A fast-curing repair mastic and a method of making the same

Abstract

This application provides a fast-curing joint repair compound and its preparation method. The fast-curing joint repair compound comprises the following raw materials in parts by weight: 50 parts silicate cement, 40-60 parts styrene-acrylic emulsion, 5-10 parts modified slag, 0.4-1 parts hollow microspheres, 0.5-1.5 parts glass fiber, 100-150 parts quartz sand, 0.1-0.3 parts dispersing suspending agent, 0.1-1 parts defoamer, and 20-40 parts water. The modified slag has a core-shell structure, comprising, in sequence, a slag core, calcium salt components loaded on the surface or in the pores of the slag core, a humate layer formed on the surface, and a quaternary ammonium salt cationic polymer layer coating the outside of the humate layer. This joint repair compound has the characteristics of short initial setting time, high early strength, and good construction rheology, and is suitable for building joint repair, road maintenance, and concrete structure repair.

Description

Technical Field

[0001] This application relates to the field of building materials, specifically to a fast-curing joint sealant and its preparation method. Background Technology

[0002] During construction and service, building walls, concrete components, and prefabricated structures often develop various forms of cracks and gaps due to shrinkage deformation, temperature and humidity changes, and external forces. To restore structural integrity and prevent the intrusion of moisture and harmful media, it is usually necessary to fill and repair these cracks with repair materials. Traditional repair materials are mostly based on silicate cement. These materials rely primarily on cement hydration to form strength. Although they have advantages such as low cost and good compatibility with concrete substrates, their fluidity and workability are poor, they are prone to bleeding and segregation, have significant hardening shrinkage, and limited early crack resistance and interfacial bonding performance, making it difficult to meet the needs for rapid repair of fine cracks and complex interfaces.

[0003] To address the aforementioned issues, existing technologies have developed cement-based polymer-modified repair materials. These materials incorporate polymer emulsions (such as styrene-acrylic emulsions, EVA emulsions, and polyurethane emulsions) into the cement system, forming a cement-polymer composite system. Polymer emulsions possess excellent film-forming properties, adhesion, and flexibility. Their introduction improves the material's crack resistance, interfacial adhesion, and ease of application, making it easier to fill micro-cracks and form an effective bond with the substrate.

[0004] For example, patent CN121377668A discloses a polymer emulsion-modified mortar, which improves the mortar's flexibility, crack resistance, and energy dissipation performance by increasing the amount of polymer emulsion. This type of technical solution improves the material's later mechanical properties and impact resistance by forming a continuous phase of polymer within the cement matrix, and has certain application value in building repair and protection engineering.

[0005] However, the modification strategies of the aforementioned technical solutions mainly focus on improving later-stage toughness and mechanical properties, while lacking effective control over the interaction between the cement hydration system and the high-content emulsion system. When the amount of polymer emulsion increases, the cement system and the emulsion system are prone to mutual interference in the early stages: the cement hydration process affects the stable dispersion and film-forming behavior of the emulsion, while the presence of the emulsion also hinders the cement hydration process, making it difficult for the two curing mechanisms to work synergistically. This results in problems such as slow early-stage curing, delayed strength formation, and prolonged drying time, failing to meet the requirements of "rapid curing, rapid strength formation, and rapid deployment" in crack repair scenarios. This problem is particularly prominent in repair materials with high polymer emulsion content and is a common and unresolved technical challenge in existing polymer-modified cement-based repair materials.

[0006] Therefore, how to obtain a joint repair material with rapid curing properties while maintaining a high polymer emulsion content has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] This application provides a fast-curing repair paste and its preparation method, aiming to solve the problems of slow early curing and delayed strength formation of high-doped polymer emulsion modified cement repair materials in the prior art.

[0008] In a first aspect, this application provides a fast-curing grout, comprising the following raw materials in parts by weight:

[0009] 50 parts silicate cement, 40-60 parts styrene-acrylic emulsion, 5-10 parts modified slag, 0.4-1 parts hollow microspheres, 0.5-1.5 parts glass fiber, 100-150 parts quartz sand, 0.1-0.3 parts dispersing and suspending agent, 0.1-1 parts defoamer, 20-40 parts water;

[0010] The modified slag has a core-shell structure, comprising, in sequence, a slag core, a calcium salt component loaded on the surface or in the pores of the slag core, a humate layer formed by surface loading, and a quaternary ammonium salt cationic polymer layer covering the outside of the humate layer.

[0011] This application designs modified slag with interface regulation function to adjust the interaction between the cement phase and the emulsion phase at the micro-interface under the condition of high styrene-acrylic emulsion dosage, so that the two solidification mechanisms can proceed synergistically in the early stage.

[0012] Specifically, slag possesses a high specific surface area and porous structure, which facilitates the formation of a solid-liquid interface in the slurry. It may also preliminarily separate cement and emulsion through the interface occupancy effect, providing an adhesion basis for subsequent interface regulation. Based on this, the slag interface can be pre-formed with a Ca-rich structure. 2+ In the interface environment of cement hydration, the humate layer interacts with Ca through its carboxyl groups and other functional groups. 2+ It can form a multi-site ion complex structure, which can participate in the rebalancing process of the interfacial ion environment in the early stage of cement hydration, helping to slow down local Ca2+ formation. 2+Rapid fluctuations in concentration affect the dispersion stability of styrene-acrylic emulsions, reducing ionic bridging and flocculation tendencies between emulsion particles and improving the dispersion stability of the emulsion in cement paste. Because the humate layer itself has strong polarity and hydrophilicity, it is prone to water absorption and swelling in the cement paste environment, affecting its stability at the slag interface. Introducing a quaternary ammonium salt-type cationic polymer layer can structurally solidify the humate layer, allowing it to maintain basic interfacial integrity in the early stages of cement hydration, thus regulating the interfacial ionic environment. Furthermore, the outer quaternary ammonium salt-type cationic polymer layer forms a hydrophilic interface in the paste, helping to improve the interfacial compatibility between modified slag and styrene-acrylic emulsion.

[0013] Through the above structural design, the modified slag enables the cement hydration zone and the emulsion film-forming zone to be coordinated to a certain extent, weakening the mutual interference between cement hydration and emulsion film-forming, and enabling the two curing mechanisms to proceed simultaneously in the early stage, thereby improving the overall curing rate of the joint sealant.

[0014] In some embodiments, the modified slag is prepared by the following steps:

[0015] S1: Disperse slag and citric acid in water to allow the carboxylic acid groups in the citric acid molecules to coordinate with the metal hydroxyl sites on the surface of the slag, thus obtaining citric acid-modified slag.

[0016] S2: Citric acid-modified slag and calcium salt are dispersed in water, so that calcium ions are enriched at the interface on the slag surface to obtain slag loaded with calcium salt components.

[0017] S3: Disperse the slag loaded with calcium salt components and humic acid salts in water, so that the humic acid salts are fixed on the surface of the slag to obtain slag with a humic acid salt layer.

[0018] S4: Disperse the slag that forms the humate layer and the quaternary ammonium salt cationic polymer in water, so that the quaternary ammonium salt cationic polymer will electrostatically associate on the surface of the slag that forms the humate layer, and obtain modified slag.

[0019] In some of the above embodiments, by introducing carboxyl sites onto the slag surface, the slag surface, which is mainly composed of silicon-oxygen structures and has strong surface chemical inertness, is transformed into an organic interface with strong polarity and hydrophilicity, thus facilitating subsequent Ca2+ processing. 2+ The preferential distribution in this interface region creates favorable conditions.

[0020] In step S2, the carboxyl groups possess certain polarity and ionization characteristics in an aqueous environment, which can alter the interfacial charge and hydrophilicity of the slag surface, making the interface more affinity-oriented for divalent cations and promoting the absorption of Ca. 2+ It is enriched at the slag interface.

[0021] In step S3, the -COO in the humate molecule - Isopolar groups can interact with Ca enriched at the interface through multi-site ion correlation. 2+ An ion-bridged structure is formed, gradually creating a humate layer on the slag surface. This ion-bridged structure is a multi-point weakly interacting network, which subsequently releases Ca during cement hydration. 2+ At this time, the humate layer can play a role in ion exchange and regulation, and may form a relatively stable ion regulation interface, weakening the Ca2+ level. 2+ Destruction of the dispersion stability of styrene-acrylic emulsion.

[0022] In step S4, the polarity and organic functional groups on the surface of the humate layer can undergo multi-site ion association with the quaternary ammonium cationic polymer, promoting the fixation of the quaternary ammonium cationic polymer on the surface of the humate layer. This polymer then volatilizes with the solution to form an outer coating, thus constructing a quaternary ammonium cationic polymer layer. Since the quaternary ammonium cationic polymer is mainly fixed at the slag interface and does not exist in large quantities in the aqueous phase in a free state, its impact on the dispersion stability of the styrene-acrylic emulsion is relatively limited.

[0023] Therefore, through the humate layer and Ca 2+ The participating interface environment affects the interface Ca 2+ The modified slag layer, through multi-level regulation of the "ionic environment" and "spatial distribution" interference pathways, helps the emulsion maintain a stable dispersion state in the early stages. This synergistic effect weakens the mutual constraints between cement hydration and emulsion film formation, thereby effectively improving the overall curing rate of the joint sealant.

[0024] In some embodiments, step S1 includes:

[0025] Mix 100 parts of slag, 1.5 to 3 parts of citric acid and 15 to 50 parts of water, and treat at 20 to 60°C for 1 to 5 hours to obtain citric acid modified slag.

[0026] In some of the above embodiments, by controlling the amount of water to 15-50 parts, a thin water film environment is formed on the slag surface. At this time, 1.5-3 parts of citric acid are in a relatively high local concentration state, which tends to undergo coordination adsorption on the slag surface. This thin water film wets and exposes the slag surface and provides an interfacial reaction environment for the carboxylic acid groups and the metal hydroxyl sites on the slag surface. Combined with the temperature and treatment time under the above conditions, it is beneficial for the carboxylic acid groups to coordinate with the metal hydroxyl sites on the slag surface, thereby increasing the loading of citric acid on the slag surface and providing sufficient anchor points for the subsequent stable coordination of calcium ions.

[0027] In some implementations, step S2 includes:

[0028] 100 parts of citric acid-modified slag and 3-5 parts of calcium salt were dispersed in 80-150 parts of water and treated at 10-40℃ for 1-3 hours to obtain slag loaded with calcium salt components.

[0029] In some of the above embodiments, controlling the amount of calcium salt to 3-5 parts helps to make Ca... 2+ An interfacial enrichment state is formed on the slag surface, maintaining good exchangeability, thus providing a favorable calcium ion environment for the subsequent fixation process of humates at the interface. Dispersed in 80-150 parts of water, Ca... 2+ It exhibits good migration and diffusion capabilities in solution, thus facilitating its migration to the highly polar interfacial regions on the slag surface. Under treatment conditions of 10–40℃ and 1–3 h, it is beneficial for Ca… 2+ The full migration and enrichment of the solution phase towards the slag interface region transforms the slag surface from a carboxyl-dominated interface to one rich in Ca. 2+ The interface environment provides a pre-set Ca2+ for the subsequent directional binding of humates at the interface. 2+ Chemical environment.

[0030] In some implementations, step S3 includes:

[0031] 100 parts of calcium-loaded slag and 2-4 parts of humate were dispersed in 80-150 parts of water. The pH was adjusted to 5-6, and the reaction was carried out for 30-90 minutes. Then, the mixture was rotary evaporated at 50-70℃ and -0.07--0.09 MPa to obtain slag with a humate layer.

[0032] In some of the above embodiments, controlling the amount of humate to 2-4 parts helps the humate in Ca... 2+ Loading occurs in the slag interface environment. By adjusting the pH to 5-6 and reacting for 30-90 minutes, humate is promoted to form in a highly polar environment with pre-existing Ca. 2+ Heterogeneous complexation occurs on the surface of slag enriched with a solid interface. Under conditions of 50–70 °C and reduced pressure rotary evaporation, the solvent volume gradually decreases, further promoting the formation of a humate layer on the slag surface. Humate is a high-molecular-weight substance derived from natural organic matter, containing multiple polar groups on its molecular chain. These natural polymers exhibit a random coiled spatial configuration, and their interaction with Ca... 2+ The bonding between them tends to exhibit a dispersed, multi-site bridging characteristic. In the early stages of cement hydration, this humate layer will not be affected by excessive complexation of Ca. 2+ The loss of interfacial function may allow the interface to maintain relative stability of the ionic environment through multi-site bridging structures, smoothing out the Ca2+ at the interface. 2+Rapid changes in concentration create a favorable interfacial environment for the emulsion to maintain stable dispersion and form a film smoothly in the early stages, playing an important role in achieving rapid curing of the grout.

[0033] In some implementations, step S4 includes:

[0034] 100 parts of slag forming a humate layer and 2-6 parts of quaternary ammonium salt cationic polymer are dispersed in 80-150 parts of water and treated at 20-60℃ for 1-4 hours to obtain modified slag.

[0035] The quaternary ammonium salt type cationic polymer includes polydimethyldiallylammonium chloride.

[0036] In some of the above embodiments, controlling the amount of quaternary ammonium salt cationic polymer to 2-6 parts helps to form a continuous but not excessively stacked polymer interface layer on the slag surface. In the aqueous system, this helps the quaternary ammonium salt cationic polymer molecular chains extend, promoting the exposure of cationic groups, which are then adsorbed onto the humate layer surface through multi-site electrostatic association, thereby improving the uniformity of its loading at the solid interface. Under the conditions described, the polymer in the system gradually changes from a fully dispersed state to an interface-preferentially enriched state, which is beneficial for forming a more uniform polymer coating layer on the outer layer of humate. Polydimethyl diallyl ammonium chloride is selected because its main chain has a high density of quaternary ammonium salt cationic groups, which easily undergo multi-site ion association on a multi-anionic surface, thereby helping to improve the integrity and stability of the organic interface layer on the modified slag surface.

[0037] In some embodiments, the hollow microspheres have a particle size of 20-100 μm and an actual density of 0.4-0.7 g / cm³. 3 .

[0038] In some of the above embodiments, the size range and density range help the hollow microspheres to be uniformly dispersed in the slurry. The continuous pore network formed between the particles may construct effective water migration microchannels in the thixotropic system with high styrene-acrylic emulsion content, which helps to reduce the phenomenon of water retention inside the slurry, thereby improving the early drying and overall curing efficiency of the repair paste.

[0039] In some embodiments, the glass fiber has a diameter of 1~15μm and a length of 1~5mm.

[0040] In some of the above embodiments, this size range helps glass fibers form a microscale bonded skeleton structure in thixotropic slurries with high styrene-acrylic emulsion content, disperses shrinkage stress during the rapid water migration and volume shrinkage of the slurry in the early stage, and enables the cement hydration and emulsion film formation processes to take place in a more continuous and stable structural environment.

[0041] In some embodiments, the particle size of the quartz sand is 80~500μm.

[0042] In some of the above embodiments, quartz sand, as a conventional aggregate in cement-based repair materials, is mainly used to construct the particle size distribution structure of the slurry, playing a role in volume filling and skeleton support, and improving the compressive strength and dimensional stability of the repair material.

[0043] In some embodiments, the dispersing agent includes hydroxypropyl methylcellulose. Using the above-mentioned dispersing agent can enhance the suspension stability of particles and inhibit bleeding and sedimentation.

[0044] In some embodiments, the defoamer includes polyether-modified siloxane defoamers. Using these defoamers can break up air bubbles introduced during stirring and suppress regenerated bubbles, thereby improving the density of the slurry.

[0045] Secondly, this application provides a method for preparing a fast-curing grout, comprising:

[0046] Provide the raw materials included in the grout as described in any embodiment of the first aspect;

[0047] The raw materials are blended to obtain a fast-curing sealant.

[0048] According to this application, the fast-curing joint repair compound is applicable to the fields of building joint repair, road maintenance and concrete structure repair, and has the beneficial effect of the first aspect, and the obtained joint repair compound has a fast curing rate.

[0049] Compared with the prior art, the beneficial effects of this application are at least as follows:

[0050] By constructing a modified slag with a core-shell composite structure, the slag core provides a high specific surface area solid-liquid interface and space occupancy, while the loaded calcium salt and outer humate form an ion-regulating interface at the interface, reducing the early-stage Ca2+ degradation during cement hydration. 2+ To mitigate interference with emulsion dispersion stability, a quaternary ammonium salt-type cationic polymer layer is further introduced to stabilize the structure and solidify the interface of the humate layer, thereby facilitating the subsequent film-forming process. This coordinates the cement hydration zone and the emulsion film-forming zone, achieving early synergistic curing under high emulsion content conditions, thus improving the overall curing rate of the joint sealant. Detailed Implementation

[0051] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this specification, unless otherwise specified, "parts" refers to "parts by weight".

[0055] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0056] Portland cement: Ordinary Portland cement with grade P·O 42.5;

[0057] Styrene-acrylic emulsion: anionic type, solid content 46%, Brookfield viscosity (25℃, rotor No. 3, 30 r / min) approximately 2000 mPa·s;

[0058] Slag: Grade S95 granulated blast furnace slag powder;

[0059] Hollow microspheres: particle size approximately 55μm, actual density 0.6g / cm³ 3 ;

[0060] Fiberglass: approximately 3mm in length and 7μm in diameter;

[0061] Quartz sand: fineness modulus approximately 2.3 (80~200μm)

[0062] Hydroxypropyl methylcellulose: CAS number 9004-65-3, viscosity at 25℃ is approximately 150,000 mPa·s;

[0063] Sodium humate: CAS number 68131-04-4;

[0064] Polydimethyl diallyl ammonium chloride: CAS No. 26062-79-3, the viscosity of a 40% solids content aqueous solution at 25°C is approximately 8000 mPa·s.

[0065] Preparation Example 1

[0066] Preparation of modified slag:

[0067] S1: Disperse 100 parts of slag and 2 parts of citric acid monohydrate in 30 parts of deionized water, stir at 40℃ (300 r / min) for 3 h, filter, wash the filter cake with deionized water, dry, grind and pass through a 100-mesh sieve to obtain citric acid modified slag.

[0068] S2: 100 parts of citric acid modified slag and 4 parts of anhydrous calcium chloride were dispersed in 100 parts of deionized water, stirred at 25°C (200 r / min) for 2 h, filtered, washed with anhydrous ethanol, and dried to obtain slag loaded with calcium salt components.

[0069] S3: Disperse 100 parts of slag loaded with calcium salt components and 3 parts of sodium humate in 100 parts of deionized water. Under stirring (40 r / min), adjust the pH value to 5.5 with 0.1M hydrochloric acid aqueous solution. Continue stirring for 60 min, then rotary evaporate to a loose powder without obvious wet lumps (60℃, -0.08MPa, 40 r / min). Cool to obtain slag with a humate layer.

[0070] S4: Disperse 100 parts of slag forming a humate layer in 100 parts of deionized water, add 10 parts of polydimethyldiallylammonium chloride aqueous solution with a solid content of 40%, stir at 50°C for 1.5 h, filter, dry, grind and pass through a 120-mesh sieve to obtain modified slag A.

[0071] Preparation Example 2

[0072] Preparation of modified slag:

[0073] S1: Disperse 100 parts of slag, 2 parts of citric acid monohydrate, and 4 parts of anhydrous calcium chloride in 30 parts of deionized water, stir at 40℃ (300 r / min) for 3 h, filter, wash the filter cake with deionized water and anhydrous ethanol, dry, grind and pass through a 100-mesh sieve to obtain slag loaded with calcium salt components.

[0074] S2: Disperse 100 parts of slag loaded with calcium salt components and 3 parts of sodium humate in 100 parts of deionized water. Under stirring (40 r / min), adjust the pH value to 5.5 with 0.1M hydrochloric acid aqueous solution. Continue stirring for 60 min, then rotary evaporate to a loose powder without obvious wet lumps (60℃, -0.08MPa, 40 r / min). Cool to obtain slag with a humate layer.

[0075] S3: Disperse 100 parts of slag forming a humate layer in 100 parts of deionized water, add 10 parts of polydimethyldiallylammonium chloride aqueous solution with a solid content of 40%, stir at 50°C for 1.5 h, filter, dry, grind and pass through a 120-mesh sieve to obtain modified slag B.

[0076] Comparative Preparation Example 1

[0077] Preparation of modified slag:

[0078] S1: Disperse 100 parts of slag and 2 parts of citric acid monohydrate in 30 parts of deionized water, stir at 40℃ (300 r / min) for 3 h, filter, wash the filter cake with deionized water, dry, grind and pass through a 100-mesh sieve to obtain citric acid modified slag.

[0079] S2: 100 parts of citric acid modified slag and 4 parts of anhydrous calcium chloride were dispersed in 100 parts of deionized water, stirred at 25°C (200 r / min) for 2 h, filtered, washed with anhydrous ethanol, and dried to obtain slag loaded with calcium salt components.

[0080] S3: Disperse 100 parts of slag loaded with calcium salt components and 3 parts of sodium humate in 100 parts of deionized water. Under stirring (40 r / min), adjust the pH value to 5.5 with 0.1M hydrochloric acid aqueous solution. Continue stirring for 60 min, then rotary evaporate to a loose powder without obvious wet lumps (60℃, -0.08MPa, 40 r / min). Cool to obtain modified slag C.

[0081] Comparative Preparation Example 2

[0082] Preparation of modified slag:

[0083] S1: Disperse 100 parts of slag and 2 parts of citric acid monohydrate in 30 parts of deionized water, stir at 40℃ (300 r / min) for 3 h, filter, wash the filter cake with deionized water, dry, grind and pass through a 100-mesh sieve to obtain citric acid modified slag.

[0084] S2: Disperse 100 parts of citric acid modified slag and 4 parts of anhydrous calcium chloride in 100 parts of deionized water, stir at 25°C (200 r / min) for 2 h, filter, wash with anhydrous ethanol, and dry to obtain modified slag D.

[0085] Comparative preparation example 3

[0086] Preparation of modified slag:

[0087] S1: Disperse 100 parts of slag in 100 parts of deionized water, add 10 parts of polydimethyldiallylammonium chloride aqueous solution with a solid content of 40%, stir at 50°C for 1.5 h, filter, dry, grind and pass through a 120-mesh sieve to obtain modified slag E.

[0088] Example 1

[0089] Preparation of fast-curing grout:

[0090] Mix 120 parts of quartz sand, 0.6 parts of hollow microspheres, 1 part of glass fiber, 8 parts of modified slag A, and 50 parts of silicate cement. Disperse the mixture at 300 rpm for 2 minutes. Add 25 parts of water at 400 rpm and continue stirring and dispersing for 2 minutes. Add 0.2 parts of hydroxypropyl methylcellulose and 0.5 parts of polyether-modified silicone oil defoamer. Disperse the mixture at 300 rpm for 2 minutes. Add 50 parts of styrene-acrylic emulsion at 400 rpm and increase the speed to 500 rpm. Disperse for 5 minutes to obtain the joint sealant.

[0091] Example 2

[0092] Preparation of fast-curing grout:

[0093] It is largely the same as Example 1, except that modified slag A is replaced with modified slag B.

[0094] Comparative Example 1

[0095] Preparation of fast-curing grout:

[0096] It is largely the same as Example 1, except that modified slag A is replaced with modified slag C.

[0097] Comparative Example 2

[0098] Preparation of fast-curing grout:

[0099] It is largely the same as Example 1, except that modified slag A is replaced with modified slag D.

[0100] Comparative Example 3

[0101] Preparation of fast-curing grout:

[0102] It is largely the same as Example 1, except that modified slag A is replaced with modified slag E.

[0103] Comparative Example 4

[0104] Preparation of fast-curing grout:

[0105] It is largely the same as Example 1, except that modified slag A is replaced with slag.

[0106] Comparative Example 5

[0107] Preparation of fast-curing grout:

[0108] Mix 120 parts quartz sand, 0.6 parts hollow microspheres, 1 part glass fiber, 7 parts slag, 0.15 parts citric acid monohydrate, 0.28 parts anhydrous calcium chloride, 0.22 parts sodium humate, 0.7 parts polydimethyl diallyl ammonium chloride aqueous solution with a solid content of 40%, and 50 parts silicate cement. Disperse the mixture at 300 r / min for 2 min. Add 25 parts water at 400 r / min and continue stirring and dispersing for 2 min. Add 0.2 parts hydroxypropyl methylcellulose and 0.5 parts polyether modified silicone oil defoamer. Disperse the mixture at 300 r / min for 2 min. Add 50 parts styrene-acrylic emulsion at 400 r / min, then increase the speed to 500 r / min and disperse for 5 min to obtain the joint sealant.

[0109] Test section

[0110] The fast-curing sealant prepared in the examples and comparative examples was filled into a 40mm×40mm×160mm mold within 15 minutes after mixing. It was then compacted and smoothed in two layers with a scraper, with each layer compacted 20 times. After curing in a curing chamber at 20℃ and relative humidity ≥90% for 24 hours, the mold was removed. The 1-day compressive strength of the specimen was tested using a compressive strength testing machine at a loading rate of 2400N / s. After demolding, the specimen was cured according to the above standard for 7 days, and the 7-day compressive strength of the specimen was tested. Three specimens were tested at each age, and the average value was taken as the final result.

[0111] The test results are shown in Table 1.

[0112] Table 1

[0113]

[0114] Table 1 shows that the joint sealant obtained in each embodiment has a higher compressive strength under the same curing time compared to the comparative example, indicating that the joint sealant provided in this application has a faster curing rate. This may be because Comparative Example 1 lacks a quaternary ammonium salt cationic polymer outer layer. The humate layer on the outer side of the slag itself has strong hydrophilicity and is prone to water absorption, swelling, and deformation in the cement paste environment, which may lead to rapid instability of the interface layer structure in the early stages. 2+ The ion regulation effect is thus weakened, and the free Ca in the system 2+It will still damage the dispersion stability of the styrene-acrylic emulsion, thus reducing the compressive strength; in Comparative Example 2, the slag is only loaded with calcium salt components. Since no further organic interface layer is constructed, the loaded Ca at this time... 2+ It is more likely to exhibit the ordinary cement-accelerating effect, while its release and diffusion are limited by adsorption on the slag surface, thus reducing the curing efficiency. In Comparative Example 3, the slag was directly treated with polydimethyldiallyl ammonium chloride during the preparation process. Without calcium salt loading and humate layer, polydimethyldiallyl ammonium chloride may have difficulty forming a stable bonding interface on the slag surface. The small amount of adsorbed polymers are also easily desorbed and dispersed in the slurry after entering the cement system, losing the interfacial positioning effect. At this time, the quaternary ammonium salt groups cannot have a beneficial effect on the emulsion particles near the slag interface, thus exhibiting a lack of bonding efficiency. The effect is similar to that of ordinary slag. In Comparative Example 4, ordinary slag exists only as an inert microfiller, which cannot regulate the interfacial ionic environment or control the emulsion particles. Cement hydration and emulsion film formation are still in a state of obvious mutual interference, so its early compressive strength is the lowest. In Comparative Example 5, the dosage of each component is calculated according to the corresponding content in modified slag A. A one-step simple mixing method is used to replace the step-by-step construction process. Homogeneous complexation or competitive reactions may occur between the components, making it difficult to form a synergistic control interface. Therefore, although the early strength is improved compared with the pure slag system, it is still lower than the example using step-by-step construction of modified slag. It can be seen from Comparative Examples 1 to 5 that the interface structure design of modified slag in this application is not a simple superposition of several functional components, but a whole interface system with hierarchical relationship. This interface system is constructed sequentially by a calcium salt layer, a humate layer, and a quaternary ammonium salt cationic polymer layer. Each layer has a clear division of labor and synergistic relationship in terms of structural stability, ionic environment regulation, and emulsion diffusion control.

[0115] As shown in Examples 1 and 2, the preparation route of the modified slag has a certain influence on the curing rate of the joint sealant. When citric acid and calcium chloride are loaded onto the slag in steps, the curing rate of the joint sealant is faster. This may be because the modified slag used in Example 1 is prepared by first carboxylating the slag surface and then directionally coordinating and loading Ca. 2+ A calcium anchoring interface was constructed, enabling subsequent humate complexation and cationic polymer coating to be established on a relatively stable Ca... 2+ Based on the bridging structure, and with the modified slag used in Example 2 simultaneously introducing citric acid and calcium salts, during this process, some citrate ions may react with Ca in the solution. 2+ Pre-complexation leads to partial Ca 2+ The presence of the sealant at the slag interface tends to be loose adsorption, which affects the stability of the overall interface structure and the synergistic regulation effect, ultimately resulting in a decrease in the curing rate of the sealant.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A fast-curing grout, characterized in that, Includes the following quantities of raw materials: 50 parts silicate cement, 40-60 parts styrene-acrylic emulsion, 5-10 parts modified slag, 0.4-1 parts hollow microspheres, 0.5-1.5 parts glass fiber, 100-150 parts quartz sand, 0.1-0.3 parts dispersing and suspending agent, 0.1-1 parts defoamer, 20-40 parts water; The modified slag is prepared through the following steps: S1: Mix 100 parts of slag, 1.5 to 3 parts of citric acid and 15 to 50 parts of water, and treat at 20 to 60°C for 1 to 5 hours to obtain citric acid modified slag; S2: Disperse 100 parts of citric acid modified slag and 3-5 parts of calcium salt in 80-150 parts of water, and treat at 10-40℃ for 1-3 hours to obtain slag loaded with calcium salt components; S3: Disperse 100 parts of calcium-loaded slag and 2-4 parts of humate in 80-150 parts of water, adjust the pH to 5-6, react for 30-90 min, and then rotary evaporate at 50-70℃ and -0.07--0.09 MPa to obtain slag with a humate layer. S4: Disperse 100 parts of slag forming a humate layer and 2-6 parts of quaternary ammonium salt cationic polymer in 80-150 parts of water, and treat at 20-60℃ for 1-4 hours to obtain modified slag; The quaternary ammonium salt type cationic polymer includes polydimethyldiallylammonium chloride.

2. The grout sealant according to claim 1, characterized in that, The hollow microspheres have a particle size of 20~100μm and an actual density of 0.4~0.7g / cm³. 3 .

3. The grout sealant according to claim 1, characterized in that, The glass fiber has a diameter of 1~15μm and a length of 1~5mm.

4. The grout sealant according to claim 1, characterized in that, The particle size of the quartz sand is 80~500μm.

5. A method for preparing a fast-curing grout, comprising: Provide the raw materials included in the grout according to any one of claims 1 to 4; The raw materials are blended to obtain a fast-curing sealant.

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