Measurement method for the release rate of asphalt self-healing capsule repair agent

Abstract

The present invention provides a method for measuring the release rate of a healing agent in asphalt self-healing capsules, comprising: recovering asphalt from an asphalt mixture; measuring the glass transition temperature of the recovered asphalt; calculating the healing agent content in the asphalt based on the glass transition temperature of the recovered asphalt and a curve showing the relationship between the glass transition temperature of the asphalt and the healing agent content in the asphalt; and calculating the release rate of the healing agent in the self-healing capsules based on the amount of asphalt in the asphalt mixture, the healing agent content in the asphalt, the dosage of the self-healing capsules, and the healing agent content in the self-healing capsules. The present invention can more accurately estimate the release rate of the healing agent in asphalt self-healing capsules and is applicable to asphalt self-healing capsules containing different types of healing agents as cores, such as asphalt regeneration agents, vegetable oils, and waste engine oils, thus having a wide range of applications.

Description

Technical Field

[0001] The invention relates to the technical field of organic polymer compounds, and in particular to a method for measuring the release rate of an asphalt self-healing capsule repair agent. Background Art

[0002] To address the aging problem of asphalt concrete, existing technology uses suitable wall materials to encapsulate asphalt repair agents into self-healing capsules, which are then incorporated into the asphalt concrete. When the asphalt concrete gradually ages and develops microcracks under the combined effects of light, heat, oxygen, and load, the self-healing capsules rupture and release the repair agent, repairing the microcracks, softening the aged asphalt, improving the performance of the asphalt concrete, and extending its service life.

[0003] The key to ensuring the healing effect of self-healing capsules is to release the repair agent at the right time. However, there is currently no accurate and reliable method to measure the release rate of the self-healing capsule repair agent. In the existing technology, some researchers have proposed that when the self-healing capsule repair agent is sunflower oil, the recovered asphalt 1745cm -1 The peak area at 1745 cm is based on the content of sunflower oil in asphalt and the peak area at 1745 cm in its infrared spectrum. -1 The oil content in the asphalt was calculated based on the standard relationship curve of the CO peak area at 400 nm. Then, the release rate of the sunflower oil in the capsule was calculated according to the dosage and oil content of the capsule.

[0004] However, the above measurement method is only applicable to self-healing capsules with sunflower oil as the repair agent, and because the asphalt is aged at 1700 cm -1 The carbonyl peak at 1745 cm -1 The overlap of CO peak of sunflower oil at 1745cm leads to large error in the test results of Fourier transform infrared spectrometer and inaccurate measurement results of capsule repair agent release rate. -1 There is no characteristic peak at this point, so the above measurement method is not applicable. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention proposes a method for measuring the release rate of asphalt self-healing capsule repair agent to solve the technical problems in the existing technology that only the release rate of sunflower oil repair agent can be measured and the measurement results have large errors.

[0006] The technical solution adopted by the present invention is a method for measuring the release rate of asphalt self-healing capsule repair agent, comprising:

[0007] Recovering bitumen from asphalt mixes;

[0008] Measuring the glass transition temperature of recycled asphalt;

[0009] The repair agent content in asphalt is calculated based on the glass transition temperature of the recycled asphalt and the relationship curve between the glass transition temperature of the asphalt and the repair agent content in the asphalt;

[0010] The release rate of the self-healing capsule healing agent is calculated based on the amount of asphalt in the asphalt mixture, the healing agent content in the asphalt, the dosage of the self-healing capsule and the healing agent content in the self-healing capsule.

[0011] Furthermore, the asphalt was recovered from the asphalt mixture using a rotary evaporator method.

[0012] Furthermore, the glass transition temperature of the recycled asphalt was measured using differential scanning calorimetry.

[0013] Furthermore, the relationship curve between the glass transition temperature of asphalt and the content of repair agent in asphalt is obtained by the following method:

[0014] Configure a variety of asphalts with different repair agent dosages;

[0015] Thermogravimetric analysis of asphalt with different repair agent dosages was performed using differential scanning calorimetry;

[0016] The midpoint method was used to determine the glass transition temperature of asphalt with different repair agent dosages;

[0017] According to the different thermogravimetric analysis results and glass transition temperatures of various asphalts, a relationship curve between the glass transition temperature of asphalt and the content of repair agent in asphalt was drawn.

[0018] Furthermore, the formula for calculating the release rate of the self-healing capsule repair agent is: y=ax / bc, where y represents the release rate of the self-healing capsule repair agent, a represents the amount of asphalt in the asphalt mixture, x represents the repair agent content in the asphalt, b represents the dosage of the self-healing capsule, and c represents the repair agent content in the self-healing capsule.

[0019] Furthermore, the repair agent includes an asphalt regeneration agent.

[0020] Further, the repair agent includes vegetable oil.

[0021] Furthermore, the repair agent includes waste engine oil.

[0022] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0023] 1. A method for accurately calculating the release rate of self-healing capsule repair agents in asphalt using thermogravimetric analysis is provided. This method provides technical support for determining and regulating the release rate of the repair agent and improving its healing effect. It also avoids the influence of the characteristic peaks of aged asphalt on the characteristic peaks of sunflower oil, and can more accurately estimate the release rate of the self-healing capsule repair agent in asphalt.

[0024] 2. Asphalt self-healing capsules with different types of repair agents such as asphalt regeneration agent, vegetable oil, waste oil as the capsule core have a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0026] Figure 1 A schematic diagram of determining the glass transition temperature of asphalt using differential scanning calorimetry according to one embodiment of the present invention;

[0027] Figure 2 A graph showing the relationship between the glass transition temperature of asphalt and the content of the repair agent in the asphalt according to an embodiment of the present invention;

[0028] Figure 3 This is a flow chart of a method for measuring the release rate of asphalt self-healing capsule repair agent according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0030] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0031] Example 1

[0032] In this embodiment, the repair agent in the self-healing capsule is vegetable oil. The repair agent is added to the asphalt at a dosage of 1.5%, 3.0%, 4.5%, and 6.0% and mixed evenly. The asphalt with different repair agent dosages is subjected to thermogravimetric analysis using differential scanning calorimetry (DSC). The glass transition temperature of the asphalt with different repair agent dosages is determined using the midpoint method. Figure 1 As shown. The intersection of the midline between the extrapolated baseline on the low temperature side and the extrapolated baseline on the high temperature side of the DSC curve and the curve is the glass transition temperature: the glass transition temperatures of pure asphalt and asphalt mixed with 1.5%, 3.0%, 4.5% and 6.0% repair agent are -19.27℃, -21.86℃, -25.72℃, -29.48℃ and -33.57℃ respectively. Based on the 5 sets of test data provided in this step, the relationship curve between the glass transition temperature of asphalt and the content of repair agent in asphalt is drawn as shown below. Figure 2As shown, the function is:

[0033] T = -2.41x -18.74 (R 2 =0.9928) (1)

[0034] In the above formula (1), T represents the glass transition temperature of asphalt, x represents the content of the repair agent in asphalt, and the repair agent is vegetable oil; R 2 Indicates goodness of fit.

[0035] After obtaining the relationship curve between the glass transition temperature of asphalt and the content of the repair agent in the asphalt, the release rate of the asphalt self-healing capsule repair agent was measured according to the following steps:

[0036] Step 1: Recover asphalt from asphalt mixture

[0037] The method for recovering asphalt from asphalt mixture is not limited and can be carried out in any feasible manner in the prior art; optionally, refer to "T 0727-2011 Method for Recovering Asphalt from Asphalt Mixture (Rotary Evaporator Method)" and use a rotary evaporator method to recover asphalt from asphalt mixture.

[0038] Step 2: Measure the glass transition temperature of recycled asphalt

[0039] The method for measuring the glass transition temperature of the recycled asphalt is not limited and can be performed in any feasible manner in the prior art; optionally, the glass transition temperature of the recycled asphalt is measured by differential scanning calorimetry (DSC) to be -24.11°C.

[0040] Step 3: Calculate the content of the repair agent in the asphalt based on the glass transition temperature of the recycled asphalt and the relationship curve between the glass transition temperature of the asphalt and the content of the repair agent in the asphalt.

[0041] According to formula (1), the repair agent content x in the asphalt is calculated to be 2.23%.

[0042] Step 4: Calculate the release rate of the self-healing capsule repair agent based on the amount of asphalt in the asphalt mixture, the repair agent content in the asphalt, the dosage of the self-healing capsule and the repair agent content in the self-healing capsule.

[0043] Since the repair agents in the asphalt mixture are all released through the self-healing capsules, the following is true: the amount of asphalt in the asphalt mixture × the content of the repair agent in the asphalt = the amount of self-healing capsules × the content of the repair agent in the self-healing capsules × the release rate of the self-healing capsule repair agent.

[0044] In this embodiment, it is known that the asphalt content in the asphalt mixture is a=4.5%, the content of the self-healing capsule is b=0.5%, and the content of the repair agent in the self-healing capsule is c=62%. The release rate of the self-healing capsule repair agent is calculated using the formula y=ax / bc=32.37%.

[0045] In the formula y=ax / bc, y represents the release rate of the self-healing capsule repair agent, a represents the amount of asphalt in the asphalt mixture, x represents the repair agent content in the asphalt, b represents the dosage of the self-healing capsule, and c represents the repair agent content in the self-healing capsule.

[0046] Example 2

[0047] In this embodiment, the repair agent in the self-healing capsule is vegetable oil, and the release rate measurement method of the self-healing capsule repair agent is basically the same as the steps in Example 1, as follows:

[0048] Referring to "T 0727-2011 Method for Recovering Asphalt from Asphalt Mixture (Rotary Evaporator Method)", asphalt was recovered from the asphalt mixture, and the glass transition temperature of the recovered asphalt was measured by differential scanning calorimetry (DSC) to be -28.73°C.

[0049] According to the relationship curve function (1) between the glass transition temperature of asphalt and the content of repair agent in asphalt mixture, the content of repair agent x in the asphalt is calculated to be 4.15%.

[0050] In this embodiment, it is known that the asphalt content in the asphalt mixture is a=4.8%, the content of the self-healing capsule is b=0.5%, and the content of the repair agent in the self-healing capsule is c=54%. The release rate of the self-healing capsule repair agent is calculated using the formula y=ax / bc=73.78%.

[0051] Example 3

[0052] In this embodiment, the repair agent in the self-healing capsule is an asphalt regeneration agent. The repair agent is added to asphalt at a dosage of 1.5%, 3.0%, 4.5%, and 6.0% and mixed evenly. The asphalt with different dosages of the repair agent is subjected to thermogravimetric analysis using differential scanning calorimetry (DSC) to obtain the glass transition temperatures of the asphalt with different dosages of the repair agent: the glass transition temperatures of pure asphalt and asphalt with 1.5%, 3.0%, 4.5%, and 6.0% of the repair agent are -19.00°C, -23.92°C, -27.29°C, -31.46°C, and -35.03°C, respectively. The relationship curve between the glass transition temperature of the asphalt and the content of the repair agent in the asphalt is plotted, and the relationship function is obtained as follows:

[0053] T = -2.64x -19.42 (R 2 =0.9965) (2)

[0054] In the above formula (2), T represents the glass transition temperature of asphalt, x represents the content of the repair agent in asphalt, and the repair agent is asphalt regeneration agent; R 2 Indicates goodness of fit.

[0055] After obtaining the relationship curve between the glass transition temperature of asphalt and the content of the repair agent in the asphalt, the release rate of the asphalt self-healing capsule repair agent was measured according to the following steps:

[0056] Referring to "T 0727-2011 Method for Recovering Asphalt from Asphalt Mixture (Rotary Evaporator Method)", asphalt was recovered from the asphalt mixture, and the glass transition temperature of the recovered asphalt was measured by differential scanning calorimetry (DSC) to be -30.17°C.

[0057] According to the relationship curve function (2) between the glass transition temperature of asphalt and the content of repair agent in asphalt, the content of repair agent x in the asphalt is calculated to be 4.07%.

[0058] According to the asphalt dosage a=4.5% in the asphalt mixture, the capsule dosage b=0.5%, and the content of the healing agent in the capsule c=80%, the release rate of the self-healing capsule healing agent in the asphalt mixture is calculated using the formula y=ax / bc=45.79%.

[0059] The technical solution of the present application provides a measurement method for accurately calculating the release rate of asphalt self-healing capsule repair agent using thermogravimetric analysis, providing technical support for determining and regulating the release rate of the repair agent and improving its healing effect; avoiding the influence of the characteristic peak of aged asphalt on the characteristic peak of sunflower oil, and being able to more accurately estimate the release rate of asphalt self-healing capsule repair agent.

[0060] The technical solution of the present application can be used for asphalt self-healing capsules with different types of repair agents such as asphalt regeneration agent, vegetable oil, waste oil, etc. as the capsule core, and has a wide range of applications.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for measuring the release rate of asphalt self-healing capsule repair agent, characterized in that: include: Recovering bitumen from asphalt mixes; Measuring the glass transition temperature of recycled asphalt; The repair agent content in the asphalt is calculated based on the glass transition temperature of the recycled asphalt and a relationship curve between the glass transition temperature of the asphalt and the repair agent content in the asphalt; the relationship curve is obtained by the following method: preparing multiple asphalts with different repair agent dosages; performing thermogravimetric analysis on the asphalts with different repair agent dosages using differential scanning calorimetry; determining the glass transition temperature of the asphalts with different repair agent dosages using the midpoint method; and plotting a relationship curve between the glass transition temperature of the asphalt and the repair agent content in the asphalt based on the different thermogravimetric analysis results and glass transition temperatures of the multiple asphalts; The release rate of the self-healing capsule healing agent is calculated based on the amount of asphalt in the asphalt mixture, the healing agent content in the asphalt, the dosage of the self-healing capsule and the healing agent content in the self-healing capsule.

2. The measuring method according to claim 1, wherein The bitumen was recovered from the asphalt mixture using the rotary evaporator method.

3. The measuring method according to claim 1, wherein The glass transition temperature of the recycled asphalt was measured using differential scanning calorimetry.

4. The measuring method according to claim 1, wherein The formula for calculating the release rate of the self-healing capsule repair agent is: y=ax / bc, where y represents the release rate of the self-healing capsule repair agent, a represents the amount of asphalt in the asphalt mixture, x represents the repair agent content in the asphalt, b represents the dosage of the self-healing capsule, and c represents the repair agent content in the self-healing capsule.

5. The measuring method according to claim 1, wherein: The repair agent includes an asphalt regeneration agent.

6. The measuring method according to claim 1, characterized in that The repair agent includes a vegetable oil.

7. The measuring method according to claim 1, characterized in that The repair agent includes waste engine oil.

Images