Method for testing raking caking rate of asphalt mixture of hot in-place recycling pavement
The agglomeration rate of the asphalt mixture of in-site thermal regenerated pavement was evaluated through the combined method of screening and showering, which solved the problem of lack of evaluation methods in the prior art, achieved scientific comparison of equipment and processes, and improved the durability of asphalt pavement.
Patent Information
- Application Number
- CN202510496432.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-08-08
AI Technical Summary
The prior art lacks effective evaluation methods to evaluate the raking quality of asphalt mixture in the in-site thermal regenerated pavement, especially the agglomeration situation, which leads to difficulty in selecting different equipment and processes, affecting the durability of in-site thermal regenerated asphalt pavement.
The asphalt mixture is processed step by step by step by screening and swelling, and the number and mass agglomeration rate of particles are calculated to provide quantitative evaluation indicators.
It provides a simple and scientific test method, which can effectively evaluate the raking effect of different equipment and processes, and improve the durability of in-site thermal regeneration asphalt pavement.
Smart Images
Figure CN120445901A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of road engineering, and in particular to a method for testing the raking and agglomeration rate of asphalt mixture of in-situ hot-regenerated pavement. Background Art
[0002] In-situ hot regeneration technology for asphalt pavement can 100% utilize the waste asphalt mixture of the original pavement and has little interference with traffic. Therefore, it has been widely promoted and applied as a preventive maintenance technology in recent years.
[0003] However, the promotion and application process has also exposed many problems. Some pavements using in-situ hot regeneration technology developed serious potholes and other defects 1-2 years after the completion of the project. This has seriously affected the promotion and application of in-situ hot regeneration technology for asphalt pavements, causing highway management personnel to believe that the technology is not yet mature and not worthy of promotion and application. In fact, with the in-depth research of highway and equipment R&D personnel in my country, in-situ hot regeneration technology for asphalt pavements has made great progress in equipment and technology. However, there are significant differences in the quality of the finished products after construction by different equipment and manufacturers. In particular, the different processes in the asphalt pavement harrowing process have led to significant differences in the construction results.
[0004] Asphalt pavement scarification involves mechanically scarifying the asphalt mixture from the original pavement into loose particles. Scarification quality significantly impacts construction quality. When the asphalt mixture agglomerates, newly added regeneration agents and modifiers cannot penetrate the asphalt mixture agglomerates, creating weak bonding areas and severely impacting the durability of hot-in-place (HSP) recycled asphalt pavements. Therefore, evaluating the scarification quality of HSP recycling technology is essential and a crucial measure for ensuring the durability of HSP recycled asphalt pavements.
[0005] However, the current lack of a robust evaluation method for asphalt pavement scarification, particularly for evaluating asphalt mixture caking, makes it difficult to compare the performance of different equipment and processes, effectively identifying the best equipment and process to improve the durability of hot-in-place recycled asphalt pavements. Therefore, a method for measuring the scarification and caking rate of asphalt mixtures in hot-in-place recycled pavements that can evaluate the performance of different processes and equipment is urgently needed. Summary of the Invention
[0006] In view of the above problems, the present invention aims to provide a method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement.
[0007] To achieve this technical purpose, the present invention provides a method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement, which comprises the following specific steps: S1. Place the hot-recycled asphalt mixture after harrowing at a specified temperature T in a room for cooling, and obtain the coarse material after the temperature drops to room temperature; S2. Use two or more sieves to screen the coarse material step by step; record the data after the screening is completed, and the number of aggregate particles on the i-th sieve is n i and particle mass m i , obtain the corresponding aggregate particles after screening; S3. Use organic solvent to flush the aggregate particles on each screen and screen them step by step until there is no obvious asphalt attached to the aggregate particles. After the flushing is completed, record the data, the number of particles N on the jth screen after the aggregate particles are flushed and screened step by step j1 and particle mass M j1 , where the number of particles N after the aggregate particles on the j+ath screen are screened twice step by step is ja and particle mass M ja , obtain the corresponding aggregate particles after flushing; S4. Calculate the particle number and agglomeration rate γ of the hot-in-place recycled asphalt mixture on the i-th screen. i , mass agglomeration rate λ i .
[0008] Preferably, in step S1, samples should be taken once on both sides and in the middle of the lane of the same harrowing section, or once at the upper, middle and lower parts of the material pile, and the mass of each sample should not be less than 2 kg; the thickness of the in-situ hot-regenerated asphalt mixture on the road surface is h, and the value range of the thickness h is 1.0-10.0 cm.
[0009] Preferably, four sieves are used in step S2, i=4, and the sizes of the sieves are a combination of 13.2 mm, 9.5 mm, 4.75 mm and 2.36 mm.
[0010] Preferably, in step S4, The particle number agglomeration rate is: ; The mass agglomeration rate is: .
[0011] Preferably, in step S4, the mesh size of the screen i is greater than or equal to 2.36 mm, and the particle number agglomeration rate γ i , mass agglomeration rate λ i It is used to evaluate the agglomeration of coarse particles in the mixture, that is, the agglomeration of aggregate particles greater than or equal to 2.36 mm.
[0012] Preferably, the organic solvent in step S3 is one or more of trichloroethylene, acetone, carbon tetrachloride, and diesel.
[0013] Preferably, the specific steps of the secondary step-by-step screening by showering in step S3 are: After flushing the 13.2 mm sieve, count and weigh the number of aggregate particles on the 13.2 mm, 9.5 mm, 4.75 mm and 2.36 mm sieves after flushing, record them as N11, N12, N13 and N14, and record the mass as M11, M12, M13 and M14; After flushing the 9.5 mm sieve, count and weigh the number of aggregate particles on the 9.5 mm, 4.75 mm, and 2.36 mm sieves after flushing, record them as N21, N22, and N23, and record the mass as M21, M22, and M23; After flushing the 4.75mm sieve, count and weigh the number of aggregate particles on the 4.75mm and 2.36mm sieves after flushing, record them as N31 and N32, and record the mass as M31 and M32; After flushing the 2.36mm sieve, calculate and weigh the number of aggregate particles on the 2.36mm sieve after flushing, record it as N41, and record the mass as M41.
[0014] The beneficial effects of the present invention are as follows: the test method for the rake-and-clumping rate of in-situ hot-regenerated pavement asphalt mixture of the present application takes samples from the site and screens them indoors, the test conforms to the actual situation on site and is fully representative of the test samples; at the same time, the method of the present application evaluates in terms of particle quantity and quality, and the results are expressed in a quantitative manner; the test results and process are highly operational and scientific; the method of the present application is highly operational, easy to understand, the data is true and reliable, and it has a good ability to distinguish the rake-and-clump effects of different equipment and process conditions, and is a simple, easy to use and intuitive test method. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a flow chart of the present invention; Figure 2 The present invention provides the hot-regenerated in-situ asphalt mixture after raking. DETAILED DESCRIPTION
[0016] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0017] like Figure 1-2 As shown, the specific embodiment of the present invention is a method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement, and the specific steps are as follows: S101. Place the hot-recycled in-situ asphalt mixture after harrowing at a specified temperature T (60-200°C) to cool indoors. After taking the material, wait until the temperature drops to room temperature to obtain the rough material. Samples should be taken once on both sides and in the middle of the lane of the same harrowing section, or once at the upper, middle and lower parts of the material pile. The mass of the material taken each time shall not be less than 2kg. The thickness of the hot-recycled in-situ asphalt mixture on the road surface is h, and the value range of the thickness h is 1.0-10.0cm.
[0018] S102, use two or more sieves of different specifications to screen the coarse material step by step; after the screening is completed, record the data, the number of aggregate particles on the i-th sieve n i and particle mass m i , and obtain the corresponding sieved aggregate particles; four sieves are used, i=4, and the sieve sizes are a combination of 13.2mm, 9.5mm, 4.75mm and 2.36mm.
[0019] S103. Use an organic solvent to rinse and screen the aggregate particles on each screen twice in a step-by-step manner until there is no obvious asphalt adhering to the aggregate particles; the organic solvent is one or more of trichloroethylene, acetone, carbon tetrachloride, and diesel. After the rinsing is completed, record the data, the number of particles N on the jth screen after the aggregate particles are rinsed and screened twice in a step-by-step manner. j1 and particle mass M j1 , where the number of particles N after the aggregate particles on the j+ath screen are screened twice step by step is ja and particle mass M ja , obtain the corresponding aggregate particles after flushing; The specific steps of secondary screening by showering are as follows: After flushing the 13.2 mm sieve, count and weigh the number of aggregate particles on the 13.2 mm, 9.5 mm, 4.75 mm and 2.36 mm sieves after flushing, record them as N11, N12, N13 and N14, and record the mass as M11, M12, M13 and M14; After flushing the 9.5 mm sieve, count and weigh the number of aggregate particles on the 9.5 mm, 4.75 mm, and 2.36 mm sieves after flushing, record them as N21, N22, and N23, and record the mass as M21, M22, and M23; After flushing the 4.75mm sieve, count and weigh the number of aggregate particles on the 4.75mm and 2.36mm sieves after flushing, record them as N31 and N32, and record the mass as M31 and M32; After flushing the 2.36mm sieve, calculate and weigh the number of aggregate particles on the 2.36mm sieve after flushing, record it as N41, and record the mass as M41.
[0020] S104. Calculate the particle number and agglomeration rate γ of the hot-in-place recycled asphalt mixture corresponding to the mesh size of the i-th sieve. i , mass agglomeration rate λ i .
[0021] The particle number agglomeration rate is: ; The mass agglomeration rate is: .
[0022] Where i=1,2,3; j=1,2,3,4.
[0023] The sieve holes of sieve i are all greater than or equal to 2.36 mm, and the particle number agglomeration rate γ i , mass agglomeration rate λ i It is used to evaluate the agglomeration of coarse particles in the mixture, that is, the agglomeration of aggregate particles greater than or equal to 2.36 mm. Example
[0024] There are great differences in the mechanical conditions of asphalt pavement under different temperature T conditions, and the harrowing effect under different temperature conditions is obviously different. When the surface temperature T of the asphalt pavement is 80~160℃, the results of harrowing and agglomeration rates under different temperature conditions are shown in Table 1 below.
[0025] Table 1: Results of harrowing and caking rate under different temperature conditions
[0026] As shown in Figure 1, the effects of asphalt pavement harrowing vary under different temperatures (80-160°C). The higher the temperature, the lower the harrowing and caking rate. Therefore, maintaining the harrowing temperature during asphalt pavement construction is crucial. The method described in this application allows for comparative analysis of the harrowing effects at different construction temperatures, thereby optimizing the appropriate construction temperature T and providing effective reference data for determining construction techniques. Example
[0027] When using an in-situ hot regeneration harrow to loosen pavement with different thicknesses h, it is obvious that the loosening effect and agglomeration rate will be different. The results of the loosening and agglomeration rate of asphalt pavement with different thicknesses h are shown in Table 2.
[0028] Table 2 The caking rate of asphalt pavement with different harrowing thicknesses
[0029] As can be seen from Table 2 above, there are significant differences in the performance of the geothermal regeneration harrowing machine when harrowing pavement of different thicknesses. When the thickness exceeds 4 cm, the particle agglomeration rate and mass agglomeration rate increase significantly. Therefore, the equipment is more suitable for a harrowing thickness of 4 cm. The method of this application can be used to compare and analyze the harrowing effects of different construction thicknesses, thereby optimizing the appropriate construction thickness h. Example
[0030] The raking power and principle of different equipment are different. Therefore, the raking and agglomeration rate of asphalt pavement using different raking equipment was compared and analyzed. The raking thickness was 4 cm, the raking temperature was 120°C, and other process parameters remained consistent. The results are shown in Table 3.
[0031] Table 3 Amount of asphalt pavement lumps and loosened by different raking equipment
[0032] As can be seen from the above table, there are differences in the asphalt pavement loosening and agglomeration rates of different equipment. The loosening effect of equipment B is better than that of equipment A. The method of this application can be used to compare and analyze the loosening effects of different equipment, so as to select the better equipment.
[0033] The test method for the raking and agglomeration rate of in-situ hot-regenerated pavement asphalt mixture in this application takes samples from the site and screens them indoors. The test conforms to the actual situation on site and is fully representative of the test samples. At the same time, the method of this application evaluates in terms of particle quantity and quality, and the results are expressed in a quantitative manner. The test results and process are highly operational and scientific, and it is a simple, easy and intuitive test method.
[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent replacements, and improvements made to the above embodiments based on the technical essence of the present invention shall be included in the scope of protection of the technical solution of the present invention.
Claims
1. A method for testing the raking and caking rate of asphalt mixture for hot-in-place regeneration of pavement, characterized in that: The specific steps are as follows: S1. Place the hot-recycled in-situ asphalt mixture loosened at a specified temperature T in a room for cooling, and obtain the coarse material after the temperature drops to room temperature; S2. Use two or more sieves to screen the coarse material step by step; record the data after the screening is completed, and the number of aggregate particles on the i-th sieve is n i and particle mass m i , obtain the corresponding aggregate particles after screening; S3. Use organic solvent to flush the aggregate particles on each screen and screen them step by step until there is no obvious asphalt attached to the aggregate particles. After the flushing is completed, record the data, the number of particles N on the jth screen after the aggregate particles are flushed and screened step by step j1 and particle mass M j1 , where the number of particles N after the aggregate particles on the j+ath screen are screened twice step by step is ja and particle mass M ja , obtain the corresponding aggregate particles after flushing; S4. Calculate the particle number and agglomeration rate γ of the hot-in-place recycled asphalt mixture on the i-th screen. i , mass agglomeration rate λ i .
2. The method for testing the raking and caking rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 1, characterized in that: In step S1, samples should be taken once on both sides and in the middle of the lane of the same harrowing section, or once at the upper, middle and lower parts of the material collection. The mass of each sample should not be less than 2kg. The thickness of the in-situ hot-recycled asphalt mixture on the road surface is h, and the value range of the thickness h is 1.0-10.0 cm.
3. The method for testing the raking and caking rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 1, characterized in that: Four sieves are used in step S2, i=4, and the sizes of the sieves are a combination of 13.2 mm, 9.5 mm, 4.75 mm and 2.36 mm.
4. The method for testing the raking and caking rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 1 or 3, characterized in that: In step S4, The particle number agglomeration rate is: ; The mass agglomeration rate is: .
5. The method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 4, characterized in that: In step S4, the mesh size of the sieve i is greater than or equal to 2.36 mm, and the particle number agglomeration rate γ i , mass agglomeration rate λ i It is used to evaluate the agglomeration of coarse particles in the mixture, that is, the agglomeration of aggregate particles greater than or equal to 2.36 mm.
6. The method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 1, characterized in that: The organic solvent in step S3 is one or more of trichloroethylene, acetone, carbon tetrachloride, and diesel.
7. The method for testing the raking and agglomeration rate of asphalt mixture for hot-in-situ regeneration of pavement according to claim 3, characterized in that: The specific steps of the secondary step-by-step screening of the shower in step S3 are: After flushing the 13.2 mm sieve, count and weigh the number of aggregate particles on the 13.2 mm, 9.5 mm, 4.75 mm and 2.36 mm sieves after flushing, record them as N11, N12, N13 and N14, and record the mass as M11, M12, M13 and M14; After flushing the 9.5 mm sieve, count and weigh the number of aggregate particles on the 9.5 mm, 4.75 mm, and 2.36 mm sieves after flushing, record them as N21, N22, and N23, and record the mass as M21, M22, and M23; After flushing the 4.75mm sieve, count and weigh the number of aggregate particles on the 4.75mm and 2.36mm sieves after flushing, record them as N31, N32, and record the mass as M31, M32; After flushing the 2.36mm sieve, calculate and weigh the number of aggregate particles on the 2.36mm sieve after flushing, record it as N41, and record the mass as M41.