Mixing method of hot mix plant recycled asphalt mixture

Abstract

The invention belongs to the field of asphalt production, and particularly relates to a mixing method of a plant-mixed hot recycled asphalt mixture, which comprises the following steps: crushing and screening recycled road asphalt wastes to obtain recycled materials, and storing the recycled materials in a graded manner according to particle sizes; historical data of asphalt mixture production are obtained, and characteristic coefficients of corresponding materials, time and temperature are extracted after data processing; establishing a dynamic configuration model based on a mixed material ratio, and dynamically configuring a mixed material mixing scheme according to process requirements; establishing a temperature control time sequence model based on a mixed material ratio, time and temperature characteristic coefficients, and dynamically configuring a temperature control time sequence scheme according to process requirements; precise graded storage of particle sizes is achieved through multi-stage crushing and screening, utilization of reclaimed materials is facilitated, matching control, temperature control and time sequence control in the mixing process are conducted in combination with historical production data, mixing of the mixture under corresponding process requirements is conducted in a standardized mode, and the output quality of the mixture is improved.

Description

Technical Field

[0001] This invention relates to the field of asphalt production, and specifically to a mixing method for plant-mixed hot recycled asphalt mixtures. Background Technology

[0002] Plant-mixed hot recycled asphalt mixture is a technology that recycles old asphalt pavement materials and reprocesses them into road materials. The specific process includes excavating the old asphalt pavement and transporting it back to the mixing plant, where it is crushed, screened, and its material composition is analyzed. Then, recycling agents, new aggregates, and asphalt are added and remixed to form a recycled mixture.

[0003] The existing technology has the following problems:

[0004] In the recycled asphalt process, waste asphalt mixtures can only be used as fillers, with a blending ratio of ≤30%, which cannot be fully utilized. During the mixing process, the mix proportions rely on experience and lack quantitative component ratios and temperature timing parameters, resulting in inconsistent quality of each batch of produced mixtures and deficiencies. Summary of the Invention

[0005] (a) Purpose of the invention

[0006] To address the technical problems existing in the background art, this invention proposes a mixing method for plant-mixed hot recycled asphalt mixtures, which features multi-stage crushing and screening to facilitate the utilization of recycled materials and standardized mixing of mixtures according to corresponding process requirements.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, the present invention provides a mixing method for plant-mixed hot recycled asphalt mixture, comprising the following steps:

[0009] Step 1: The recycled road asphalt waste is crushed and screened into recycled material, which is then stored according to particle size.

[0010] Step 2: Obtain historical data on asphalt mixture production, and extract the characteristic coefficients corresponding to the materials, time, and temperature after data processing;

[0011] Step 3: Establish a dynamic configuration model based on the proportion of mixed materials, and dynamically configure the mixing scheme of the mixture according to process requirements;

[0012] Step 4: Establish a temperature control timing model based on the mixing ratio of the mixed materials, time and temperature characteristic coefficients, and dynamically configure the temperature control timing scheme according to process requirements;

[0013] Step 5: Strictly monitor the temperature and mixing time of each process during production to ensure that the production conforms to the mixing plan and temperature control sequence plan.

[0014] Preferably, the processing steps for recycled road asphalt waste include:

[0015] Jaw crushers and impact crushers are used to crush road asphalt waste in multiple stages, producing recycled material with a particle size of less than 30mm after graded crushing.

[0016] Recycled material particles are screened using a vibrating screen with four layers of mesh, and then stored in separate bins according to particle size.

[0017] Preferably, detailed production records of all types of asphalt mixtures that meet quality standards have been collected in the past.

[0018] The material characteristic data obtained include: the actual proportion of recycled materials used, the proportion of recycling additives, and the proportion of new asphalt.

[0019] The acquired time characteristic data includes the processing time data of each process, the dry mixing time of recycled materials and recycling additives, and the wet mixing time after adding new asphalt material;

[0020] Temperature characteristic data includes processing temperature data for each process, heating temperature of recycled material, heating temperature of recycled material and recycling additive mixture, and heating temperature after adding new asphalt material;

[0021] The quality data includes the final key quality indicators of this batch of mixture, Marshall stability, flow value, void ratio, aggregate void ratio, asphalt saturation, and field compaction degree.

[0022] Preferably, a multiple linear regression model is established to quantify the contribution weight of each input—material characteristic data, time characteristic data, and temperature characteristic data—to the output quality data, and these weights are then converted into corresponding values.

[0023] Material characteristic coefficients: actual proportion coefficient of recycled material α, proportion coefficient of recycling additive β, and proportion coefficient of new asphalt material γ;

[0024] Time characteristic coefficients: dry mixing time coefficient td and wet mixing time coefficient tw;

[0025] Temperature characteristic coefficients: heating temperature coefficient X of recycled material, heating temperature coefficient Y of the mixture of recycled material and recycling additives, and heating temperature coefficient Z after the addition of new asphalt material;

[0026] Quality characteristic coefficient: Quality index coefficient C.

[0027] Preferably, the actual proportion of recycled material of each particle size after grading is determined based on the actual proportion coefficient α of the recycled material, and the proportion analysis of the graded recycled material is performed.

[0028] Preferably, the dynamic configuration model uses material characteristic coefficients and mass characteristic coefficients to construct an optimization model. This model is based on the mass characteristic coefficient C and the material characteristic coefficients α, β, and γ, and combines process requirements to solve for the optimal material ratio through an optimization algorithm.

[0029] Preferably, according to the meaning of coefficient α, the total recycled material ratio R needs to be allocated to recycled materials of various particle sizes. Let the particle size classification of the recycled materials be i, such as 3-5mm, 5-10mm, etc., then: , ;

[0030] in This is the proportion of recycled material with particle size of grade i. It is the proportionality coefficient for that particle size.

[0031] Preferably, based on steps one, two, and three, the proportions of recycled material (R), recycled additive (A), and new asphalt (N) during the mixing process are confirmed. The proportion of recycled material of each particle size in the recycled material proportion R is further confirmed, and the dry mixing time is determined based on these proportions. and wet mixing time The formulation of the formula, during the mixing process and The heating temperature is distributed accordingly.

[0032] Preferably, the dynamic configuration model and temperature control timing model are repeatedly validated using historical data and production data.

[0033] Preferably, an external infrared thermal imaging device and an embedded thermocouple sensor are installed to monitor the heating process of recycled material, the heating process of mixing recycled material and recycling additives, and the heating process of new asphalt material in stages.

[0034] The timer and drive unit work together. The timer starts when the material enters the corresponding mixing device. The drive unit works to mix the mixture according to the corresponding process. The current output of the corresponding drive unit is recorded to confirm whether the drive unit has reached the preset mixing efficiency.

[0035] The above-mentioned technical solution of the present invention has the following beneficial technical effects: it achieves precise particle size classification and storage through multi-stage crushing and screening, which facilitates the utilization of recycled materials; it combines historical production data to control the proportion, temperature and timing of the mixing process, and standardizes the mixing of the mixture under the corresponding process requirements, thereby improving the output quality of the mixture. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the mixing steps of the plant-mixed hot recycled asphalt mixture of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0038] like Figure 1 As shown, the present invention proposes a mixing method for plant-mixed hot recycled asphalt mixtures, comprising the following steps:

[0039] Step 1: The recycled road asphalt waste is crushed and screened into recycled material, which is then stored according to particle size.

[0040] Jaw crushers and impact crushers are used to crush road asphalt waste in multiple stages. The output particle size of the jaw crusher is 30-50mm, and the output particle size of the impact crusher is less than 30mm. The road asphalt waste is crushed in stages to produce recycled material with a particle size of less than 30mm.

[0041] The recycled material particles are screened by a vibrating screen with four layers of screens, with the screen grades from bottom to top being 3-5mm, 5-10mm, 10-16mm, and 16-25mm.

[0042] Recycled materials at each stage are screened out in layers and stored in separate bins according to particle size;

[0043] The storage silo has a sealed, moisture-proof structure, and the storage temperature is below 30℃.

[0044] Step 2: Obtain historical data on asphalt mixture production, and extract the characteristic coefficients corresponding to the materials, time, and temperature after data processing;

[0045] Collect detailed production records of all types of asphalt mixtures that meet quality standards from the past production.

[0046] The material characteristic data obtained include: the actual proportion of recycled materials used, the proportion of recycling additives, and the proportion of new asphalt.

[0047] The acquired time characteristic data includes the processing time data of each process, the dry mixing time of recycled materials and recycling additives, and the wet mixing time after adding new asphalt material;

[0048] Temperature characteristic data includes processing temperature data for each process, heating temperature of recycled material, heating temperature of recycled material and recycling additive mixture, and heating temperature after adding new asphalt material;

[0049] The quality data includes the final key quality indicators of this batch of mixture, Marshall stability, flow value, void ratio, aggregate void ratio, asphalt saturation, and field compaction degree.

[0050] The acquired data is cleaned and preprocessed to remove data that is incomplete, contains obvious errors, or is from periods of equipment failure. All material ratio data, time records, temperature records, and final quality data of the same batch are matched to ensure that the format and timestamps of different data sources are consistent.

[0051] Establish a multiple linear regression model to quantify the contribution weight of each input—material characteristic data, time characteristic data, and temperature characteristic data—to the output quality data, and transform these weights into corresponding values:

[0052] Material characteristic coefficients: actual proportion coefficient of recycled material α, proportion coefficient of recycling additive β, and proportion coefficient of new asphalt material γ;

[0053] Time characteristic coefficients: dry mixing time coefficient td and wet mixing time coefficient tw;

[0054] Temperature characteristic coefficients: heating temperature coefficient X of recycled material, heating temperature coefficient Y of the mixture of recycled material and recycling additives, and heating temperature coefficient Z after the addition of new asphalt material;

[0055] Quality characteristic coefficient: Quality index coefficient C.

[0056] Understandably, the actual proportion of recycled material at each particle size can be determined based on the actual proportion coefficient α, thus making full use of the graded recycled material and solving the problem of resource waste.

[0057] Step 3: Establish a dynamic configuration model based on the proportion of mixed materials, and dynamically configure the mixing scheme of the mixture according to process requirements;

[0058] The dynamic configuration model uses material characteristic coefficients and mass characteristic coefficients to construct an optimization model. This model is based on the mass characteristic coefficient C and the material characteristic coefficients α, β, and γ, and combines process requirements to solve for the optimal material ratio through an optimization algorithm.

[0059] The actual proportion coefficient of recycled material α: represents the contribution weight of the recycled material proportion R to the quality index. The larger the value of α, the more significant the impact of the change in the recycled material proportion on the quality.

[0060] Recycling aid ratio coefficient β: represents the contribution weight of recycling aid ratio A to quality indicators. β is usually small because recycling aids are additives, and although the amount used is small, they can improve the performance of recycled materials.

[0061] The new asphalt mix proportion coefficient γ represents the contribution weight of the new asphalt mix proportion N to the quality index. The γ value reflects the direct impact of the new asphalt on the quality.

[0062] Quality index coefficient C: From the intercept term of the regression model, it represents the basic quality level. C is a constant used to adjust the benchmark for quality prediction.

[0063] Based on the multiple linear regression model, quality indicators The prediction is: ;

[0064] It is a quality indicator for prediction;

[0065] R represents the proportion of recycled materials;

[0066] A represents the regeneration aid formulation;

[0067] N is the new asphalt mix proportion;

[0068] The proportions are satisfied .

[0069] Forecast cost metrics include: ;

[0070] The unit cost (RMB / ton) of recycled materials, recycling additives, and new asphalt is derived from real-time market prices or historical data.

[0071] The predicted quality must meet the target quality indicators. ;

[0072] Based on material availability, process limitations, and recycled material grading requirements:

[0073] , : Range of recycled material proportions;

[0074] ;

[0075] ; : New asphalt mix proportion range;

[0076] Based on the meaning of coefficient α, the total recycled material proportion R needs to be allocated to recycled materials of various particle sizes. Let the particle size classification of the recycled materials be i, such as 3-5mm, 5-10mm, etc., then: , ;

[0077] in This is the proportion of recycled material with particle size of grade i. This is a proportion coefficient for that particle size. For example, historical data shows that 10-16mm recycled material accounts for 30% of the total recycled material. =0.3.

[0078] As an example, suppose the historical regression coefficients are: C=5.0, α=0.2, β=0.1, γ=0.3;

[0079] Process requirements: Target stability Qt = 8.0 kN, minimum cost =100 yuan / ton =500 yuan / ton, =300 yuan / ton;

[0080] Mixing ratio range: R: 20-50%, A: 0.5-2%, N: 30-70%.

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] Using linear programming, R=0.35, A=0.01, N=0.64;

[0087] Cost = 100 × 0.35 + 500 × 0.01 + 300 × 0.64 = 35 + 5 + 192 = 232 yuan / ton;

[0088] The grading ratio ki of recycled material is: 3-5mm:20%, 5-10mm:30%, 10-16mm:30%, 16-25mm:20%, and the ratio of each particle size is Ri=ki×R=[0.07,0.105,0.105,0.07];

[0089] The model enables efficient resource utilization by maximizing R and grading constraints, dynamically responding to process changes and customizing the mixing scheme of the mixture. This improves the quality and economy of the mixture while ensuring that the recycled asphalt waste can be fully utilized after grading.

[0090] Step 4: Establish a temperature control timing model based on the mixing ratio of the mixed materials, time and temperature characteristic coefficients, and dynamically configure the temperature control timing scheme according to process requirements;

[0091] Combining steps two and three, the complete quality prediction equation is:

[0092]

[0093] Predicting quality indicators;

[0094] : Fundamental mass constant;

[0095] R,A,N: Material ratio;

[0096] , , Material characteristic coefficients;

[0097] Dry mixing time, : Wet mixing time;

[0098] , Time characteristic coefficient ∈[0.5,5]min,, ∈[1,6]min;

[0099] Heating temperature of recycled materials; : Mixing temperature of recycled materials and additives; Temperature after new asphalt is added;

[0100] ∈[150,180]℃, ∈[140,170]℃, ∈[130,160]℃;

[0101]

[0102]

[0103] Temperature characteristic coefficient;

[0104]

[0105] ;

[0106]

[0107] As an example of dynamically configuring a temperature control timing scheme based on process requirements: Based on steps one, two, and three, confirm the recycled material ratio R, the recycling additive ratio A, and the new asphalt ratio N during the mixing process. Further confirm the proportion of recycled material of each particle size in the recycled material ratio R, and determine the dry mixing time based on these proportions. and wet mixing time The formulation of the formula, during the mixing process and The heating temperature is allocated and combined with the exothermic impact threshold to ensure that the temperature does not overheat and cause over-processing of the mixture in all processing steps. The mixing time and heating temperature are precisely controlled in the formulation of the mixture mixing plan, which effectively solves the problems of resource waste and energy consumption in the recycling asphalt mixing process, and provides a quantifiable and replicable solution for asphalt recycling.

[0108] In one embodiment, the dynamic configuration model and the temperature control time series model are repeatedly validated using historical data and production data. The data source is the record of 400 batches of qualified asphalt mixtures produced in the past year, including material proportions, time, temperature parameters and quality results.

[0109] Real-time production data: For the 20 newly put into production batches of mixture, parameters are generated according to the dynamic configuration model and the temperature control time sequence model to assist production.

[0110] As a validation example: 400 batches of historical data were backtested, and 20% of the data were randomly selected as the validation set;

[0111] Model prediction error compared to actual mass: stability MAE ≤ 0.15kN, porosity error ≤ 0.3%;

[0112] Twenty batches of mixed materials were produced, and verification batches were produced according to the model output parameters. The pass rate of key indicators was ≥98%.

[0113] Continuous production monitoring of 50 batches of mixed materials, real-time collection of temperature, time and quality data points for each process.

[0114] Step 5: Strictly monitor the temperature and mixing time of each process during production to ensure that the production conforms to the mixing plan and temperature control sequence plan.

[0115] As an example of temperature monitoring in each process of production: an external infrared thermal imaging device and an embedded thermocouple sensor are set up to monitor the heating process of recycled material, the heating process of mixing recycled material and recycled additives, and the heating process of new asphalt material in stages. The temperature of the monitored material is required to be ±3℃ from the temperature control sequence scheme. When the temperature error occurs, an alarm is triggered to prompt the staff to adjust the temperature of the corresponding heating process.

[0116] As an example of the mixing time for each process in the production process: the timer and the drive device work together to start timing from the moment the material enters the corresponding mixing device. The drive device works to mix the mixture for the corresponding process. The machine stops after the predetermined dry mixing or wet mixing time is reached. The dry mixing starts at the moment the recycled material enters the mixing tank, which is triggered by the material level sensor.

[0117] The wet mixing start signal is the injection of new asphalt, triggered by a pressure sensor ≥0.5MPa;

[0118] Record the current output of the corresponding drive device when it is working to confirm whether the drive device has reached the preset mixing efficiency.

[0119] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for mixing plant-mixed hot recycled asphalt mixtures, characterized in that, Includes the following steps: Step 1: The recycled road asphalt waste is crushed and screened into recycled material, which is then stored according to particle size. Step 2: Obtain historical data on asphalt mixture production, and extract the characteristic coefficients corresponding to the materials, time, and temperature after data processing; Step 3: Establish a dynamic configuration model based on the proportion of mixed materials, and dynamically configure the mixing scheme of the mixture according to process requirements; Step 4: Establish a temperature control timing model based on the mixing ratio of the mixed materials, time and temperature characteristic coefficients, and dynamically configure the temperature control timing scheme according to process requirements; Step 5: Strictly monitor the temperature and mixing time of each process during production to ensure that the production conforms to the mixing plan and temperature control sequence plan.

2. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, The processing steps for recycled road asphalt waste include: Jaw crushers and impact crushers are used to crush road asphalt waste in multiple stages, producing recycled material with a particle size of less than 30mm after graded crushing. Recycled material particles are screened using a vibrating screen with four layers of mesh, and then stored in separate bins according to particle size.

3. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, Collect detailed production records of all types of asphalt mixtures that meet quality standards from the past production. The material characteristic data obtained include: the actual proportion of recycled materials used, the proportion of recycling additives, and the proportion of new asphalt. The acquired time characteristic data includes the processing time data of each process, the dry mixing time of recycled materials and recycling additives, and the wet mixing time after adding new asphalt material; Temperature characteristic data includes processing temperature data for each process, heating temperature of recycled material, heating temperature of recycled material and recycling additive mixture, and heating temperature after adding new asphalt material; The quality data includes the final key quality indicators of this batch of mixture, Marshall stability, flow value, void ratio, aggregate void ratio, asphalt saturation, and field compaction degree.

4. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, Establish a multiple linear regression model to quantify the contribution weight of each input—material characteristic data, time characteristic data, and temperature characteristic data—to the output quality data, and transform these weights into corresponding values: Material characteristic coefficients: actual proportion coefficient of recycled material α, proportion coefficient of recycling additive β, and proportion coefficient of new asphalt material γ; Time characteristic coefficients: dry mixing time coefficient td and wet mixing time coefficient tw; Temperature characteristic coefficients: heating temperature coefficient X of recycled material, heating temperature coefficient Y of the mixture of recycled material and recycling additives, and heating temperature coefficient Z after the addition of new asphalt material; Quality characteristic coefficient: Quality index coefficient C.

5. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 4, characterized in that, Based on the actual proportion coefficient α of the recycled material, the actual proportion of recycled material of each particle size after grading is determined, and the proportion analysis of the graded recycled material is carried out.

6. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, The dynamic configuration model uses material characteristic coefficients and mass characteristic coefficients to construct an optimization model. Based on the mass characteristic coefficient C and material characteristic coefficients α, β, and γ, the model uses an optimization algorithm to solve for the optimal material ratio in combination with process requirements.

7. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, Based on the meaning of coefficient α, the total recycled material ratio R needs to be allocated to recycled materials of various particle sizes. Let the particle size classification of the recycled materials be i. , ; in This is the proportion of recycled material with particle size of grade i. It is the proportionality coefficient for that particle size.

8. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, Based on steps one, two, and three, confirm the recycled material ratio R, the recycling additive ratio A, and the new asphalt ratio N during the mixing process. Further confirm the proportion of recycled material of each particle size in the recycled material ratio R, and determine the dry mixing time based on the proportions of the mixture. and wet mixing time The formulation of the formula, during the mixing process and The heating temperature is distributed accordingly.

9. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, The dynamic configuration model and temperature control timing model were repeatedly validated using historical and production data.

10. The mixing method for plant-mixed hot recycled asphalt mixture according to claim 1, characterized in that, An external infrared thermal imaging device and an embedded thermocouple sensor are installed to monitor the heating process of recycled materials, the heating process of mixing recycled materials and recycling additives, and the heating process of new asphalt materials in stages. The timer and drive unit work together. The timer starts when the material enters the corresponding mixing device. The drive unit works to mix the mixture according to the corresponding process. The current output of the corresponding drive unit is recorded to confirm whether the drive unit has reached the preset mixing efficiency.

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