A normal and low-temperature curable foaming anti-cracking repair material, its preparation method and application

Abstract

The present invention provides a normal and low temperature curable foaming anti-cracking repair material, its preparation method and application, including: Component A: 80-120 parts of α,ω-dihydroxy polydimethylsiloxane, 180-220 parts of methyltriacetoxysilane, 20-40 parts of dimethyl silicone oil; Component B: 80-120 parts of α,ω-dihydroxy polydimethylsiloxane, 8-12 parts of platinum catalyst; Component C: 80-120 parts of hydrogen-containing silicone oil, 20-40 parts of nano calcium carbonate, 10-20 parts of silica micropowder, 10-20 parts of nano silica. The anti-cracking repair material of the present invention has the advantages of high repair efficiency, good repair effect and excellent durability at normal and low temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of crack-resistant repair materials, and particularly to a normal-temperature and low-temperature curing foaming type crack-resistant repair material, a preparation method thereof, and an application thereof. Background Art

[0002] During the service process of asphalt pavements, they are long-term under the combined action of harsh climate environments and complex traffic loads. Coupled with the low construction quality level of some sections, various disease damages inevitably occur on asphalt pavements. Among them, cracks are the most main damage form in asphalt pavement diseases, accounting for about 70% of the total amount of asphalt pavement diseases. After cracks appear, surface water and various impurities will invade the pavement structure through the cracks. Under the combined action of vehicle loads and natural environments, diseases such as loosening, potholes, and subsidence will be induced, seriously affecting the normal use of the pavement. More seriously, once surface water seeps into the roadbed through through-cracks, the stability of the roadbed will be weakened, the load-bearing capacity will be reduced, resulting in the damage of the pavement structure and shortening the service life of the pavement.

[0003] To reduce the harm caused by asphalt pavement cracks, researchers and maintenance personnel in the road industry use various crack repair materials to repair pavement cracks, mainly including hot-melt asphalt types, emulsified asphalt types, normal-temperature chemical grouting materials, and crack tapes, etc., which can delay the expansion of cracks to a certain extent and maintain the service function of the pavement. Among them, hot-melt asphalt type repair materials are the most widely used in actual maintenance work, but they can only seal the top of the cracks and have a poor bonding effect with the crack walls, and are very easy to crack again under low-temperature conditions; emulsified asphalt, as a common crack repair material, although has strong permeability, its strength and bonding performance after forming are inferior to those of hot-melt type materials, and its durability is insufficient; normal-temperature chemical grouting repair materials are limited in their application due to disadvantages such as large slurry viscosity, short pot life, and high cost; while crack tapes, although having the characteristics of convenience and quickness, can only play the role of sealing the surface of the cracks, and the repair effect is extremely limited.

[0004] In summary, the existing crack repair materials generally have problems such as low repair efficiency, poor repair effect, and insufficient durability in actual applications. There is an urgent need for a new type of repair material that can cure at normal temperature or low temperature and has sufficient mechanical properties, bonding properties, temperature stability, and chemical stability.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The present invention provides a normal-temperature and low-temperature curing foaming type crack-resistant repair material, a preparation method thereof, and an application thereof, so as to solve the technical problems of low repair efficiency, poor repair effect, and insufficient durability of crack-resistant repair materials in the prior art at normal temperature and low temperature.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A normal and low temperature curable foaming anti-cracking repair material, comprising:

[0009] Component A: 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 180 - 220 parts of methyltriacetoxysilane, 20 - 40 parts of dimethyl silicone oil;

[0010] Component B: 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 8 - 12 parts of platinum catalyst;

[0011] Component C: 80 - 120 parts of hydrogen-containing silicone oil, 20 - 40 parts of nano calcium carbonate, 10 - 20 parts of silicon dioxide micropowder, 10 - 20 parts of nano silica white carbon black.

[0012] Optionally, in Component A and Component B, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 2000 - 4000 mP·s.

[0013] Optionally, the platinum catalyst in Component B is prepared by dissolving chloroplatinic acid in isopropanol, and the concentration of effective platinum is 2000 - 4000 ppm.

[0014] Optionally, the viscosity of dimethyl silicone oil is 300 - 400 mPa·s.

[0015] Furthermore, the present invention also provides a preparation method of the above anti-cracking repair material, comprising:

[0016] Step S1, preparing Component A: adding 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 180 - 220 parts of methyltriacetoxysilane, 20 - 40 parts of dimethyl silicone oil into a vacuum kneader, mixing evenly at normal temperature, and storing the evenly mixed Component A after evacuating;

[0017] Step S2, preparing Component B: dispersing 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 8 - 12 parts of platinum catalyst by a non-invasive homogenizer for 10 - 20 min, and storing in an environment of 20 - 30 °C;

[0018] Step S3, preparing Component C: dispersing 80 - 120 parts of hydrogen-containing silicone oil, 20 - 40 parts of nano calcium carbonate, 10 - 20 parts of silicon dioxide micropowder, 10 - 20 parts of nano silica white carbon black by a non-invasive homogenizer for 10 - 20 min, and storing in an environment of 20 - 30 °C for standby.

[0019] Optionally, before preparing Component C, soaking nano calcium carbonate, silicon dioxide micropowder, nano silica white carbon black in a hexamethyldisilazane solution at normal temperature for 1 - 5 h for modification treatment.

[0020] Optionally, the viscosity of the hydrogen-containing silicone oil is 20-50 mPa·s, and the molar fraction of active hydrogen in the hydrogen-containing silicone oil is 0.3%-0.5%.

[0021] Optionally, the raw material of component B and the raw material of component A are premixed, and then uniformly mixed at room temperature in a vacuum kneader. The obtained uniformly mixed A+B component is evacuated and stored.

[0022] Furthermore, the crack-resistant repair material of the present invention can be used for repairing road surfaces.

[0023] The beneficial effects brought by the technical solution provided by the present invention at least include:

[0024] The crack-resistant repair material of the present invention is in a liquid state without heating during use and has a certain fluidity; a dense foam is generated through the condensation dehydrogenation foaming process of the polymer, which enhances the fluidity of the repair adhesive in the crack, and the filling degree of the crack is further improved through volume expansion during the foam generation process; during the curing process, it reacts with water in the air to form a cross-linked network at room temperature or low temperature, thereby achieving curing at room temperature or low temperature, meeting its use requirements in the cold season in North China; it reduces the energy consumption during heating, reduces carbon emissions, and realizes the balance and unity among construction performance - use performance - carbon emissions. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a SEM diagram of the foam cross-section formed by the crack-resistant repair material in Embodiment 1 of the present invention;

[0027] Figure 2 It is a view of the appearance of the foam formed by the crack-resistant repair material in Embodiment 1 of the present invention;

[0028] Figure 3 It is a schematic diagram of the vertical crack repair composite structure specimen in Embodiment 2 of the present invention;

[0029] Figure 4 It is a schematic diagram of the V-shaped crack repair composite structure specimen in Embodiment 2 of the present invention;

[0030] Figure 5 It is a schematic diagram of the fatigue test model of the present invention. Detailed Embodiments

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] The present invention realizes the polymer room-temperature foaming process by adding a platinum catalyst and hydrogen-containing silicone oil, and utilizes the volume expansion after foaming to improve the penetration ability of the repair adhesive in cracks; the coupling agent and the structure control agent are used to surface-modify the filler particles to improve the bonding ability between the filler particles and the polymer molecular chain segments, thereby enhancing the overall mechanical properties; the water in the air reacts with the chain extender to achieve the curing of the repair adhesive at room temperature. When preparing the repair material of the present invention, the dispersion of the filler particles in the repair adhesive is ensured by a specific feeding order.

[0033] The reaction mechanism in the preparation process of the repair material of the present invention is as follows: First, let the hydroxyl-terminated polydimethylsiloxane and an excessive amount of crosslinking agent (methyltriacetoxysilane) form a crosslinking-agent-terminated polydimethylsiloxane, and adding dimethyl silicone oil to reduce viscosity gives Component A. This is because on the one hand, the hydroxyl-terminated polydimethylsiloxane cannot directly undergo a condensation reaction, and only the crosslinking-agent-terminated polydimethylsiloxane can continue to react with water; on the other hand, preparing the crosslinking-agent-terminated polydimethylsiloxane first can make the molecular chains after condensation more orderly, making its performance more stable and suitable for long-term storage. The reaction process is as follows:

[0034]

[0035] Foaming mechanism: The hydroxyl-terminated dimethylsiloxane and the hydrogen-containing silicone oil undergo a condensation reaction under the catalysis of a platinum catalyst to generate hydrogen. The reaction process is as follows:

[0036]

[0037] Curing mechanism: When the crosslinking-agent-terminated polydimethylsiloxane contacts the moisture in the air, the functional groups are quickly hydrolyzed to generate silanol groups, and then condensation reactions occur between the silanol and the hydrolyzable groups or between the silanol and the silanol, thereby curing and crosslinking the polymer to form a three-dimensional network structure. After the three acetoxy groups of the crosslinking-agent-terminated polydimethylsiloxane are completely hydrolyzed, each side will have one more hydroxyl group than the hydroxyl-terminated polydimethylsiloxane, so a three-dimensional network structure can be formed after the condensation reaction instead of a linear structure, further enhancing its mechanical properties. At the same time, the acetic acid generated by the reaction can react with the nano-reinforcing material nano-calcium carbonate to generate water and carbon dioxide, which can not only solve the influence of possible insufficient water vapor in the air and improve the deep curing rate, but also accelerate the reaction rate, make up for the long curing time in dry and cold regions, and the influence of water molecule crystallization on curing. The reaction process is as follows:

[0038]

[0039] Example 1:

[0040] Preparation of Component A: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 200 parts of methyltriacetoxysilane, and 30 parts of dimethyl silicone oil were added to a vacuum kneader and mixed evenly at room temperature, and then stored in a vacuum;

[0041] Preparation of Component B: 100 parts of α,ω-dihydroxypolydimethylsiloxane and 10 parts of platinum catalyst were dispersed by a non-invasive homogenizer for 15 minutes, and then stored in an environment of 20-30 °C for standby;

[0042] Preparation of Component C: 100 parts of hydrogen-containing silicone oil, 30 parts of nano calcium carbonate, 15 parts of silica micropowder, and 15 parts of nano silica white carbon black were dispersed by a non-invasive homogenizer for 15 minutes, and then stored in an environment of 20-30 °C for standby.

[0043] Among them, the viscosity of α,ω-dihydroxypolydimethylsiloxane in Component A and Component B is 3000 mP·s, and the concentration of platinum catalyst is 3000 ppm; the viscosity of dimethyl silicone oil in Component B is 350 mPa·s; the viscosity of hydrogen-containing silicone oil in Component C is 30 mPa·s, and the molar fraction of active hydrogen is 0.4%; before preparing Component C, nano calcium carbonate, silica micropowder, and nano silica white carbon black were pre-soaked in hexamethyldisilazane solution for 4 hours for modification.

[0044] The prepared Components A, B, and C were mixed to obtain a repair material. The foam cross-section and appearance formed by the foaming of the repair material are respectively as shown in Figure 1 and Figure 2 shown.

[0045] Test data of the basic properties of the repair material:

[0046]

[0047] Example 2:

[0048] The repair material prepared in Example 1 was used for the asphalt pavement crack repair simulation scale test:

[0049] The rutting plate was cut into specimens of the required size with a concrete cutting machine (vertical crack specimen size: 17×40×80 mm; V-shaped crack specimen size: upper bottom 17 mm, lower bottom 20 mm, height 80 mm, thickness 40 mm). The cutting surface of the specimen was wiped clean with a wet towel. After drying, a 6-mm-wide vertical crack and a V-shaped crack were respectively simulated. The specimen was placed in a customized mold (40×40×80 mm), and the repair material was poured in from the opening. After curing, it was demolded and cured at room temperature for seven days to obtain a combined structure specimen as shown in Figure 3 and Figure 4 shown.

[0050] Perform a uniaxial compression test on the specimens that have been cured as described above to obtain the following test data:

[0051]

[0052] Comparative Example

[0053] Use the same specimens and procedures as in Example 2, and use a warm mix asphalt repair material (composed of 90# base asphalt, TPS modifier, EVA modifier, naphthenic oil, and SAK warm mix agent) for repairing cracks in asphalt pavements.

[0054] Perform a uniaxial compression test on the specimens to obtain the following test data:

[0055]

[0056]

[0057] It can be seen from Example 2 and the comparative example that the repair material of the present invention not only plays a role in bonding and filling cracks during the repair process, but also can flow into the original cracks and voids, and through foaming, the repair is bonded into a whole to further improve the strength, so that the damaged cracks are on both sides of the repair material - at the original specimen. Compared with traditional warm mix asphalt repair, this repair material not only has the advantage of good bonding performance, but also has good strength.

[0058] Fatigue test:

[0059] After standard curing the rutting plate for 7 days, cut it into rectangular blocks of 50mm * 10mm * 30mm, and process the metal molds required for the specimens. Apply glycerin talcum powder on the metal molds, and place the repair material in the middle for molding. Use a UTM universal testing machine to conduct a fatigue test on it. Considering the vertical deformation generated by the wheel load at the crack of the asphalt concrete pavement and the complexity of the actual situation, simplify the parameters. The horizontal deformation amount of the fatigue test is 2mm, the vertical deformation is 0.7mm, and the spindle eccentricity angle of the fixture is 19°.

[0060] The parameters are summarized as follows:

[0061]

[0062] Test data:

[0063] Test type Fatigue life / number of cycles Whether the test is passed Shear compression ＞40000 Yes Shear tension ＞40000 Yes

[0064] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A normal and low-temperature curing foaming anti-cracking repair material, characterized in that, Comprising: Component A: 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 180 - 220 parts of methyltriacetoxysilane, 20 - 40 parts of dimethyl silicone oil; Component B: 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 8 - 12 parts of platinum catalyst; Component C: 80 - 120 parts of hydrogen-containing silicone oil, 20 - 40 parts of nano calcium carbonate, 10 - 20 parts of silica micropowder, 10 - 20 parts of nano silica white carbon black.

2. The crack-resistant repair material according to claim 1, wherein In Component A and Component B, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 2000 - 4000 mP·s.

3. The crack-resistant repair material according to claim 1, wherein The platinum catalyst in Component B is prepared by dissolving chloroplatinic acid in isopropanol, and the effective platinum content is 2000 - 4000 ppm.

4. The crack-resistant repair material according to claim 1, characterized in that, The viscosity of dimethyl silicone oil is 300 - 400 mPa·s.

5. A method for preparing the crack-resistant repair material according to any one of claims 1-4, characterized in that, Comprising: Step S1, preparing Component A: Add 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane, 180 - 220 parts of methyltriacetoxysilane, and 20 - 40 parts of dimethyl silicone oil into a vacuum kneader and mix evenly at room temperature, and then store the evenly mixed Component A after evacuating. Step S2, preparing Component B: Disperse 80 - 120 parts of α,ω-dihydroxypolydimethylsiloxane and 8 - 12 parts of platinum catalyst in a non-invasive homogenizer for 10 - 20 min, and then store it in an environment of 20 - 30°C. Step S3, preparing Component C: Disperse 80 - 120 parts of hydrogen-containing silicone oil, 20 - 40 parts of nano calcium carbonate, 10 - 20 parts of silica micropowder, and 10 - 20 parts of nano silica white carbon black in a non-invasive homogenizer for 10 - 20 min, and then store it in an environment of 20 - 30°C for standby.

6. The method according to claim 5, characterized in that, Before preparing Component C, soak nano calcium carbonate, silica micropowder, and nano silica white carbon black in hexamethyldisilazane at room temperature for 1 - 5 h for modification treatment.

7. The method according to claim 5, characterized in that The viscosity of the hydrogen-containing silicone oil is 20 - 50 mPa·s, and the molar fraction of active hydrogen in the hydrogen-containing silicone oil is 0.3% - 0.5%.

8. The method according to claim 5, characterized in that, Pre-mix the raw materials of Component B and Component A, then mix evenly in a vacuum kneader at room temperature, and store the evenly mixed A + B component after evacuating.

9. Application of the crack-resistant repair material according to any one of claims 1 - 4 in road surface repair.

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