A design method for a flowable asphalt mixture skeleton

Abstract

This invention discloses a method for designing the skeleton of a flowable asphalt mixture. The method includes: determining the maximum particle size of the gradation, and using the V-shape of the flowable asphalt mixture... ag The wet mixing test method was used to measure V under different n values. ag V ag -n relationship model; determine the asphalt-aggregate ratio and powder-adhesive ratio according to site requirements, and calculate the amount of adhesive P required for FMA. ma The amount of adhesive P used was calculated using the MaFF method. ma The corresponding V ag Then calculate the V ag Substitute V ag The relationship model of -n is used to obtain the corresponding range of n values; finally, substituting the n values ​​into the Talbol formula allows for the rapid determination of the skeleton gradation composition design of the FMA. Compared with existing gradation theories, the method proposed in this invention can effectively solve the V ag The limitations can be effectively addressed by improving the current FMA skeleton design method, which lacks scientific basis in the design process and has not yet formed an effective theory.

Description

Technical Field

[0001] This invention belongs to the field of road transportation, and specifically relates to a design method for a flowable asphalt mixture skeleton. Background Technology

[0002] Currently, the service life of asphalt pavements is generally short, and the maintenance frequency is too high. Therefore, improving the durability of asphalt pavements remains a key issue that the industry urgently needs to address. Based on this, Guangzhou University proposed the theory of Fluidmastic Asphalt (FMA), and the main findings, in the article "Theory and Design Method of Fluidmastic Asphalt Mixtures," were published in the *China Journal of Highway and Transport* in June 2024. Fluidmastic asphalt mixtures refer to skeleton-ultra-dense asphalt mixtures formed by filling the gaps in the aggregate structure with highly fluid asphalt slurry through its own flow or vibration-assisted compaction techniques, resulting in an internal porosity close to zero. The term "flowing slurry" is in contrast to the "no slurry leakage" characteristic of current hot-mix asphalt (HMA) construction processes. Compared to current HMA mixtures, FMA mixtures form a skeleton-ultra-dense structure with a near-zero internal porosity, an increased and widely adjustable asphalt-aggregate ratio, enhanced tensile deformation capacity, increased flexibility, and enhanced toughness, exhibiting comprehensive performance advantages. FMA (Fluorescent Aggregate Mixture) is expected to solve current early-stage problems in asphalt pavements, such as water damage, fatigue and reflective cracking, aging, and skid resistance and durability, significantly improving the durability of asphalt pavements. In particular, due to its wide-range adjustable asphalt-aggregate ratio, FMA can meet various pavement construction and maintenance needs: it can be used not only for road maintenance to extend the life of existing pavements, but also for various layers of new and upgraded long-life pavement structures, as a functional layer of pavement structures, or as a surface layer to achieve skid resistance and durability.

[0003] However, since FMA is still in the initial research stage, the skeleton design is not yet perfect. The coarse and fine aggregates in the skeleton design are only determined by the volume relationship of the skeleton gap filling. They are often designed as discontinuous gradation based on experience, and a unified and reliable design method has not yet been formed.

[0004] Currently, most gradation designs for dense HMA mixtures are based on the maximum density line theory, relying on empirical gradation design, or on the Talbol formula P. i =100(d i / D) nThe passing rate of each particle size is calculated, with n ranging from 0.3 to 0.7. SUPERPAVE, based on the maximum density line at n=0.45, sets control points and restriction zones to design the aggregate gradation curve. Then, five asphalt-aggregate ratios are selected, and specimens are molded using different methods to conduct mechanical and volumetric property tests to determine the optimal asphalt-aggregate ratio. From the design process perspective, selecting a specific gradation first, and then determining the optimal asphalt-aggregate ratio, prioritizes gradation.

[0005] Clearly, this gradation design method cannot be applied to FMA theory, cannot design FMA skeletons suitable for different amounts of binder, and cannot achieve the wide-range adjustable asphalt-aggregate ratio characteristic of FMA. For example, in the Talbol formula, the gradation range of the mineral mixture, n, is between 0.3 and 0.7, which results in a void ratio (V0.05) in the skeleton. ag The oil-stone ratio can only be varied within a limited range, meaning it can only be adjusted within a small range and cannot achieve the wide-range adjustable oil-stone ratio characteristic of FMA.

[0006] Furthermore, FMA is still in the preliminary research stage, and its skeleton design is not yet perfect. Currently, the method of controlling the asphalt-aggregate ratio in FMA mainly relies on adjusting the content of fine aggregates, while the VCA of coarse aggregates... DRC The void volume is fixed, and this void volume is filled by both fine aggregate and cementitious mortar. The substitution relationship between fine aggregate and cementitious mortar indicates that increasing the amount of fine aggregate leads to decreasing the amount of cementitious mortar, i.e., a lower asphalt-aggregate ratio; conversely, decreasing the amount of fine aggregate leads to an increased asphalt-aggregate ratio. Current design processes often rely on experience, lacking scientific basis and effective methods. Summary of the Invention

[0007] To address the shortcomings and deficiencies of existing technologies, the present invention aims to provide a design method for the skeleton of fluid mastic asphalt mixtures. The main concept of this method is to achieve a wide range of adjustable asphalt-aggregate ratios in fluid mastic asphalt (FMA) mixtures, breaking through the upper limit of 0.7. While ensuring that road performance requirements are met, the value of n is significantly changed to obtain an FMA with an asphalt-aggregate ratio that meets engineering requirements.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A method for designing a skeleton for a flowable asphalt mixture includes the following steps:

[0010] (1) Determine the maximum particle size of the gradation according to the actual needs; then assume several different n values ​​and use the Talbol formula to calculate the passing rate of each grade of aggregate under different n values, and obtain the content of each grade of aggregate; then remove the content of the part below 0.075mm, and redistribute the remaining part according to the proportion to obtain the content of each grade of aggregate after removing the part below 0.075mm; finally, according to the wet mixing test method, measure the V of each gradation under different n values. ag V can be obtained by fitting the data. ag The relational model of -n is shown in equation (A):

[0011]

[0012] In formula (A):

[0013] a1 is V when n approaches 0 in theory. ag value,%;

[0014] a2 is V when n takes an infinite value in theory. ag The value, i.e., a2, is the asymptote of the model, %;

[0015] χ0 is theoretically V ag The value of n when taking the median value is dimensionless;

[0016] p reflects the speed at which the model approaches the asymptote; the larger the value, the faster the model approaches the asymptote.

[0017] (2) Determine the required oil-aggregate ratio and powder-rubber ratio according to the actual needs, and then calculate the amount of adhesive P of FMA mixture using the following formula (B). ma :

[0018] P ma = (oil-stone ratio / (1 + oil-stone ratio)) × (1 + powder-to-glue ratio) × 100% (B);

[0019] (3) Combine the amount of adhesive P of FMA mixture calculated in step (2) ma The amount of adhesive P was determined using the MaFF method. ma The corresponding V ag ;

[0020] (4) The V calculated in step (3) ag Substituting V into equation (A) ag The relationship model of -n is used to determine the corresponding n value; the determined n value is then substituted into the Talbol formula to determine the skeleton gradation composition design of FMA.

[0021] Preferably, the wet mixing test method in step (1) refers to the method disclosed in Chinese patent application No. 202510470312.7.

[0022] Preferably, the number of different n values ​​in step (1) is ≥4.

[0023] More preferably, the selection of the value of n includes four point values: 0.00001, 0.45, 3.5, and 11.

[0024] Preferably, in step (3), the amount of aggregate P in the FMA mixture is... ag , Adhesive dosage P ma and V ag The relationship between the parameters is shown in equations (C) and (D):

[0025] P ma +P ag =100% (C)

[0026] In formula (C):

[0027] P ag The aggregate content (by weight) of FMA mixture is %

[0028] P ma The amount of adhesive used in FMA mixture (by weight percentage), %

[0029]

[0030] In formula (D):

[0031] V ag The skeleton gap ratio of the FMA mixture, %

[0032] VV represents the design internal porosity, expressed as a percentage (measured). The measured internal porosity of FMA is less than 1%, typically between 0.4% and 0.6%.

[0033] F d The filling degree represents the extent to which the adhesive fills the voids in the skeleton. The value ranges from 0 to 1.0, is dimensionless, and can be selected according to design requirements.

[0034] γ c The bulk density of aggregate in compacted or compacted state, in g / cm³ 3 Actual measurement;

[0035] P ma0 The amount of adhesive paste used (by weight) can be determined through a mixing test, % .

[0036] γ ma The relative density of the adhesive is dimensionless and measured.

[0037] Preferably, in step (4), a suitable reduction factor α is determined based on the actual working conditions, and the reduction factor is first substituted into V. ag In the relational model of -n, V ag After reduction, V is calculated in step (3). ag Substitute the reduced V ag The corresponding value of n is determined in the relational model of -n; the reduction coefficient α ranges from 0.7 to 0.9.

[0038] Preferably, in step (4), considering that the results of different experimental environments may fluctuate, the value of n is allowed to fluctuate by 0.1, that is, the range of the value when substituted into the Talbol formula is n-0.1~n+0.1.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] (1) Compared with existing gradation theories, the method proposed in this invention can effectively solve the problem of V ag The limitation can be overcome by changing the value of n in the Talbol formula, thus breaking through the existing upper limit of 0.7 for the value of n in mineral mixtures. Theoretically, it can be 0. + By going to ~ +∞, we can obtain a V that can be adjusted over a wide range. ag The gradation design enables the FMA oilstone ratio to be adjusted over a wide range.

[0041] (2) Compared with existing FMA skeleton designs, the method proposed in this invention is based on the maximum compaction curve theory, which can effectively solve the shortcomings of current FMA skeleton design methods, such as imperfections, lack of scientific basis in the design process, and the absence of an effective theoretical framework. This invention proposes to determine the required amount of adhesive and the ratio of oilstone to cement paste for FMA by adjusting the n value of the Talbol formula. The smaller the n value, the higher the V... ag The smaller the value of n, the less adhesive is needed for FMA, and the smaller the oil-stone ratio; the larger the n value, the lower the V. ag The larger the value, the more adhesive is used in FMA, and the higher the asphalt-aggregate ratio becomes. While ensuring that the road performance of FMA meets requirements, the method of this invention not only achieves a wide range of adjustable asphalt-aggregate ratios in FMA, but also provides an effective approach for aggregate design based on FMA theory, possessing both theoretical significance and engineering application value. Attached Figure Description

[0042] Figure 1 V was measured when the maximum particle size of the gradation was 13.2 mm. ag The graph shows the relationship between x and n values, where x represents the n value and y represents the skeleton gap ratio V. ag a1 is V when n approaches 0 in theory. ag Value; a2 is the theoretical V when n takes the value of infinity.ag The value, i.e., a2, is the asymptote of the model; χ0 is V. ag The value of n when taking the middle value; p is the speed at which the model approaches the asymptote.

[0043] Figure 2 This is a diagram of the calculation process in step (3) of Example 1. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.

[0045] This invention discloses a gradation design method for the skeleton of a flowable asphalt mixture: First, the maximum particle size (D) of the gradation is determined according to actual needs. Then, as many n values ​​as possible are assumed (the more n values, the higher the model accuracy), and the V of the flowable asphalt mixture is used as the gradation design method. ag The wet mixing test method (i.e., the method disclosed in Chinese patent application 202510470312.7) was used to measure V under different n values. ag By fitting the data, we can find these n values ​​and the skeleton gap ratio V. ag A functional relationship is obtained to obtain V ag -n relational model. Then, based on site requirements (e.g., according to the stress characteristics and functional requirements of the strata), the asphalt-aggregate ratio and the powder-binder ratio are determined, and the amount of FMA adhesive P is calculated. ma Subsequently, the amount of adhesive P used was calculated using the MaFF method. ma The corresponding V ag Then calculate the V ag Substitute V ag The relationship model of -n is used to obtain the corresponding value of n. Finally, the final determined value of n is substituted into the Talbol formula to quickly determine the skeleton gradation design of FMA. When the value of n is not too large, the skeleton gradation is often a continuous gradation; when the value of n is large, there is less fine material, and the skeleton gradation is closer to a discontinuous gradation design. The specific steps include:

[0046] (1) Determine the maximum particle size of the gradation according to the actual needs, then assume several different n values, and use the Talbol formula to obtain the passing rate of each grade of aggregate under different n values, and obtain the content of each grade of aggregate; then remove the content of the part below 0.075mm, and redistribute the remaining part according to the proportion to obtain the content of each grade of aggregate after removing the part below 0.075mm; finally, according to the V disclosed in Chinese patent application 202510470312.7 ag The wet-mix test method was used to measure the V of each gradation under different n values.ag V can be obtained by fitting the data. ag The relational model of -n is shown in equation (A):

[0047]

[0048] In formula (A):

[0049] a1 is V when n approaches 0 in theory. ag value,%;

[0050] a2 is V when n takes an infinite value in theory. ag The value, i.e., a2, is the asymptote of the model, %;

[0051] χ0 is theoretically V ag The value of n when taking the median value is dimensionless;

[0052] p reflects the speed at which the model approaches the asymptote; the larger the value, the faster the model approaches the asymptote.

[0053] (2) Determine the required oil-aggregate ratio and powder-rubber ratio according to the actual needs, and then calculate the amount of adhesive P of FMA mixture using the following formula (B). ma :

[0054] P ma = (oil-stone ratio / (1 + oil-stone ratio)) × (1 + powder-to-glue ratio) × 100% (B);

[0055] The derivation process of equation (B) is as follows:

[0056] First, according to the formula and The formula is obtained by conversion. and ,

[0057] Asphalt-aggregate ratio = (asphalt content / (aggregate content + mineral powder content)) * 100% = (asphalt content / (1 - asphalt content)) * 100%

[0058] Powder-to-binder ratio = Mineral powder content / Asphalt content

[0059] Asphalt content = (asphalt-aggregate ratio / (1 + asphalt-aggregate ratio)) * 100%

[0060] Mineral powder content = Powder-to-binder ratio * Asphalt content * 100%

[0061] Since the amount of adhesive used is the sum of the asphalt content and the mineral powder content, it can be converted to formula (B).

[0062] (3) Combine the amount of adhesive P of FMA mixture calculated in step (2) ma The amount of adhesive P was determined using the MaFF method. ma The corresponding V ag ;

[0063] (4) The V calculated in step (3) ag Substituting V into equation (A) ag The relationship model of -n is used to determine the corresponding n value; the determined n value is then substituted into the Talbol formula to determine the skeleton gradation composition design of FMA.

[0064] Preferably, the wet mixing test method in step (1) refers to the method disclosed in Chinese patent application No. 202510470312.7, including Marshall compaction or rotary compaction.

[0065] Preferably, the number of different n values ​​in step (1) is ≥4. More preferably, the selection of n values ​​includes at least four points: 0.00001, 0.45, 3.5, and 11. The V values ​​corresponding to different n values ​​are measured. ag Then, the data was fitted using Origin to obtain V. ag -n relational model.

[0066] In step (1), due to differences in aggregates, maximum particle size, or molding methods, V ag In a relational model with -n, all parameters will change. In practical applications, V is determined... ag The simplest method to determine the relationship with the n value is: after determining the maximum particle size, use a wet mixing test method to measure the V of the gradation corresponding to at least four n values. ag The value of n can be used to quickly determine the magnitude of each parameter in the model. The four n values ​​can take values ​​that approach 0, infinity, and any two numbers. For ease of distinction and use, n values ​​can be 0.00001, 0.45, 3.5, and 11 (when n values ​​are 0.00001 and 11, the throughput of each aggregate grade has stabilized; changes in n values ​​that are further smaller or larger have negligible impact, so they can be considered as values ​​approaching 0 and infinity, respectively). The V obtained from gradation measurements when n values ​​are 0.00001 and 11... ag The values ​​are a1 and a2, and the remaining two unknowns, χ0 and p, can be determined with just two equations.

[0067] The MaFF method mentioned in step (3) refers to the Mastic Flow for Filling (MaFF) method disclosed in the literature (Wu Kuanghuai, Wu Chuanhai, Nie Guihai, et al. Theory and design method of Flowable Asphalt Mixture (FMA) [J]. China Journal of Highway and Transport, 2025, 38(2):102-113.DOI:10.19721 / j.cnki.1001-7372.2025.02.008.). In this method, the actual measurement of the parameters refers to first molding FMA specimens according to the calculated mix proportions, and then conducting the tests.

[0068] According to the MaFF method, the aggregate dosage P of FMA mixtures ag , Adhesive dosage P ma and V ag The relationship between the parameters is shown in equations (C) and (D):

[0069] P ma +P ag =100% (C)

[0070] In formula (C):

[0071] P ag The aggregate content (by weight) of FMA mixture is %

[0072] P ma The amount of adhesive used in FMA mixture (by weight percentage), %

[0073]

[0074] In formula (D):

[0075] V ag The skeleton gap ratio of the FMA mixture, %

[0076] VV represents the design internal porosity, expressed as a percentage (measured). The measured internal porosity of FMA is less than 1%, typically between 0.4% and 0.6%.

[0077] F d The filling degree represents the extent to which the adhesive fills the voids in the skeleton. The value ranges from 0 to 1.0, is dimensionless, and can be selected according to design requirements.

[0078] γ c The bulk density of aggregate in compacted or compacted state, in g / cm³ 3 Actual measurement;

[0079] P ma0 The amount of adhesive paste used (by weight) can be determined through a mixing test, % .

[0080] γma The relative density of the adhesive is dimensionless and measured.

[0081] Furthermore, the bulk density γ of the aggregate in the compacted or compacted state c The density, also known as the compacted density of aggregates, can be measured by referring to the method disclosed in Chinese patent application No. 202510470312.7. First, FAM specimens are molded according to the mix proportions, and then their height, bottom area and weight are measured to calculate their density.

[0082] Preferably, in step (4), a suitable reduction factor α is determined based on the actual working conditions, and the reduction factor is first substituted into V. ag In the relational model of -n, V ag After reduction, the V calculated in step (3) is then used. ag Substitute the reduced V ag The corresponding value of n is determined in the relational model of -n; the reduction coefficient α ranges from 0.7 to 0.9.

[0083] Due to the V described in this invention ag The relationship model of -n was obtained by referring to the wet mixing test method disclosed in Chinese patent application No. 202510470312.7. Considering the boundary effect caused by the small volume of the test specimen, and that the aggregate will be more evenly and densely distributed when the fully formed flowing asphalt mixture is formed, and the lubrication effect of asphalt will also make the skeleton more dense, the reduction coefficient α can be substituted into V in step (4). ag In the relational model of -n, V ag After reduction, the V calculated in step (3) is then used. ag Substitute into the reduced V ag The corresponding value of n is determined in the relational model of -n.

[0084] Preferably, in step (4), considering that the results of different experimental environments may fluctuate, the value of n is allowed to fluctuate by 0.1, that is, the range of the value when substituted into the Talbol formula is n-0.1~n+0.1.

[0085] The following are embodiments of the present invention. The aggregate used in the embodiments is diabase with a particle size range of 0.075mm to 13.2mm. The test results of the aggregate and the technical requirements of the specifications are shown in Table 1, all of which meet the technical requirements of the "Technical Specification for Construction of Highway Asphalt Pavement" (JTG E42-2005). The asphalt is high-viscosity modified asphalt, and the test results of the asphalt are shown in Table 2, all of which meet the technical requirements of the "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025).

[0086] Table 1 Technical Specifications of Coarse and Fine Aggregates

[0087]

[0088] Table 2 Technical Indicators of High Viscosity Modified Asphalt

[0089]

[0090] The V mentioned in step (1) of the following embodiments ag The -n relational model is determined as shown in step (I) or (II) below:

[0091] Step (1): Determine the maximum particle size of the gradation as 13.2 mm. After determining the maximum particle size, calculate the passing rate of each aggregate grade under different n values ​​using the Talbol formula to obtain the content of each aggregate grade. Then, remove the content of the portion below 0.075 mm, and redistribute the remaining portion according to the proportion to obtain the content of each aggregate grade after removing the portion below 0.075 mm. Determine the n value to be 0.00001, 0.1... and 11. According to the method disclosed in Example 1 (Marshall compaction method) of Chinese Patent Application 202510470312.7, test the skeleton gap ratio V of the flowing mortar mixture under different n values. ag V obtained under the Marshall test method ag The numerical relationship between the values ​​of n and n is shown in Table 3:

[0092] Table 3. n value and V obtained by Marshall compaction method ag Correspondence table

[0093]

[0094] Observation of the data reveals that as the value of n increases, V ag The value gradually flattens out, which closely matches the curve of the Logistic model. By importing the data into Origin and performing data fitting, the function expression is obtained as follows: Figure 1 As shown (a1=20.93743±0.52068, a2=38.8968±0.61978, χ0=1.2753±0.15277, p=1.69658±0.15277). The R-squared value after fitting is 0.989, indicating that the fitting result is very ideal.

[0095] Step (II): Referring to Step (I) above, modify the method disclosed in Example 4 (rotational compaction method) of Chinese Patent Application 202510470312.7 to test the skeleton gap ratio V of the flowable mortar mixture under different n values. ag V was obtained under the rotary compaction method. ag The numerical relationship between the n value and the n value is shown in Table 4:

[0096] Table 4. n value and V obtained by rotary compaction method ag Correspondence table

[0097]

[0098] Observation of the data reveals that as the value of n increases, V ag The value gradually flattens out, which closely matches the curve of the Logistic model. By importing the data into Origin and performing data fitting, the function expression is obtained as follows: Figure 1 As shown (a1=17.90708±0.76525, a2=37.33583±0.50942, χ0=1.19373±0.06262, p=1.80412±0.15973). The R-squared value after fitting is 0.993, indicating that the fitting result is very ideal.

[0099] The V measured in the above steps ag V in the -n relational model ag The values ​​are the original values. Considering the boundary effect caused by the small volume of the test specimens, and that the aggregates are more evenly and densely distributed when the asphalt mixture is formed into a complete flowing asphalt mixture, and that the lubrication effect of the asphalt also makes the skeleton more compact, the V values ​​corresponding to the Marshall compaction method and the rotary compaction method are adjusted in the indoor test. ag The values ​​need to be multiplied by reduction factors of 0.84 and 0.89 respectively before use. However, in actual on-site construction, due to differences in construction methods and compaction work compared to indoor tests, some minor adjustments may be needed to the reduction factors.

[0100] Example 1:

[0101] According to the method described in this invention, the maximum particle size is determined to be 13.2 mm, the oil-stone ratio is 7.0%, the powder-to-binder ratio is 1.0, and the filling degree F is [not specified]. d The gradation design of FMA when the internal porosity VV is 0 is as follows:

[0102] (1) The skeleton gap ratio V of the flowable adhesive mixture was tested using the method disclosed in Example 1 of Chinese Patent Application 202510470312.7. ag This step measures the Vi of the gradation at the maximum particle size of 13.2 mm. ag Numerical relationship V between n and n ag -n relational model, and draw the relational diagram, such as Figure 1 As shown, V ag =a2+(a1+a2) / (1+(n / χ0) ∧ After simplification, a1=20.94, a2=38.89, χ0=1.275, p=1.697.

[0103] (2) The amount of adhesive P required for FMA is calculated according to formula (B). ma It is 13.08%.

[0104] P ma =(0.07 / (1+0.07))×(1+1)×100% =13.08%.

[0105] (3) Combine the amount of adhesive P of FMA mixture calculated in step (2) ma The amount of adhesive P was determined using the MaFF method. ma The corresponding V ag ;

[0106] Aggregate dosage P of FMA mixture ag , Adhesive dosage P ma and V ag The relationship between the parameters is shown in equations (C) and (D):

[0107] P ma +P ag =100% (C)

[0108] In the formula:

[0109] P ag The aggregate content (by weight) of FMA mixture is %

[0110] P ma The amount of adhesive used in the FMA mixture (by weight percentage).

[0111]

[0112] In formula (D):

[0113] V ag The skeleton gap ratio of the FMA mixture, %

[0114] VV represents the design internal porosity, expressed as a percentage (measured). The measured internal porosity of FMA is less than 1%, typically between 0.4% and 0.6%.

[0115] F d The filling degree represents the extent to which the adhesive fills the voids in the skeleton. The value ranges from 0 to 1.0, is dimensionless, and can be selected according to design requirements.

[0116] γ c The bulk density of aggregate in compacted or compacted state, in g / cm³ 3 Actual measurement;

[0117] P ma0The amount of adhesive paste used (by weight) can be determined through a mixing test, % .

[0118] γ ma The relative density of the adhesive is dimensionless and measured.

[0119] The amount of adhesive P was determined using the Maff method. ma When =13.08%, the corresponding V ag It is 22.57%.

[0120] (4) Determine a suitable reduction factor α of 0.84 based on the actual working conditions, and substitute it into V. ag In the -n model, for V ag After reduction, the V calculated in step (3) is finally reduced. ag Substitute the reduced V ag In the relational model of -n, determining the corresponding value of n allows us to derive V. ag When the percentage is 22.57%, the corresponding value of n is 0.84.

[0121] (5) Considering that the results may fluctuate under different test environments, the fluctuation is allowed to be 0.1 above and below the determined n value of 0.84, that is, the range of n value is 0.74~0.94. Substituting into Talbol, the FMA gradation design required for this actual situation can be obtained (see Table 5).

[0122] In step (3), due to the designed fill degree F d Since the value is 1, equation (D) is actually:

[0123]

[0124] Where, γ ma The relative density of the gel can be calculated using the formula γ. ma =100 / ( P b / ρ b +P f / ρ f P is obtained. b P f The percentages of asphalt and mineral powder by mass (in %) are ρ. b ρ f These are the relative densities of asphalt and mineral powder, respectively (dimensionless, calculated according to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025)). In reality, VV cannot be 100% zero; it is recommended to use 0.5% for calculation. In this embodiment, since the powder-to-binder ratio is 1, P... b P f Both are 50; ρ b ρ fGiven 1.03 and 2.817 respectively, we can obtain γ ma =1.508.

[0125] In practical applications, step (3) is performed by P. ma Find V ag This step, due to V ag With γ c There is a functional relationship between them, so in P ma Find V ag The process is actually similar to finding an implicit function, that is, (parameters such as oil-stone ratio) → (P) ma )→(V ag Solving for V in the forward direction (n) is quite difficult. However, V can be determined in step (1). ag Under the premise of the -n model, the solution is obtained by inverse calculation, i.e., (n) → (V) ag ) →(P ma → (parameters such as oil-stone ratio), such as Figure 2 As shown, by adjusting the value of n multiple times and iterating multiple times, the required oil-stone ratio can also be obtained. This method can also find the relationship between parameters such as the oil-stone ratio and the value of n. For example, in this embodiment:

[0126] When n is 0.84, substitute it into model V ag =38.89+(20.94-38.89) / (1+(n / 1.275) ∧ From 1.697), we can obtain V. ag =26.86%, after multiplying by the reduction factor of 0.89, V ag =22.56%; according to V ag With γ c Relationship V ag =(1-γ c We can obtain 22.56 = (1-γ) / ρ2)×100. c (2.855)×100 gives V ag After reduction γ c =2.21g / cm 3 The composite bulk density ρ2 of the gradation can be obtained according to the method T0304-2024 in the "Specifications for Testing Aggregates in Highway Engineering" (JTG 3432—2024). When the value of n is 0.84, the composite bulk density of the gradation is 2.855.

[0127] Then V ag =22.56, VV=0.5, γ c =2.21、F d =1、γ ma Substituting 1.508 into equations (C) and (D), we get P. ma =13.08, Pag =86.92. Finally, according to P... ma = (oil-stone ratio / (1 + oil-stone ratio)) × (1 + powder-glue ratio) × 100%, where the powder-glue ratio is 1, so the oil-stone ratio is 7%.

[0128] By using the reverse solution method described above, after finalizing the formula in the table, and adjusting the value of n multiple times, the relationship between the value of n and parameters such as the oil-stone ratio can be obtained more easily than by the forward solution.

[0129] Track performance verification

[0130] This experiment verifies that the maximum particle size designed by the method in Example 1 is 13.2 mm, the oil-aggregate ratio is 7.0%, the powder-to-binder ratio is 1.0, and the filling degree F is [missing information]. d 1. The rutting performance of FMA when the internal porosity VV is 0. The specific test procedure is as follows:

[0131] 1. According to the gradation design method described in Example 1, the value of n under this condition can be taken as 0.84 (with an allowable fluctuation of 0.1, the calculated range of n is 0.74~0.94). Substituting this into the Talbol formula P... i =100(d i / D) n After removing the content of aggregates smaller than 0.075mm, the remaining aggregate content was redistributed, and the aggregate content of each grade was calculated as shown in Table 5.

[0132] According to the model obtained from the wet-mix test method (Marshall compaction method), when the reduction factor α is 0.84 and the value of n is 0.84, V ag It is 22.57%, according to the formula V ag =(1-γ c / ρ2)×100, where ρ2 is the composite bulk density of the graded aggregate, the aggregate bulk density γ can be obtained. c It is 2.21 g / cm 3 The aggregate consumption P can be calculated using the MaFF method. ag The percentage was 86.92%, and the amount of adhesive used was P. ma The total content is 13.08%, meaning the asphalt content is 6.54% and the mineral powder content is 6.54%. A standard rutting slab has a volume of 4500 cm³. 3 Therefore, the weight of the aggregate is 4500*2.21=9945 g, and the weight of the asphalt and the weight of the mineral powder are both (9945 / 0.8692)*0.0654=748 g;

[0133] 2. Rutting slab specimens formed according to the T 0703-2025 standard in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410—2025);

[0134] 3. Conduct rutting tests according to T 0719-2025 of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025);

[0135] 4. The data recorded by the rutting tester is shown in Table 6. It can be seen that the rutting performance of FMA with an asphalt-aggregate ratio of 7.0 under this design method meets the requirement of rutting dynamic stability greater than 3000 times / mm in the "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004).

[0136] Table 5. Content of aggregates in each grade when n is 0.84

[0137]

[0138] Table 6. Dynamic stability of FMA-13 ​​at an oil-stone ratio of 7.0

[0139]

[0140] Example 2:

[0141] According to the method described in this invention, the maximum particle size is determined to be 13.2 mm, the oil-stone ratio is 8.0%, the powder-to-binder ratio is 1.0, and the filling degree F is [not specified]. d 1. The gradation design of FMA when the internal porosity VV is 0 is the same as in Example 1:

[0142] (1) Following the same method as in Example 1, the V of the gradation with a maximum particle size of 13.2 mm was measured. ag Numerical relationship V between n and n ag -n relational model, and draw the relational diagram, such as Figure 1 As shown, V ag =a2+(a1+a2) / (1+(n / χ0) ∧ After simplification, a1=20.94, a2=38.89, χ0=1.275, p=1.697.

[0143] (2) The amount of adhesive P required for FMA is calculated according to formula (B). ma It is 14.81%.

[0144] P ma =(0.08 / (1+0.08))×(1+1)×100%=14.81%.

[0145] (3) Combine the amount of adhesive P of FMA mixture calculated in step (2) ma =14.81%, referring to the same method as in Example 1, the amount of adhesive P was determined by the MaFF method (Equations (C) and (D)). maWhen =14.81%, the corresponding V ag It is 25.06%.

[0146] (4) Determine a suitable reduction factor α of 0.84 based on the actual working conditions, and substitute it into V. ag In the -n model, for V ag After reduction, the V calculated in step (3) is finally reduced. ag Substitute the reduced V ag In the relational model of -n, determining the corresponding value of n allows us to derive V. ag When the percentage is 25.06%, the corresponding value of n is 1.26.

[0147] (5) Considering that the results may fluctuate under different test environments, the fluctuation is allowed to be 0.1 above and below the determined n value of 1.26, that is, the range of n value is 1.16~1.36. Substituting into Talbol, the FMA gradation design required for this actual situation can be obtained (see Table 7).

[0148] Track performance verification

[0149] This experiment verifies the rutting performance of FMA with a maximum particle size of 13.2 mm, an oil-aggregate ratio of 8.0%, a powder-to-binder ratio of 1.0, a filling degree of 1, and an internal porosity of 0, as designed in Example 2. The specific experimental procedure is as follows:

[0150] 1. According to the gradation design method described in Example 2, the value of n under this condition can be 1.26. Substituting this into the Talbol formula P i =100(d i / D) n After removing the content of aggregates smaller than 0.075mm, the remaining aggregate content is redistributed, and the aggregate content of each grade is calculated as shown in Table 7.

[0151] According to the model obtained from the wet-mix test method (Marshall compaction method), when the reduction factor α is 0.84 and the value of n is 1.26, V ag It is 25.06%, according to the formula V ag =(1-γ c / ρ2)×100, where ρ2 is the composite bulk density of the graded aggregate, the aggregate bulk density γ can be obtained. c It is 2.13 g / cm 3 The aggregate consumption P can be calculated using the MaFF method. ag The percentage was 85.19%, and the amount of adhesive used was P. ma The percentage is 14.81%, meaning the asphalt content is 7.40% and the mineral powder content is 7.40%. A standard rutting slab has a volume of 4500 cm³. 3Therefore, the weight of the aggregate is 4500*2.13=9585g, and the weight of the asphalt and the weight of the mineral powder are both (9585 / 0.8519)*0.074=833g;

[0152] 2. Rutting slab specimens formed according to the T 0703-2025 standard in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410—2025);

[0153] 3. Conduct rutting tests according to T 0719-2011 of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410—2025);

[0154] 4. The data recorded by the rutting tester is shown in Table 8. It can be seen that the rutting performance of FMA with an asphalt-aggregate ratio of 8.0 under this design method meets the requirement of rutting dynamic stability greater than 3000 times / mm in the "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004).

[0155] Table 7. Content of aggregates in each grade when n is 1.26

[0156]

[0157] Table 8. Dynamic stability of FMA-13 ​​at an oil-stone ratio of 8.0

[0158]

[0159] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method of designing a skeleton of a flowing cement asphalt mixture, characterized in that, Comprising the following steps: (1) Determine the maximum particle size of the gradation according to the actual needs; then assume several different n values ​​and use the Talbol formula to calculate the passing rate of each grade of aggregate under different n values, and obtain the content of each grade of aggregate; then remove the content of the part below 0.075mm, and redistribute the remaining part according to the proportion to obtain the content of each grade of aggregate after removing the part below 0.075mm; finally, according to the wet mixing test method, measure the V of each gradation under different n values. ag V can be obtained by fitting the data. ag The relational model of -n is shown in equation (A): In formula (A): a1 is the value of V theoretically when n tends to 0 ag value a2 is the value of V theoretically when n takes infinite, i.e. a2 is the asymptote of the model; ag value of V theoretically when n takes infinite, i.e. a2 is the asymptote of the model; X0 is the theoretical V ag n value at mid-value, dimensionless P reflects the speed of the model approaching the asymptote, the larger the value, the faster the speed of approaching the asymptote; (2) According to the actual situation, determine the required oil stone ratio and powder glue ratio, and then calculate the glue pulp amount P of FMA mixture through formula (B) ma : P ma = (oil to rock ratio / (1 + oil to rock ratio)) x (1 + ratio of powder to glue) x 100% (B); (3) the amount P of the cement paste of the FMA mixture calculated in step (2) ma , the amount P of the cement paste calculated by the MaFF method ma corresponding to V ag ; (4) the V ag substitute the V ag n relationship model to determine the corresponding n value; the determined n value is substituted into the Talbol formula to determine the skeleton grading composition design of the FMA.

2. The method of designing a skeleton of flowing cement asphalt mixture according to claim 1, characterized in that, The number of different n values in step (1) is greater than or equal to 4.

3. The method of designing a skeleton of flowing cement asphalt mixture according to claim 2, characterized in that, The selection of n values includes four point values of 0.00001, 0.45, 3.5 and 11.

4. The method of designing a skeleton of flowing cement asphalt mixture according to claim 1, wherein, In step (3), in the MaFF method, the relationship between the aggregate amount P of the FMA mixture ag , the mortar amount P ma , and V ag is shown in equations (C) and (D): P ma +P ag =100% (C) In formula (C): P ag The amount of aggregate (in weight percent) for the FMA mixture is P ma P is the amount of cement paste (in weight percent) for the FMA mixture. In formula (D): V ag FMA mixture is the skeleton porosity; VV is the designed internal porosity, % measured; the measured value of the internal porosity of FMA is less than 1%; F d For the filling degree, it represents the filling degree of the paste to the skeleton gap, the value range is 0~1.0, dimensionless; γ c Bulk density of the aggregate in the tamped or compacted state, g / cm 3 , measured; P ma0 For the amount of adhesive paste, by mixing test measured; gamma ma Relative density of the cement paste, dimensionless, measured.

5. The method of designing a skeleton of flowing cement asphalt mixture according to claim 1, wherein, In step (4), a suitable reduction factor α is determined based on the actual working conditions. First, the reduction factor is substituted into V. ag In the relational model of -n, V ag After reduction, V is calculated in step (3). ag Substitute the reduced V ag The corresponding value of n is determined in the relational model of -n; the reduction coefficient α ranges from 0.7 to 0.

9.

6. A method of designing the skeleton of a flowing cement asphalt mixture according to any one of claims 1 to 5, characterized in that, In step (4), considering that there will be fluctuations in the results of different test environments, on the basis of the finally determined n value, an upward and downward fluctuation of 0.1 is allowed, that is, the numerical range when substituting into the Talbol formula is n-0.1~n+0.1.

Images