Cold patch material for cold paving, paving method and application of cold patch material

Abstract

The invention belongs to the technical field of pavement paving materials of roads, and particularly relates to a cold patch material for cold paving, a paving method and application of the cold patch material. The cold patch material is characterized by being prepared from the following raw materials in parts by weight: 20 to 30 parts of matrix asphalt, 10 to 20 parts of waste rubber particles, 1 to 2 parts of 3MK520 primer, 10 to 15 parts of solvent oil, 20 to 30 parts of mineral powder, 50 to 60 parts of aggregate, 1 to 3 parts of quick setting agent and 5 to 8 parts of water. The invention also discloses an application of the 3MK520 primer in preparation of a cold patch material for cold paving. The solvent oil is petroleum ether or xylene; the quick-setting agent is an epoxy modified quick-setting agent; and 90 # matrix asphalt. The prepared cold patch material for cold paving has the characteristics of rapid forming strength, high initial strength, long service life and rapid traffic after paving, is suitable for paving in different seasons, and is free of excavation, base oil and edge sealing in the paving process, so that the paving process is greatly simplified, the paving labor intensity is reduced, and the cold patch material for cold paving greatly reduces exhaust emission.

Description

Technical Field

[0001] The invention belongs to the technical field of highway pavement paving materials, and relates to a cold patch material for cold paving, a paving method and application thereof. Background Art

[0002] With the rapid development of my country's highway construction, asphalt-based pavement, owing to its advantages of driving comfort and low noise, has become widely popular, becoming the preferred paving material for highways, municipal roads, park roads, and rural roads. At the same time, public transportation has become more diverse, heavily loaded, and used in large numbers, causing serious damage to asphalt-paved pavements. Therefore, repairing damaged asphalt mixture pavements and extending their lifespan have become core technical issues of concern in the road industry.

[0003] After a pavement is paved and officially opened to traffic, it will be subjected to long-term vehicle loads and erosion from water and snow, causing damage. This can lead to pavement loosening, flaking, potholes, and other defects, impacting road safety and driving comfort. Therefore, timely pavement repair and maintenance are necessary. Traditional repair materials are mainly divided into hot patching and cold patching. Hot patching requires large construction equipment and complex construction techniques. It is suitable for large-scale construction on newly paved surfaces but is not suitable for repairing small, localized damage. Cold patch material, as a road repair material, is suitable for repairing small-scale damage. It can be used in all weather and environments to repair various types of road surface layers, such as asphalt concrete roads, cement concrete roads, parking lots, and airport runways. In order to meet the storage performance and workability requirements of asphalt cold patch materials, however, existing cold patch materials often fail to quickly develop strength, have low initial strength, and have poor cohesiveness. After opening to traffic, they are prone to loosening again and peeling off at pothole interfaces and joints. They also suffer from technical issues such as a short service life and complex paving processes.

[0004] At present, the existing cold patch materials for cold laying are used in the cold areas of northern my country, where the temperature is below 10°C. After paving is completed, the road needs to be closed for more than 10 hours before it can be opened to traffic. Therefore, the development of a cold patch material that can be quickly paved and opened to traffic at low temperatures and has a long service life has become a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] The present invention is to solve the above technical problems and provides a cold patch material for cold laying. It has the characteristics of rapid strength formation, high initial strength, long service life, and can be quickly opened to traffic after paving. It is suitable for paving in different seasons. During the paving process, no excavation, no primer, and no edge sealing are required, which greatly simplifies the paving process and reduces the labor intensity of paving. The cold patch material for cold laying reduces exhaust emissions.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: A cold patch material for cold laying is prepared from the following raw materials in the stated weight parts: 20-30 parts of matrix asphalt, 10-20 parts of waste rubber particles, 1-2 parts of 3MK520 primer, 10-15 parts of solvent oil, 20-30 parts of mineral powder, 50-60 parts of aggregate, 1-3 parts of quick-setting agent, and 5-8 parts of water.

[0007] Preferably, the waste rubber particles have a particle size of 3-7 mm.

[0008] Preferably, the solvent oil is petroleum ether or xylene.

[0009] Preferably, the above-mentioned fast-setting agent is an epoxy-modified fast-setting agent.

[0010] Preferably, the above-mentioned matrix asphalt is 90# matrix asphalt.

[0011] Preferably, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3.

[0012] Preferably, the particle size of the coarse aggregate is 5-10 mm, the particle size of the medium aggregate is 3-5 mm, and the particle size of the fine aggregate is 1-3 mm.

[0013] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: crush the waste rubber to make waste rubber particles with a particle size of 3-7 mm for later use; Preparation of rubber asphalt: Heat the base asphalt in the amount specified by weight to 130-150°C, add the waste rubber particles in the amount specified by weight, stir for 30-35 minutes, and cool to 100°C to obtain the rubber asphalt for use; Cold patching fluid synthesis: add solvent oil and 3MK520 primer in the rubber asphalt in the specified weight proportions, stir and mix, cool to 55-60°C and shear at low speed for 12-15 minutes to obtain cold patching fluid, which is then set aside; Mixing of cold mix cold patch material: at room temperature, take aggregate and mineral powder dry materials that meet the specified weight proportions, stir evenly, then add cold patch liquid and water that meet the specified weight proportions and mix for 3-5 minutes, add quick setting agent that meets the specified weight proportions and stir for 1-2 minutes to obtain cold patch material for cold laying.

[0014] Preferably, the specific steps for preparing the above-mentioned waste rubber particles are as follows: after washing and drying the waste rubber, using a shear crusher to preliminarily crush the dried rubber blocks into particles of 50-100 mm, using a roller crusher to further crush the coarsely crushed rubber to produce particles with a particle size of 3-7 mm, and screening the crushed rubber particles with a vibrating screen to separate particles that meet the particle size requirements.

[0015] The invention discloses an application of 3MK520 primer in preparing cold patch material for cold laying.

[0016] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: The cold patch material for cold laying prepared by the present invention has the characteristics of rapid strength formation, high initial strength, long service life, and rapid traffic after paving. During the paving process, no excavation, no primer, and no edge sealing are required, which greatly simplifies the paving process and reduces the labor intensity of paving. The cold patch material for cold laying greatly reduces exhaust gas emissions. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below with reference to specific embodiments. However, the scope of protection of the present invention is not limited by the specific embodiments but is subject to the claims. In addition, any changes or modifications to the present invention that are easily implemented by a person of ordinary skill in the art without departing from the technical solution of the present invention shall fall within the scope of the claims of the present invention.

[0018] Example 1

[0019] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: After washing and drying the waste rubber, use a shear crusher to initially crush the dried rubber blocks into 50-65mm particles. Use a roller crusher to further crush the coarsely crushed rubber to make particles with a size of 3-7mm. Use a vibrating screen to screen the crushed rubber particles to separate the particles that meet the particle size requirements and set aside. Preparation of rubber asphalt: Take 20 parts by weight of 90# base asphalt and heat it to 130°C, then add 20 parts by weight of waste rubber particles and stir for 30 minutes, then cool to 100°C to obtain rubber asphalt for use; Cold patching fluid synthesis: Add 15 parts by weight of petroleum ether and 2 parts by weight of 3MK520 primer to the rubber asphalt, stir and mix, cool to 60°C and shear at low speed for 15 minutes to obtain the cold patching fluid, which is set aside; Mixing of cold mix cold patch material: Take 60 parts by weight of aggregate and 30 parts by weight of mineral powder dry material at room temperature, mix them evenly, then add cold patch liquid and 5 parts by weight of water and mix for 5 minutes, add 3 parts by weight of epoxy modified quick setting agent and stir for 1 minute to obtain cold patch material for cold laying.

[0020] In this embodiment, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3, the particle size of coarse aggregate is 5-10mm, the particle size of medium aggregate is 3-5mm, and the particle size of fine aggregate is 1-3mm.

[0021] Example 2

[0022] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: After washing and drying the waste rubber, use a shear crusher to initially crush the dried rubber blocks into 60-80mm particles. Use a roller crusher to further crush the coarsely crushed rubber to make particles with a size of 3-7mm. Use a vibrating screen to screen the crushed rubber particles to separate the particles that meet the particle size requirements and set aside. Preparation of rubber asphalt: Take 30 parts by weight of 90# base asphalt and heat it to 150°C, then add 10 parts by weight of waste rubber particles and stir for 31 minutes, then cool to 100°C to obtain rubber asphalt for use; Cold patching fluid synthesis: Add 10 parts by weight of petroleum ether and 1 part by weight of 3MK520 primer to the rubber asphalt, stir and mix, cool to 55°C and shear at low speed for 12 minutes to obtain the cold patching fluid, which is set aside; Mixing of cold mix cold patch material: Take 50 parts by weight of aggregate and 20 parts by weight of mineral powder dry material at room temperature, stir evenly, then add cold patch liquid and 8 parts by weight of water and mix for 3 minutes, add 1 part by weight of epoxy modified quick setting agent and stir for 2 minutes to obtain cold patch material for cold laying.

[0023] In this embodiment, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3, the particle size of coarse aggregate is 5-10mm, the particle size of medium aggregate is 3-5mm, and the particle size of fine aggregate is 1-3mm.

[0024] Example 3

[0025] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: After washing and drying the waste rubber, use a shear crusher to initially crush the dried rubber blocks into 75-100mm particles. Use a roller crusher to further crush the coarsely crushed rubber to produce particles with a size of 3-7mm. Use a vibrating screen to screen the crushed rubber particles to separate the particles that meet the particle size requirements and set aside. Preparation of rubber asphalt: Take 25 parts by weight of 90# base asphalt and heat it to 140°C, then add 15 parts by weight of waste rubber particles and stir for 35 minutes, then cool to 100°C to obtain rubber asphalt for use; Cold patching fluid synthesis: Add 12 parts by weight of petroleum ether and 1.5 parts by weight of 3MK520 primer to the rubber asphalt, stir and mix, cool to 58°C and shear at low speed for 13 minutes to obtain the cold patching fluid, which is set aside; Mixing of cold mix cold patch material: At room temperature, take 55 parts by weight of aggregate and 25 parts by weight of mineral powder dry material, stir evenly, then add cold patch liquid and 6 parts by weight of water and mix for 4 minutes, add 2 parts by weight of epoxy modified quick setting agent and stir for 1.5 minutes to obtain cold patch material for cold laying.

[0026] In this embodiment, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3, the particle size of coarse aggregate is 5-10mm, the particle size of medium aggregate is 3-5mm, and the particle size of fine aggregate is 1-3mm.

[0027] Example 4

[0028] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: After washing and drying the waste rubber, use a shear crusher to initially crush the dried rubber blocks into 55-75mm particles. Use a roller crusher to further crush the coarsely crushed rubber to make particles with a size of 3-7mm. Use a vibrating screen to screen the crushed rubber particles with a size of 3-7mm to separate the particles that meet the particle size requirements and set aside. Preparation of rubber asphalt: Take 22 parts by weight of 90# base asphalt and heat it to 135°C, then add 13 parts by weight of waste rubber particles and stir for 33 minutes, then cool to 100°C to obtain rubber asphalt for use; Cold patching fluid synthesis: Add 14 parts by weight of xylene and 1.3 parts by weight of 3MK520 primer to the rubber asphalt, stir and mix, cool to 58°C and shear at low speed for 13 minutes to obtain the cold patching fluid, which is set aside; Mixing of cold mix cold patch material: At room temperature, take 53 parts by weight of aggregate and 27 parts by weight of mineral powder dry material, stir evenly, then add cold patch liquid and 7 parts by weight of water and mix for 4 minutes, add 1.3 parts by weight of epoxy modified quick setting agent and stir for 1 minute to obtain cold patch material for cold laying.

[0029] In this embodiment, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3, the particle size of coarse aggregate is 5-10mm, the particle size of medium aggregate is 3-5mm, and the particle size of fine aggregate is 1-3mm.

[0030] Example 5

[0031] A method for preparing the cold patch material for cold laying, comprising the following steps: Preparation of waste rubber particles: After washing and drying the waste rubber, use a shear crusher to initially crush the dried rubber blocks into 70-90mm particles. Use a roller crusher to further crush the coarsely crushed rubber to make particles with a size of 3-7mm. Use a vibrating screen to screen the crushed rubber particles to separate the particles that meet the particle size requirements and set aside. Preparation of rubber asphalt: Take 27 parts by weight of 90# base asphalt and heat it to 145°C, then add 17 parts by weight of waste rubber particles and stir for 34 minutes, then cool to 100°C to obtain rubber asphalt for use; Cold patching fluid synthesis: Add 12 parts by weight of xylene and 1.8 parts by weight of 3MK520 primer to the rubber asphalt, stir and mix, cool to 56°C and shear at low speed for 14 minutes to obtain the cold patching fluid, which is set aside; Mixing of cold mix cold patch material: At room temperature, take 57 parts by weight of aggregate and 22 parts by weight of mineral powder dry material, stir evenly, then add cold patch liquid and 6.5 parts by weight of water and mix for 3 minutes, add 2.6 parts by weight of epoxy modified quick setting agent and stir for 2 minutes to obtain cold patch material for cold laying.

[0032] In this embodiment, the aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:3, the particle size of coarse aggregate is 5-10mm, the particle size of medium aggregate is 3-5mm, and the particle size of fine aggregate is 1-3mm.

[0033] The cold patch material prepared in Examples 1-5 of the present invention is installed as follows: loose material at the bottom of the area to be repaired is removed, and the cold patch material is directly poured onto the area to be repaired. The cold patch material is then directly leveled and compacted without excavation, primer, or edge sealing. The cold patch material of the present invention is simple and convenient to install; the applicable temperature range for installation is -20°C to 60°C, the mixing and installation time is no more than 1 hour, and the traffic-accessible time at room temperature is no more than 1 hour. This fully meets the needs of highway damaged pavement maintenance projects and can be installed in winter.

[0034] The effects of the present invention are further illustrated below through test examples. The test objects in all test examples are prepared according to conventional test methods and are manufactured according to the relevant specifications and standards.

[0035] Test Example 1 The cold-laid cold patch materials prepared by the methods of Examples 1-5 of the present invention were tested for surface drying time. The test method and results are as follows: 1. Test objectives: The dry time of cold-laid cold patch materials is measured, that is, the time from the time the material surface is applied to the time when tools no longer adhere to the material surface. This is used to confirm the feasibility of initial opening to traffic after construction.

[0036] 2. Test basis and methods: According to the "Test Procedure for Asphalt and Asphalt Mixtures in Road Engineering" (JTG E20) "Determination of Surface Drying Time of Asphalt Mixture" (T0752).

[0037] The test equipment includes a stopwatch, an electronic balance, a thermometer, a constant temperature curing box, a stainless steel scraper, and gloves; the test material is the cold-laid cold patch material prepared in Examples 1-5 of the present invention.

[0038] 4. The cold patch materials prepared in each example were subjected to 50 parallel tests. The simulated test environment temperature is shown in Table 1, and the humidity is 55-65%.

[0039] The test results are shown in Table 1 below. Table 1 Surface drying time of the cold-laid cold patch materials prepared in Examples 1-5 at different temperatures.

[0040]

[0041] 5. Result analysis: As can be seen from Table 1, the cold-laid cold patch materials prepared in various embodiments of the present invention can be initially cured and surface dried at room temperature and above 10°C in about 30 minutes after construction, meeting the demand for rapid opening of traffic after small-area repairs. They can also be cured and surface dried at low temperatures of minus 20 degrees Celsius, meeting the needs of winter road repairs in cold northern regions.

[0042] Test Example 2 The cold-laid cold patch materials prepared by the methods of Examples 1-5 of the present invention were tested for initial strength formation time and initial strength performance.

[0043] 1. Test objectives: The cold-laid cold patch materials prepared by the methods of Examples 1-5 of the present invention were tested to determine whether they could quickly develop sufficient strength to open traffic and withstand initial transportation loads under different temperature conditions.

[0044] 2. The test temperature conditions set five temperature environments: -20℃, 0℃, 10℃, 25℃, and 30℃ to simulate the actual construction environment, and the humidity is 55-65%.

[0045] 3. Test materials: The test materials are the cold-laid cold patch materials prepared in Examples 1-5 of the present invention.

[0046] 4. Initial strength determination at different temperatures and times: (1) Test indicators: 30-minute compressive strength, compressive strength 30 minutes after cold patch material mixing, to evaluate the early strength development rate.

[0047] (2) Test method: For the compressive strength test, refer to the "Uniaxial Compression Test Method for Asphalt Mixtures" (T 0713-2011). The cold patch material was compacted and formed into a standard shape (diameter × height = Φ200 mm × 200 mm). After curing at a set temperature for 30 minutes, it was loaded at a rate of 0.5 mm / min until failure. The maximum load was recorded and the compressive strength (unit: MPa) was calculated. The test results are shown in Table 2.

[0048] 5. Initial strength determination: (1) Test indicators: 30min-2h compressive strength, the compressive strength 30min-2 hours after the cold patch material is mixed, reflecting the short-term high-strength characteristics. 24-hour compressive strength: the compressive strength 24 hours after the cold patch material is mixed, evaluating the final early strength.

[0049] (2) Test method: Compressive strength test, referring to the "Uniaxial Compression Test Method for Asphalt Mixture" (T 0713-2011), the cold patch material was compacted and formed according to the standard (diameter × height = Φ200mm × 200mm). After curing at the set temperature for 2 hours and 24 hours, it was loaded at a rate of 0.5mm / min until failure. The maximum load was recorded and the compressive strength (unit: MPa) was calculated. The test results are shown in Table 2.

[0050] 6. Test results Table 2 Strength measurement of the cold-laid cold patch materials prepared in Examples 1-5 of the present invention at different temperatures.

[0051]

[0052] It can be seen from Table 2 that the cold patch material of the present invention can quickly form strength initially, and the compressive strength increases significantly with increasing temperature. At -20°C, the material solidifies slowly due to the low temperature, but it can also be solidified. The 30-min compressive strength is only 0.6-0.8 MPa, and the 24-h compressive strength is ≥5.2 MPa; at 30°C, the 30-min compressive strength is ≥6 MPa, indicating that high temperature can form strength more quickly. Temperatures of 10°C and above can meet the "rapid opening of traffic" requirements, and the 30-min compressive strength is ≥3.1 MPa. The cold patch material of the present invention has high initial strength, and the 2-h compressive strength is ≥4.5 MPa above 10°C; the 24-h compressive strength is more than ≥15.4 MPa at 25°C and above. The cold patch material fully meets the temporary repair traffic load requirements.

[0053] 7. Conclusion Applicable Temperature Range: The cold patch material rapidly develops strength (compressive strength ≥ 3.1 MPa after 30 minutes) at temperatures above 10°C. It is also suitable for emergency repairs in low-temperature environments (-20°C). At temperatures between 10°C and 30°C, the cold patch material can reach traffic-safe strength 30 minutes after mixing. During actual construction, it is recommended to extend the duration by approximately 15 minutes.

[0054] Test Example 3 The elongation at break test was performed on the cold-laid cold patch materials prepared in Examples 1-5 of the present invention and the cold patch materials of the comparative example.

[0055] 1. Test objectives: The elongation at break of cold-laid cold patch materials at different temperature conditions was measured to test their low-temperature adaptability and high-temperature stability.

[0056] 2. The test temperature conditions set 5 temperature environments: -20℃, 0℃, 10℃, 25℃, 30℃, and 40℃ to simulate the actual construction environment, and the humidity is 55-65%.

[0057] 3. Test materials: The test materials are as follows: the test group is the cold-laid cold patch material prepared in Examples 1-5 of the present invention; the control group is the method of Examples 1-5 of the present invention, without adding 3MK520 primer, and the other steps are exactly the same, to make 5 groups of control groups.

[0058] 4. Test equipment: Constant temperature test chamber, asphalt ductility meter, thermometer, mold, balance, scraper, oven.

[0059] 5. Determination method: According to the relevant methods in the "Low-Temperature Flexural Test for Asphalt Mixtures" (T 0715) and "Ductility Test for Asphalt" (T 0605) sections of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the insulated test piece was mounted on the ductility tester fixture, fixed at both ends with an initial spacing of 10 cm. The specimen was stretched at a constant speed of 5 cm / min until it broke. The maximum stretched length (L, in cm) at the time of fracture was recorded and calculated. The test results are shown in Table 3.

[0060] 6. Test results Table 3 Elongation at break of the cold-laid cold patch materials prepared in Examples 1-5 of the present invention and the control group at different temperatures.

[0061]

[0062] As can be seen from the test results in Table 3, the elongation at break of the experimental group of the present invention is 10.2-10.8% at -20°C, indicating that the cold patch material has low-temperature crack resistance and can be used in cold areas. When the temperature rises from -20°C to 0°C, the elongation increases to 28.5-29.6%. In the range of 10°C to 30°C, the elongation continues to increase by 42.5-44.2% with increasing temperature, indicating that the elastic components of the waste rubber particles, the plasticizing effect of the solvent oil, and the synergistic effect of the 3MK520 primer effectively improve the temperature adaptability of the cold patch material. The cold patch material has excellent flexibility at room temperature and slightly high temperature environments, which is conducive to rapid compaction and molding after construction. At 40°C, the elongation drops slightly to 38.1-39.4%, which may be related to the softening point of asphalt and the high-temperature stability of rubber particles, but it still meets the needs of road repair. The elongation at break of the control group is obviously weaker than that of the experimental group.

[0063] 7. Conclusion The cold-laid cold patch material of the present invention exhibits good elongation at break in the range of -20°C to 40°C, especially high elongation at medium and low temperatures (10°C to 45°C), and is suitable for road repair in areas with large seasonal temperature differences.

[0064] Test Example 4 The water stability TSR test was carried out on the cold-laid cold patch materials prepared in Examples 1-5 of the present invention and the comparative cold patch materials.

[0065] 1. Test objectives: To determine the ability of cold-laid cold patch materials to resist water damage under saturated water conditions.

[0066] 2. Test materials: The test materials are as follows: the test group is the cold-laid cold patch material prepared in Examples 1-5 of the present invention; the control group is the method of Examples 1-5 of the present invention, without adding 3MK520 primer, and the other steps are exactly the same, to make 5 groups of control groups.

[0067] 3. Test equipment: Asphalt mixture specimen forming machine (Marshall compactor), freeze-thaw cycle test chamber, splitting test machine, balance, vernier caliper, constant temperature water tank, etc.

[0068] 4. Determination method: According to the T0709-2011 "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the freeze-thaw splitting test (TSR test) for asphalt mixtures was used to evaluate the resistance of cold patch materials to water damage under saturated conditions. The cold patch materials were formed using the Marshall compaction method. Ten groups (five experimental groups and five control groups) of standard test specimens (diameter × height = 101.6 mm × 63.5 mm) were prepared according to the designed compaction degree of the cold patch materials (typically 95%-98%). Curing conditions were as follows: the specimens were allowed to stand at room temperature for 24 hours after forming. Testing continued after demolding. For the saturated test, the specimens were immersed in a tank of water at room temperature for 24 hours. After removal, the surface moisture was wiped dry with a wet towel, and the pre-saturated mass was measured. The saturated specimens were placed in a freeze-thaw cycle test chamber with the following conditions: -20°C freezing for 4 hours → 60°C thawing for 4 hours (one cycle), and 50 cycles. After the freeze-thaw cycle is completed, the specimen is taken out and immersed again for 24 hours. The surface moisture is wiped off and the mass after saturation is measured. For the splitting strength test, the specimens before and after saturation are placed in a normal temperature water tank for 2 hours to ensure that the internal and external temperatures are consistent. For the loading test, a vertical load is applied to the middle of the specimen at a loading rate of 50 mm / min using a splitting tester. The maximum load at which the specimen fails is recorded. P (Unit: N). Calculate the splitting strength. See Table 4 for test results.

[0069] 5. Test results Table 4 Water stability TSR test of cold-laid cold patch materials prepared in Examples 1-5 of the present invention and the control group.

[0070]

[0071] 6. Conclusion TSR Criteria: According to JTG F40-2004, "Technical Specifications for Highway Asphalt Pavement Construction," the TSR requirement for hot-mix asphalt mixtures is ≥75%. Due to the specific construction environment, cold-mix asphalt mixtures are typically required to have a TSR of ≥80%. Conclusion: The TSR value of the cold-mix asphalt mixture of the present invention ranges from 88.3% to 91.4%, significantly higher than the standard requirement and the control group, demonstrating its excellent water stability and ability to effectively resist strength degradation caused by moisture intrusion, making it suitable for road repairs in humid or freeze-thaw environments.

[0072] Test Example 5 A rutting test was performed on the cold-laid cold patch materials prepared in Examples 1-5 of the present invention.

[0073] 1. Test purpose: To determine the ability of cold-laid cold patch materials to resist deformation caused by repeated wheel rolling under high temperature conditions and to verify their high temperature stability.

[0074] 2. Test materials: The test materials are as follows: the test group is the cold-laid cold patch material prepared in Examples 1-5 of the present invention, and the control group is ordinary cold patch material.

[0075] 3. Experimental equipment: rutting test machine (wheel pressure 0.7 MPa, test temperature 60°C), constant temperature box.

[0076] 4. Test Method: Based on the "Asphalt and Asphalt Mixture Test Procedure for Highway Engineering" (JTG E20-2011), T0719-2011 "Asphalt Mixture Rutting Test." After mixing the cold patch according to the mix ratio, place it in a mold and vibrate-compact it at room temperature until dense (simulating on-site cold mix compaction conditions). After demolding, cure it under standard curing conditions (25°C, humidity ≥ 50%) for 24 hours. Test Conditions: The test specimen is placed in a constant temperature chamber of a rutting tester and preheated at 60°C for at least 5 hours. Test Procedure: The rutting tester is started, and a rubber wheel is rolled back and forth over the specimen at a frequency of 21 times / minute. The deformation (unit: mm) of the specimen's wheel track is recorded over 60 minutes. Dynamic stability (DS) = (42 × deformation) / number of rolls (unit: rolls / mm), reflecting the material's rutting resistance. Results are shown in Table 5.

[0077] 5. Test results Table 5 Dynamic stability and deformation of rutting test

[0078]

[0079] 6. Conclusion The stability is ≥3000 times / mm (meeting the requirements of high-grade roads), which is slightly improved compared with ordinary cold patch materials, indicating that the cold patch material of the present invention has significant high-temperature deformation resistance.

[0080] Test Example 6 Fatigue tests were performed on the cold-laid cold patch materials and comparative cold patch materials prepared in Examples 1-5 of the present invention.

[0081] 1. Test objectives: Determine the durability (fatigue life) of cold-laid cold patch materials under repeated loads and verify their ability to resist crack propagation.

[0082] 2. Test materials: The test materials are as follows: the test group is 5 groups of cold-laid cold patch materials prepared according to Examples 1-5 of the present invention; the control group 1 is a control group made by adopting the method of Examples 1-5 of the present invention, without adding 3MK520 primer, and the other steps are exactly the same; the control group 2 is an ordinary cold patch material group.

[0083] 3. Test equipment: Four-point bending fatigue testing machine.

[0084] 4. Determination method: The test was conducted according to the "Asphalt Mixture Fatigue Test Method" (JTG E20-2011 T 0739-2011). Eleven groups of cold patch materials (five experimental groups, five control groups, and one control group) were mixed and placed into beam molds. They were vibrated and compacted at room temperature and then cured for 24 hours after demolding. Test conditions: The test temperature was set at 16°C (Jiamusi outdoor temperature), and the loading mode was controlled strain (strain level 500 με). Cyclic loading (sine wave, 10 Hz frequency) was applied, and the number of loading cycles (Nf) until the specimens broke was recorded. Fatigue life (Nf) was calculated as the number of cyclic loading cycles until the specimen broke; a higher number indicates better durability. The results are shown in Table 6.

[0085] 5. Test results Table 6 Fatigue life of fatigue test.

[0086]

[0087] 6. Conclusion The fatigue life of the experimental group reached over 12,700, a significant improvement, demonstrating that the material is more durable under repeated loads and suitable for high-traffic roads. This is attributed to the elastic recovery properties of the waste rubber particles and the bonding enhancement effect of the 3MK520 primer.

[0088] The above tests show that the cold patch material of the present invention is suitable for the rapid repair of rutting-prone sections and roads with high traffic loads, and can extend the service life of the road surface.

[0089] The present invention adopts 90# matrix asphalt as the bonding matrix, and mixes it with waste rubber particles (elastic polymer material, waste recycling) and asphalt to form rubber asphalt. The elasticity of the rubber particles of 3-7mm can absorb the impact energy of the road surface, delay the expansion of cracks, and improve the low-temperature crack resistance. The innovative use of 3MK520 primer as a functional polymer material can enhance the interfacial adhesion between asphalt and aggregate / mineral powder; solvent oil is used as a dispersion medium to dissolve the 3MK520 primer and promote its uniform dispersion in the asphalt. At the same time, it can further soften the asphalt, reduce the construction viscosity, and facilitate subsequent cold mixing and paving. Mineral powder is a fine-particle filler used to fill the gaps between aggregates and improve the density of the mixture; the aggregates of the present invention are matched with different particle sizes to provide skeleton support for the entire cold patch material to enhance the anti-rutting ability and load-bearing performance; the fast-setting agent accelerates the curing reaction of the asphalt mixture and shortens the time to open to traffic; water is used as a dispersion medium to promote the uniform dispersion of the fast-setting agent and at the same time adjust the moisture content of the mixture to avoid construction defects caused by excessive dryness or excessive wetness. This method enables paving at room temperature, reducing energy consumption and carbon emissions. Rubber granules enhance low-temperature crack resistance (no brittle cracking at -20°C), while the base asphalt and rapid-setting agent synergistically ensure high-temperature rutting resistance. The combination of primer and solvent oil enhances adhesion between asphalt and aggregate / mineral powder, minimizing water damage (residual stability ≥ 88%). Utilizing waste rubber granules reduces material costs, and the cold-paving process reduces exhaust emissions.

[0090] The cold patch material of the present invention was tested for repairing roads in the urban area and township auxiliary roads of Jiamusi City, Heilongjiang Province. The earliest repaired road surface has been 23 months old and is still in good use.

[0091] The cold patch material for cold laying of the present invention adopts a combination of waste rubber and matrix asphalt, solvent oil and 3MK520 primer, which can achieve the purpose of high elasticity and high viscosity, increase the elongation at break of the cold patch material, and will not crack at low temperatures of minus 20 degrees Celsius. It can be constructed in any season, the strength increases quickly, and it can be opened to traffic in 1 hour at room temperature. The present invention adopts 3MK520 primer to increase the cross-linking of molecular chains, improve the overall toughness of the binder, and perfectly solve the problem of poor water resistance of traditional cold patch materials.

Claims

1. A cold patch material for cold laying, characterized in that The invention is prepared from the following raw materials in parts by weight: 20-30 parts of matrix asphalt, 10-20 parts of waste rubber particles, 1-2 parts of 3MK520 primer, 10-15 parts of solvent oil, 20-30 parts of mineral powder, 50-60 parts of aggregate, 1-3 parts of quick-setting agent and 5-8 parts of water.

2. A cold patch material for cold laying according to claim 1, characterized in that The particle size of the waste rubber particles is 3-7 mm.

3. The cold patch material for cold laying according to claim 1, characterized in that The solvent oil is petroleum ether or xylene.

4. The cold patch material for cold laying according to claim 1, characterized in that The quick-setting agent is an epoxy-modified quick-setting agent.

5. The cold patch material for cold laying according to claim 1, characterized in that The matrix asphalt is 90# matrix asphalt.

6. The cold patch material for cold laying according to claim 1, characterized in that The aggregate is a mixture of coarse aggregate, medium aggregate and fine aggregate, wherein the weight ratio of coarse aggregate: medium aggregate: fine aggregate is 2:5:

3.

7. The cold patch material for cold laying according to claim 6, characterized in that The coarse aggregate particle size is 5-10 mm, the medium aggregate particle size is 3-5 mm, and the fine aggregate particle size is 1-3 mm.

8. A method for preparing the cold patch material for cold laying according to claim 1, characterized in that Here are the steps: Preparation of waste rubber particles: crush the waste rubber to make waste rubber particles with a particle size of 3-7 mm for later use; Preparation of rubber asphalt: Heat the base asphalt in the amount specified by weight to 130-150°C, add the waste rubber particles in the amount specified by weight, stir for 30-35 minutes, and cool to 100°C to obtain the rubber asphalt for use; Cold patching fluid synthesis: add solvent oil and 3MK520 primer in the rubber asphalt in the specified weight proportions, stir and mix, cool to 55-60°C and shear at low speed for 12-15 minutes to obtain cold patching fluid, which is then set aside; Mixing of cold mix cold patch material: at room temperature, take aggregate and mineral powder dry materials that meet the specified weight proportions, stir evenly, then add cold patch liquid and water that meet the specified weight proportions and mix for 3-5 minutes, add quick setting agent that meets the specified weight proportions and stir for 1-2 minutes to obtain cold patch material for cold laying.

9. The method for preparing cold patch material for cold laying according to claim 8, characterized in that The specific steps of preparing the waste rubber particles are as follows: after washing and drying the waste rubber, using a shear crusher to preliminarily crush the dried rubber blocks into particles of 50-100 mm, using a roller crusher to further crush the coarsely crushed rubber to produce particles with a particle size of 3-7 mm, and using a vibrating screen to screen the crushed rubber particles with a particle size of 3-7 mm to separate particles that meet the particle size requirements.

10. Application of 3MK520 primer in the preparation of cold patch material for cold laying.

Images