A method for optimizing design of asphalt mixture containing smoke-suppressing additive

Abstract

The present application belongs to the technical field of road engineering materials, and particularly relates to an optimization design method of asphalt mixture containing smoke suppressing additive. The optimization design method constructs a target function about the negative influence of the asphalt smoke generated by the asphalt mixture in the construction process on the ecological environment and the road performance of the asphalt mixture after construction; collects the emission data of the asphalt smoke generated by the asphalt mixture in the construction process and performs principal component analysis to obtain an ecological environment negative influence function x of the asphalt mixture; collects the road performance data of the asphalt mixture after construction and performs weighted analysis to obtain a road performance function y of the asphalt mixture; and calculates a target function Target(x, y) and takes the minimization thereof as the optimization target. The optimization design method simultaneously considers the technical performance and the environmental problem, meets the demand of the common development of the low-carbon environmental protection and the good technical performance of the tunnel asphalt pavement paving, and the balance optimization design method has a wide application range and is simple to calculate.

Description

Technical Field

[0001] This invention belongs to the field of road engineering materials technology, specifically relating to an optimized design method for asphalt mixtures containing smoke suppressant additives. Background Technology

[0002] With the rapid development of highway construction, the highway network is becoming increasingly sophisticated. Tunnels play a vital role in improving the technical condition of highways, shortening travel distances, increasing transport capacity, and reducing accidents, making tunnel engineering a key project in highway construction.

[0003] During the construction of asphalt concrete pavement inside tunnels, the high temperatures generate significant amounts of asphalt fumes (mainly including particulate matter, volatile organic compounds, sulfur dioxide, and nitrogen oxides), severely impacting the ecological environment and posing substantial environmental remediation challenges. Existing research indicates that fume suppressants can effectively inhibit asphalt fume generation, but they negatively affect road performance. Optimizing the balance between the environmental and technical performance of tunnel asphalt pavement materials has become a key research focus. This aims to extend the service life of tunnel asphalt pavements while significantly reducing asphalt fume emissions during construction.

[0004] Therefore, inventing a method for balancing and optimizing the environmental technical performance of tunnel asphalt pavement materials is of great significance for tunnel asphalt pavement construction. Summary of the Invention

[0005] The purpose of this invention is to balance the environmental pollution and technical performance of asphalt pavement materials, and to provide an optimized design method for asphalt mixtures containing smoke-suppressing additives. This addresses the imbalance between increasingly sophisticated technologies and the still-emerging need for environmental protection in the field of road engineering, especially in tunnel paving. This invention focuses on effectively mitigating negative ecological and environmental impacts, prioritizing environmental pollution reduction while ensuring pavement technical performance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An optimization design method for asphalt mixtures containing smoke suppressant additives includes the following steps:

[0008] 1) Taking the type and / or dosage of smoke suppressant additives as design variables, and seeking the balance between the negative impact of asphalt mixtures on the ecological environment during construction and the road performance of asphalt mixtures after construction as optimization objectives, the environmental technical performance balance optimization design objective function Target(x,y) of asphalt mixtures containing smoke suppressant additives is established using the negative ecological environment function x and the road performance function y.

[0009] 2) Design asphalt mixtures containing different types and / or dosages of smoke-suppressing additives;

[0010] 3) Collect data on the emission of asphalt fumes generated during the construction of the asphalt mixture designed in step 2), as well as the road performance data of the asphalt mixture after construction;

[0011] 4) Principal component analysis was performed on the collected asphalt fume emission data to obtain the comprehensive index of pollution control effect of asphalt mixture; the negative ecological and environmental impact function x is reflected by the comprehensive index of pollution control effect.

[0012] 5) Using a weighted method, the collected road performance data are analyzed to obtain the road performance function y of the asphalt mixture;

[0013] 6) Based on the negative ecological environment function obtained in step 4) and the road performance function obtained in step 5), calculate the objective function Target(x,y), and determine the optimal design scheme with the goal of maximizing Target(x,y).

[0014] Preferably, in step 1), the formula for calculating the objective function Target(x,y) is:

[0015] Target(x,y)=σx+ηy

[0016] In the formula, σ is the weight coefficient of the negative ecological and environmental impact function x, η is the weight coefficient of the road performance function y, σ≥0, η≥0, and σ+η=1.

[0017] Preferably, in step 3), the emission data of the asphalt fumes is the concentration of key components in the asphalt fumes, and the key components include one or more of particulate matter, volatile organic compounds, sulfur dioxide, nitrogen oxides, hydrogen sulfide, and carbon dioxide.

[0018] Preferably, in step 4), the comprehensive index of pollution control effectiveness is C. i The formula for calculating the negative ecological and environmental impact function x is as follows:

[0019]

[0020] In the formula, W is the measured emission concentration of the i-th key component; e i The contribution rate of the i-th key component; i = 1, 2, 3, ..., m, where m is the i-th key component;

[0021]

[0022] Where λ is the covariance matrix (S ij ) mn eigenvalues.

[0023] More preferably, the covariance matrix is ​​calculated by measuring the dimensionless matrix (y). ij ) mn Since the physical dimensions of the characteristic values ​​of various indicators are different, the characteristic values ​​of the indicators are standardized, that is, the characteristic values ​​of the indicators are transformed into the relative membership degree of the indicators to the fuzzy concept A_. Because the measured indicators are all of the type where smaller is better, the formula is:

[0024]

[0025] In the formula, x ij Let be the measured emission concentration of the i-th key component in the asphalt fumes generated during the construction of the j-th asphalt mixture containing smoke suppressant additives; j = 1, 2, 3, ..., n, where n is the j-th asphalt mixture containing smoke suppressant additives.

[0026] Preferably, in step 3), the road performance data includes dynamic stability, flexural stiffness modulus, and freeze-thaw splitting tensile strength.

[0027] More preferably, in step 5), the formula for calculating the road performance function y is:

[0028]

[0029] In the formula, α, β, and χ represent weighting coefficients, α≥0, β≥0, χ≥0, and α+β+χ=1; H represents the dynamic stability of asphalt mixture containing smoke suppressant additives; Ha represents the dynamic stability of base asphalt mixture; W represents the flexural stiffness modulus of asphalt mixture containing smoke suppressant additives; Wa represents the flexural stiffness modulus of base asphalt mixture; T represents the freeze-thaw splitting tensile strength of asphalt mixture containing smoke suppressant additives; Wa represents the freeze-thaw splitting tensile strength of base asphalt.

[0030] High-temperature stability is reflected by the dynamic stability measured by the rutting test; low-temperature crack resistance is reflected by the flexural stiffness modulus of the low-temperature beam bending test; and water stability is reflected by the freeze-thaw splitting tensile strength of the freeze-thaw splitting test.

[0031] The present invention also provides an asphalt mixture containing smoke suppressant additives obtained by the above-described optimization design method.

[0032] This invention also provides the application of the aforementioned asphalt mixture containing smoke suppressant additives in the paving and repair of tunnel asphalt pavements. The optimized design method provided in this aspect is particularly suitable for tunnel asphalt pavements, taking into account both the technical performance of tunnel asphalt pavements and the environmental pollution caused by asphalt pavement paving in the enclosed environment inside the tunnel; it has a wide range of applications, applicable to both small tunnels with relatively simple tunnel conditions and medium-length tunnels with complex tunnel conditions and stronger spatial sealing.

[0033] The beneficial effects of this invention are at least as follows:

[0034] The present invention provides an optimization design method for asphalt mixtures containing smoke suppressing additives. By constructing a multi-objective optimization mathematical model, it solves the problem of the uncoordinated development of the ecological environment and technical performance of pavement materials, and meets the needs of low-carbon and environmentally friendly asphalt pavement with good technical performance. Furthermore, this balanced optimization design method has a wide range of applications, and the calculation method is simple and practical with accurate and reliable results. Attached Figure Description

[0035] Figure 1 This is a flowchart of the optimized design method for asphalt mixtures containing smoke suppressant additives provided by the present invention. Detailed Implementation

[0036] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and essence of the invention are within the scope of the invention.

[0037] Example 1

[0038] This embodiment uses No. 70 base asphalt with an AC-13 gradation type. Activated carbon is used as the flue gas suppressant, with dosages of 3% and 5% of the asphalt mass, respectively. This can be partially referenced. Figure 1 It is done in the following steps:

[0039] (1) Define the objective function of negative impact on ecological environment and technical performance, determine the design variables, and construct a multi-objective optimization mathematical model.

[0040] Target(x,y) is defined as the objective function of negative environmental impact and technical performance: Target(x,y) = σx + ηy. The weights of these two components, based on the specific circumstances of this embodiment, are σ = 0.55 and η = 0.45, respectively.

[0041] (2) Add different amounts of activated carbon to asphalt mixtures, test the road performance of different asphalt pavement materials and collect asphalt fume emission data.

[0042] The road performance of asphalt pavement materials with different amounts of activated carbon were tested, and the test results were summarized and recorded. The flue gas generated during the construction of asphalt pavement materials with different amounts of activated carbon was collected, and the emissions of NO and H2S were analyzed in this embodiment. The results are shown in Table 1.

[0043] Table 1. Concentration of flue gas generated during the construction process of asphalt pavement materials with different activated carbon contents.

[0044] Additive dosage 3% activated carbon 5% activated carbon <![CDATA[NO(mg / m 3 )]]> 0.2 0.1 <![CDATA[H2S(mg / m 3 )]]> 0.5 0.4 <![CDATA[CO2(mg / m 3 )]]> 0.2 0.3

[0045] That is, the original data Where, x 11 =0.2, x 12 =0.1, x 21 =0.5, x 22 =0.4, x 31 =0.2, x 32 =0.3;

[0046] (3) Using principal component analysis, the experimental design results are processed and analyzed to obtain the comprehensive index of the sample.

[0047] Firstly, through The dimensionless data with the same trend were calculated and are shown in Table 2.

[0048] Table 2 Data after trending and dimensionless transformation

[0049] Additive dosage 3% activated carbon 5% activated carbon <![CDATA[NO(mg / m 3 )]]> 0.75 1 <![CDATA[H2S(mg / m 3 )]]> 0 0.25 <![CDATA[CO2(mg / m 3 )]]> 0.75 0.5

[0050] Secondly, the corresponding covariance matrix is ​​obtained by analyzing the dimensionless data with the same trend. Then, the eigenvalues ​​of the covariance matrix are solved, and the contribution rate is calculated. The contribution rates are 0.27, 0.10, 0.23, 0.18, 0.04, and 0.18, respectively.

[0051] Calculations showed that when the additive was 3% activated carbon, x = 0.15; and when the additive was 5% activated carbon, x = 0.088. A lower comprehensive pollution control index indicates better pollution control effectiveness, and vice versa.

[0052] (4) Technical performance evaluation

[0053] The road performance of asphalt mixtures with different admixtures was evaluated, and the experimental data on high temperature stability, low temperature crack resistance and water temperature qualitative properties were summarized and compiled. See Table 3 below. The weights in the y function were assigned according to the actual conditions of the tunnel construction site. The weights selected in this embodiment are 0.4, 0.3 and 0.3 respectively, according to the actual conditions of this embodiment.

[0054] Table 3

[0055] Additive dosage Dynamic stability Flexural stiffness modulus Freeze-thaw splitting tensile strength 3% activated carbon 3900 3850 6 5% activated carbon 3750 3400 8 Base asphalt 3000 3200 4

[0056] The base asphalt is an asphalt mixture that does not contain smoke suppressant additives.

[0057] Calculations show that when the additive contains 3% activated carbon, y = 0.33; and when the additive contains 5% activated carbon, y = 0.42. A higher technical performance evaluation index indicates better pavement performance, and vice versa.

[0058] (5) Calculate the objective function Target(x,y) to obtain the optimal combination of design variables.

[0059] The weights of Target(x,y) are assigned according to the actual needs of the tunnel project. In this embodiment, the weights selected are 0.55 and 0.45, respectively, based on the actual situation. Calculations show that when the additive is 3% activated carbon, Target(x,y) = 0.231; when the additive is 5% activated carbon, Target(x,y) = 0.2374. A smaller Target(x,y) indicates a better optimization effect, and vice versa.

[0060] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for the optimal design of asphalt mixtures containing smoke suppressing additives, characterized in that, It comprises the following steps: 1) Taking the type and / or amount of smoke-suppressing additive as design variable, taking the balance between the negative impact on ecological environment of asphalt mixture during construction and the road performance of asphalt mixture after construction as optimization target, using the negative impact on ecological environment function x and the road performance function y, establishing the target function Target(x, y) of the balance optimization design of the environmental technical performance of asphalt mixture containing smoke-suppressing additive; 2) Designing asphalt mixture containing smoke-suppressing additive with different types and / or amounts; 3) Collecting the emission data of asphalt smoke generated during the construction of the asphalt mixture designed in step 2) and the road performance data of the asphalt mixture after construction; 4) Performing principal component analysis on the collected emission data of asphalt smoke to obtain a comprehensive index of pollution control effect of the asphalt mixture; the negative impact on ecological environment function x is reflected by the comprehensive index of pollution control effect; 5) Using the weighted method to analyze the collected road performance data to obtain the road performance function y of the asphalt mixture; 6) According to the negative impact on ecological environment function obtained in step 4) and the road performance function obtained in step 5), calculating the target function Target(x, y), and determining the optimal design scheme by minimizing Target(x, y); In step 3), the emission data of asphalt smoke is the concentration of one or more than two of the key components in asphalt smoke, including particulate matter, volatile organic compounds, sulfur dioxide, nitrogen oxides, hydrogen sulfide, and carbon dioxide; In step 4), the pollution treatment effect comprehensive index is C i The calculation formula of the ecological environment negative influence function x is: In the formula, Wi is the measured value of the emission concentration of the ith key component; e i is the contribution rate of the ith key component; i = 1, 2, 3, …, m, and m is the ith key component. where λi is the eigenvalue of the covariance matrix (S ij ) mn of the ith key component. The covariance matrix is obtained by calculating a dimensionless matrix (y ij ) mn The formula for the dimensionless matrix (y ij ) mn ​ wherein x ij is the measured emission concentration of the i-th key component in the asphalt fume generated during the construction of the j-th asphalt mixture containing smoke-suppressing additive; j = 1, 2, 3, …, n, n is the j-th asphalt mixture containing smoke-suppressing additive; In step 5), the calculation formula of the road performance function y is: In the formula, α, β, χ represent weight coefficients respectively, α≥0, β≥0, χ≥0, and α+β+χ=1; H represents the dynamic stability of asphalt mixture containing smoke-suppressing additive; Ha represents the dynamic stability of base asphalt mixture; W represents the bending stiffness modulus of asphalt mixture containing smoke-suppressing additive; Wa represents the bending stiffness modulus of base asphalt mixture; T represents the freeze-thaw splitting tensile strength of asphalt mixture containing smoke-suppressing additive; Wa represents the freeze-thaw splitting tensile strength of base asphalt.

2. The smoke suppressing additive containing asphalt mixture optimization design method according to claim 1, characterized in that, In step 1), the calculation formula of the target function Target(x, y) is: Target(x, y)=σx+ηy In the formula, σ is the weight coefficient of the negative impact on ecological environment function x, η is the weight coefficient of the road performance function y, σ≥0, η≥0, and σ+η=1.

3. An asphalt mixture containing smoke-suppressing additive obtained by the optimization design method of claim 1 or 2.

4. The application of the asphalt mixture containing smoke-suppressing additive of claim 3 in the paving and repairing of tunnel asphalt pavement.

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