Foamed asphalt mixture warm mixing seepage process
By setting the static seepage step of foam asphalt before stirring, the problem that foam asphalt fails to penetrate into the aggregate is solved, and the uniform mixing and energy-saving and emission-reducing effects of the mixture are achieved.
Patent Information
- Application Number
- CN202510921939.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-08-08
AI Technical Summary
In the traditional warm mixing process of foam asphalt mixture, foam asphalt fails to penetrate into the aggregate effectively, resulting in uneven mixing and quality problems such as white material.
A static seepage step is set before stirring, and the low viscosity characteristics of foam asphalt are used to allow it to seepage naturally in the aggregate gap, and then mechanical mixing is performed.
It significantly improves the mixing uniformity of the mixture, reduces the generation of white materials, and maintains the energy-saving and emission-reducing advantages of the warm mixing process.
Smart Images
Figure CN120443527A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of asphalt mixing, in particular to a foamed asphalt mixture warm mix infiltration process. Background Art
[0002] Asphalt pavement is one of the most commonly used road types worldwide due to its rapid construction, relatively low cost, and easy maintenance. However, traditional road construction requires high-temperature heating of aggregates, which produces large amounts of toxic and hazardous gases, such as asphalt fumes, during the mixing process. To address this issue, warm-mix asphalt technology began to develop in the late 20th and early 21st centuries, aiming to reduce production and construction temperatures, thereby reducing energy consumption and emissions. Warm-mix technology generally utilizes foaming technology to reduce the viscosity of asphalt, making it easier to mix and lay at lower temperatures. Traditional mixing processes involve spraying foamed asphalt into a precisely graded aggregate to form a foamed asphalt mixture, followed by direct mixing. This mixing method causes the foamed asphalt to accumulate on the surface of the aggregate, requiring forced mixing in a mixer to coat the foamed asphalt with multiple layers of aggregate. Because direct mixing fails to effectively utilize the seepage of the foamed asphalt in the interstices between the aggregates prior to mixing, it struggles to fully penetrate the internal pores of the aggregate pile. This can lead to uneven coating during subsequent mixing, resulting in quality issues such as whitening.
[0003] In view of the shortcomings of the existing technology, the main purpose of the present invention is to provide a warm mix infiltration process for foamed asphalt mixture, which utilizes the infiltration effect of foamed asphalt in the gaps between aggregates before mixing to make the mixing of foamed asphalt and aggregate more uniform. Summary of the Invention
[0004] The purpose of the present invention is to provide a foamed asphalt mixture warm mix infiltration process to solve the technical problem of uneven mixing of asphalt mixture caused by the lack of asphalt infiltration link in the current traditional foamed asphalt mixture warm mix process.
[0005] The technical problem solved by the present invention can be achieved by adopting the following solutions: A foamed asphalt mixture warm mix infiltration process comprises the following steps: S100, heating the aggregate and then putting it into a mixing device; S200, start the mixing equipment to preliminarily mix the aggregate; S300, spraying foamed asphalt and allowing it to stand for a predetermined time, utilizing the low viscosity of the foamed asphalt to seep into the gaps between the aggregates for a predetermined time; S400: Start the mixing equipment again to mix and obtain the foamed asphalt mixture.
[0006] Furthermore: in step S100, the aggregate is heated to 90-160°C.
[0007] Furthermore: in the step S300, the spraying time of the foamed asphalt is 5-15 seconds.
[0008] Furthermore: the mixing time in step S400 is 15-45s.
[0009] Further: In step S400, the rotation speed of the stirring equipment is 50-100 r / min.
[0010] Further: The parameters of foamed asphalt are: asphalt proportion is 3-5% of aggregate mass, asphalt temperature is 140-170℃, water proportion is 1.5-5% of asphalt mass, expansion rate is greater than 10 times, and half-life is greater than 8s.
[0011] Furthermore: the gradation of aggregate includes coarse aggregate, fine aggregate, mineral powder and cement, the coarse aggregate includes aggregate with a particle size of 9.5-16 mm and aggregate with a particle size of 4.75-9.5 mm, and the fine aggregate includes aggregate with a particle size of 2.36-4.75 mm and aggregate with a particle size of 0-2.36 mm.
[0012] Furthermore: the mixing time in step S200 is 10-15s.
[0013] The foamed asphalt mixture warm mix infiltration process of the present invention, by providing the key step of static infiltration, has brought about significant technological progress and beneficial effects. The process first heats the aggregate and then puts it into a mixing device. The mixing device is then started to preliminarily mix the aggregate. After that, foam is sprayed in and allowed to stand for a predetermined time. The low viscosity of the foamed asphalt is utilized to infiltrate the gaps between the aggregates for a predetermined time. Finally, the mixing device is started again for mechanical mixing to produce the foamed asphalt mixture. This innovative process design fully utilizes the low viscosity of the foamed asphalt, allowing it to naturally penetrate into the interior of the aggregate by relying on its own fluidity during the static stage. It effectively solves the technical problem of traditional processes in which foamed asphalt only accumulates on the surface of the aggregate and requires complete reliance on mechanical mixing to achieve coating. It significantly improves the mixing uniformity of the mixture and reduces the generation of white material, while maintaining the advantages of the warm mix process in energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0015] Figure 1 This is a process flow chart of a warm mix infiltration process of foamed asphalt mixture according to the present invention; Figure 2 Schematic diagram of the sampling position of the foamed asphalt mixture of the present invention; Figure 3 is a sample of the foamed asphalt mixture of Comparative Example 1 of the present invention; Figure 4 This is a sampling sample of the foamed asphalt mixture according to an embodiment of the present invention. DETAILED DESCRIPTION
[0016] In order to more clearly illustrate the objectives, technical solutions and advantages of the present invention, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
[0017] This embodiment provides a foamed asphalt mixture warm mix infiltration process, such as Figure 1 As shown, the following steps are included: S100, heating the aggregate and then putting it into a mixing device; S200, start the mixing equipment to preliminarily mix the aggregate; S300, spraying foamed asphalt and allowing it to stand for a predetermined time, utilizing the low viscosity of the foamed asphalt to seep into the gaps between the aggregates for a predetermined time; S400: Start the mixing equipment again to mix and obtain the foamed asphalt mixture.
[0018] Specifically, in step S100, the aggregate is heated to 90-160° C. Specifically, in step S200, the mixing time is 10-15 seconds, so that aggregates of different particle sizes are evenly distributed in the mixing equipment.
[0019] Specifically, the aggregate gradation includes coarse aggregate, fine aggregate, mineral powder and cement, the coarse aggregate includes aggregate with a particle size of 9.5-16 mm and aggregate with a particle size of 4.75-9.5 mm, and the fine aggregate includes aggregate with a particle size of 2.36-4.75 mm and aggregate with a particle size of 0-2.36 mm.
[0020] Specifically, in step S300, the spraying time of the foamed asphalt is 5-15 seconds.
[0021] Specifically, the parameters of foamed asphalt are: asphalt proportion (mass ratio) is 3-5% of the aggregate mass, asphalt temperature is 140-170℃, water proportion (mass ratio) is 1.5-5% of the asphalt mass, expansion rate is greater than 10 times, and half-life is greater than 8s.
[0022] Specifically, the mixing time in step S400 is 15-45 seconds.
[0023] Specifically, in step S400, the rotation speed of the stirring device is 50-100 r / min.
[0024] Example: This example provides a foamed asphalt mixture warm mix infiltration process, comprising the following steps: S101, heat the aggregate to 110°C and then put it into the mixing equipment; Specifically, the aggregate gradation is shown in Table 1, and the parameters of the mixing equipment are shown in Table 2. The total mass of the aggregate is 20 kg. Coarse aggregate can be selected from materials such as crushed stone and gravel, and fine aggregate can be selected from materials such as natural sand, machine-made sand, and stone chips.
[0025] Table 1 Aggregate gradation table
[0026] Table 2 Parameters of stirring parts of stirring equipment
[0027] S201, start the mixing equipment to preliminarily mix the aggregates for 10 seconds, so that the aggregates of different particle sizes are evenly distributed in the mixing equipment, and then turn off the mixing equipment; S301, spraying foamed asphalt and letting it stand for 5 seconds, using the low viscosity of the foamed asphalt to seep into the gaps between the aggregates for 5 seconds; the spraying time of the foamed asphalt is 5 seconds; Specifically, the parameters of foamed asphalt are shown in Table 3, where the asphalt ratio is the mass ratio of asphalt mass to aggregate mass, and the water ratio is the mass ratio of water mass to asphalt mass.
[0028] Table 3 Foamed asphalt parameters
[0029] S401. Start the mixing equipment again to mix and obtain a foamed asphalt mixture. The mixing time is 35 seconds and the speed of the mixing equipment is 80 r / min.
[0030] Comparative Example 1: A foamed asphalt mixture warm mix process is provided, comprising the following steps: S102, heating the aggregate to 110°C and then putting it into a mixing device; S202, start the mixing equipment to preliminarily mix the aggregates for 10 seconds, so that aggregates of different particle sizes are evenly distributed in the mixing equipment, and then turn off the mixing equipment; S303. After spraying the foamed asphalt, the stirring equipment is directly restarted to mix to obtain a foamed asphalt mixture. The mixing time is 35 seconds and the rotation speed of the stirring equipment is 80 r / min.
[0031] The other operating conditions of Comparative Example 1 are exactly the same as those of Example 1.
[0032] Effect example: The asphalt extraction test of foamed asphalt mixture was used to measure the asphalt content of different mixture samples, and the asphalt content dispersion coefficient was calculated. The asphalt content dispersion coefficient was used to evaluate the mixing uniformity of foamed asphalt mixture under different seepage conditions.
[0033] After the mixing of the embodiment and the comparative example is completed, each embodiment and the comparative example is selected as follows Figure 2 At the five sampling points shown in the figure, 600g of foamed asphalt mixture was taken from each sampling point and placed in a tin foil box. The samples were marked according to different working conditions and sampling locations, and a total of 15 samples were taken. Figure 3 、 4 As shown, by observing the foamed asphalt mixtures under different working conditions, it can be seen that the foamed asphalt mixture of Example 1 has less white material than that of Comparative Example 1.
[0034] In order to more accurately determine the effect of foamed asphalt seepage on the mixing uniformity of the mixture, asphalt extraction tests were carried out on foamed asphalt mixture samples, the asphalt content of different samples was measured, and the asphalt content dispersion coefficient was calculated to analyze the effect of foamed asphalt seepage on the mixing uniformity of the mixture.
[0035] The asphalt extraction test is to separate the components of the foamed asphalt mixture to measure the asphalt content of the foamed asphalt mixture. The specific test steps are as follows: R100. Place the tin foil box containing the foamed asphalt mixture sample in an oven and heat it to 130°C.
[0036] R200, take out the heated foamed asphalt mixture and weigh the total mass of the foamed asphalt mixture and the tin paper box Pour the heated foamed asphalt mixture into the sieve of the asphalt extractor and weigh the mass of the tin box after taking out the mixture. Since there is mineral powder in the mixture, filter paper needs to be placed in the mineral powder collection bucket of the asphalt extractor. The filter paper is used to collect the mineral powder. The mass of the filter paper is .
[0037] R300, use trichloroethylene to flush the foamed asphalt mixture in the asphalt extraction instrument to clean the asphalt attached to the aggregate surface.
[0038] R400, after the mixture is cleaned, the mineral powder will adhere to the filter paper. Put the filter paper and the cleaned aggregate into stainless steel trays and put them into the oven for drying. Weigh the mass of the dried filter paper. The increased mass of the filter paper is the mass of the mineral powder Weigh the mass of coarse aggregate and fine aggregate after drying The mass of the coarse aggregate and the fine aggregate after drying plus the mass of the mineral powder is the mass of the aggregate particles after washing asphalt. Since quicklime accounts for a small proportion in the aggregate, the mass of quicklime is not considered in the calculation.
[0039] Based on the above test, the dispersion coefficient of the asphalt content of the foamed asphalt mixture is calculated. The smaller the dispersion coefficient, the better the mixing uniformity of the foamed asphalt mixture. The steps for calculating the dispersion coefficient of the asphalt content of the foamed asphalt mixture are as follows: The mass of mineral powder in foamed asphalt mixture is calculated according to formula (1): (1) Where: —mass of mineral powder, g; —Mass of filter paper after drying, g; —Mass of filter paper before test, g.
[0040] The total mass of aggregate in foamed asphalt mixture is calculated according to formula (2): (2) Where: —Total mass of aggregate after drying, g; —Mass of coarse aggregate and fine aggregate after drying, g.
[0041] Quality of asphalt component in foamed asphalt mixture in test samples Calculate according to formula (3): (3) Where: —mass of asphalt in the test sample, g; —Total mass of test sample foamed asphalt mixture, g; —Mass of the tin box after cleaning the foamed asphalt mixture, g.
[0042] Asphalt content in foamed asphalt mixture Calculate according to formula (4): (4) Asphalt content dispersion coefficient of foamed asphalt mixture Calculate according to formula (5): (5) Where: —Standard deviation of asphalt content of five foamed asphalt mixture samples in a single embodiment or comparative example; —The average asphalt content of the foamed asphalt mixture of 5 samples in a single embodiment or comparative example.
[0043] The calculated asphalt content of foamed asphalt mixture under different samples is shown in Table 4.
[0044] Table 4 Record of asphalt content in foamed asphalt mixture
[0045] To quantitatively study the impact of foamed asphalt seepage on the mixing uniformity of foamed asphalt mixtures, the asphalt content dispersion coefficient was used to evaluate the mixing uniformity of foamed asphalt mixtures under different operating conditions. The asphalt content dispersion coefficient indicates the stability of the asphalt content in the foamed asphalt mixture. The smaller the dispersion coefficient, the greater the stability of the foamed asphalt content and the better the mixing uniformity of the foamed asphalt mixture.
[0046] Based on the asphalt contents of the various mixture samples calculated in Table 4, the asphalt content dispersion coefficients for different operating conditions were calculated. This dispersion coefficient was used to evaluate the effect of foamed asphalt seepage on the mixing uniformity of the foamed asphalt mixture. The asphalt content dispersion coefficients for the foamed asphalt mixtures under different operating conditions are shown in Table 5.
[0047] Table 5 Dispersion coefficient of asphalt content in foamed asphalt mixture
[0048] As shown in Table 5, since the asphalt content of foamed asphalt under different operating conditions accounts for 3.5% of the aggregate mass, after mixing the foamed asphalt with the aggregate, the asphalt content of the foamed asphalt mixture at different sampling locations should theoretically be 3.5%. In practice, the average values of the foamed asphalt content of Comparative Example 1 and Example were 3.39% and 3.52%, respectively. It can be concluded that the asphalt content of the foamed asphalt mixture of Example was closest to the theoretical value, followed by Comparative Example 1. The asphalt content dispersion coefficients of the foamed asphalt mixture under the two operating conditions of Comparative Example 1 and Example were 0.028 and 0.019, respectively. Comparing the dispersion coefficients under the two operating conditions, the asphalt content dispersion coefficient of the foamed asphalt mixture of Example 1 was smaller than that of Comparative Example 1, indicating that the mixing uniformity of the foamed asphalt when seepage was set was better than that of Comparative Example 1 without seepage.
[0049] Table 5 shows that the foamed asphalt mixture in this example has the smallest coefficient of dispersion for asphalt content. This indicates that the mixture produced by allowing foamed asphalt to seep through the interstices between aggregates exhibits greater uniformity in the coating between the foamed asphalt and the aggregate than when the seepage effect is not considered. When seepage is implemented, the foamed asphalt is evenly distributed throughout the aggregate before mixing, coming into contact with a large number of aggregate particles, facilitating the mixing of the foamed asphalt mixture.
[0050] It should be noted that the protection scope of the present invention is not limited to specific technical parameters such as seepage time, aggregate gradation, asphalt quality, temperature or asphalt type. Although the best implementation effect is demonstrated with a seepage time of 5 seconds in the embodiment, the core of the present invention is to set up the key process step of static seepage, and utilize the unique low viscosity characteristics of foamed asphalt to enable it to naturally penetrate into the internal voids of the aggregate by relying on its own fluidity within the predetermined seepage time. This technical means can effectively improve the initial distribution state of foamed asphalt in the aggregate, thereby significantly improving the mixing uniformity of the final mixture. This basic process principle is applicable to the adjustment of different seepage time parameters. Any technical solution that adopts this core technical concept should fall within the protection scope of the present invention regardless of how the specific process parameters are adjusted.
[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.
Claims
1. A foamed asphalt mixture warm mix infiltration process, characterized by: The steps include: S100, heating the aggregate and then putting it into a mixing device; S200, start the mixing equipment to preliminarily mix the aggregate; S300, spraying foamed asphalt and allowing it to stand for a predetermined time, utilizing the low viscosity of the foamed asphalt to seep into the gaps between the aggregates for a predetermined time; S400: Start the mixing equipment again to mix and obtain the foamed asphalt mixture.
2. The warm mix infiltration process of foamed asphalt mixture according to claim 1, characterized in that: In step S100, the aggregate is heated to 90-160°C.