_cu,0An upper limit strength estimated value of (2); f. of_ce,gThe grade strength of the cement; k is a radical of₁And k₂Are all empirical constants; alpha is alpha_aAnd alpha_bAre all regression coefficients; alpha is alpha_flaIs the coefficient of the cementing material of the fly ash; alpha is alpha_slagIs the cementitious material coefficient of the slag; gamma ray_flaIs the influence coefficient of the fly ash; gamma ray_slagThe influence coefficient of the slag; gamma ray_siThe influence experience coefficient of the silica fume is used; gamma ray_ceThe cement strength surplus coefficient; beta is a_ceThe mass ratio of the cement in the cementing material is shown; beta is a_flaThe mass ratio of the fly ash in the cementing material is shown; beta is a_slagThe mass ratio of the slag in the cementing material is shown; beta is a_siThe mass ratio of the silica fume in the cementing material is shown;

7. The self-compacting concrete mix proportion design method according to any one of claims 4-6, wherein in step S2.1, the grading parameters of the coarse aggregate comprise a first particle size interval and a second particle size interval, wherein the first particle size interval is 10-16mm, and the second particle size interval is 5-10 mm; grading parameters of the fine aggregate comprise a third particle size interval, wherein the third particle size interval is 0.075mm-5 mm; the PD is_tolCalculated by expressions (S2.2-7) - (S2.2-14):

PD_tol＝Φ_agg (S2.2-7)

y₁＝0.6(1-d_fa) (S2.2-12)

y₂＝0.4(1-d_fa) (S2.2-13)

y₃＝d_fa (S2.2-14)

in the expressions (S2.2-7) to (S2.2-14), Φ_aggActual filling rate of the solid phase material mixed accumulation body; k is a framework compaction coefficient; y is₁The volume ratio of the coarse aggregate in the first particle size interval in the solid-phase material mixed accumulation body is shown; y is₂Is of the second particle sizeThe volume ratio of the coarse aggregate in the interval in the solid-phase material mixed accumulation body; y is₃The volume ratio of the fine aggregate in the third particle size interval in the solid-phase material mixed accumulation body is; beta is a₁The virtual filling rate of the coarse aggregate in the first particle size interval is shown; beta is a₂The virtual filling rate of the coarse aggregate in the second particle size interval is obtained; beta is a₃The virtual filling rate of the fine aggregate in the third particle size interval is shown; gamma ray₁The virtual filling rate is the virtual filling rate when the coarse aggregate in the first particle size interval occupies the space dominance; gamma ray₂The virtual filling rate is the virtual filling rate when the coarse aggregate in the second particle size interval occupies the space dominance; gamma ray₃The virtual filling rate is the virtual filling rate when the fine aggregate in the third particle size interval occupies the space domination; alpha₁₂The loosening effect coefficient between the first particle size interval and the second particle size interval; alpha₁₃The loosening effect coefficient between the first particle size interval and the third particle size interval is obtained; alpha₂₃The loosening effect coefficient between the second particle size interval and the third particle size interval is obtained; b₂₁Is the wall effect coefficient between the second particle size interval and the first particle size interval; b₃₁Is the wall effect coefficient between the third particle size interval and the first particle size interval; b₃₂Is the wall effect coefficient between the third particle size interval and the second particle size interval.