High-performance reactive asphalt cold patch mixture and preparation process thereof

Abstract

The invention relates to a high-performance reactive asphalt cold patch mixture and a preparation process thereof. The mixture comprises a sulfonated fatty acid diluent, a graded aggregate, an atomic layer deposition (ALD) modified basalt aggregate and a solid waste-based composite curing agent. The sulfonated fatty acid diluent is prepared by sulfonating oleic acid, linoleic acid and palmitic acid through sulfamic acid, the sulfonation degree is 15-20%, and the sulfonated fatty acid diluent contains an epoxy three-membered ring structure; the 3-5mm aggregate is used as a transition layer to block the caking path of the fine aggregate; the basalt aggregate is subjected to TDMAT and TMA alternate deposition to form a Ti < x > Al < gamma > O < 2 > nano film; the curing agent comprises calcium strontium sulphoaluminate minerals, a titanium gypsum-carbide slag compound and magnesium-loaded lithium slag. During preparation, the modified aggregate, the sulfonated diluent and the curing agent are mixed at normal temperature. The problems that a traditional cold repairing material is poor in low-temperature fluidity and weak in interface bonding are solved, the viscosity at-20 DEG C is smaller than or equal to 450 mPa.s, the 7-day strength is larger than or equal to 5.2 kN, and the cold repairing material is suitable for low-temperature emergency repairing.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of road construction, in particular to high-performance reactive asphalt cold patch mixture and a preparation process thereof. BACKGROUND

[0002] The asphalt cold patch mixture is a key material for road emergency repair. The traditional solvent type cold patch material relies on the volatilization of an organic solvent to form strength, and has problems of low initial strength, poor water stability, and storage caking. CN115650637A uses a reactive diluent and a fiber reinforced system, which improves the early strength, but the fiber causes the mixture to clump and caking, and the water absorption of nano clay affects long-term storage. The existing products on the market are prone to hardening during low temperature construction, and caking occurs when the stone powder ratio exceeds 15%, and reducing the stone powder leads to insufficient strength. The reasons are as follows: 1) the fiber adsorbs free asphalt to cause surface oiling and accelerate aggregate separation; 2) the mineral powder gradation is unreasonable, causing uneven oiling of fine aggregate; and 3) the hot mixing process (>100 DEG C) promotes asphalt aging. The use of an electromagnetic oven for heating in the technical disclosure causes asphalt aging, and the comparative document still needs to heat the aggregate to 135 DEG C, which is high in energy consumption and destroys the reaction components.

[0003] The breakthrough of the application is that: 1) a sulfonated fatty acid diluent (sulfonated product of oleic acid / linoleic acid / palmitic acid) is used as a liquid carrier, and a SrCl2 catalyst is used to form an epoxy ternary ring to improve low temperature activity; basalt aggregate is subjected to 80 times of ALD circulation to deposit Ti x Al O2 nano film to enhance the interfacial bonding; the curing agent is composed of a strontium aluminate calcium mineral (co-firing of molybdenum tailings and SrCO3), a titanium gypsum-calcium carbide slag compound, and a magnesium-lithium slag carrier, and the hydrolysis heat of Mg(OH)2 is used to accelerate the crosslinking of calcium soap. During preparation, the modified aggregate and the curing agent are dry-mixed, and then the 60 DEG C diluent is added, and water is sprayed to activate the curing reaction. 2) The specific gradation aggregate (0-3mm / 3-5mm / 5-10mm=40:30:30) makes the fine aggregate form a dense matrix, and the coarse aggregate provides skeleton support. The innovative combination of the low temperature mixing process retains the advantages of the rapid curing of the reactive diluent, and realizes the balance between the storage period and the construction performance.

[0004] The asphalt cold patch material is a key material for road emergency repair, but the existing technology has significant defects. The traditional solvent volatilization type cold patch material (such as CN115650637A) relies on the volatilization of a diluent to form strength, and has low initial adhesion and is prone to loosening. The viscosity increases sharply during low temperature construction, making paving difficult. Although the patent uses a fatty acid diluent to improve fluidity, the viscosity at -20 DEG C is still 3500 mPa·s, and the interfacial bonding between the aggregate and the asphalt is weak, resulting in a loss rate of >12% after opening to traffic. In addition, the curing agent uses natural silicate cement, does not use industrial solid waste, and is high in cost and insufficient in environmental protection.

[0005] It is found through experiments that the defects of traditional cold patching materials are caused by three technical bottlenecks: molecular level flowability defects: the molecular chain of the fatty acid diluent crystallizes at low temperature, and the viscosity suddenly rises; weak interfacial adhesion: the basalt aggregate surface is inert, and the asphalt is difficult to penetrate; low curing efficiency: the cement hydration is slow, and the early strength is insufficient.

[0006] The application solves the above problems through cross-scale innovation: chemical modification: introducing sulfonic acid groups (-SO3H) and epoxy rings into fatty acids to destroy the crystalline structure; nano interface engineering: using ALD technology to construct an active nano film on the aggregate surface; solid waste reconstruction: replacing natural gypsum with titanium gypsum / calcium carbide slag to stimulate the rapid nucleation of ettringite.

[0007] The scheme is derived from the cross-research of industrial solid waste high-value and nano surface engineering, and it is accidentally found that the synergistic effect of sulfonic acid group and strontium ettringite can accelerate crosslinking. SUMMARY

[0008] The application discloses a kind of high-performance reactive asphalt cold patching mixture and preparation process thereof, to solve the systematic technical defects of traditional asphalt cold patching mixture in low temperature construction and long-term service: first, overcome the problem of viscosity sudden increase caused by diluent molecular crystallization in severe cold environment, avoid mixture hardening failure when paving at low temperature;Second, break through the technical bottleneck of weak interfacial adhesion of aggregate and asphalt, prevent aggregate loose and scatter after opening traffic;Third, eliminate the curing mode of relying on organic solvent volatilization or high temperature hot mixing, solve the problems of low initial strength, poor water stability and high energy consumption;Fourth, through gradation optimization and reaction activity control, inhibit the tendency of fine aggregate caking during storage and construction, while guarantee the compactness and early strength development of mixture. Finally realize the collaborative improvement of construction convenience, structural durability and environmental adaptability of material in low temperature emergency repair scene.

[0009] A kind of high-performance reactive asphalt cold patching mixture, by weight, including the following components: reactive dilution asphalt 5.5-6.5 parts, graded aggregate 92-95 parts, ALD surface modified basalt aggregate 90-95 parts by weight, solid waste-based composite curing agent 2.0-3.5 parts by weight, polypropylene fiber 0.15-0.3 parts by weight.

[0010] The reactive dilution asphalt is mixed by base asphalt and sulfonated fatty acid diluent in a weight ratio of (70-80) : (15-30).

[0011] The sulfonated fatty acid diluent is prepared by sulfonating oleic acid, linoleic acid and palmitic acid with aminosulfonic acid, with a sulfonation degree of 17±2%, containing an epoxy three-membered ring structure in the molecule, and a viscosity of 400±20 mPa·s at 60±3℃.

[0012] The oleic acid, linoleic acid, and palmitic acid are mixed in a weight ratio of (40-50):(35-45):(5-10), and the iodine value is 120-180.

[0013] The graded aggregate is composed of 0-3 mm, 3-5 mm, and 5-10 mm particle size aggregate in a weight ratio of (38-42):(28-32):(28-32).

[0014] The base asphalt is No. 70 or No. 90 road petroleum asphalt.

[0015] The preparation method of the ALD surface modified basalt aggregate is as follows:

[0016] S1. Basalt aggregate is vacuum dehydrated at 300±10℃ for 2±0.5 hours;

[0017] S2. Continue to alternately introduce tetra(dimethylamino) titanium and H2O plasma to deposit a TiO2 layer in the above step S1, and cycle 50±4 times; the tetra(dimethylamino) titanium is referred to as TDMAT;

[0018] S3. Continue to alternately introduce trimethylaluminum and O2 plasma to deposit an Al2O3 layer in the above step S2, and cycle 30±3 times; the trimethylaluminum is referred to as TMA;

[0019] S4. Form a Ti x Al γ O2 nanometer gradient film with a thickness of 15±3 nm.

[0020] The solid waste-based composite curing agent comprises strontium calcium sulphoaluminate mineral; a compounded body of titanium gypsum and calcium carbide slag in a mass ratio of 75:25; and molten lithium slag loaded with 50 nm particle size nano-MgO.

[0021] A high-performance reactive asphalt cold patch mixture, the preparation process comprising the following steps:

[0022] (1) Heat the base asphalt to a liquid state in an oven at 105-110℃;

[0023] (2) Add a sulfonated fatty acid diluent to the liquid asphalt, and stir at 300-500 r / min for 40-50 minutes;

[0024] (3) After drying the aggregate at 100±3℃, pour it into a mixer according to the grading ratio;

[0025] (4) Add the ALD surface modified basalt aggregate, the solid waste-based composite curing agent, and the polypropylene fiber in sequence, and mix at 40-60 r / min for 60-90 seconds at 25-30℃;

[0026] (5) Package and store the mixture.

[0027] The polypropylene fiber length is 6-8 mm.

[0028] The beneficial technical effects of the present application are:

[0029] The present application fundamentally breaks through the technical bottleneck of traditional asphalt cold patch material, and realizes efficient construction and long-term service in low temperature environment. The core effect is to give the mixture excellent low temperature fluidity through molecular design, and the unique chemical structure of sulfonated fatty acid diluent effectively inhibits the molecular crystallization trend, ensures the soft and plastic state under severe cold conditions, and significantly improves the paving operation efficiency. At the same time, the active nanometer film constructed on the surface of aggregate by atomic layer deposition technology and the curing system synergistically form a strong and tough chemical-physical double bonding network at the interface, which completely overcomes the defect of easy loose and scattering of traditional materials. The reconstruction of industrial by-products by solid waste-based composite curing agent greatly accelerates the formation of early strength, so that the repair layer can quickly bear traffic load, and the optimized aggregate gradation design balances the dense filling and skeleton support, giving the mixture excellent impermeability and structural stability. Finally, this technology realizes the unity of construction convenience, service reliability and environmental friendliness by using normal temperature preparation process and solid waste resource utilization in the whole process, while ensuring the quality of road emergency repair, significantly reducing energy consumption and carbon emissions. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Figure 1 is a schematic diagram of the preparation process of a high-performance reactive asphalt cold patch mixture according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] Before further describing the specific embodiments of the present application, it should be understood that the scope of protection of the present application is not limited to the following specific embodiments; it should also be understood that the terms used in the embodiments of the present application are for the purpose of describing the specific embodiments, but not for limiting the scope of protection of the present application. The test methods not specified in the following examples are usually carried out under conventional conditions, or under the conditions recommended by the manufacturers.

[0032] When the embodiments give numerical ranges, it should be understood that, unless otherwise stated by the present application, each numerical range has two endpoints and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by the skilled person. In addition to the specific methods, devices, materials used in the embodiments, any method, device, material of the prior art similar or identical to the methods, devices, materials described in the embodiments of the present application can also be used to implement the present application according to the master of the prior art by the skilled person in the art and the description of the present application.

[0033] Unless otherwise indicated, the test methods, detection methods, preparation methods disclosed in the present application all adopt the conventional techniques in the technical field.

[0034] Example 1

[0035] Components (parts by weight): 6.0 parts of reactive dilution asphalt (75 parts of base asphalt, 25 parts of sulfonated fatty acid diluent), 94 parts of graded aggregate (0-3 mm: 3-5 mm: 5-10 mm = 40:30:30), 93 parts of ALD surface modified basalt aggregate, 3.0 parts of solid waste-based composite curing agent, 0.2 parts of polypropylene fiber (length 7 mm).

[0036] Preparation process: the base asphalt (70#) is heated and liquefied at 108℃; the sulfonated fatty acid diluent (oleic acid: linoleic acid: palmitic acid = 45:40:8, sulfonation degree 17%, containing epoxy three-membered ring) is added to the asphalt, stirred at 400r / min for 45 minutes; the graded aggregate is dried at 100℃ before feeding; the ALD modified basalt aggregate (Ti x Al γ O2 film thickness 15nm), solid waste-based curing agent (strontium calcium sulfoaluminate mineral, titanium gypsum: carbide slag = 75:25 compound, loaded with 50nm MgO lithium slag), polypropylene fiber, 50r / min stirring at 28℃ for 75 seconds; sealed packaging.

[0037] The number of ALD cycles is modified to "TiO2 layer 50 times, Al2O3 layer 30 times.

[0038] Strontium calcium sulfoaluminate mineral preparation: mix molybdenum tailings with SrCO3 at a mass ratio of 1:2, calcine at 1350℃ for 2 hours, ball mill to a particle size of ≤10μm;

[0039] Magnesium-loaded lithium slag preparation: immerse molten lithium slag in a magnesium nitrate solution (concentration 20wt%), ultrasonic treatment for 30 minutes, calcine at 600℃ for 1 hour to obtain 50nm MgO-loaded lithium slag.

[0040] Innovation: all parameters are in the optimal range, reflecting the synergy of sulfonated diluent, ALD interface engineering, and solid waste curing agent.

[0041] Example 2

[0042] Adjustment: sulfonation degree 19% (slightly higher boundary), graded aggregate 42:28:30 (slightly more fine aggregate), diluent ratio in reactive dilution asphalt 30 parts (upper limit).

[0043] Components: Reactive dilution asphalt 6.5 parts (base asphalt 70 parts, diluent 30 parts), graded aggregate 95 parts (0-3mm:3-5mm:5-10mm = 42:28:30), ALD modified basalt aggregate 90 parts, solid waste based solidifying agent 2.5 parts, polypropylene fiber 0.15 parts (length 6mm).

[0044] Process: Same as Example 1, but mixing temperature 25°C.

[0045] Example 3

[0046] Adjustment: Sulfonation degree 15% (lower limit), grading 38:32:30 (slightly more coarse aggregate), use of No. 90 base asphalt.

[0047] Components: Reactive dilution asphalt 5.5 parts (base asphalt 80 parts, diluent 15 parts), graded aggregate 92 parts (0-3mm:3-5mm:5-10mm = 38:32:30), ALD modified basalt aggregate 95 parts, solid waste based solidifying agent 3.5 parts, polypropylene fiber 0.3 parts (length 8mm).

[0048] Process: Same as Example 1, but mixing time 50 minutes.

[0049] Comparative Example 1

[0050] Prior art CN115650637A.

[0051] Rely: The traditional solvent type cold patch material described in the background art relies on solvent evaporation.

[0052] Components: Fatty acid diluent (not sulfonated, oleic acid:linoleic acid:palmitic acid = 45:40:8, no epoxy ring) 6.0 parts, graded aggregate 94 parts (same proportions as Example 1), unmodified basalt aggregate 93 parts, ordinary Portland cement solidifying agent 3.0 parts, polypropylene fiber 0.2 parts.

[0053] Process: Aggregate heated to 135°C hot mixing, same as Example 1.

[0054] Purpose of comparison: absence of sulfonated diluent, ALD modification, solid waste solidifying agent, to prove that the traditional technology has poor low temperature fluidity and weak interface.

[0055] Comparative Example 2

[0056] No sulfonated diluent.

[0057] Components: Same as Example 1, but diluent is unsulfonated fatty acid mixture (iodine value 150), no epoxy ring.

[0058] Process: Same as Example 1.

[0059] Comparative purpose: to verify the key role of sulfonated groups (-SO3H) and epoxy rings on low temperature viscosity.

[0060] Comparative example 3

[0061] No ALD aggregate modification.

[0062] Composition: same as example 1, but basalt aggregate is not modified (surface inert).

[0063] Process: same as example 1.

[0064] Comparative purpose: to demonstrate the effect of ALD nanofilm (Ti x Al γ O2) to enhance the aggregate-bitumen interface adhesion.

[0065] Comparative example 4

[0066] Natural curing agent.

[0067] Composition: same as example 1, but solid waste based curing agent is replaced by ordinary Portland cement, natural gypsum.

[0068] Process: same as example 1.

[0069] Comparative purpose: to highlight the fast hydration and environmental advantages of solid waste based curing agent (titanium gypsum / carbide slag / magnesium-lithium slag carrying residue).

[0070] Comparative example 5

[0071] Unreasonable gradation.

[0072] Composition: same as example 1, but gradation aggregate ratio 0-3mm:3-5mm:5-10mm = 50:20:30 (excess of fine aggregate, stone powder ratio > 15%).

[0073] Process: same as example 1.

[0074] Comparative purpose: to verify the necessity of the specific gradation (38-42:28-32:28-32) of the invention to prevent caking and balance strength.

[0075] Test items

[0076] Four tests are carried out on the examples and comparative examples:

[0077] Viscosity test: measured by rotary viscometer at -20℃ (unit: mPa·s), to evaluate low temperature workability.

[0078] Water permeability test: refer to technical disclosure, measure water permeability coefficient (unit: ml / min), the lower the value, the better the waterproof performance.

[0079] Friction coefficient test: using a pendulum friction tester, the modified pendulum value is reported, the higher the value, the better the slip resistance. All tests were carried out at -20℃, humidity 60% RH, viscosity test according to ASTM D4402, friction coefficient test according to JT / T758-2009.

[0080] Stability test: 7-day Marshall stability (unit: kN), the higher the value, the better the strength.

[0081] Table 1 Test results of various data (viscosity test (-20℃, mPa·s), water permeability coefficient (ml / min), friction coefficient (modified pendulum value), 7-day stability (kN)) of the inventive examples and comparative examples

[0082]

[0083] According to the above Table 1, it can be seen that the high-performance reactive asphalt cold patch mixture prepared in Example 1 of the present application has excellent performance. The possible reasons are analyzed as follows:

[0084] First paragraph: Synergistic mechanism at the molecular and interface level.

[0085] The core of the difference in test data is the synergistic effect of molecular structure design and interface engineering. In terms of low-temperature viscosity, the example (400-490 mPa·s) is much lower than Comparative Example 1 (3500 mPa·s) and Comparative Example 2 (1800 mPa·s), the key is that the sulfonic acid group (-SO3H) in the sulfonated fatty acid diluent and the epoxy three-membered ring destroy the low-temperature crystallization tendency of the fatty acid molecular chain (the background technology mentions that "molecular chain crystallization leads to a sharp rise in viscosity"), and at the same time, the ring-opening reaction of the epoxy ring under the catalysis of SrCl2 enhances the activity, forming steric hindrance to inhibit orderly arrangement. The ALD surface modification (Ti x Al γ O2 nanometer film) enhances performance through two ways: first, the high surface energy of the 15 nm gradient film promotes the wetting and penetration of asphalt, so that the interfacial adhesion energy is improved; second, the Ti / Al oxide nanometer layer has a strong affinity for sulfur and forms a chemical anchor with the sulfonic acid group, reducing the free asphalt precipitation, thereby inhibiting oil bleeding and improving the friction coefficient.

[0086] Second paragraph: Multi-scale structure regulation and reaction kinetics optimization.

[0087] The macroscopic performance difference is affected by the coupling of the gradation design and the reaction path of the solid waste-based curing agent. The specific aggregate gradation (0-3 mm / 3-5 mm / 5-10 mm = 40:30:30) blocks the fine aggregate agglomeration path through the 3-5 mm transition layer, forming a dual structure of fine aggregate dense filling-coarse aggregate skeleton support, so that the permeability coefficient of the example (0.30 ml / min) is reduced by 80% compared with the comparative example 5 (1.50 ml / min). At the same time, the strontium calcium sulphoaluminate mineral in the solid waste-based curing agent provides [Sr 2+ ] catalyzes the cross-linking of epoxy, while the hydrolysis heat of Mg(OH)2 in the magnesium-lithium slag accelerates the nucleation of ettringite at low temperature, so that the stability reaches 5.5 kN at 7 days (only 2.9 kN for the comparative example 4 using ordinary cement). This synergistic effect of gradation-chemical reaction enables the mixture to realize cross-scale performance integration at the molecular scale (sulfonation inhibits crystallization), the nanoscale (ALD enhances the interface), and the macroscopic scale (gradation optimizes the pore), breaking through the inherent bottleneck of traditional cold patch materials.

[0088] Finally, it should be noted that the above examples are used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A high-performance reactive asphalt cold patch mixture, characterized in that: The invention comprises the following components in parts by weight: 5.5-6.5 parts of reactive diluted asphalt, 92-95 parts of graded aggregate, 90-95 parts by weight of ALD surface-modified basalt aggregate, 2.0-3.5 parts by weight of solid waste-based composite curing agent, and 0.15-0.3 parts by weight of polypropylene fiber.

2. The high-performance reactive asphalt cold patch mixture according to claim 1, characterized in that: The reactive diluted asphalt is prepared by mixing base asphalt and sulfonated fatty acid diluent in a weight ratio of (70-80):(15-30).

3. The high-performance reactive asphalt cold patch mixture according to claim 2, characterized in that: The sulfonated fatty acid diluent is prepared by sulfonating oleic acid, linoleic acid, and palmitic acid with aminosulfonic acid, with a sulfonation degree of 17±2%. The molecule contains an epoxy three-membered ring structure and a viscosity of 400±20mPa·s at 60±3°C. 0.5-1.5wt% SrCl2 catalyst is added during the preparation of the sulfonated fatty acid diluent.

4. The high-performance reactive asphalt cold patch mixture according to claim 3, characterized in that: The oleic acid, linoleic acid and palmitic acid are mixed in a weight ratio of (40-50):(35-45):(5-10), and the iodine value is 120-180.

5. The high-performance reactive asphalt cold patch mixture according to claim 1, characterized in that: The graded aggregate is composed of 0-3mm, 3-5mm, and 5-10mm particle size aggregates in a weight ratio of (38-42):(28-32):(28-32).

6. The high-performance reactive asphalt cold patch mixture according to claim 2, characterized in that: The matrix asphalt is No. 70 or No. 90 road petroleum asphalt.

7. The high-performance reactive asphalt cold patch mixture according to claim 1, characterized in that: The preparation method of the ALD surface-modified basalt aggregate is as follows: S1. Dehydrate basalt aggregate under vacuum at 300±10℃ for 2±0.5 hours; S2. Continue to alternately pass tetrakis(dimethylamino)titanium and H2O plasma to deposit TiO2 layer in step S1 above, and cycle 50±4 times; the tetrakis(dimethylamino)titanium is referred to as TDMAT; S3 continues to the above step S2 alternately into trimethylaluminum and O2 plasma deposition Al2O3 layer, cycle 30 ± 3 times; the trimethylaluminum referred to as TMA; S4. Form a Ti layer with a thickness of 15±3nm x Al γ O2 nano-gradient membrane.

8. The high-performance reactive asphalt cold patch mixture according to claim 1, characterized in that: The solid waste-based composite curing agent comprises calcium strontium sulfoaluminate mineral; a compound of titanium gypsum and carbide slag in a mass ratio of 75:25; and molten lithium slag loaded with nano-MgO with a particle size of 50 nm.

9. A high-performance reactive asphalt cold patch mixture according to any one of claims 1 to 8, characterized in that: The preparation process includes the following steps: (1) heating the matrix asphalt in an oven at 105-110°C to a liquid state; (2) adding the sulfonated fatty acid diluent to the liquid asphalt and stirring at 300-500 r / min for 40-50 minutes; (3) After the aggregate is dried at 100±3℃, it is put into the mixer according to the grading ratio; (4) adding ALD surface-modified basalt aggregate, solid waste-based composite curing agent, and polypropylene fiber in sequence, and mixing at 40-60 r / min for 60-90 seconds at 25-30°C; (5) The mixture should be sealed and stored.

10. The high-performance reactive asphalt cold patch mixture according to claim 9, characterized in that: The polypropylene fiber has a length of 6-8 mm.

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