Pavement repair control method and system based on cold regeneration

Abstract

The invention provides a pavement repair control method and system based on cold regeneration, and relates to the technical field of road engineering. The method comprises the following steps: obtaining a plurality of pavement material samples; obtaining a mixed material sample corresponding to each proportion; adding different dosages of water to each part of the mixed material sample, and determining a target water content corresponding to the mixed material sample in each proportion; manufacturing a test piece corresponding to each proportion; obtaining a mechanical property index of the test piece corresponding to each ratio; determining an optimized ratio and an optimized target water content corresponding to the optimized ratio; determining the spraying flow of water and the adding flow of a stabilizer; and controlling the cold regeneration construction equipment. According to the method and the device, the optimal proportion and the optimal water content of the stabilizer and the pavement material can be determined based on the mixed material sample corresponding to each proportion, so that the cold regeneration construction equipment is controlled, the accuracy of determining the optimal proportion and the optimal water content of the pavement material is improved, and the pavement repairing quality is improved.

Description

Technical Field

[0001] This invention relates to the field of road engineering technology, and in particular to a pavement repair control method and system based on cold recycling. Background Technology

[0002] With the continuous increase in traffic volume, road surface damage is becoming more frequent. Damaged road surfaces affect driving safety and require timely repair to ensure traffic safety. According to relevant technologies, the ratio of stabilizer to road surface materials and water content is usually determined by the experience of employees. However, human determination has a certain degree of randomness, resulting in problems such as inaccurate determination of the ratio of stabilizer to road surface materials and water content, and low efficiency of road surface repair. It is difficult to accurately determine the optimal ratio of stabilizer to road surface materials and the optimal water content, resulting in lower mechanical properties of the repaired road surface.

[0003] The information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] This invention provides a road repair control method based on cold recycling, which can solve the technical problem that it is difficult to accurately determine the optimal ratio of stabilizer to road material and the optimal moisture content in related technologies.

[0005] According to a first aspect of the present invention, a pavement repair control method based on cold recycling is provided, comprising:

[0006] The road surface to be repaired was sampled and crushed to obtain multiple road surface material samples;

[0007] According to various ratios, the stabilizer is mixed with the road material sample to obtain the mixed material sample corresponding to each ratio;

[0008] Divide each ratio of mixed material sample into multiple equal parts, add different amounts of water to each mixed material sample, and determine the target moisture content corresponding to each ratio of mixed material sample;

[0009] Based on the stated ratio and the target moisture content, test specimens corresponding to each ratio are prepared by mixing material samples and water;

[0010] Mechanical tests were conducted on the test specimens corresponding to various ratios to obtain the mechanical performance indicators of the test specimens for each ratio.

[0011] Based on the aforementioned mechanical performance indicators, an optimized mix ratio and an optimized target moisture content corresponding to the optimized mix ratio are determined.

[0012] Based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content, the water spraying flow rate and the stabilizer addition flow rate are determined.

[0013] The cold recycling construction equipment is controlled based on the water spray flow rate and the stabilizer addition flow rate.

[0014] According to the present invention, determining the target moisture content corresponding to each ratio of the mixed material sample includes:

[0015] Different amounts of water were added to each sample of the mixed material to obtain multiple samples of the mixed material containing water.

[0016] Each sample of the water-containing mixed material was subjected to a compaction test to obtain the compaction test sample;

[0017] The wet density and moisture content of the compaction test samples were measured.

[0018] The dry density of the compaction test sample is obtained based on the wet density and moisture content of the compaction test sample.

[0019] Based on the moisture content and dry density of the compaction test samples, obtain the dry density function corresponding to the mix proportion;

[0020] The target moisture content corresponding to the ratio is determined based on the dry density function.

[0021] According to the present invention, obtaining the dry density function corresponding to the proportion includes:

[0022] According to the formula

[0023]

[0024] The first equation to be fitted for the dry density function is obtained, where ρ d,i,j Let ρ be the dry density of the j-th sample of the aqueous mixture corresponding to the i-th proportion. d,i,max ρ represents the maximum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. d,i,min w represents the minimum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. i,j Let err represent the moisture content of the j-th sample of the aqueous mixture corresponding to the i-th proportion. i,j Let α be the residual of the j-th sample of the aqueous mixture corresponding to the i-th proportion. 1,i α 2,i α 3,i α 4,i The first coefficient of the first equation to be fitted;

[0025] Based on the dry density and moisture content of multiple samples of water-containing mixed materials with the i-th ratio, the first coefficient to be fitted is solved to obtain the solution value of the first coefficient to be fitted.

[0026] Based on the solved values ​​of the first coefficients to be fitted and the first equation to be fitted, the dry density function corresponding to the i-th ratio is obtained.

[0027] According to the present invention, the mechanical property indicators of the test specimens corresponding to each formulation are obtained, including:

[0028] Place the test piece on the test bench, take a reference top view image of the test piece, and take reference side view images of the test piece from multiple angles on the side.

[0029] The test piece was subjected to multiple loads in a vertically downward direction. After each load application, a comparative top view image and a comparative side view image of the test piece were taken. The loads applied each time were not equal and increased successively.

[0030] The tensile performance index of the test specimen is obtained based on the reference top view image and the comparison top view image;

[0031] Based on the reference side image and the comparison side image, the deformation resistance index of the test piece is obtained;

[0032] The mechanical properties of the test specimen are obtained based on the tensile strength index and the deformation resistance index.

[0033] According to the present invention, obtaining the tensile properties of a test specimen includes:

[0034] Determine the first centroid and first edge of the region where the test piece is located in the reference top view image;

[0035] Obtain the first inscribed circle of the first edge;

[0036] Within the first inscribed circle, a plurality of first circular test lines are set, wherein the first circular test lines are centered on the first centroid.

[0037] After each load is applied, determine the second centroid and second edge of the region where the test piece is located in the comparative top view image;

[0038] Obtain the second inscribed circle of the second edge;

[0039] Within the second inscribed circle, a plurality of second circular test lines are set, wherein the second circular test lines are centered on the second centroid, and the number of second circular test lines is the same as that of the first circular test lines;

[0040] The tensile properties of the test specimen are determined based on the applied load, the first circular test line, and the second circular test line.

[0041] According to the present invention, determining the tensile properties of a test specimen includes:

[0042] According to the formula

[0043]

[0044] The tensile deformation index ΔD of the test specimen with the i-th mix ratio after the k-th load application was obtained. i,k , where L 2,i,k,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s L represents the number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 1,i,s,t+1 L represents the brightness value of the (t+1)th pixel on the (s)th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s,t Let n be the brightness value of the t-th pixel on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s L represents the number of pixels on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 2,i,k-1,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)th load application. 2,i,k-1,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)-th load application. 2,i,k-1,s N represents the number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test piece with the i-th ratio after the (k-1)th load application, and N is the number of the first circle center test lines.

[0045] Determine the maximum value of the tensile deformation index of the test specimen with the i-th mix ratio after each load application, and the number of load applications corresponding to the maximum value of the tensile deformation index;

[0046] According to the formula

[0047]

[0048] Determine the tensile property index T of the test specimen with the i-th mix ratio. i , of which F i,kmaxF is the load corresponding to the number of times the load is applied, which corresponds to the maximum value of the deformation index of the test piece with the i-th mix ratio. max For the maximum load, ΔD i,ave Let ΔD be the average tensile deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max L represents the maximum tensile deformation index of the test specimen with the i-th mix ratio. 2,i,max,s,t+1 L is the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th ratio after the number of load applications reaches the number of load applications corresponding to the maximum value of the tensile deformation index. 2,i,max,s,t The brightness value of the t-th pixel on the s-th second circular test line in the top view image of the test piece with the i-th ratio after the number of loads applied reaches the number of loads corresponding to the maximum value of the tensile deformation index.

[0049] According to the present invention, obtaining the deformation resistance index of the test specimen includes:

[0050] According to the formula

[0051]

[0052] The lateral deformation index ΔDE of the test specimen with the i-th mix ratio after the k-th load application is obtained. i,k , where Ω c,i,k,h Ω represents the region in the comparative side image at the h-th angle after the k-th load application for the test specimen with the i-th mix ratio. r,i,h Ω represents the region of the test specimen with the i-th formulation located in the reference side image at the h-th angle, where M is the number of angles. c,i,k-1,h S(*) represents the area in the comparative side image of the test piece with the i-th mix ratio at the h-th angle after the (k-1)-th load is applied. S(*) is the area calculation function, and min is the minimum value function.

[0053] Determine the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after each load application, and the number of load applications corresponding to the maximum value of the lateral deformation index.

[0054] According to the formula

[0055]

[0056] The deformation resistance index RD of the test specimen with the i-th formulation was obtained. i , where ΔDE i,ave Let ΔDE be the average value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max Ω represents the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications.c,i,max,h The area in the comparative side image of the i-th mix test piece at the h-th angle after the number of load applications reaches the maximum number of load applications corresponding to the maximum value of the side deformation index.

[0057] According to the present invention, determining the optimized ratio and the optimized target moisture content corresponding to the optimized ratio includes:

[0058] By fitting various proportions to their corresponding mechanical performance indicators, mechanical performance functions are obtained.

[0059] Determine the maximum mechanical property value based on the mechanical property function;

[0060] The proportion corresponding to the maximum mechanical property value is determined as the target proportion, and the target moisture content is determined based on the target proportion;

[0061] If the target ratio does not belong to one of the multiple ratios, then the target test specimen shall be prepared according to the target ratio and its target moisture content;

[0062] Obtain the target mechanical performance index of the target test specimen. If the target mechanical performance index is higher than the mechanical performance index corresponding to the various ratios, then the target ratio is determined as the optimized ratio, and the target moisture content corresponding to the target ratio is determined as the optimized target moisture content.

[0063] According to a second aspect of the present invention, a pavement repair control system based on cold recycling is provided, comprising:

[0064] The first acquisition module samples and breaks down the road surface to be repaired to obtain multiple road surface material samples;

[0065] The second acquisition module mixes the stabilizer with the road material sample according to various ratios to obtain a mixed material sample corresponding to each ratio.

[0066] The target water content module divides the mixed material sample of each ratio into multiple equal parts, adds different amounts of water to each mixed material sample, and determines the target water content corresponding to each ratio of mixed material sample.

[0067] The test piece module, based on the ratio and the target moisture content, prepares test pieces corresponding to each ratio by mixing material samples and water;

[0068] The mechanical performance index module performs mechanical tests on test specimens corresponding to various ratios to obtain the mechanical performance index of the test specimens for each ratio.

[0069] The optimization module determines the optimized ratio and the optimized target moisture content corresponding to the optimized ratio based on the mechanical performance indicators.

[0070] The flow rate determination module determines the water spraying flow rate and the stabilizer addition flow rate based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content.

[0071] The control module controls the cold recycling construction equipment based on the water spray flow rate and the stabilizer addition flow rate.

[0072] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0073] According to the present invention, test specimens can be prepared based on the mixed material samples corresponding to each mix ratio and the corresponding target moisture content, and mechanical tests can be performed to obtain the mechanical performance indicators of the test specimens corresponding to each mix ratio. This allows for the determination of the optimized mix ratio and the optimized target moisture content corresponding to the optimized mix ratio, thereby determining the water spraying flow rate and the stabilizer addition flow rate, and controlling the cold recycling construction equipment. This reduces reliance on manual labor, improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, and enhances the efficiency of pavement repair and the mechanical properties of the repaired pavement. Furthermore, the pavement to be repaired can be sampled and crushed into multiple pavement material samples to obtain mixed material samples corresponding to various mix ratios, providing basic experimental samples for determining the optimized mix ratio and the optimized target moisture content corresponding to the optimized mix ratio. When determining the target moisture content, the dry density function corresponding to each mix ratio can be determined based on the wet density, moisture content, and dry density of each compacted test sample, thereby determining the target moisture content corresponding to each mix ratio. This takes into account the changing trend of the dry density of the mixed material samples, improving the accuracy, objectivity, and comprehensiveness of the target moisture content determination. When determining mechanical performance indicators, the tensile strength of the test specimen can be determined based on a reference top-view image and a comparison top-view image, and the deformation resistance can be determined based on a reference side image and a comparison side image, thus determining the mechanical performance indicators of the test specimen. By comprehensively evaluating the mechanical performance of the test specimen from both tensile and deformation resistance perspectives, the accuracy, objectivity, and comprehensiveness of determining the mechanical performance indicators are improved. Furthermore, based on the mechanical performance indicators, an optimized mix ratio and the corresponding optimized target moisture content can be determined. Considering the case where the optimized mix ratio does not belong to any of the multiple mix ratios, further verification was conducted. Then, based on the moving speed, paving width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content, the water spraying flow rate and stabilizer addition flow rate are determined, and the cold recycling construction equipment is controlled for pavement repair. This improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, and enhances the efficiency of pavement repair.

[0074] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Other features and aspects of the invention will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0075] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0076] Figure 1 An exemplary flowchart of a pavement repair control method based on cold recycling according to an embodiment of the present invention is shown.

[0077] Figure 2 A flowchart illustrating the mechanical performance indicators of test specimens corresponding to each formulation is provided as an example according to an embodiment of the present invention.

[0078] Figure 3 A block diagram of a cold recycling-based pavement repair control system according to an embodiment of the present invention is shown as an example. Detailed Implementation

[0079] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0080] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0081] Figure 1 An exemplary flowchart of a pavement repair control method based on cold recycling according to an embodiment of the present invention is shown, the method comprising:

[0082] Step S1: Sample and break up the road surface to be repaired to obtain multiple road surface material samples;

[0083] Step S2: Mix the stabilizer with the road material sample according to various ratios to obtain a mixed material sample corresponding to each ratio;

[0084] Step S3: Divide the mixed material sample of each ratio into multiple equal parts, add different amounts of water to each mixed material sample, and determine the target moisture content corresponding to each ratio of mixed material sample.

[0085] Step S4: Based on the ratio and the target moisture content, prepare test specimens corresponding to each ratio by mixing material samples and water;

[0086] Step S5: Perform mechanical tests on the test pieces corresponding to various ratios to obtain the mechanical performance indicators of the test pieces corresponding to each ratio.

[0087] Step S6: Determine the optimized ratio and the optimized target moisture content corresponding to the optimized ratio based on the mechanical performance indicators.

[0088] Step S7: Determine the water spraying flow rate and stabilizer addition flow rate based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content.

[0089] Step S8: Control the cold recycling construction equipment according to the water spray flow rate and the stabilizer addition flow rate.

[0090] According to embodiments of the present invention, a cold recycling-based pavement repair control method can prepare test specimens based on mixed material samples corresponding to each mix ratio and the corresponding target moisture content, and conduct mechanical tests to obtain the mechanical performance indicators of the test specimens corresponding to each mix ratio. This allows for the determination of the optimal mix ratio and the corresponding optimal target moisture content, thereby determining the water spraying flow rate and the stabilizer addition flow rate, and controlling the cold recycling construction equipment. This reduces reliance on manual labor, improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, and enhances the efficiency of pavement repair and the mechanical properties of the repaired pavement.

[0091] According to an embodiment of the present invention, in step S1, the road surface to be repaired is sampled and broken to obtain multiple road surface material samples. Asphalt from the road surface to be repaired is collected using a road surface sampling method (e.g., milling sampling, core drilling, etc.), and the obtained asphalt is broken into multiple smaller pieces, which are the road surface material samples.

[0092] According to an embodiment of the present invention, in step S2, the stabilizer is mixed with the road material sample according to multiple ratios to obtain a mixed material sample corresponding to each ratio. Mixing the stabilizer (e.g., cement, lime, etc.) with the road material sample according to multiple ratios (e.g., 2%, 2.5%, 3%, 3.5%, 4%, etc.) yields mixed material samples corresponding to multiple ratios. The ratio is the ratio of the mass of the stabilizer to the mass of the road material sample. For example, if the mass of the stabilizer is 4 kg and the mass of the road material sample is 100 kg, the mass of the mixed material sample is 104 kg, and the ratio of this mixed material sample is 4%. A large number of ratios can be set; for example, within the range of 2% to 5%, a ratio can be set every 0.5% to provide a sufficient number of mixed material samples for subsequent experiments and analyses.

[0093] In this way, the road surface to be repaired can be sampled and broken into multiple road surface material samples, thereby obtaining mixed material samples corresponding to various ratios, providing basic experimental samples for determining the optimal ratio and the optimized target moisture content corresponding to the optimized ratio.

[0094] According to an embodiment of the present invention, in step S3, the mixed material sample of each ratio is divided into multiple equal parts, different amounts of water are added to each mixed material sample, and the target moisture content corresponding to each ratio of mixed material sample is determined, including: adding different amounts of water to each mixed material sample to obtain multiple moisture-containing mixed material samples; performing a compaction test on each moisture-containing mixed material sample to obtain a compaction test sample; detecting the wet density and moisture content of the compaction test sample; obtaining the dry density of the compaction test sample based on the wet density and moisture content; obtaining a dry density function corresponding to the ratio based on the moisture content and dry density of the compaction test sample; and determining the target moisture content corresponding to the ratio based on the dry density function.

[0095] According to embodiments of the present invention, samples of mixed materials with each ratio can be divided into multiple equal portions (e.g., 8 portions), and different amounts of water can be added to each portion of the mixed material sample to obtain multiple samples of hydrated mixed materials. The amount of water used is the ratio of the mass of water to the mass of the mixed material sample. For example, if the mass of water is 30g, the mass of the mixed material sample is 1000g, and the mass of the hydrated mixed material sample after adding water is 1030g, then the amount of water used is 3%. Each sample of hydrated mixed material is subjected to a compaction test (e.g., a Procter compaction test) to remove water that the hydrated mixed material sample cannot absorb and to reduce the gaps between the particles, making the hydrated mixed material sample more compact, thereby obtaining a compacted test sample. The mass and volume of the compacted test sample are measured, and the ratio of the mass to the volume of the compacted test sample is the wet density of the compacted test sample. Furthermore, the compaction test samples are dried to obtain dried compaction test samples. The difference in mass between the undried and dried compaction test samples, expressed as a percentage of the mass of the dried compaction test samples, is the moisture content of the compaction test samples. The dry density of the compaction test samples is the wet density of the compaction test samples / (1 + moisture content of the compaction test samples).

[0096] According to an embodiment of the present invention, a dry density function corresponding to the mix proportion is obtained based on the moisture content and dry density of the compaction test sample, including: obtaining a first equation to be fitted for the dry density function according to formula (1).

[0097]

[0098] Where, ρ d,i,j Let ρ be the dry density of the j-th sample of the aqueous mixture corresponding to the i-th proportion. d,i,max ρ represents the maximum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. d,i,min w represents the minimum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. i,j Let err represent the moisture content of the j-th sample of the aqueous mixture corresponding to the i-th proportion. i,j Let α be the residual of the j-th sample of the aqueous mixture corresponding to the i-th proportion. 1,i α 2,i α 3,i α 4,i Let be the first coefficient to be fitted in the first equation to be fitted; based on the dry density and moisture content of multiple samples of water-containing mixed materials with the i-th ratio, solve for the first coefficient to be fitted to obtain the solution value of the first coefficient to be fitted; based on the solution value of the first coefficient to be fitted and the first equation to be fitted, obtain the dry density function corresponding to the i-th ratio.

[0099] According to an embodiment of the present invention, the dry density can be normalized in formula (1) to obtain... This ratio is based on the water content w of the j-th sample of the aqueous mixture corresponding to the i-th ratio. i,j This is achieved under certain conditions. Furthermore, when the moisture content changes, because moisture can wet the surface of particles in the mixed material, the gaps between particles decrease, and the particle distribution becomes more compact. Therefore, the dry density initially increases with increasing moisture content. After increasing to a certain extent, the particle distribution becomes compact, and moisture fills the gaps, at which point the maximum dry density is reached. Afterward, if the moisture content continues to increase, the gaps between particles will widen, leading to a decrease in dry density. That is, the dry density decreases with increasing moisture content. In the above process of dry density changing with moisture content, the absolute difference between the rate of increase of dry density with increasing moisture content and the rate of decrease of dry density with increasing moisture content after reaching the maximum dry density is significant. The values ​​are not the same. Before reaching the maximum dry density, moisture can fill the air gaps between particles, making the particles more compact, and the rate of increase in dry density is relatively high. After reaching the maximum dry density, the gaps between particles are already filled with moisture. Further increases in moisture content only widen the gaps and fill the already filled gaps with more moisture. Therefore, before reaching the maximum dry density, the gaps change from air to moisture; after reaching the maximum dry density, the moisture content in the gaps increases. Thus, the absolute value of the rate of increase in dry density before reaching the maximum is higher than the absolute value of the rate of decrease in dry density after reaching the maximum. Therefore, the graph of the dry density function has a maximum value, and the graphs on both sides of the maximum value are asymmetrical. Therefore, a setting can be made regarding w. i,j The equation to be fitted This can be used as the first equation to be fitted as the dry density function. Furthermore, by using a fitting method, based on the dry density and moisture content of multiple samples of the hydrated mixed material with the i-th ratio, the first coefficient α to be fitted can be... 1,i α 2,i α 3,i and α 4,i By performing the solution, the solution value can be obtained. Since multiple sets of solution values ​​for the first coefficient to be fitted can be obtained from the dry density and moisture content of multiple samples of the hydrated mixed material with the i-th ratio when solving for the first coefficient to be fitted, these multiple sets of solution values ​​can be substituted into the first equation to be fitted, and the residual err obtained after multiple substitutions can be found. i,j The first coefficient to be fitted, which corresponds to minimizing the sum of squares, is used as the solution value of the first coefficient to be fitted. Substituting this value into the first equation to be fitted yields the dry density function corresponding to the i-th proportion. Where, α 1,i,A α 2,i,A α 3,i,A α 4,i,A α1,i α 2,i α 3,i α 4,i The solution value shows that the dry density function has a maximum value, and the function graphs on both sides of the maximum value are asymmetrical. This is consistent with the trend that the dry density of the mixed material sample first increases and then decreases with the increase of water content, and the rate of increase is relatively fast while the rate of decrease is relatively slow.

[0100] According to an embodiment of the present invention, the target moisture content corresponding to the proportion is determined based on the dry density function. When the dry density function corresponding to the i-th proportion reaches its maximum value, the corresponding moisture content is the target moisture content. For example, when the derivative of the dry density function corresponding to the i-th proportion is 0, the corresponding moisture content is the target moisture content, which can describe the moisture content of the water-containing mixed material sample corresponding to that proportion when it reaches its maximum dry density after compaction. At this point, the water-containing mixed material sample corresponding to that proportion is the most compact. Based on the same processing method, the target moisture content corresponding to each proportion can be obtained.

[0101] In this way, based on the wet density, moisture content, and dry density of each compaction test sample, the dry density function corresponding to each mix ratio can be determined, thereby determining the target moisture content for each mix ratio. This approach takes into account the changing trends in the dry density of the mixed material samples, improving the accuracy, objectivity, and comprehensiveness of the target moisture content determination.

[0102] According to an embodiment of the present invention, in step S4, test specimens corresponding to each ratio are prepared by mixing material samples and water according to the ratio and the target moisture content. In each paired mixed material sample, the target moisture content of that ratio is added in the appropriate amount of water, stirred, and added to the same mold (e.g., a cylindrical mold). After compaction, demolding, and curing, test specimens corresponding to each ratio are obtained. Of course, each test specimen has the same shape and volume.

[0103] Figure 2 An exemplary flowchart is shown below for obtaining the mechanical performance indicators of test specimens corresponding to each formulation according to an embodiment of the present invention.

[0104] According to an embodiment of the present invention, in step S5, mechanical tests are performed on test specimens corresponding to various proportions to obtain mechanical performance indicators for each proportion of the test specimen, including: step S51, placing the test specimen on a test bench, taking a reference top view image of the test specimen, and taking reference side view images of the test specimen from multiple angles on the side; step S52, applying loads to the test specimen multiple times in a vertically downward direction, and taking a comparative top view image and a comparative side view image of the test specimen after each application of load, wherein the loads applied each time are not equal and increase progressively; step S53, obtaining the tensile performance index of the test specimen based on the reference top view image and the comparative top view image; step S54, obtaining the deformation resistance index of the test specimen based on the reference side image and the comparative side image; step S55, obtaining the mechanical performance index of the test specimen based on the tensile performance index and the deformation resistance index.

[0105] According to an embodiment of the present invention, in step S51, the test piece is placed on a test bench, and a reference top view image of the test piece is captured, as well as reference side images of the test piece from multiple angles on the side. A camera or other photographic device can be used to capture a top view image of the test piece directly above it, which is the reference top view image, and side images of the test piece can be captured from multiple angles on the side, which are the reference side images. For example, starting from the front of a cylindrical test piece, the camera is moved clockwise, and a shot is taken every 45 degrees, resulting in a total of 8 reference side images of the test piece.

[0106] According to an embodiment of the present invention, in step S52, a load is applied multiple times to the test piece in a vertically downward direction. After each load application, a comparative top view image and a comparative side view image of the test piece are captured. The loads applied each time are unequal and increase progressively. Using a jack or similar device, multiple loads are applied to the test piece in a vertically downward direction, with the load increasing progressively and each application lasting for the same duration, simulating the situation of a road being compressed by a moving car. For example, the jack is first set to a force of 1000N and applied for 2 seconds; the second time, the jack is set to a force of 1500N and applied for 2 seconds, and so on, increasing the force by 500N each time, with each application lasting 2 seconds. After each load application, a comparative top view image and a comparative side view image of the test piece are captured in the same manner as the reference top view image and reference side view image to observe whether cracks or deformation have occurred in the test piece.

[0107] According to an embodiment of the present invention, in step S53, obtaining the tensile performance index of the test piece based on the reference top view image and the comparison top view image includes: determining the first centroid and the first edge of the region where the test piece is located in the reference top view image; obtaining the first inscribed circle of the first edge; setting a plurality of first circular test lines within the first inscribed circle, wherein the first circular test lines are centered on the first centroid; after each load is applied, determining the second centroid and the second edge of the region where the test piece is located in the comparison top view image; obtaining the second inscribed circle of the second edge; setting a plurality of second circular test lines within the second inscribed circle, wherein the second circular test lines are centered on the second centroid, and the number of second circular test lines is consistent with the number of first circular test lines; and determining the tensile performance index of the test piece based on the applied load, the first circular test lines, and the second circular test lines.

[0108] According to an embodiment of the present invention, the edge of the area where the test piece is located in the reference top view image is determined as the first edge, and the centroid of the shape of the area where the test piece is located (e.g., the center of a circle) is determined as the first centroid. Since the first edge may not be a circle, the inscribed circle of the first edge can be determined as the first inscribed circle. Within the first inscribed circle, multiple circular test lines are uniformly arranged with the first centroid as the center and different lengths as radii (i.e., the radius of each circular test line increases uniformly), which are the first circular test lines. For example, if the radius of the first inscribed circle is 10 cm, five first circular test lines are drawn with the first centroid as the center, and each circular test line is spaced 2 cm apart, with the largest first circular test line coinciding with the first inscribed circle. Similar to determining the first circular test line of the test specimen in the reference top view image, after each load is applied, the second centroid and second edge of the region where the test specimen is located in the comparative top view image are determined, thereby obtaining the second inscribed circle of the second edge. Within the second inscribed circle, multiple evenly distributed second circular test lines are set with the second centroid as the center, and the number of second circular test lines is consistent with that of the first circular test lines. This facilitates the determination of whether the test specimen has developed cracks by using the first center test line and multiple sets of second circular test lines. Since the test specimen is subjected to tensile stress when a vertically downward load is applied, causing the test specimen to gradually flatten, the region where the test specimen is located in the top view image gradually increases. Therefore, the perimeter of the second circular test lines gradually increases relative to the perimeter of the first circular test lines, and the distance between each second circular test line also increases. Therefore, the second circular test lines can be used to evaluate the tensile properties of the test specimen.

[0109] According to an embodiment of the present invention, the tensile performance index of the test specimen is determined based on the applied load, the first circular test line, and the second circular test line, including: obtaining the tensile deformation index ΔD of the test specimen with the i-th mix ratio after the k-th load application according to formula (2). i,k ,

[0110]

[0111] Among them, L 2,i,k,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s L represents the number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 1,i,s,t+1 L represents the brightness value of the (t+1)th pixel on the (s)th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s,t Let n be the brightness value of the t-th pixel on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s L represents the number of pixels on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 2,i,k-1,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)th load application. 2,i,k-1,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)-th load application. 2,i,k-1,s The number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test specimen with the i-th ratio after the (k-1)th load application, where N is the number of first circle center test lines; determine the maximum value of the tensile deformation index of the test specimen with the i-th ratio after each load application, and the number of load applications corresponding to the maximum value of the tensile deformation index.

[0112] The tensile performance index T of the test specimen with the i-th mix ratio is determined according to formula (3). i ,

[0113]

[0114] Among them, F i,kmax F is the load corresponding to the number of times the load is applied, which corresponds to the maximum value of the deformation index of the test piece with the i-th mix ratio. maxFor the maximum load, ΔD i,ave Let ΔD be the average tensile deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max L represents the maximum tensile deformation index of the test specimen with the i-th mix ratio. 2,i,max,s,t+1 L is the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th ratio after the number of load applications reaches the number of load applications corresponding to the maximum value of the tensile deformation index. 2,i,max,s,t The brightness value of the t-th pixel on the s-th second circular test line in the top view image of the test piece with the i-th ratio after the number of loads applied reaches the number of loads corresponding to the maximum value of the tensile deformation index.

[0115] According to an embodiment of the present invention, in formula (2), |L 2,i,k,s,t+1 -L 2,i,k,s,t | represents the absolute value of the difference in brightness between the (t+1)th pixel and the tth pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. It can be considered as the brightness difference between the (t+1)th pixel and the tth pixel. Therefore… This can represent the sum of brightness differences between multiple groups of adjacent pixels, that is, the total brightness difference of the s-th second circular test line. Similarly, The total brightness difference of multiple groups of adjacent pixels in the first circular test line of the reference top view image of the test piece with the i-th ratio can be represented.

[0116] According to an embodiment of the present invention, since cracks may appear in the top view image of the test piece when a vertically downward load is applied, and the brightness value of the pixel where the crack is located is low, when the test piece withstands the load, the total brightness difference of the s-th second circular test line is similar to the total brightness difference of the corresponding first circular test line. Conversely, when the test piece fails to withstand the load and cracks appear, the total brightness difference of the s-th second circular test line differs significantly from the total brightness difference of the corresponding first circular test line. Therefore... This can represent the difference between the total brightness difference of the s-th second circular test line and the total brightness difference of the corresponding first circular test line. It can also be used as a value describing the deformation of the position of the s-th second circular test line relative to the position of the corresponding first circular test line. Therefore... This can represent the sum of the values ​​of the deformation variables described above, and can be used as the value of the deformation variable of the test piece relative to the original test piece after the k-th load application, thus describing the degree of deformation of the test piece relative to the original test piece after the k-th load application. Similarly, This can be used as a value describing the deformation of the test specimen relative to the original test specimen after the (k-1)th load application, and thus the difference between the values ​​describing the deformation of the test specimen relative to the original test specimen after the k-th and (k-1)th load applications can be obtained. It can be considered as the value describing the increase in deformation of the test piece after the kth load is applied. It can be used as the tensile deformation index of the test piece with the i-th mix ratio after the kth load is applied. It can be used to determine how many loads the test piece with the i-th mix ratio has developed cracks.

[0117] According to an embodiment of the present invention, the maximum value of the tensile deformation index of the test specimen with the i-th mix ratio after each load application is determined, as well as the number of load applications corresponding to the maximum value of the tensile deformation index. When the tensile deformation index of the test specimen with the i-th mix ratio reaches its maximum value after each load application, the single increase in deformation of the test specimen reaches its maximum value, and it can be considered that the test specimen failed to withstand the load and developed a crack. The number of load applications corresponding to the maximum value of the tensile deformation index is the number of load applications corresponding to the occurrence of a crack in the test specimen. For example, if the tensile deformation index of the test specimen with the i-th mix ratio reaches its maximum value after the 5th load application, the number of load applications corresponding to the occurrence of a crack in the test specimen is 5. The greater the number of load applications corresponding to the maximum value of the tensile deformation index, the more loads the test specimen can withstand, the greater the load value it can withstand, and the better its tensile performance.

[0118] According to an embodiment of the present invention, in formula (3), F i,kmax This represents the load corresponding to the number of times the load was applied when the tensile deformation index of the test specimen with the i-th mix ratio reaches its maximum value; that is, the load corresponding to the number of times the load was applied when the test specimen cracked. Therefore... This represents the ratio of the load corresponding to the number of times a load is applied when a crack appears in the test specimen to the maximum value of the load applied during the test. It can be used as a value to describe the test specimen's ability to withstand loads. The larger this value is, the stronger the test specimen's ability to withstand loads and the better its tensile properties. The ratio of the average tensile deformation index of the test specimen with the i-th mix ratio after multiple load applications to the maximum tensile deformation index can be used as a value to describe the stability of the deformation of the test specimen. The larger the value, the more stable the deformation of the test specimen, the lower the probability of sudden cracking of the test specimen, and the better the tensile performance.

[0119] According to an embodiment of the present invention, similar to formula (2), When the tensile deformation index of the test specimen with the i-th mix ratio reaches its maximum value, the sum of the values ​​of the deformation values ​​of each second circular test line relative to the corresponding first circular test line can be used as the value of the deformation value of the test specimen relative to the original test specimen when cracks occur, and can describe the degree of cracking of the test specimen relative to the original test specimen when cracks occur. The total brightness difference between multiple groups of adjacent pixels in the s-th first circular test line of the reference top view image of the test piece with the i-th ratio can be used as a value describing the original shape of the location of the s-th first circular test line. Therefore... The sum of values ​​describing the original shape of each of the first circular test lines on the test piece can be used as a value describing the original shape of the test piece. The ratio of this value describing the original shape of the test piece to the value describing the deformation of the test piece relative to the original test piece when a crack occurs can be used as a value describing the degree of cracking after the crack occurs. The larger this value, the smaller the crack and the smaller the deformation, resulting in better tensile strength.

[0120] According to an embodiment of the present invention, the product of the value describing the load-bearing capacity of the test specimen, the value describing the stability of the deformation of the test specimen, and the value describing the degree of cracking after the test specimen develops a crack, can be used as the tensile performance index T of the test specimen with the i-th mix ratio. i The higher this index, the stronger the test specimen's ability to withstand loads, the more stable the deformation, the smaller the cracks generated, and the better the tensile properties of the test specimen. Based on the same processing method, the tensile properties of test specimens with various ratios can be obtained.

[0121] According to an embodiment of the present invention, in step S54, obtaining the deformation resistance index of the test specimen based on the reference side image and the comparison side image includes: obtaining the side deformation index ΔDE of the test specimen with the i-th mix ratio after the k-th load application according to formula (4). i,k ,

[0122]

[0123] Among them, Ω c,i,k,h Ω represents the region in the comparative side image at the h-th angle after the k-th load application for the test specimen with the i-th mix ratio. r,i,h Ω represents the region of the test specimen with the i-th formulation located in the reference side image at the h-th angle, where M is the number of angles. c,i,k-1,hLet S(*) be the region in the comparative side image of the i-th mix specimen at the h-th angle after the (k-1)-th load application, where S(*) is the area calculation function and min is the minimum value function; determine the maximum value of the side deformation index of the i-th mix specimen after each load application and the number of load applications corresponding to the maximum value of the side deformation index.

[0124] The deformation resistance index RD of the test piece with the i-th ratio is obtained according to formula (5). i ,

[0125]

[0126] Where, ΔDE i,ave Let ΔDE be the average value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max Ω represents the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. c,i,max,h The area in the comparative side image of the i-th mix test piece at the h-th angle after the number of load applications reaches the maximum number of load applications corresponding to the maximum value of the side deformation index.

[0127] According to an embodiment of the present invention, in formula (4), S(Ω) c,i,k,h ∩Ω r,i,h S(Ω) represents the area of ​​the test specimen with the i-th mix ratio located in the comparative side image at the h-th angle after the k-th load application, and the area of ​​the intersection between this area and the area of ​​the test specimen in the corresponding reference side image. c,i,k,h ∪Ω r,i,hLet represent the area of ​​the region in the comparative side image at the h-th angle after the k-th load application of the test specimen with the i-th mix ratio, and the area of ​​the region in the corresponding reference side image. Since deformation of the test specimen can be observed in the side image when a vertically downward load is applied, the area of ​​the test specimen in the comparative side image changes, reducing the overlap with the area in the corresponding reference side image. Therefore, when the test specimen withstands the load, the area in the comparative side image is close to the area in the corresponding reference side image, with a high degree of overlap and a small deformation. Conversely, when the test specimen fails to withstand the load and deforms, the area in the comparative side image... The region where the test piece is located differs significantly from the region in the corresponding reference side image, has a low degree of overlap, and a large deformation. Therefore, the ratio of the area of ​​the intersection to the area of ​​the union can represent the degree of overlap between the region where the test piece with the i-th ratio is located in the comparison side image at the h-th angle after the k-th load application and the region where the test piece is located in the corresponding reference side image. This can be used as a value describing the deformation of the test piece relative to the original test piece at the h-th angle after the k-th load application. Therefore, This can represent the minimum value of the deformation of multiple test specimens relative to the original test specimen after the k-th load application, and can also represent the maximum deformation of the test specimen relative to the original test specimen after the k-th load application. Similarly, This represents the minimum value describing the deformation of the test specimen relative to the original test specimen after the (k-1)th load application. The difference between the minimum values ​​of the deformation of the test specimen relative to the original test specimen after the k-th and (k-1)th load applications can be used as the lateral deformation index ΔDE of the test specimen with the i-th mix ratio after the k-th load application. u,k It can describe the increase in deformation of the test piece after the kth load is applied, and is used to determine after which load the test piece failed to withstand the load and produced a large deformation.

[0128] According to an embodiment of the present invention, the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after each load application and the number of load applications corresponding to the maximum value of the lateral deformation index are determined. Similar to determining the maximum value of the tensile deformation index of the test specimen with the i-th mix ratio after each load application and the number of load applications corresponding to the maximum value of the tensile deformation index, when the lateral deformation index of the test specimen with the i-th mix ratio reaches its maximum value after each load application, it can be considered that the test specimen failed to withstand the load and deformed. The number of load applications corresponding to the maximum value of the lateral deformation index is the number of load applications corresponding to the test specimen producing a large deformation. The larger this number, the more loads the test specimen withstands, the higher the load value it can withstand, and the better its deformation resistance.

[0129] According to an embodiment of the present invention, in formula (5), This represents the ratio of the average to the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. Similar to formula (3), this ratio can be used as a value to describe the stability of the deformation of the test specimen. The larger the value, the more stable the deformation of the test specimen, the lower the probability of sudden deformation, and the better the deformation resistance. The minimum value of the deformation of the test specimen relative to the original test specimen after significant deformation can be used to describe the maximum deformation of the test specimen after deformation, thus describing the degree of maximum deformation. The larger this value, the smaller the deformation of the test specimen after deformation, and the better its deformation resistance. The product of the value describing the smoothness of deformation and the value describing the maximum deformation of the test specimen after deformation can be used as the deformation resistance performance index RD of the test specimen with the i-th mix ratio. i The higher this index, the more stable the deformation of the test specimen and the smaller the deformation after deformation, indicating better deformation resistance of the test specimen. Based on the same processing method, deformation resistance indices for test specimens with various ratios can be obtained.

[0130] According to an embodiment of the present invention, in step S55, the mechanical property index of the test piece is obtained based on the tensile strength index and the deformation resistance index. The product of the tensile strength index and the deformation resistance index is the mechanical property index of the test piece. The larger the index, the stronger the tensile strength and the stronger the deformation resistance of the test piece, and the better the mechanical properties of the test piece.

[0131] In this way, the tensile strength of the test specimen can be determined based on a reference top-view image and a comparison top-view image, and the deformation resistance can be determined based on a reference side image and a comparison side image, thereby determining the mechanical properties of the test specimen. By comprehensively evaluating the mechanical properties of the test specimen from both tensile and deformation resistance perspectives, the accuracy, objectivity, and comprehensiveness of determining the mechanical property indicators are improved.

[0132] According to an embodiment of the present invention, in step S6, determining the optimized ratio and the optimized target moisture content corresponding to the optimized ratio based on the mechanical performance indicators includes: fitting multiple ratios to their corresponding mechanical performance indicators to obtain a mechanical performance function; determining the maximum mechanical performance value based on the mechanical performance function; determining the ratio corresponding to the maximum mechanical performance value as the target ratio, and determining the target moisture content based on the target ratio; if the target ratio does not belong to any of the multiple ratios, then preparing a target test specimen based on the target ratio and its target moisture content; obtaining the target mechanical performance indicators of the target test specimen; if the target mechanical performance indicators are higher than the mechanical performance indicators corresponding to the multiple ratios, then determining the target ratio as the optimized ratio, and determining the target moisture content corresponding to the target ratio as the optimized target moisture content.

[0133] According to an embodiment of the present invention, the trend of the dry density of the mixed material sample with the increase of water content is similar to the trend of the mechanical properties of the test specimen with the increase of the target ratio. That is, the mechanical properties of the test specimen first increase and then decrease with the increase of the target ratio (i.e., the increase of stabilizer), and the rate of increase is relatively fast while the rate of decrease is relatively slow. Therefore, based on a method similar to formula (1), various ratios and corresponding mechanical properties can be fitted to obtain a mechanical property function. The derivative of the above mechanical property function is then calculated. When the derivative is 0, the corresponding ratio is the target ratio. The test specimen with this ratio has the largest mechanical properties and the best mechanical performance. Furthermore, if the target ratio is one of the multiple ratios, the target moisture content corresponding to that ratio can be directly obtained. Otherwise, based on a similar method to obtaining the target moisture content corresponding to each ratio, a mixed material sample corresponding to the target ratio can be prepared and divided into multiple equal parts. Different amounts of water are added, and a compaction test is performed on each part of the mixed material sample corresponding to the target ratio to obtain the compaction test sample corresponding to the target ratio. The wet density, moisture content, and dry density of the compaction test sample corresponding to the target ratio are then detected, and the dry density function corresponding to the target ratio is determined, thereby determining the target moisture content corresponding to the target ratio. If the target ratio belongs to one of the multiple ratios, it can be directly determined as the optimized ratio. If the target ratio does not belong to one of the multiple ratios, further verification is required. Based on the same method used to obtain the mechanical performance indicators of the test specimens, a target test specimen can be fabricated according to the target ratio and its target moisture content to determine the target mechanical performance indicators of the test specimen. If the target mechanical performance indicators are higher than those corresponding to the multiple ratios, meaning the test specimen fabricated with this target ratio has the best mechanical performance among the multiple test specimens fabricated with various ratios, the target ratio can be determined as the optimized ratio, and the target moisture content corresponding to the target ratio can be determined as the optimized target moisture content. In this case, the test specimen corresponding to the optimized ratio has the tightest internal connection and achieves optimal mechanical performance. Otherwise, the maximum value among the mechanical performance indicators corresponding to the multiple ratios is obtained, and the ratio corresponding to this maximum value is taken as the optimized ratio. The target moisture content corresponding to this ratio is the optimized target moisture content.

[0134] According to an embodiment of the present invention, in step S7, the water spraying flow rate and the stabilizer addition flow rate are determined based on the moving speed, paving width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content. The product of the moving speed, paving width, and working depth of the cold recycling construction equipment is the volume of pavement that the cold recycling construction equipment breaks up and needs to repair per second, that is, the volume of pavement material required per second. For example, if the moving speed of the cold recycling construction equipment is 1 m / s, the paving width is 2 m, and the working depth is 0.1 m, the volume of pavement material required per second is 0.2 m³.3 The product of the volume of road material required per second and the density of the road material is the mass of road material required per second. Furthermore, the water spraying flow rate (e.g., 4 kg / s) and the stabilizer addition flow rate (e.g., 4.5 kg / s) can be determined based on the optimized mix ratio and optimized moisture content. In addition, considering water evaporation, the water spraying flow rate can be appropriately increased, for example, by 2%, to 4.08 kg / s.

[0135] According to an embodiment of the present invention, in step S8, the cold recycling construction equipment is controlled according to the water spraying flow rate and the stabilizer addition flow rate. After the road surface is broken up, water is sprayed into the road surface material at the spraying flow rate, and a stabilizer is added at the addition flow rate, so that the road surface material after mixing reaches the optimized ratio and optimized moisture content, that is, the road surface material reaches the optimal mechanical properties during paving, so as to improve the strength of the repaired road surface.

[0136] In this way, an optimal mix ratio and corresponding target moisture content can be determined based on mechanical performance indicators. Further verification is conducted, taking into account cases where the optimal mix ratio does not belong to any of the multiple ratios. Then, based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content, the water spraying flow rate and stabilizer addition flow rate are determined, and the cold recycling construction equipment is controlled for pavement repair. This improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, thereby increasing the efficiency of pavement repair.

[0137] According to embodiments of the present invention, a cold recycling-based pavement repair control method can prepare test specimens based on mixed material samples corresponding to each mix ratio and the corresponding target moisture content, and conduct mechanical tests to obtain the mechanical performance indicators of the test specimens corresponding to each mix ratio. This allows for the determination of the optimized mix ratio and the optimized target moisture content corresponding to the optimized mix ratio, thereby determining the water spraying flow rate and the stabilizer addition flow rate, and controlling the cold recycling construction equipment. This reduces reliance on manual labor, improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, and enhances the efficiency of pavement repair and the mechanical properties of the repaired pavement. Furthermore, the method can sample and break the pavement to be repaired into multiple pavement material samples to obtain mixed material samples corresponding to various mix ratios, providing basic experimental samples for determining the optimized mix ratio and the optimized target moisture content corresponding to the optimized mix ratio. When determining the target moisture content, the dry density function corresponding to each mix ratio can be determined based on the wet density, moisture content, and dry density of each compacted test sample, thereby determining the target moisture content corresponding to each mix ratio. The variation trend of the dry density of the mixed material samples was considered, improving the accuracy, objectivity, and comprehensiveness of determining the target moisture content. When determining mechanical performance indicators, the tensile strength of the test specimen can be determined based on a reference top-view image and a comparison top-view image, and the deformation resistance can be determined based on a reference side image and a comparison side image, thus determining the mechanical performance indicators of the test specimen. By comprehensively evaluating the mechanical performance of the test specimen from both tensile and deformation resistance perspectives, the accuracy, objectivity, and comprehensiveness of determining the mechanical performance indicators are improved. Furthermore, based on the mechanical performance indicators, an optimized mix ratio and the corresponding optimized target moisture content can be determined. Further verification was conducted considering cases where the optimized mix ratio does not belong to any of the multiple mix ratios. Then, based on the moving speed, paving width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content, the water spraying flow rate and stabilizer addition flow rate are determined, and the cold recycling construction equipment is controlled for pavement repair. This improves the accuracy of determining the optimal mix ratio and optimal moisture content of pavement materials, and enhances the efficiency of pavement repair.

[0138] Figure 3 An exemplary block diagram of a cold recycling-based pavement repair control system according to an embodiment of the present invention is shown, the system comprising:

[0139] The first acquisition module samples and breaks down the road surface to be repaired to obtain multiple road surface material samples;

[0140] The second acquisition module mixes the stabilizer with the road material sample according to various ratios to obtain a mixed material sample corresponding to each ratio.

[0141] The target water content module divides the mixed material sample of each ratio into multiple equal parts, adds different amounts of water to each mixed material sample, and determines the target water content corresponding to each ratio of mixed material sample.

[0142] The test piece module, based on the ratio and the target moisture content, prepares test pieces corresponding to each ratio by mixing material samples and water;

[0143] The mechanical performance index module performs mechanical tests on test specimens corresponding to various ratios to obtain the mechanical performance index of the test specimens for each ratio.

[0144] The optimization module determines the optimized ratio and the optimized target moisture content corresponding to the optimized ratio based on the mechanical performance indicators.

[0145] The flow rate determination module determines the water spraying flow rate and the stabilizer addition flow rate based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content.

[0146] The control module controls the cold recycling construction equipment based on the water spray flow rate and the stabilizer addition flow rate.

[0147] This invention can be a method, apparatus, system, and / or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of the invention.

[0148] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pavement repair control method based on cold recycling, characterized in that, include: The road surface to be repaired was sampled and crushed to obtain multiple road surface material samples; According to various ratios, the stabilizer is mixed with the road material sample to obtain the mixed material sample corresponding to each ratio; Divide each ratio of mixed material sample into multiple equal parts, add different amounts of water to each mixed material sample, and determine the target moisture content corresponding to each ratio of mixed material sample; Based on the stated ratio and the target moisture content, test specimens corresponding to each ratio are prepared by mixing material samples and water; Mechanical tests were conducted on the test specimens corresponding to various ratios to obtain the mechanical performance indicators of the test specimens for each ratio. Based on the aforementioned mechanical performance indicators, an optimized mix ratio and an optimized target moisture content corresponding to the optimized mix ratio are determined. Based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content, the water spraying flow rate and the stabilizer addition flow rate are determined. The cold recycling construction equipment is controlled based on the water spray flow rate and the stabilizer addition flow rate.

2. The pavement repair control method based on cold recycling according to claim 1, characterized in that, Each ratio of mixed material sample was divided into multiple equal portions. Different amounts of water were added to each portion of the mixed material sample, and the target moisture content for each ratio of mixed material sample was determined, including: Different amounts of water were added to each sample of the mixed material to obtain multiple samples of the mixed material containing water. Each sample of the water-containing mixed material was subjected to a compaction test to obtain the compaction test sample; The wet density and moisture content of the compaction test samples were measured. The dry density of the compaction test sample is obtained based on the wet density and moisture content of the compaction test sample. Based on the moisture content and dry density of the compaction test samples, obtain the dry density function corresponding to the mix proportion; The target moisture content corresponding to the ratio is determined based on the dry density function.

3. The pavement repair control method based on cold recycling according to claim 2, characterized in that, Based on the moisture content and dry density of the compaction test samples, obtain the dry density function corresponding to the mix proportion, including: According to the formula The first equation to be fitted for the dry density function is obtained, where ρ d,i,j Let ρ be the dry density of the j-th sample of the aqueous mixture corresponding to the i-th proportion. d,i,max ρ represents the maximum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. d,i,min w represents the minimum dry density of multiple samples of the aqueous mixture corresponding to the i-th proportion. i,j Let err represent the moisture content of the j-th sample of the aqueous mixture corresponding to the i-th proportion. i,j Let α be the residual of the j-th sample of the aqueous mixture corresponding to the i-th proportion. 1,i α 2,i α 3,i α 4,i The first coefficient of the first equation to be fitted; Based on the dry density and moisture content of multiple samples of water-containing mixed materials with the i-th ratio, the first coefficient to be fitted is solved to obtain the solution value of the first coefficient to be fitted. Based on the solved values ​​of the first coefficients to be fitted and the first equation to be fitted, the dry density function corresponding to the i-th ratio is obtained.

4. The pavement repair control method based on cold recycling according to claim 1, characterized in that, Mechanical tests were conducted on test specimens corresponding to various formulation ratios to obtain the mechanical performance indicators of the test specimens for each formulation ratio, including: Place the test piece on the test bench, take a reference top view image of the test piece, and take reference side view images of the test piece from multiple angles on the side. The test piece was subjected to multiple loads in a vertically downward direction. After each load application, a comparative top view image and a comparative side view image of the test piece were taken. The loads applied each time were not equal and increased successively. The tensile performance index of the test specimen is obtained based on the reference top view image and the comparison top view image; Based on the reference side image and the comparison side image, the deformation resistance index of the test piece is obtained; The mechanical properties of the test specimen are obtained based on the tensile strength index and the deformation resistance index.

5. The pavement repair control method based on cold recycling according to claim 4, characterized in that, Based on the reference top view image and the comparison top view image, the tensile performance indicators of the test specimen are obtained, including: Determine the first centroid and first edge of the region where the test piece is located in the reference top view image; Obtain the first inscribed circle of the first edge; Within the first inscribed circle, a plurality of first circular test lines are set, wherein the first circular test lines are centered on the first centroid. After each load is applied, determine the second centroid and second edge of the region where the test piece is located in the comparative top view image; Obtain the second inscribed circle of the second edge; Within the second inscribed circle, a plurality of second circular test lines are set, wherein the second circular test lines are centered on the second centroid, and the number of second circular test lines is the same as that of the first circular test lines; The tensile properties of the test specimen are determined based on the applied load, the first circular test line, and the second circular test line.

6. The pavement repair control method based on cold recycling according to claim 5, characterized in that, Based on the applied load, the first circular test line, and the second circular test line, the tensile properties of the test specimen are determined, including: According to the formula The tensile deformation index ΔD of the test specimen with the i-th mix ratio after the k-th load application was obtained. i,k , where L 2,i,k,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 2,i,k,s L represents the number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the k-th load application. 1,i,s,t+1 L represents the brightness value of the (t+1)th pixel on the (s)th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s,t Let n be the brightness value of the t-th pixel on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 1,i,s L represents the number of pixels on the s-th first circular test line in the reference top view image of the test piece with the i-th ratio. 2,i,k-1,s,t+1 L represents the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)th load application. 2,i,k-1,s,t Let n be the brightness value of the t-th pixel on the s-th second circular test line in the comparative top view image of the test piece with the i-th mix ratio after the (k-1)-th load application. 2,i,k-1,s N represents the number of pixel values ​​on the s-th second circular test line in the comparative top view image of the test piece with the i-th ratio after the (k-1)th load application, and N is the number of the first circle center test lines. Determine the maximum value of the tensile deformation index of the test specimen with the i-th mix ratio after each load application, and the number of load applications corresponding to the maximum value of the tensile deformation index; According to the formula Determine the tensile property index T of the test specimen with the i-th mix ratio. i , of which F i,kmax F is the load corresponding to the number of times the load is applied, which corresponds to the maximum value of the deformation index of the test piece with the i-th mix ratio. max ΔD represents the maximum value of the load. i,ave Let ΔD be the average tensile deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max L represents the maximum tensile deformation index of the test specimen with the i-th mix ratio. 2,i,max,s,t+1 L is the brightness value of the (t+1)th pixel on the second circular test line in the comparative top view image of the test piece with the i-th ratio after the number of load applications reaches the number of load applications corresponding to the maximum value of the tensile deformation index. 2,i,max,s,t The brightness value of the t-th pixel on the s-th second circular test line in the top view image of the test piece with the i-th ratio after the number of loads applied reaches the number of loads corresponding to the maximum value of the tensile deformation index.

7. The pavement repair control method based on cold recycling according to claim 4, characterized in that, Based on the reference side image and the comparison side image, the deformation resistance index of the test specimen is obtained, including: According to the formula The lateral deformation index ΔDE of the test specimen with the i-th mix ratio after the k-th load application is obtained. i,k , where Ω c,i,k,h Ω represents the region in the comparative side image at the h-th angle after the k-th load application for the test specimen with the i-th mix ratio. r,i,h Ω represents the region of the test specimen with the i-th formulation located in the reference side image at the h-th angle, where M is the number of angles. c,i,k-1,h S(*) represents the area in the comparative side image of the test piece with the i-th mix ratio at the h-th angle after the (k-1)-th load is applied. S(*) is the area calculation function, and min is the minimum value function. Determine the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after each load application, and the number of load applications corresponding to the maximum value of the lateral deformation index. According to the formula The deformation resistance index RD of the test specimen with the i-th formulation was obtained. i , where ΔDE i,ave Let ΔDE be the average value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. i,max Ω represents the maximum value of the lateral deformation index of the test specimen with the i-th mix ratio after multiple load applications. c,i,max,h The area in the comparative side image of the i-th mix test piece at the h-th angle after the number of load applications reaches the maximum number of load applications corresponding to the maximum value of the side deformation index.

8. The pavement repair control method based on cold recycling according to claim 1, characterized in that, Based on the aforementioned mechanical performance indicators, an optimized mix proportion and an optimized target moisture content corresponding to the optimized mix proportion are determined, including: By fitting various proportions to their corresponding mechanical performance indicators, mechanical performance functions are obtained. Determine the maximum mechanical property value based on the mechanical property function; The proportion corresponding to the maximum mechanical property value is determined as the target proportion, and the target moisture content is determined based on the target proportion; If the target ratio does not belong to one of the multiple ratios, then the target test specimen shall be prepared according to the target ratio and its target moisture content; Obtain the target mechanical performance index of the target test specimen. If the target mechanical performance index is higher than the mechanical performance index corresponding to the various ratios, then the target ratio is determined as the optimized ratio, and the target moisture content corresponding to the target ratio is determined as the optimized target moisture content.

9. A road surface repair control system based on cold recycling, characterized in that, include: The first acquisition module samples and breaks down the road surface to be repaired to obtain multiple road surface material samples; The second acquisition module mixes the stabilizer with the road material sample according to various ratios to obtain a mixed material sample corresponding to each ratio. The target water content module divides the mixed material sample of each ratio into multiple equal parts, adds different amounts of water to each mixed material sample, and determines the target water content corresponding to each ratio of mixed material sample. The test specimen module, based on the stated ratio and the target moisture content, prepares test specimens corresponding to each ratio by mixing material samples and water; The mechanical performance index module performs mechanical tests on test specimens corresponding to various ratios to obtain the mechanical performance index of the test specimens for each ratio. The optimization module determines the optimized ratio and the optimized target moisture content corresponding to the optimized ratio based on the mechanical performance indicators. The flow rate determination module determines the water spraying flow rate and the stabilizer addition flow rate based on the moving speed, laying width, and working depth of the cold recycling construction equipment, as well as the optimized mix ratio and optimized moisture content. The control module controls the cold recycling construction equipment based on the water spray flow rate and the stabilizer addition flow rate.

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