Rare earth tailings modified emulsified asphalt asphalt grouting material and application thereof

Abstract

This invention relates to the field of waterproof coating technology, and more particularly to a rare earth tailings-modified emulsified asphalt grouting material and its application. The asphalt grouting material comprises a modified emulsified asphalt composition, which includes asphalt and modifying components; the modifying components include SBR emulsion, rare earth tailings, and a coupling agent; by weight, the asphalt is 300-1200 parts, the SBR emulsion is 75-250 parts, and the rare earth tailings are 3-24 parts. This invention uses rare earth tailings to modify the emulsified asphalt, resulting in modified emulsified asphalt that can better deposit on the interface during the demulsification stage, exhibiting higher interfacial adhesion and water resistance. This has significant application value in the field of emulsified asphalt grouting materials.

Description

Technical Field

[0001] This invention relates to the field of waterproof coating technology, and in particular to a rare earth tailings modified emulsified asphalt grouting material and its application. Background Technology

[0002] Asphalt grouting material refers to asphalt or modified asphalt materials used for waterproofing and seepage prevention. The mechanism of asphalt grouting for leak sealing involves heating the asphalt to a suitable temperature to give it a certain fluidity, then transporting it to the leaking area via a heat-resistant pump and pipeline. Because asphalt and water are immiscible, the hot asphalt disperses upon cooling. With continuous injection, the dispersed asphalt coagulates and spreads, gradually adhering to the joint walls. As the asphalt adhesion layer thickens, the seepage channel gradually shrinks until it is completely blocked. However, this method has a significant drawback: the asphalt requires a relatively high heating temperature, and the high viscosity of the heated asphalt makes grouting difficult.

[0003] Emulsified asphalt is an unstable mixture of asphalt and water. At room temperature, it exhibits the flow properties of water and resembles water in appearance. Under certain conditions, the asphalt separates from the water, a process known as demulsification. Demulsification of emulsified asphalt occurs as the asphalt emulsion gradually comes into contact with the aggregate during and after construction. The properties of the emulsion gradually change; water is absorbed and evaporated, gradually decreasing, and the asphalt separates from the aqueous phase of the emulsion, thus acquiring the inherent properties of asphalt: repulsion from water and solidification upon contact with water. The time required for this process is the demulsification rate of the asphalt emulsion. This demulsification mainly occurs after the emulsion comes into contact with the aggregate, due to the adsorption of ionic charges and the evaporation of water. However, traditional emulsified asphalt suffers from problems such as solid particle sedimentation, random and disordered deposition, and difficulty in accurately controlling the demulsification rate. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a rare earth tailings-modified emulsified asphalt grouting material and its application.

[0005] In a first aspect, the present invention provides a modified emulsified asphalt composition, comprising: asphalt and a modifying component; the modifying component comprises: an elastomer emulsion, rare earth tailings and a coupling agent; by weight, the modified emulsified asphalt composition comprises: 300-1200 parts of the asphalt, 75-250 parts of the elastomer emulsion and 3-24 parts of the rare earth tailings.

[0006] This invention incorporates rare earth tailings into an emulsified asphalt system. This improves the colloidal structure, allowing it to initially form an interconnected network with the asphalt, effectively mitigating the problem of solid particle settling in the finished emulsified asphalt product. More importantly, during the demulsification stage, when the asphalt modified with rare earth tailings reaches the contact interface, the outermost active sites of the rare earth elements coordinate with the polar groups of the asphalt and the active sites at the interface, resulting in more stable and efficient adhesion of the asphalt to the interface. Meanwhile, the rare earth tailings, elastomer polymers, and asphalt on the inner side form a more stable network structure, reducing the influence of external conditions on the demulsification process and significantly improving its controllability. The designable demulsification rate can meet various construction requirements.

[0007] The rare earth tailings described in this invention are generally added to the modified emulsified asphalt composition in the form of rare earth tailings powder, which can better play a role in the emulsified asphalt system.

[0008] The asphalt described in this invention can be any type of asphalt that can be used to prepare emulsified asphalt, such as 50#, 70#, 90# or 100# asphalt, preferably 70# asphalt.

[0009] Further, by weight, the asphalt is 400-900 parts, the elastomer emulsion is 90-175 parts, and the rare earth tailings are 4-18 parts.

[0010] In some specific embodiments of the present invention, the asphalt is 500-700 parts by weight, the elastomer emulsion is 110-140 parts, and the rare earth tailings are 5-14 parts.

[0011] Furthermore, the rare earth tailings account for 0.8 to 2.2% of the mass of the asphalt.

[0012] Furthermore, the rare earth tailings are light rare earth tailings;

[0013] Preferably, the rare earth tailings include: lanthanum, cerium, neodymium, samarium, yttrium, and gadolinium;

[0014] More preferably, the total mass of light rare earth elements in the rare earth tailings accounts for more than 90% of all rare earth elements.

[0015] Furthermore, the elastomer emulsion includes one or more of the following: SBR emulsion, CR emulsion, NR emulsion, or NVR emulsion.

[0016] The rare earth tailings of this invention preferably contain more than 90% light rare earth elements by mass, and the elastomer emulsion is preferably an SBR emulsion. The preferred rare earth tailings and SBR emulsion can form a relatively more stable network structure, which can more effectively control the demulsification process.

[0017] Furthermore, the coupling agent includes one or more of the following: silane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, or polymeric coupling agents.

[0018] Preferably, the coupling agent is a silane coupling agent.

[0019] More preferably, the mass ratio of the coupling agent to the rare earth tailings is 1:(1000~3000).

[0020] The coupling agent described in this invention is used for coupling bitumen and rare earth tailings.

[0021] This invention achieves coupling between rare earth tailings powder and asphalt through a coupling agent, which facilitates the formation of an interconnected network structure between the rare earth tailings powder and asphalt, and provides anchoring points for the elastomer.

[0022] Furthermore, it also includes: an emulsifying component, the emulsifying component comprising: an emulsifier, and one or more of a stabilizer, a pH adjuster, or a saponifying agent; preferably, the mass ratio of the asphalt to the emulsifying component is (1.8~2.4):1.

[0023] As a preferred embodiment, the present invention provides a modified emulsified asphalt composition, comprising, by weight: 500-700 parts of 70# asphalt, 110-140 parts of SBR emulsion, 5-7 parts of rare earth tailings, 0.0002-0.001 parts of coupling agent, 20-35 parts of emulsifier, 0.2-1 parts of pH adjuster, and 280-340 parts of water.

[0024] The emulsifier is composed of sodium petroleum sulfonate, lignin sulfonate and long-chain alkyl sulfonate, and the pH adjuster is sodium hydroxide.

[0025] In a second aspect, the present invention provides a method for preparing the aforementioned modified emulsified asphalt composition, comprising: mixing a coupling agent, ethanol and water in a predetermined ratio, and drying the mixture on the surface of rare earth tailings to obtain surface-modified rare earth tailings.

[0026] The asphalt and the surface-modified rare earth tailings were mixed at 145-160°C and subjected to high-speed shearing to obtain a melt blend phase.

[0027] The soap liquid phase is obtained by mixing water and emulsifying components;

[0028] The modified emulsified asphalt composition is obtained by mixing the molten blend phase and the soap liquid phase.

[0029] Further, the drying process includes: drying at 100~140°C for 1.5~3 hours; and / or,

[0030] The high-temperature conditions include: 140~160℃; and / or,

[0031] The high-speed shearing includes: shearing at 1000-1500 rpm for 30-50 minutes; and / or,

[0032] The mass ratio of the melt blend phase to the soap solution phase is (5~8):(2~5); and / or,

[0033] The emulsification process is carried out at 4000~5500 rpm.

[0034] Thirdly, the present invention provides an asphalt grouting material, comprising: the aforementioned modified emulsified asphalt composition.

[0035] Furthermore, it also includes: functional additives, demulsifiers, fillers, and water; the modified emulsified asphalt composition accounts for 30-45% by mass in the asphalt grout.

[0036] Furthermore, the demulsifier comprises polyvinyl alcohol and calcium chloride; the demulsifier accounts for 2-7.5% of the mass percentage of the asphalt grout.

[0037] Based on the more controllable demulsification process of the aforementioned modified emulsified asphalt composition, this invention further regulates the charge balance of the asphalt grout (emulsified state) by using polyvinyl alcohol and calcium chloride, thereby breaking the intrinsic interfacial tension balance of the emulsified asphalt mixture at an appropriate time, and thus achieving accurate adjustment of the demulsification rate.

[0038] Furthermore, the functional additives include one or more of the following: defoamer, preservative, thickener, and pH adjuster; the functional additives constitute 0.5-1.5% of the mass of the asphalt grout.

[0039] Fourthly, the present invention provides the application of the aforementioned asphalt grout in waterproofing of road engineering, bridge engineering, building engineering, water conservancy engineering, underground engineering or tunnel engineering.

[0040] The asphalt grouting material disclosed in this invention is applicable to various situations. For example, when road cracks appear due to vehicle loads, temperature changes, etc., the asphalt grouting material can be injected into the cracks to fill the gaps, prevent rainwater from seeping into and eroding the roadbed, and restore the integrity and waterproofness of the road surface. For instance, if cracks or leaks appear in a basement, the asphalt grouting material can be injected into the leaking area through pressure grouting to form a waterproof layer, effectively preventing groundwater infiltration. For example, if the roof waterproofing layer ages or is damaged, causing leaks, the asphalt grouting material can be used to repair cracks and leak points, enhancing the roof's waterproofing performance. Furthermore, the asphalt grouting material disclosed in this invention can also be used in similar scenarios in other bridge engineering, tunnel engineering, or water conservancy projects.

[0041] The present invention has the following beneficial effects:

[0042] This invention utilizes rare earth tailings to modify emulsified asphalt. The resulting modified emulsified asphalt can deposit better at the interface during the demulsification stage, exhibiting higher interfacial adhesion and water resistance. Furthermore, the rare earth tailings-modified emulsified asphalt provided by this invention also possesses a suitable gel time, making it suitable for various construction scenarios such as road and bridge construction, water conservancy facilities, building construction, and tunnel engineering. This has significant application value in the field of emulsified asphalt grouting materials. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] Unless otherwise specified, the experimental methods involved in the following embodiments are conventional methods in the art. For example, you can refer to the experimental manual in the art or follow the conditions recommended in the manufacturer's instructions.

[0045] Unless otherwise specified, all experimental materials and reagents used in the following examples are commercially available.

[0046] The coupling agent used in the following examples is a silane coupling agent, preferably an aminopropyltriethoxysilane coupling agent.

[0047] The asphalt used in the following examples is 70# asphalt, which is commercially available (Jingbo 70# base asphalt).

[0048] Unless otherwise specified, the rare earth tailings powder in the following examples is mainly composed of light rare earth elements, including lanthanum, cerium and neodymium, as well as samarium, yttrium and gadolinium.

[0049] The content of light rare earth elements such as lanthanum, cerium, neodymium and samarium accounts for more than 90% of the total mass of all rare earth elements.

[0050] For example, in addition to Example 3, rare earth tailings powder can be made from Bayan Obo rare earth tailings, including the following rare earth elements: lanthanum 19.1 μg / g, cerium 57.86 μg / g, neodymium 21.26 μg / g, samarium 3.306 μg / g, yttrium 2.762 μg / g, and gadolinium 3.243 μg / g.

[0051] The SBR emulsion used in the following examples is called styrene-butadiene emulsion, preferably BASF 7623 styrene-butadiene emulsion with a solid content of 51%.

[0052] The filler used in the following examples is gypsum, preferably desulfurized gypsum (particle size optional, preferably 1000 mesh).

[0053] The defoamer used in the following examples is a silicone-based defoamer, which is commercially available (e.g., Kefeng Chemical DA480).

[0054] The preservatives used in the following examples are isothiazolinone preservatives, which are commercially available (e.g., MERGAL K14 from Troy Pharmaceuticals, Inc.).

[0055] The thickeners used in the following examples are cellulose ether thickeners, preferably hydroxyethyl cellulose, which are commercially available (e.g., Lotte Chemicals, Korea, model B30K).

[0056] The pH adjusters used in the following examples are commercially available (e.g., Dow AMP-95 pH adjuster).

[0057] Example 1

[0058] In this embodiment, an asphalt grout is prepared by the following method:

[0059] 1. Rare earth tailings modified emulsified asphalt.

[0060] (1) Mix silane coupling agent, anhydrous ethanol and distilled water in a mass ratio of 5:45:50 until homogeneous, and stir and hydrolyze at room temperature for 20 min. Spray the resulting mixture onto the surface of rare earth tailings powder, control the mass ratio of silane coupling agent solution to rare earth tailings powder to be 1:100, and dry at 120℃ for 2 h to obtain surface-modified rare earth tailings powder.

[0061] (2) Rare earth tailings powder modified asphalt was prepared by melt blending.

[0062] First, heat the base asphalt to 150-155℃. Then, slowly add the surface-modified rare earth tailings powder (controlling its dosage to 1% of the asphalt mass) to the preheated asphalt. Perform high-speed shearing for 40 minutes to obtain the modified asphalt phase. Maintain the temperature at 160-170℃ for later use.

[0063] (3) Prepare soap liquid phase.

[0064] The weight parts of each component are shown below:

[0065] Table 1. Weight parts of each component in the soap liquid phase

[0066]

[0067] Start stirring, and add water, SBR emulsion, sodium petroleum sulfonate, lignin sulfonate, long-chain alkyl sulfonate, and sodium hydroxide into the reactor in sequence. Heat to 60-75℃ and set aside for use to obtain the soap liquid phase.

[0068] (4) Turn on the colloid mill, adjust the speed to 4500 r / min, and feed the modified asphalt phase and soap liquid phase into the colloid mill at a mass ratio of 6:4 to obtain the finished rare earth modified emulsified asphalt.

[0069] 2. Preparation of asphalt grouting material.

[0070] (1) The weight parts of each component are as follows:

[0071] Table 2. Weight parts of each component of asphalt grout

[0072]

[0073] Components A and B are mixed in a 1:1 mass ratio.

[0074] (2) Production process:

[0075] (2.1) Component A.

[0076] i) Draw the required amount of water into the mixing tank, turn on the mixer, and set the speed to 600 r / min.

[0077] ii) Add 1000 mesh dehydrated gypsum into the mixing tank and stir at 600 r / min for 15 min.

[0078] iii) Add the defoamer, preservative, and thickener to the mixing tank and stir for 10 minutes, maintaining a speed of 600 r / min.

[0079] iv) Add the pH adjuster into the stirred tank and stir for 30 minutes, maintaining a speed of 600 r / min.

[0080] v) Finally, add rare earth modified asphalt, stir for 30 minutes, and maintain a speed of 500-600 r / min.

[0081] vi) Filter the material using a 100-mesh filter.

[0082] (2.2) Component B.

[0083] i) Draw the required amount of water into the mixing tank, turn on the mixer, and set the speed to 600 r / min.

[0084] ii) Add polyvinyl alcohol powder into a mixing tank and stir at a speed of 600 r / min for 30 min.

[0085] iii) Add anhydrous calcium chloride, defoamer, and preservative to the mixing tank and stir for 10 minutes, maintaining a speed of 600 r / min.

[0086] iv) Filter the material using a 100-mesh filter.

[0087] Mix components A and B thoroughly to obtain asphalt grout.

[0088] Example 2

[0089] In this embodiment, the components of an asphalt grout are the same as those in Example 1, except that in the preparation process of rare earth tailings modified emulsified asphalt, the amount of surface-modified rare earth tailings powder added to the asphalt is 2%.

[0090] The preparation method of the asphalt grout is the same as in Example 1.

[0091] Example 3

[0092] In this embodiment, the components of an asphalt grout are the same as in Example 1, except that in the preparation process of rare earth tailings modified emulsified asphalt, the rare earth tailings powder used is light rare earth tailings from the Yakuping mining area in Mianning County, and the contents of each rare earth element are as follows:

[0093] Lanthanum 16.91 μg / g, Cerium 15.47 μg / g, Neodymium 9.82 μg / g, Samarium 5.11 μg / g, Yttrium 3.14 μg / g, Gadolinium 1.13 μg / g.

[0094] Example 4

[0095] In this embodiment, the components of an asphalt grout are the same as those in Example 1, except that the weight of component A is adjusted to: 700 parts of rare earth modified emulsified asphalt, 291 parts of filler, 2 parts of defoamer, 2 parts of preservative, 4 parts of thickener, and 1 part of pH adjuster.

[0096] Example 5

[0097] In this embodiment, the components of an asphalt grout are the same as those in Example 1, except that in the preparation process of rare earth tailings modified emulsified asphalt, the SBR emulsion is replaced with an equal amount of CR emulsion.

[0098] Example 6

[0099] In this embodiment, the components of an asphalt grout are the same as those in Example 1, except that in the preparation process of the asphalt grout: polyvinyl alcohol in component B is replaced with xanthan gum, and anhydrous calcium chloride is replaced with calcium nitrate.

[0100] Comparative Example 1

[0101] In this comparative example, the components of an asphalt grout are the same as those in Example 1, except that iron tailings powder is used instead of rare earth tailings powder in the preparation process of rare earth tailings modified emulsified asphalt.

[0102] Comparative Example 2

[0103] In this comparative example, the components of an asphalt grout are the same as those in Example 1, except that in the preparation process of rare earth tailings modified emulsified asphalt, the amount of surface-modified rare earth tailings powder added to the asphalt is 0.5% of the asphalt mass.

[0104] Comparative Example 3

[0105] In this comparative example, the components of an asphalt grout are the same as in Example 1, except that in the preparation process of rare earth tailings modified emulsified asphalt, rare earth tailings powder is not used to modify the emulsified asphalt; instead, rare earth tailings powder is directly mixed into component A. Specifically, component A in step 2 of Example 1 is replaced as follows:

[0106] Table 3 Asphalt Grouting Material A Component

[0107]

[0108] In this case, the preparation of emulsified asphalt is that in step 1 of Example 1, processes (1) and (2) are not performed, and the modified asphalt in process (4) is replaced with base asphalt.

[0109] Comparative Example 4

[0110] In this comparative example, the components of an asphalt grout are the same as those in Example 1, except that asphalt is used instead of rare earth tailings modified emulsified asphalt in the preparation process of the rare earth tailings modified emulsified asphalt to prepare the asphalt grout.

[0111] Experimental Example 1

[0112] In this experimental example, performance tests were conducted on the asphalt grouting materials prepared in the examples and comparative examples. The procedure is as follows:

[0113] The gel time properties of asphalt grout were tested using the JC / T 1018-2006 method.

[0114] The penetration height performance of asphalt grout was tested using the JC / T 1018-2006 method.

[0115] The bonding strength of asphalt grout was tested using the method specified in JC / T 408-2005.

[0116] The results are shown in the table below:

[0117] Table 3 Performance comparison results of each embodiment and comparative example

[0118]

[0119] The results above show that the gelation times of Comparative Examples 1, 2, and 4 far exceed the standard, exceeding 400 minutes, which does not meet the construction requirements. The impermeability of Comparative Examples 2-4 also exceeds 35mm, indicating insufficient water resistance. The asphalt grouting materials in Examples 1-6 all meet the construction requirements, with Examples 1-3 exhibiting the best performance.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified emulsified asphalt composition, comprising: The asphalt, the modifying component, and the emulsifying component are characterized in that the modifying component comprises: an elastomer emulsion, rare earth tailings, and a coupling agent; and the modified emulsified asphalt composition comprises, by weight, 300-1200 parts of the asphalt, 75-250 parts of the elastomer emulsion, and 3-24 parts of the rare earth tailings. The emulsifying component includes: emulsifier and water, and one or more of stabilizer, pH adjuster or saponifier, wherein the mass ratio of the asphalt to the emulsifying component is (1.8~2.4):

1.

2. The modified emulsified asphalt composition according to claim 1, characterized in that, By weight, the asphalt is 400-900 parts, the elastomer emulsion is 90-175 parts, and the rare earth tailings are 4-18 parts.

3. The modified emulsified asphalt composition according to claim 2, characterized in that, By weight, the asphalt is 500-700 parts, the elastomer emulsion is 110-140 parts, and the rare earth tailings are 5-14 parts.

4. The modified emulsified asphalt composition according to claim 1, characterized in that, The asphalt is 50#, 70#, 90#, or 100# asphalt; and / or, The elastomer emulsion comprises one or more of the following: SBR emulsion, CR emulsion, NR emulsion, or NVR emulsion; and / or, The rare earth tailings are light rare earth tailings.

5. The modified emulsified asphalt composition according to claim 4, characterized in that, The asphalt is 70# asphalt; And / or, The elastomer emulsion is an SBR emulsion; And / or, The rare earth tailings include: lanthanum, cerium, neodymium, samarium, yttrium, and gadolinium.

6. The modified emulsified asphalt composition according to claim 5, characterized in that, The total mass of light rare earth elements in the rare earth tailings accounts for more than 90% of all rare earth elements.

7. The modified emulsified asphalt composition according to any one of claims 1-6, characterized in that, The coupling agent includes one or more of the following: silane coupling agent, titanate coupling agent, aluminate coupling agent, zirconate coupling agent, or polymer coupling agent.

8. The modified emulsified asphalt composition according to claim 7, characterized in that, The coupling agent is a silane coupling agent.

9. The modified emulsified asphalt composition according to claim 8, characterized in that, The mass ratio of the coupling agent to the rare earth tailings is 1:(1000~3000).

10. A method for preparing the modified emulsified asphalt composition according to any one of claims 1-9, characterized in that, include: The coupling agent, ethanol and water are mixed in a predetermined ratio and then placed on the surface of rare earth tailings for drying treatment to obtain surface-modified rare earth tailings. The asphalt and the surface-modified rare earth tailings were mixed at 145-160°C and subjected to high-speed shearing to obtain a melt blend phase. A soap liquid phase is obtained by mixing water, emulsifying components, and elastomer emulsion. The modified emulsified asphalt composition is obtained by mixing the molten blend phase and the soap liquid phase.

11. An asphalt grouting material, characterized in that, include: The modified emulsified bitumen composition according to any one of claims 1-6.

12. The asphalt grouting material according to claim 11, characterized in that, The modified emulsified asphalt composition comprises 30-45% by mass in the asphalt grout.

13. The asphalt grouting material according to claim 11 or 12, characterized in that, Also includes: Functional additives, demulsifiers, fillers, and water; The demulsifier comprises polyvinyl alcohol and calcium chloride; the demulsifier accounts for 2-7.5% of the mass of the asphalt grout.

14. The asphalt grouting material according to claim 13, characterized in that, The functional additives include one or more of the following: defoamer, preservative, thickener, and pH adjuster; the mass percentage of the functional additives in the asphalt grout is 0.5-1.5%.

15. The application of the asphalt grouting material according to any one of claims 11-14 in waterproofing of road engineering, bridge engineering, building engineering, water conservancy engineering, underground engineering or tunnel engineering.

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