A total adhesion work-based method for predicting water stability of hot recycled asphalt mixture
Patent Information
- Application Number
- CN202611112676.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-25
- Publication Date
- 2026-10-09
AI Technical Summary
[0005]为了克服现有技术的不足，本发明的目的是提供一种基于总粘附功的热再生沥青混合料水稳定性预测方法，本发明解决了现有技术中热再生沥青混合料中回收沥青路面材料（RAP）导致混合料整体粘附性能下降，而目前评价其水稳定性的冻融劈裂试验过程繁琐、耗时较长，无法实现拌和前对水稳定性能的快速、准确预测，易造成材料浪费与工期延误的问题
本发明提供了一种基于总粘附功的热再生沥青混合料水稳定性预测方法，本发明通过获取热再生沥青混合料的材料本征参数、界面作用参数以及配合比与级配参数，利用建立的微观总粘附功计算式与宏观冻融劈裂强度比TSR的映射关系式，实现了在拌和前对热再生沥青混合料水稳定性能的快速、准确预测，有效弥补了现有试验周期长、过程繁琐的不足，便于及时优化施工参数并避免质量问题，从而确保了路面材料的耐久性。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of performance prediction technology for hot recycled asphalt mixtures, and in particular to a method for predicting the water stability of hot recycled asphalt mixtures based on total adhesion work. Background Technology
[0002] The adhesion properties of hot recycled asphalt mixtures are negatively affected by the addition of recycled asphalt pavement material (RAP). This is mainly because RAP contains aged asphalt, which has reduced activity and weakened interfacial bonding with new asphalt and aggregates, thus leading to a decline in the overall adhesion properties of the mixture. The adhesion properties of the mixture directly affect its various pavement performance characteristics, especially its water stability.
[0003] The adhesion properties of an asphalt mixture are most closely related to its water stability. Good adhesion properties effectively resist the erosion of the asphalt-aggregate interface by moisture, preventing asphalt film peeling and thus ensuring the durability of the mixture in humid or freeze-thaw environments. Currently, water stability is usually evaluated using the freeze-thaw splitting test. However, a complete freeze-thaw splitting test is time-consuming, typically requiring about a week. The test process includes multiple steps such as specimen molding, vacuum saturation, freeze-thaw cycles, water bath heating, and splitting strength testing, which is cumbersome and time-consuming. This means that if the water stability of the mixture fails to meet the requirements, the results will only be available after a week, easily leading to material waste and project delays.
[0004] Therefore, rapid and accurate prediction of the water stability of the hot recycled asphalt mixture before mixing is crucial. Advance prediction allows for timely adjustments to parameters such as RAP content, new asphalt type, and mixing process, thereby optimizing the water stability of the mixture and preventing quality problems during subsequent construction. However, current research on the prediction of water stability in hot recycled asphalt mixtures is limited. Summary of the Invention
[0005] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a method for predicting the water stability of hot recycled asphalt mixtures based on total adhesion work. This invention solves the problem that the use of recycled asphalt pavement material (RAP) in hot recycled asphalt mixtures leads to a decrease in the overall adhesion performance of the mixture. Currently, the freeze-thaw splitting test process for evaluating its water stability is cumbersome and time-consuming, making it impossible to quickly and accurately predict the water stability performance before mixing, which easily leads to material waste and construction delays.
[0006] To achieve the above objectives, the present invention provides the following solution: A method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work includes: The intrinsic material parameters, interfacial parameters, and mix proportion and gradation parameters of the hot recycled asphalt mixture to be predicted are obtained. Among them, the intrinsic material parameters include: the hot melt surface energy of the new asphalt at the mixing temperature, the surface energy of the old asphalt at room temperature, and the surface energy of the old asphalt at the preheating temperature; the interfacial parameters include: the contact angle between the old asphalt and the new aggregate at the preheating temperature; the mix proportion and gradation parameters include: RAP content, the old asphalt content in the hot recycled asphalt mixture, and the sieve analysis curves of RAP and new aggregate at different grades. The surface energy of the old asphalt at room temperature is taken as the surface energy of the unactivated old asphalt, and the surface energy of the old asphalt at the preheating temperature is taken as the surface energy of the activated old asphalt; and the surface energy of the fused asphalt is calculated based on the surface energy of the activated old asphalt, the content of old asphalt in the hot recycled asphalt mixture, and the hot melt surface energy of the new asphalt at the mixing temperature. Based on the RAP dosage and the screening curves of RAP and new aggregate at different grades, the proportion of new aggregate, the proportion of RAP, the specific surface area of new aggregate without mineral powder, and the specific surface area of RAP are calculated. The total adhesion work of the hot recycled asphalt mixture is calculated by substituting the hot melt surface energy of the new asphalt at the mixing temperature, the contact angle between the old asphalt and the new aggregate at the preheating temperature, the surface energy of the unactivated old asphalt, the surface energy of the activated old asphalt, the surface energy of the fused asphalt, the proportion of new aggregate, the proportion of RAP, the specific surface area of the new aggregate without mineral powder, and the specific surface area of RAP into the preset total adhesion work calculation formula. By substituting the total adhesion work into the preset relationship between total adhesion work and freeze-thaw splitting strength ratio (TSR), the freeze-thaw splitting strength ratio (TSR) of the hot recycled asphalt mixture is predicted.
[0007] The present invention discloses the following technical effects: This invention provides a method for predicting the water stability of hot recycled asphalt mixtures based on total adhesion work. By obtaining the intrinsic material parameters, interfacial parameters, mix proportions, and gradation parameters of the hot recycled asphalt mixture, and utilizing the established mapping relationship between the microscopic total adhesion work calculation formula and the macroscopic freeze-thaw splitting strength ratio (TSR), this invention achieves rapid and accurate prediction of the water stability performance of hot recycled asphalt mixtures before mixing. This effectively compensates for the shortcomings of existing methods, such as long test cycles and cumbersome processes, and facilitates timely optimization of construction parameters and avoidance of quality problems, thereby ensuring the durability of pavement materials. Attached Figure Description
[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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 drawings can be obtained based on these drawings without creative effort.
[0009] Figure 1 A flowchart of a method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work, provided in an embodiment of the present invention; Figure 2 A flowchart of the mixing process provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the mixing interface of hot recycled asphalt mixture provided in an embodiment of the present invention. Detailed Implementation
[0010] 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.
[0011] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0012] like Figure 1 As shown, this invention provides a method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work, comprising: Step 100: Obtain the intrinsic material parameters, interfacial parameters, and mix proportion and gradation parameters of the hot recycled asphalt mixture to be predicted; wherein, the intrinsic material parameters include: the hot melt surface energy of the new asphalt at the mixing temperature, the surface energy of the old asphalt at room temperature, and the surface energy of the old asphalt at the preheating temperature; the interfacial parameters include: the contact angle between the old asphalt and the new aggregate at the preheating temperature; the mix proportion and gradation parameters include: RAP content, the old asphalt content in the hot recycled asphalt mixture, and the sieve analysis curves of RAP and new aggregate at different grades; Step 200: Take the surface energy of the old asphalt at room temperature as the unactivated old asphalt surface energy, and take the surface energy of the old asphalt at the preheating temperature as the activated old asphalt surface energy; and calculate the fused asphalt surface energy based on the activated old asphalt surface energy, the old asphalt content in the hot recycled asphalt mixture, and the hot melt surface energy of the new asphalt at the mixing temperature. Step 300: Based on the RAP dosage and the screening curves of RAP and new aggregate at different grades, calculate the proportion of new aggregate, the proportion of RAP, the specific surface area of new aggregate without mineral powder, and the specific surface area of RAP. Step 400: Substitute the hot melt surface energy of the new asphalt at the mixing temperature, the contact angle between the old asphalt and the new aggregate at the preheating temperature, the surface energy of the unactivated old asphalt, the surface energy of the activated old asphalt, the surface energy of the fused asphalt, the proportion of new aggregate, the proportion of RAP, the specific surface area of the new aggregate without mineral powder, and the specific surface area of RAP into the preset total adhesion work calculation formula to calculate the total adhesion work of the hot recycled asphalt mixture; Step 500: Substitute the total adhesion work into the preset relationship between total adhesion work and freeze-thaw splitting strength ratio (TSR) to predict the freeze-thaw splitting strength ratio (TSR) of the hot recycled asphalt mixture.
[0013] Furthermore, the formula for calculating the surface energy of the fused asphalt is as follows: ; in, The surface energy of the new asphalt in its hot molten state. To activate the surface energy of old asphalt, This represents the amount of old asphalt in a hot recycled asphalt mixture.
[0014] Furthermore, the formula for calculating the total adhesion work of the hot recycled asphalt mixture is: ; in, Total adhesion work of hot recycled asphalt mixture To activate the surface energy of old asphalt, The contact angle between old asphalt and new aggregate at the preheated temperature. To integrate the surface energy of asphalt, This refers to the content of old asphalt in hot recycled asphalt mixtures. It is a natural constant. The surface energy of the new asphalt in its hot molten state. The specific surface area of the new aggregate excluding mineral powder. The proportion of new aggregate The surface energy of the old asphalt has not been activated. RAP specific surface area. This represents the percentage of RAP (rap).
[0015] Specifically, the flow chart of the mixing process is as follows: Figure 2 As shown in the diagram, the interface is illustrated below. Figure 3 As shown.
[0016] First, RAP is dry-mixed with new aggregates, then new asphalt is added and mixed, and finally mineral powder is added and mixed before being removed from the pot. Figure 3 The evolution mechanism of the interface during mixing was demonstrated, and a corresponding hierarchical adhesion model was constructed. Preheated new aggregate was first dry-mixed with RAP. During this stage, some of the aged asphalt on the RAP surface was activated by heat and peeled off, transferring to the surface of the new aggregate. Subsequently, new asphalt was added, and the activated old asphalt on the surface of the new aggregate diffused and fused with the new asphalt. Due to the incomplete miscibility of the old and new asphalt, the interface exhibited obvious hierarchical characteristics. For new aggregate, the surface was first coated with activated old asphalt, followed by fused asphalt and new asphalt. For old aggregate, the innermost layer of RAP was coated with unactivated old asphalt, followed by fused asphalt fused with the new asphalt, and the outermost layer was new asphalt. Therefore, for the interface model after mixing, the new aggregate interface is represented by a "aggregate-old asphalt (activated)-fused asphalt-new asphalt" model; the old aggregate interface is represented by a "old aggregate-old asphalt (unactivated)-fused asphalt-new asphalt" model.
[0017] The adhesion process of new aggregates before and after mixing involves adhesion between the new aggregates and activated old asphalt, forming a three-phase model of "new aggregates - old asphalt (activated) - fused asphalt". This process is quantitatively expressed using the adhesion work: ; In the formula, The adhesion work on the surface of new aggregates, mJ / m2; The change in adhesion energy on the surface of new aggregates, mJ / m2; The surface energy of the aggregate is mJ / m2; To activate the surface energy of old asphalt, mJ / m2; The surface energy of the new asphalt is mJ / m2; The interfacial energy for aggregates and activation of old asphalt is mJ / m2; To activate the interfacial energy of asphalt and fused asphalt, mJ / m2; To integrate the surface energy of asphalt, mJ / m2; To activate the adhesion work of asphalt and fused asphalt, mJ / m2; To activate the contact angle between the old asphalt and aggregate, °; is a natural constant, 2.718…; These are constants in the equation. .
[0018] The adhesion process of old aggregates before and after mixing involves the adhesion between unactivated old asphalt and new asphalt. Since the adhesion between old aggregates and old asphalt remains unchanged, it can be disregarded when designing the adhesion equation, resulting in a two-phase model of "old asphalt (unactivated) - fused asphalt". This process is illustrated by the following equation: ; In the formula, The work done on the RAP surface is mJ / m2; The change in adhesion energy on the RAP surface is expressed in mJ / m². The surface energy of unactivated old asphalt is mJ / m2; The surface energy of the new asphalt is mJ / m2; The interfacial energy between unactivated asphalt and fused asphalt is mJ / m2; To integrate the surface energy of asphalt, mJ / m2; The adhesion work between unactivated asphalt and fused asphalt is expressed in mJ / m2. is a natural constant, 2.718…; These are constants in the equation. .
[0019] The theoretical definitions of total adhesion work are as follows: ; In the formula, The total adhesion work of hot recycled asphalt mixture is expressed in mJ / m2. The specific surface area of the new aggregate excluding mineral powder, in m2 / kg; The adhesion work on the surface of new aggregates, mJ / m2; RAP specific surface area, m2 / kg; The percentage of new aggregates is % The work done on the RAP surface is mJ / m2; RAP percentage, %.
[0020] The above and Substituting into the theoretical formula, we get expression.
[0021] Furthermore, the relationship between total adhesion work and freeze-thaw splitting strength ratio (TSR) is as follows: ; Wherein, TSR is the freeze-thaw splitting strength ratio.
[0022] Furthermore, the surface energy of the old asphalt at room temperature ranges from 20℃ to 30℃.
[0023] Furthermore, the mixing temperature range of the new asphalt is 140℃~190℃.
[0024] Furthermore, the preheating temperature of the old asphalt ranges from 90℃ to 170℃.
[0025] Furthermore, the present invention also provides the following specific embodiments: Design an AC13 hot recycled asphalt mixture with an asphalt content of 5.5%, a RAP content of 25%, a RAP preheating temperature of 110℃, new aggregate of limestone, new asphalt of 70# base asphalt, and a mixing temperature of 160℃. The asphalt content in the RAP is shown in Table 1, and the mixture gradation is shown in Table 2.
[0026] Table 1
[0027] Table 2
[0028] Intrinsic material parameters of the mixture: Hot melt surface energy of new asphalt at a mixing temperature of 160℃ =29.80mJ / m 2 Surface energy of old asphalt at room temperature =22.21 mJ / m 2 Surface energy of old asphalt at a preheating temperature of 110℃ =34.84mJ / m 2 ; Interfacial parameters of the mixture: including the contact angle between old asphalt and new aggregate at the preheated temperature. =59.33°; Mixture proportions and gradation parameters: RAP content 25%, old asphalt content in hot recycled asphalt mixture is shown in Table 1, and sieve curves of RAP and new aggregate at different grades are shown in Table 2.
[0029] The RAP asphalt content is 4.38×0.2+2.99×0.05=1.03%, and the newly added asphalt content is 5.5-4.38×0.2-2.99×0.05=4.47%. The asphalt content in RAP accounts for a certain percentage of the total asphalt content in the mixture. for: ; Integrating asphalt surface energy: ; The specific surface area of the aggregate is calculated according to Equation III based on the specific surface area coefficient of each particle size (see Table 3).
[0030] Table 3
[0031] ; In the formula, The specific surface area of the aggregate is m. 2 / kg; , where represents the percentage of each sieve opening.
[0032] Specific surface area of new aggregate: ; Specific surface area of RAP: ; Based on these parameters, the total adhesion energy of the mixture under this working condition can be calculated to be 301.76 mJ / m. 2 The total adhesion work yields a TSR of 92.322%. A freeze-thaw splitting test was conducted to determine the TSR of the mixture under this condition to be 91.93%. Specific test data are shown in Table 4. The relative difference between the true value and the predicted value is 0.43%, indicating a good prediction effect.
[0033] Table 4
[0034] The present invention also provides the following embodiments: Design an AC13 hot recycled asphalt mixture with an asphalt content of 5.5%, a RAP content of 40%, a RAP preheating temperature of 110℃, new aggregate of limestone, new asphalt of 70# base asphalt, and a mixing temperature of 160℃. The asphalt content in the RAP is shown in Table 1, and the mixture gradation is shown in Table 5.
[0035] Table 5
[0036] Intrinsic material parameters of the mixture: Hot melt surface energy of new asphalt at a mixing temperature of 160℃ =29.80mJ / m 2 Surface energy of old asphalt at room temperature =22.21 mJ / m 2 Surface energy of old asphalt at a preheating temperature of 110℃ =34.84mJ / m 2 ; Interfacial parameters of the mixture: including the contact angle between old asphalt and new aggregate at the preheated temperature. =59.33°; Mixture proportions and gradation parameters: RAP content 40%, old asphalt content in hot recycled asphalt mixture is shown in Table 1, and sieve curves of RAP and new aggregate at different grades are shown in Table 5.
[0037] The RAP asphalt content is 4.38×0.3+2.99×0.1=1.61%, and the newly added asphalt content is 5.5-4.38×0.3-2.99×0.1=3.89%. The asphalt content in RAP accounts for a certain percentage of the total asphalt content in the mixture. for: ; Integrating asphalt surface energy: ; The specific surface area of the aggregate is calculated based on the specific surface area coefficient of each particle size (see Table 3).
[0038] ; In the formula, The specific surface area of the aggregate is m. 2 / kg; , where represents the percentage of each sieve opening.
[0039] Specific surface area of new aggregate: ; Specific surface area of RAP: ; Based on these parameters, the total adhesion energy of the mixture under this working condition can be calculated to be 268.93 mJ / m. 2 The total adhesion work yields a TSR of 89.56%. A freeze-thaw splitting test was conducted to determine the TSR of the mixture under this condition to be 89.69%. Specific test data are shown in Table 6. The relative difference between the true value and the predicted value is 0.15%, indicating a good prediction effect.
[0040] Table 6
[0041] The present invention further provides the following embodiments: Design an AC13 hot recycled asphalt mixture with an asphalt content of 5.5%, a RAP content of 25%, a RAP preheating temperature of 110℃, new aggregate of limestone, new asphalt of SBS modified asphalt, and a mixing temperature of 180℃. The asphalt content in the RAP is shown in Table 1, and the mixture gradation is shown in Table 2.
[0042] Intrinsic material parameters of the mixture: Hot melt surface energy of new asphalt at a mixing temperature of 180℃ =36.84mJ / m 2 Surface energy of old asphalt at room temperature =22.21 mJ / m 2 Surface energy of old asphalt at a preheating temperature of 110℃ =34.84mJ / m 2 ; Interfacial parameters of the mixture: including the contact angle between old asphalt and new aggregate at the preheated temperature. =59.33°; Mixture proportions and gradation parameters: RAP content 25%, old asphalt content in hot recycled asphalt mixture is shown in Table 1, and sieve curves of RAP and new aggregate at different grades are shown in Table 2.
[0043] The RAP asphalt content is 4.38×0.2+2.99×0.05=1.03%, and the newly added asphalt content is 5.5-4.38×0.2-2.99×0.05=4.47%. The asphalt content in RAP accounts for a certain percentage of the total asphalt content in the mixture. for: ; Integrating asphalt surface energy: The specific surface area of the aggregate is calculated based on the specific surface area coefficient of each particle size (see Table 3).
[0044] ; In the formula, The specific surface area of the aggregate is m. 2 / kg; , where represents the percentage of each sieve opening.
[0045] Specific surface area of new aggregate: ; Specific surface area of RAP: ; Based on these parameters, the total adhesion energy of the mixture under this working condition can be calculated to be 322.06 mJ / m. 2 The total adhesion work yields a TSR of 94.03%. The TSR of the mixture under this condition was measured to be 93.09% through a freeze-thaw splitting test. Specific test data are shown in Table 7. The relative difference between the true value and the predicted value is 1.01%, indicating a good prediction effect.
[0046] Table 7
[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0048] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work, characterized in that, include: The intrinsic material parameters, interfacial parameters, and mix proportion and gradation parameters of the hot recycled asphalt mixture to be predicted are obtained. Among them, the intrinsic material parameters include: the hot melt surface energy of the new asphalt at the mixing temperature, the surface energy of the old asphalt at room temperature, and the surface energy of the old asphalt at the preheating temperature; the interfacial parameters include: the contact angle between the old asphalt and the new aggregate at the preheating temperature; the mix proportion and gradation parameters include: RAP content, the old asphalt content in the hot recycled asphalt mixture, and the sieve analysis curves of RAP and new aggregate at different grades. The surface energy of the old asphalt at room temperature is taken as the surface energy of the unactivated old asphalt, and the surface energy of the old asphalt at the preheating temperature is taken as the surface energy of the activated old asphalt; and the surface energy of the fused asphalt is calculated based on the surface energy of the activated old asphalt, the content of old asphalt in the hot recycled asphalt mixture, and the hot melt surface energy of the new asphalt at the mixing temperature. Based on the RAP dosage and the screening curves of RAP and new aggregate at different grades, the proportion of new aggregate, the proportion of RAP, the specific surface area of new aggregate without mineral powder, and the specific surface area of RAP are calculated. The total adhesion work of the hot recycled asphalt mixture is calculated by substituting the hot melt surface energy of the new asphalt at the mixing temperature, the contact angle between the old asphalt and the new aggregate at the preheating temperature, the surface energy of the unactivated old asphalt, the surface energy of the activated old asphalt, the surface energy of the fused asphalt, the proportion of new aggregate, the proportion of RAP, the specific surface area of the new aggregate without mineral powder, and the specific surface area of RAP into the preset total adhesion work calculation formula. By substituting the total adhesion work into the preset relationship between total adhesion work and freeze-thaw splitting strength ratio (TSR), the freeze-thaw splitting strength ratio (TSR) of the hot recycled asphalt mixture is predicted.
2. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The formula for calculating the surface energy of the fused asphalt is: ； in, The surface energy of the new asphalt in its hot molten state. To activate the surface energy of old asphalt, This represents the amount of old asphalt in a hot recycled asphalt mixture.
3. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The formula for calculating the total adhesion work of the hot recycled asphalt mixture is: ； in, Total adhesion work of hot recycled asphalt mixture To activate the surface energy of old asphalt, The contact angle between old asphalt and new aggregate at the preheated temperature. To integrate the surface energy of asphalt, This refers to the content of old asphalt in hot recycled asphalt mixtures. It is a natural constant. The surface energy of the new asphalt in its hot molten state. The specific surface area of the new aggregate excluding mineral powder. The proportion of new aggregate The surface energy of the old asphalt has not been activated. RAP specific surface area. This represents the percentage of RAP (rap).
4. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The relationship between total adhesion work and freeze-thaw splitting strength ratio (TSR) is as follows: ； Wherein, TSR is the freeze-thaw splitting strength ratio.
5. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The range of surface energy of the old asphalt at room temperature is 20℃~30℃.
6. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The mixing temperature range for the new asphalt is 140℃~190℃.
7. The method for predicting the water stability of thermally recycled asphalt mixtures based on total adhesion work according to claim 1, characterized in that, The preheating temperature range for the old asphalt is 90℃~170℃.