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CN-121974600-A - Composite modified cold patch asphalt mixture and preparation method thereof

CN121974600ACN 121974600 ACN121974600 ACN 121974600ACN-121974600-A

Abstract

The invention discloses a composite modified cold-patch asphalt mixture which comprises, by mass, 92.0% -93.0% of basalt aggregate, 2.0% -2.6% of limestone mineral powder, 0.2% of basalt fiber and 4.8% -5.3% of SBS rubber composite modified cold-patch liquid, wherein the SBS rubber composite modified cold-patch liquid comprises, by mass, 73.0% -77.0% of 90# matrix asphalt, 2.6% -3.4% of linear SBS, 3.1% -3.9% of activated rubber, 15.5% -18.5% of kerosene, 0.5% -1.5% of calcium stearate and 0.3% -0.7% of POE-g-MAH compatilizer. The invention also discloses a preparation method of the asphalt mixture. The asphalt mixture has the characteristics of high storage stability, good high-temperature rut resistance and low-temperature crack resistance, and high-efficiency and durable strength formation.

Inventors

  • HAN ZHILIN
  • SHANG ANFAN
  • HE ZILONG
  • ZHAO DONG
  • YANG HUAN
  • ZHANG XIAOYU
  • MA JIAJI
  • Liu Qinkun

Assignees

  • 中国电建集团西北勘测设计研究院有限公司

Dates

Publication Date
20260505
Application Date
20260206

Claims (8)

  1. 1. The composite modified cold patch asphalt mixture is characterized by comprising the following raw material components in percentage by mass: 92.0 to 93.0 percent of basalt aggregate, 2.0 to 2.6 percent of limestone mineral powder, 0.2 percent of basalt fiber, 4.8 to 5.3 percent of SBS rubber composite modified cold-filling liquid, and the total content of the raw materials is 100 percent; The SBS rubber composite modified cold-filling liquid comprises the following raw material components in percentage by mass: 73.0% -77.0% of 90# matrix asphalt, 2.6% -3.4% of linear SBS, 3.1% -3.9% of activated rubber, 15.5% -18.5% of kerosene, 0.5% -1.5% of calcium stearate, 0.3% -0.7% of POE-g-MAH compatilizer and 100% of the total content of the raw materials.
  2. 2. The composite modified cold-patch asphalt mixture according to claim 1, wherein the basalt fiber has a length of 6-7mm and a diameter of 13-20 μm, and the fiber surface is modified by a silane coupling agent; the molecular weight of the linear SBS is 10-15 ten thousand, the styrene content is 30% -35%, and the volatile component is less than or equal to 0.5%; the activated rubber is obtained by activating waste styrene-butadiene rubber powder with the particle size of less than 5mm, and the specific activation method comprises the steps of adding 0.5% of sulfur and 1.2% of zinc oxide by mass of the rubber powder into the rubber powder, and pre-treating for 20-30 minutes at 120-150 ℃; the kerosene is a narrow fraction product with the distillation range of 200-280 ℃, the aromatic hydrocarbon content is less than 15%, the sulfur content is less than or equal to 0.05%, and the flash point is more than or equal to 65 ℃; The grafting rate of maleic anhydride of the POE-g-MAH compatilizer is 1.5% -2.0%, the melt flow rate is 10-15g/10min, and the volatile component is less than or equal to 0.3%.
  3. 3. The method for preparing the composite modified cold-patch asphalt mixture according to claim 2, which is characterized by comprising the following steps: Step 1, weighing all raw materials according to mass percentage; step 2, heating 90# matrix asphalt, adding POE-g-MAH compatilizer into the asphalt, uniformly stirring, sequentially adding linear SBS and activated rubber, and stirring to obtain composite modified asphalt; Step 3, adding calcium stearate and kerosene into the composite modified asphalt obtained in the step 2 in batches to obtain SBS rubber composite modified cold-repairing liquid; And 4, mixing basalt aggregate, limestone mineral powder and basalt fiber, uniformly stirring, and adding the SBS rubber composite modified cold-patch liquid obtained in the step 3 into the mixture for two times to obtain the composite modified cold-patch asphalt mixture.
  4. 4. The method for preparing the composite modified cold-patch asphalt mixture according to claim 3, wherein the step2 is specifically: Heating the weighed 90# matrix asphalt to 170-175 ℃, adding POE-g-MAH compatilizer at 4300-4700 r/min, stirring for 8-12 min for pre-dispersing, adding linear SBS, standing for 12-18 min to pre-swell, continuously shearing at 4300-4700 r/min for 35-45 min, controlling the temperature at 170-175 ℃ in the shearing process, finally adding activated rubber, and continuously shearing at 4300-4700 r/min for 25-35 min to obtain the composite modified asphalt.
  5. 5. The method for preparing the composite modified cold-patch asphalt mixture according to claim 3, wherein the step 3 is specifically: And (2) cooling the composite modified asphalt obtained in the step (2) to 100-120 ℃ for standby at the speed of 5 ℃ per minute, mixing and stirring calcium stearate and kerosene accounting for 1/3 of the total amount of kerosene until the calcium stearate and the kerosene are completely dissolved and dispersed to form uniform premix, and adding the premix and the residual 2/3 of the kerosene into the composite modified asphalt three times to obtain the SBS rubber composite modified cold-make-up liquid.
  6. 6. The method for preparing the composite modified cold-patch asphalt mixture according to claim 5, wherein the specific steps of adding the premix and the residual 2/3 kerosene to the composite modified asphalt three times are as follows: And (3) slowly pouring the 1/3 premixed liquid and 1/3 residual kerosene into the cooled composite modified asphalt after mixing each time, stirring at a constant speed of 600r/min for 10min, and repeating the operation for three times until all materials are added.
  7. 7. The method for preparing the composite modified cold-patch asphalt mixture according to claim 3, wherein the step 4 is specifically: And (3) drying the weighed basalt aggregate until the water content is less than or equal to 0.8%, preheating to 45-55 ℃, mixing the preheated aggregate, limestone mineral powder and basalt fiber, stirring at the rotating speed of 900-1100 r/min for 4-6 min to uniformly mix, and adding the cold-patch liquid prepared in the step (3) into the mixture for two times to obtain the composite modified cold-patch asphalt mixture.
  8. 8. The method for preparing the composite modified cold-patch asphalt mixture according to claim 7, wherein the specific process of adding the cold-patch liquid twice is as follows: Adding 2/3 of the total amount of the cold-patch liquid for the first time, stirring for 7-9 min at the rotating speed of 900-1100 r/min, adding the rest cold-patch liquid for the second time, and continuously stirring for 6-8 min at the same rotating speed.

Description

Composite modified cold patch asphalt mixture and preparation method thereof Technical Field The invention belongs to the technical field of road engineering materials, relates to a composite modified cold patch asphalt mixture, and also relates to a preparation method of the asphalt mixture. Background In the field of road rapid maintenance, the cold patch asphalt mixture becomes a key material for road emergency repair by virtue of the core advantage of no need of heating and convenient construction, and is widely applied to rapid treatment of various diseases such as pavement pits, cracks and the like. However, the existing cold-patch asphalt mixture is faced with multiple technical bottlenecks in practical application, is difficult to meet the requirements of modern roads on efficient, durable and reliable repair, has more prominent defects especially in the northern low-temperature complex environment, and severely restricts the large-scale application of the cold-patch asphalt mixture in important traffic trunks and high-standard maintenance engineering. The core contradiction of the existing cold-patch asphalt mixture is concentrated on the incompatibility of a modified system and a dilution system, namely in the modified cold-patch material taking SBS as a core, the SBS modified asphalt is easy to generate phase separation after being mixed with diluents such as kerosene, diesel oil and the like, so that the storage stability of the material is poor, layering and caking are usually generated after the material is stored for 1 to 2 weeks, the attenuation rate of the modified effect exceeds 15 percent, the forming process of the strength is obviously delayed when the dosage of the diluents is increased for ensuring the construction workability, the initial strength of most products after being compacted is lower than 4kN, the traffic is required to be closed for more than 12 hours, and the core requirement of expressway emergency repair and quick traffic cannot be met. Meanwhile, the material has strong temperature sensitivity, unbalanced high-temperature rut resistance and low-temperature crack resistance, the dynamic stability at 60 ℃ is generally lower than 4500 times/mm, the low-temperature bending damage strain at-10 ℃ is less than 3000 mu epsilon, cracking and peeling easily occur in the freeze-thawing cycle environment at minus 30 ℃ to minus 10 ℃ in the north, the repair service life is only 6-12 months, the adhesion of asphalt and aggregate interfaces in normal-temperature construction is weak, the adhesiveness is at most 4 grades, the water damage resistance is poor, the residual stability is lower than 85%, and the problems of aggregate falling off, pit secondary breakage and the like easily occur under the combined action of the running load and rain and snow erosion. From the technical system, the current solvent-based, reactive-type and emulsion-type cold-patch asphalt mixtures have the limitations that the solvent-based depends on petroleum-based diluents, the solvent-based asphalt mixture is convenient to construct and good in storage property, but is slow in strength formation and high in emission of organic volatile compounds (VOCs), the reactive-type asphalt mixture can realize quick emergency patching, but is short in storage life, high in cost and difficult to apply in a large scale, the emulsion-type asphalt mixture has the advantages of environmental protection and low cost, is greatly influenced by demulsification environment, and is easy to generate storage layering, and the high-temperature stability and low-temperature crack resistance are insufficient. In the whole, the prior art has not broken through the balance dilemma of performance-cost-environment adaptability, and has obvious short plates in the aspects of greenization, long-acting, extreme environment adaptability and the like, and the method is characterized in that the dependence of petroleum resources is high, the discharge amount of partial VOCs (volatile organic compounds) is more than 10g/m < 2 >, the low-carbon maintenance requirement is not met, the utilization of solid waste resources such as waste rubber and the like is insufficient, the problem of compatibility with asphalt is not solved, the cost is increased or the performance is reduced, the aggregate selection and grading design is single, the abrasion resistance and the heavy load resistance are insufficient, and the phenomena of loose surface, polishing and the like occur 3-6 months after the heavy-load traffic road section is repaired. Therefore, the cold patch asphalt mixture with excellent storage stability, high-low temperature balance performance, rapid strength forming capability, environmental protection economy and wide engineering suitability is developed, the core defects of poor compatibility, short service life and weak environmental suitability of the existing product are overcome, the long-acting maintenance requirement under the northe