Airfield pavement special-purpose asphalt and preparation method thereof

Abstract

This invention provides a special asphalt for airport pavements, prepared from raw materials comprising the following components: 85-100 parts by weight of base asphalt; 1-3 parts by weight of naphthenic oil; 2.5-3.5 parts by weight of modifier; 2.5-3 parts by weight of EPDM rubber; and 0.2-0.4 parts by weight of silane coupling agent. Compared with existing technologies, the special asphalt for airport pavements provided by this invention uses specific component content to achieve better overall interaction. The product has better high-temperature and low-temperature performance, can resist deformation and cracking under high stress conditions, has strong anti-aging properties, and improves the performance of asphalt pavements.

Description

Technical Field

[0001] This invention relates to the field of airport pavement materials technology, and more specifically, to a special asphalt for airport pavements and its preparation method. Background Technology

[0002] Asphalt pavement is characterized by its smooth surface, seamless construction, low noise, short construction period, and rapid traffic opening, making it a dominant type of asphalt pavement in civil airports. Aircraft landing generates significant vertical impact, placing high demands on the strength and toughness of the runway surface, requiring it to resist deformation and cracking under high stress conditions. During landing and deceleration, pilots may activate engine thrust reversers; some of the engine exhaust, normally directed forward, is diverted forward to aid in deceleration. This process generates high-temperature airflow that erodes the asphalt pavement, leading to thermal aging. The friction between brake discs during deceleration after landing generates substantial heat between the tires and the asphalt pavement, further contributing to thermal aging. In areas with extremely strong solar radiation, ultraviolet rays can cause photo-oxidation of the asphalt surface, resulting in discoloration, hardening, and cracking. Asphalt pavement ages, its durability deteriorates, exhibiting loosening, aging, and cracking. If not addressed promptly, this can compromise aircraft takeoff and landing safety. Therefore, it is necessary to develop a special asphalt for airports to improve asphalt performance and reduce the occurrence of airport pavement defects.

[0003] Currently, the types of asphalt used for airport pavements include epoxy asphalt, rubber-modified asphalt, high-modulus asphalt, and SBS-modified asphalt. Epoxy asphalt, as a new type of material, has good durability, but it is expensive. Rubber-modified asphalt has good fatigue resistance, but its low-temperature performance is poor, limiting its use in cold regions. High-modulus asphalt has good rutting resistance, but its low-temperature performance is poor, its cost is high, and there may be supply chain challenges, which limits its application in large-scale airport pavement projects. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a special asphalt for airport pavement and its preparation method. The special asphalt for airport pavement provided by this invention has good high-temperature performance and low-temperature performance, and can resist deformation and cracking under high stress conditions. It also has strong anti-aging properties and improves the performance of asphalt pavement.

[0005] This invention provides a special asphalt for airport pavements, prepared from raw materials comprising the following components:

[0006] 85 to 100 parts by weight of base bitumen;

[0007] 1 to 3 parts by weight of naphthenic oil;

[0008] Modifier 2.5 parts by weight to 3.5 parts by weight;

[0009] 2.5 to 3 parts by weight of ethylene propylene diene monomer (EPDM) rubber;

[0010] 0.2 to 0.4 parts by weight of silane coupling agent.

[0011] Preferably, the base bitumen has a C / H atomic ratio of 0.5 to 1.0, a residual penetration ratio of not less than 65%, a colloidal instability index of not more than 0.45, a penetration of 63 to 75 dmm at 25°C, and a weight-average molecular weight of 1400 to 2200 g / mol.

[0012] Preferably, the naphthenic oil contains 80%–90% naphthenic hydrocarbons, 5%–10% hydrocarbon-based naphthenic hydrocarbons, and <5% aliphatic alkanes.

[0013] Preferably, the flash point of the naphthenic oil is ≥200℃.

[0014] Preferably, the modifier is a styrene-butadiene-styrene block copolymer with a molecular weight of 100,000 to 150,000.

[0015] Preferably, the silane coupling agent is morpholinopropyltrimethoxysilane.

[0016] The present invention also provides a method for preparing the airport pavement special asphalt described in the above technical solution, comprising the following steps:

[0017] The base asphalt, naphthenic oil, modifier, and EPDM rubber are mixed, swelled, sheared, and then a silane coupling agent is added for development to obtain airport pavement special asphalt.

[0018] Preferably, the swelling temperature is 170℃~185℃ and the time is 40min~60min.

[0019] Preferably, the shearing temperature is 180℃~185℃, the rotation speed is 4000r / min~5000r / min, and the time is 50min~60min.

[0020] Preferably, the development temperature is 175℃~185℃ and the time is 120min~150min.

[0021] This invention provides a special asphalt for airport pavements, prepared from raw materials comprising the following components: 85-100 parts by weight of base asphalt; 1-3 parts by weight of naphthenic oil; 2.5-3.5 parts by weight of modifier; 2.5-3 parts by weight of EPDM rubber; and 0.2-0.4 parts by weight of silane coupling agent. Compared with existing technologies, the special asphalt for airport pavements provided by this invention uses specific component content to achieve better overall interaction. The product has better high-temperature and low-temperature performance, can resist deformation and cracking under high stress conditions, has strong anti-aging properties, and improves the performance of asphalt pavements.

[0022] In addition, the preparation method provided by this invention is simple, has mild and easy-to-control conditions, and uses readily available and low-cost raw materials, making it a promising candidate for application in airport asphalt. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention provides a special asphalt for airport pavements, prepared from raw materials comprising the following components:

[0025] 85 to 100 parts by weight of base bitumen;

[0026] 1 to 3 parts by weight of naphthenic oil;

[0027] Modifier 2.5 parts by weight to 3.5 parts by weight;

[0028] 2.5 to 3 parts by weight of ethylene propylene diene monomer (EPDM) rubber;

[0029] 0.2 to 0.4 parts by weight of silane coupling agent.

[0030] In this invention, the airport pavement asphalt is prepared from raw materials including base asphalt, naphthenic oil, modifier, EPDM rubber and silane coupling agent, preferably from base asphalt, naphthenic oil, modifier, EPDM rubber and silane coupling agent.

[0031] In this invention, the C / H atomic ratio of the base asphalt is preferably 0.5 to 1.0, the residual penetration ratio is preferably not less than 65%, the colloidal instability index is preferably not greater than 0.45, the penetration at 25°C is preferably 63 to 75 dmm, and the weight-average molecular weight is preferably 1400 to 2200 g / mol. This invention does not impose any special restrictions on the source of the base asphalt; commercially available products well-known to those skilled in the art can be used.

[0032] In this invention, the airport pavement special asphalt comprises 85 to 100 parts by weight of base asphalt, preferably 100 parts by weight.

[0033] In this invention, the naphthenic oil preferably contains 80%–90% naphthenes, preferably 5%–10% hydrocarbon-based naphthenes, and preferably <5% aliphatic alkanes; the flash point of the naphthenic oil is preferably ≥200℃. This invention optimizes the auxiliary component selection, which can improve the storage stability of airport pavement asphalt and reduce product quality instability caused by fluctuations in auxiliary component composition. This invention does not impose any special restrictions on the source of the naphthenic oil; commercially available products well-known to those skilled in the art can be used.

[0034] In this invention, the airport pavement asphalt comprises 1 to 3 parts by weight of naphthenic oil, preferably 2 parts by weight.

[0035] In this invention, the modifier is preferably a styrene-butadiene-styrene block copolymer (SBS), preferably linear SBS, with a molecular weight preferably between 100,000 and 150,000. In a preferred embodiment of this invention, the modifier is polymer modifier 791H. This invention does not impose any special restrictions on the source of the modifier; commercially available products well-known to those skilled in the art can be used.

[0036] In this invention, the airport pavement asphalt includes 2.5 to 3.5 parts by weight of a modifier, preferably 3.5 parts by weight.

[0037] In this invention, the ethylene propylene diene monomer (EPDM) rubber exhibits good compatibility with asphalt. During the modification process, it readily forms a spatial network structure with good compatibility and high stability. This results in the prepared airport pavement asphalt possessing good strength and toughness, resisting deformation and cracking under high stress conditions, and improving the material's light and thermal aging performance. This invention does not impose any special restrictions on the source of the EPDM rubber; commercially available products well-known to those skilled in the art can be used.

[0038] In this invention, the airport pavement asphalt comprises 2.5 to 3 parts by weight of EPDM rubber, preferably 3 parts by weight.

[0039] In this invention, the silane coupling agent is preferably morpholinopropyltrimethoxysilane, which mainly functions as a stabilizer. This invention does not impose any special restrictions on the source of the silane coupling agent; commercially available products well-known to those skilled in the art can be used.

[0040] In this invention, the airport pavement asphalt includes 0.2 to 0.4 parts by weight of silane coupling agent, preferably 0.25 parts by weight.

[0041] The airport pavement-specific asphalt provided by this invention uses specific component content to achieve better overall interaction. The product has good high-temperature performance and low-temperature performance, and can resist deformation and cracking under high stress conditions. It also has strong anti-aging properties and improves the performance of asphalt pavement.

[0042] The present invention also provides a method for preparing the airport pavement special asphalt described in the above technical solution, comprising the following steps:

[0043] The base asphalt, naphthenic oil, modifier, and EPDM rubber are mixed, swelled, sheared, and then a silane coupling agent is added for development to obtain airport pavement special asphalt.

[0044] In this invention, the matrix asphalt, naphthenic oil, modifier, EPDM rubber and silane coupling agent are the same as those in the above technical solution, and will not be repeated here.

[0045] In this invention, the swelling temperature is preferably 170°C to 185°C, more preferably 185°C, and the swelling time is preferably 40 min to 60 min, more preferably 50 min.

[0046] In this invention, the swollen asphalt is sheared; the shearing temperature is preferably 180℃~185℃, more preferably 180℃, the rotation speed is preferably 4000r / min~5000r / min, more preferably 4500r / min, and the time is preferably 50min~60min, more preferably 60min.

[0047] In this invention, the sheared asphalt is added with a silane coupling agent for development; the development temperature is preferably 175℃~185℃, more preferably 185℃, and the development time is preferably 120min~150min, more preferably 120min.

[0048] The preparation method provided by this invention only requires swelling, shearing, and development of the raw materials to obtain the product. The preparation process is simple, the conditions are mild and easy to control, the raw materials are readily available and low in cost. The obtained product has good storage stability, the modifier has good compatibility with asphalt, and it can resist deformation and cracking under high stress conditions, improve the light aging and thermal aging performance of the material, and has broad application prospects in airport asphalt.

[0049] This invention provides a special asphalt for airport pavements and its preparation method, which has the following beneficial effects:

[0050] (1) This invention improves the compatibility between asphalt and modifier by optimizing the micro-components of the base asphalt and selecting base asphalt with suitable components; it also improves the anti-aging performance of modified asphalt by optimizing the molecular weight and residual penetration ratio of the base asphalt.

[0051] (2) The present invention optimizes the naphthenic oil components to improve the storage stability of airport pavement asphalt and reduce product instability caused by fluctuations in raw material components.

[0052] (3) The specific modifier used in this invention improves the strength and toughness of airport pavement asphalt and can resist deformation and cracking under high stress conditions, thereby improving the light aging and thermal aging performance of the material.

[0053] (4) The modifier used in this invention is inexpensive, which reduces the cost of asphalt materials for airport pavements.

[0054] This invention provides a special asphalt for airport pavements, prepared from raw materials comprising the following components: 85-100 parts by weight of base asphalt; 1-3 parts by weight of naphthenic oil; 2.5-3.5 parts by weight of modifier; 2.5-3 parts by weight of EPDM rubber; and 0.2-0.4 parts by weight of silane coupling agent. Compared with existing technologies, the special asphalt for airport pavements provided by this invention uses specific component content to achieve better overall interaction. The product has better high-temperature and low-temperature performance, can resist deformation and cracking under high stress conditions, has strong anti-aging properties, and improves the performance of asphalt pavements.

[0055] In addition, the preparation method provided by this invention is simple, has mild and easy-to-control conditions, and uses readily available and low-cost raw materials, making it a promising candidate for application in airport asphalt.

[0056] To further illustrate the present invention, the following embodiments are provided for detailed description. The raw materials used in the following embodiments of the present invention are all commercially available products; the various indicators of the base asphalt are shown in Table 1 below.

[0057] Table 1 Key Indicators of Base Asphalt

[0058] Test Project Base asphalt 1 Base Asphalt 2 Matrix Asphalt 3 Test methods Needle penetration (25℃, 100g, 5s) / 0.1mm 68 69 68 T 0604 Residual penetration ratio / % 64 69 68 T 0605 Colloidal Instability Index 0.4 0.55 0.4 T 0606 C / H atomic ratio of bitumen / % 0.8 0.76 0.75 / <![CDATA[Asphalt weight-average molecular weight / g·mol -1 > 1940 2030 2200 /

[0059] The various indicators of naphthenic oils are shown in Table 2 below.

[0060] Table 2 Key Indicators of Naphthenic Oil

[0061] Test Project Naphthenic oil 1 Naphthenic oil 2 Naphthenic oil 3 Test methods Flash point / °C 230 200 232 T 0611 Cycloalkanes / % 70.3 88.0 89.2 / Hydrocarbon cycloalkanes / % 25.1 8.3 7.5 / Aliphatic alkanes / % 4.6 3.7 3.3 /

[0062] The above methods for determining the C / H atomic ratio of asphalt use an elemental analyzer to determine the C / H atomic ratio. An organic elemental analyzer (EA test) is used to determine the carbon and hydrogen content to obtain the C / H mass ratio. The weight-average molecular weight of asphalt is determined using gel permeation chromatography (GPC). The method for detecting cycloalkanes is gas chromatography-mass spectrometry (GC-MS).

[0063] Comparative Example 1

[0064] Base asphalt #1 (indicators shown in Table 1) was 500g mixed with 17.5g of modifier 791H SBS, 15g of EPDM, and 10g of naphthenic oil #3 (indicators shown in Table 2) for swelling. The swelling temperature was 185℃ and the swelling time was 50min. A direct heating mantle was used to control the temperature at 180℃ and the rotation speed at 4500r / min. The mixture was sheared for 60min. After shearing, the sample was transferred to a temperature-controlled heating mantle, and 1.25g of silane coupling agent (morpholinopropyltrimethoxysilane) was added. The temperature was controlled at 185℃, and the mixture was stirred and developed for 120min to obtain the airport pavement asphalt product.

[0065] Comparative Example 2

[0066] Base asphalt #2 (indicators shown in Table 1) was 500g mixed with 17.5g of modifier 791H SBS, 15g of EPDM, and 10g of naphthenic oil #3 (indicators shown in Table 2) for swelling. The swelling temperature was 185℃ and the swelling time was 50min. The temperature was controlled at 180℃ using a direct heating jacket, the rotation speed was 4500r / min, and the sample was sheared for 60min. After shearing, the sample was transferred to a temperature-controlled heating jacket, and 1.25g of silane coupling agent (morpholinopropyltrimethoxysilane) was added. The temperature was controlled at 185℃, and the mixture was stirred and developed for 120min to obtain the airport pavement asphalt product.

[0067] Comparative Example 3

[0068] Base asphalt #3 (indicators shown in Table 1) was 500g mixed with 17.5g of modifier 791H SBS, 15g of EPDM, and 10g of naphthenic oil #1 (indicators shown in Table 2) for swelling. The swelling temperature was 185℃ and the swelling time was 50min. The temperature was controlled at 180℃ using a direct heating mantle, the rotation speed was 4500r / min, and the sample was sheared for 60min. After shearing, the sample was transferred to a temperature-controlled heating mantle, and 1.25g of silane coupling agent (morpholinopropyltrimethoxysilane) was added. The temperature was controlled at 185℃, and the mixture was stirred and developed for 120min to obtain the airport pavement asphalt product.

[0069] Comparative Example 4

[0070] Base asphalt #3 (indicators shown in Table 1) was swelled by adding 17.5g of modifier 791H SBS, 15g of EPDM, and 10g of naphthenic oil #2 (indicators shown in Table 2) to 500g of base asphalt. The swelling temperature was 185℃ and the swelling time was 50min. The temperature was controlled at 180℃ using a direct heating jacket, the rotation speed was 4500r / min, and the sample was sheared for 60min. After shearing, the sample was transferred to a temperature-controlled heating jacket, and 1.25g of silane coupling agent (morpholinopropyltrimethoxysilane) was added. The temperature was controlled at 185℃, and the mixture was stirred and developed for 120min to obtain the airport pavement asphalt product.

[0071] Example 1

[0072] Base asphalt #3 (indicators shown in Table 1) was 500g mixed with 17.5g of modifier 791H SBS, 15g of EPDM, and 10g of naphthenic oil #3 (indicators shown in Table 2) for swelling. The swelling temperature was 185℃ and the swelling time was 50min. A direct heating mantle was used to control the temperature at 180℃ and the rotation speed at 4500r / min. The mixture was sheared for 60min. After shearing, the sample was transferred to a temperature-controlled heating mantle, and 1.25g of silane coupling agent (morpholinopropyltrimethoxysilane) was added. The temperature was controlled at 185℃, and the mixture was stirred and developed for 120min to obtain the airport pavement asphalt product.

[0073] The performance of various airport pavement asphalt products was tested, and the results are shown in Tables 3 and 4 below.

[0074] Table 3 Basic Performance Indicators of Products

[0075]

[0076] Table 4 Product Road Performance Data

[0077] Test Project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Test methods Marshall stability / N 8.3 8.6 8.5 9.0 15.2 T 0604 Dynamic stability / cycles / mm 2312 2400 2514 2300 5150 T 0605 Bending failure strain / μ∈ 2804 2903 2800 2812 3538 T 0606

[0078] As shown in the table above: Table 3 compares the modified asphalt indices of Examples 1-4 and Example 1. Compared with Comparative Examples 1 and 4, Example 1 has a 6cm higher ductility index after aging and a 9% higher UV aging ductility ratio. Compared with Comparative Examples 2 and 3, Comparative Examples 2 and 3 have poorer segregation indices. Table 4 compares the pavement performance indices of Examples 1-4 and Example 1. Example 1 has higher Marshall stability, indicating stronger destructive strength and resistance to plastic flow under high-temperature conditions. Its higher dynamic stability index indicates stronger rutting resistance under high-temperature conditions. Its better flexural failure strain index indicates stronger low-temperature crack resistance. In summary, through optimization of raw material components and corresponding adjustments to the preparation method, the airport pavement-specific asphalt provided by this invention exhibits higher destructive strength, better rutting resistance, and lower-temperature crack resistance.

[0079] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An airport pavement special-purpose asphalt prepared from raw materials comprising the following components: 85-100 parts by weight of base asphalt; 1-3 parts by weight of naphthenic oil; 2.5-3.5 parts by weight of modifier; 2.5-3 parts by weight of ethylene-propylene-diene rubber; 0.2-0.4 parts by weight of silane coupling agent; the C / H atomic ratio of the base asphalt is 0.5-1.0, the residual penetration ratio is not less than 65%, the colloidal instability index is not more than 0.45, the 25℃ penetration is 63-75 dmm, and the weight average molecular weight is 1400-2200 g / mol; the naphthenes in the naphthenic oil are 80-90%, the hydrocarbyl naphthenes are 5-10%, and the aliphatic alkanes are <5%; the flash point of the naphthenic oil is ≥200℃; the modifier is styrene-butadiene-styrene block copolymer with a molecular weight of 100-150 thousand; the silane coupling agent is morpholinopropyltrimethoxysilane.

2. A preparation method of the airport pavement special-purpose asphalt according to claim 1, comprising the following steps: mixing the base asphalt, naphthenic oil, modifier and ethylene-propylene-diene rubber, and then swelling, shearing and developing with the addition of silane coupling agent to obtain the airport pavement special-purpose asphalt.

3. The preparation method according to claim 2, characterized in that, the swelling temperature is 170-185℃, and the time is 40-60 min; 4. The production method according to claim 2, characterized by, the shearing temperature is 180-185℃, the rotation speed is 4000-5000 r / min, and the time is 50-60 min; 5. The preparation method according to claim 2, characterized in that, the developing temperature is 175-185℃, and the time is 120-150 min.

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