Early-strength fast-repair grouting material and preparation method thereof

Abstract

This invention provides an early-strength rapid repair grouting material and its preparation method. The early-strength rapid repair grouting material of this invention is mainly prepared from the following raw materials: 50-150 parts of sulfoaluminate cement, 10-150 parts of aluminate cement, 200-350 parts of recycled cementitious powder, 1200-1400 parts of quartz sand, 50-100 parts of silica fume, 10-150 parts of mineral powder, 10-100 parts of fly ash, 15-50 parts of composite retarder, 0.1-2 parts of water-reducing agent, 1-10 parts of early-strength agent, 0.01-1 part of water-retaining agent, and 200-300 parts of water. The early-strength rapid repair grouting material of this invention is characterized by using activated low-cementing-activity mineral solid waste as the main cementing material. This product has excellent construction stability, low-carbon weather resistance, corrosion resistance, micro-expansion rapid hardening early strength, and economic efficiency.

Description

Technical Field

[0001] This invention relates to the field of grouting material preparation, and more specifically, to an early-strength rapid repair grouting material and its preparation method. Background Technology

[0002] Traditional grouting materials, including cement grout and chemical grouting agents, generally suffer from slow curing speed, low early strength, poor rheological properties, insufficient corrosion resistance and impermeability, and poor thixotropy and controllability. These problems make them unsuitable for all types of foundation and structural repair needs. They are particularly pronounced in complex engineering environments such as emergency repair projects requiring rapid repair, special geological conditions, low-temperature environments, or structures requiring large loads or complex stress states. Furthermore, the poor rheological and thixotropic controllability of traditional grouting materials makes precise quality control difficult, posing significant challenges to construction applications. Some traditional grouting materials using organic solvents or chemical components pose potential hazards to the environment and human health, failing to meet the environmental protection requirements of sustainable development. Early-strength, high-performance traditional grouting materials often require large amounts of adhesive or have high costs.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide an early-strength, rapid-setting grouting material and its preparation method, to solve the problems of slow curing speed, low early strength, poor rheological properties, insufficient corrosion resistance and impermeability, and poor thixotropy and controllability of traditional grouting materials. The advantages of this rapid-setting grouting material lie in replacing early-strength ordinary silicate cement with activated low-cementing-activity mineral solid waste. A composite retarder is used, formulated with desulfurized gypsum, borax, sodium p-aminobenzenesulfonate, sodium pyrophosphate, and other components in specific proportions. Based on an assessment of the environmental level of the actual grouting and reinforcement site, the proportions of recycled cementitious powder, sulfoaluminate cement, aluminate cement, composite retarder, and micro / nano-grade silica fume, ultrafine mineral powder, fly ash, powder water-reducing agent, and early-strength agent are optimized and controlled. This results in reinforcement projects using this prepared grouting material exhibiting superior construction thixotropic controllability, rapid hardening and early strength, corrosion resistance, impermeability, and economic efficiency.

[0005] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0006] This invention provides an early-strength, rapid-repair grouting material, mainly made from the following raw materials: by mass parts, 50-150 parts of sulfoaluminate cement, 10-150 parts of aluminate cement, 200-350 parts of recycled cementitious powder material, 1200-1400 parts of quartz sand, 50-100 parts of silica fume, 10-150 parts of mineral powder, 10-100 parts of fly ash, 15-50 parts of composite retarder, 0.1-2 parts of water-reducing agent, 1-10 parts of early-strength agent, 0.01-1 parts of water-retaining agent, and 200-300 parts of water;

[0007] The recycled cementitious powder material is mainly prepared from particles with a particle size ≤4.75mm from primary crushing of concrete construction waste, solid waste steel slag, overburned coal gangue, magnesium slag, lithium slag, active activator, and grinding aid.

[0008] In this invention, the recycled cementitious powder material constitutes the largest portion of all raw material components of the early-strength rapid repair grouting material. Sulfoaluminate cement and aluminate cement serve as auxiliary materials to supplement the recycled cementitious material, and their addition amounts are not large. The advantage of this combination is that by using recycled cementitious powder material as the main material, it achieves low-carbon and environmentally friendly results. The optimal ratio of these three cementitious materials effectively improves the system's volume stability and early-stage mechanical properties, meeting the requirements for rapid repair operations in low-temperature winter conditions or emergency rescue situations. Furthermore, to ensure good working stability, a certain amount of water-reducing agent and water-retaining agent are added, along with a certain amount of early-strength agent and composite retarder. The main purpose is to improve the early-strength and rapid-setting effect of the grouting material while enhancing its rheological properties and workability controllability, making it more suitable for harsh construction environments.

[0009] Preferably, as a further feasible option, the following components are included by weight: 80-120 parts of sulfoaluminate cement, 30-150 parts of aluminate cement, 230-350 parts of recycled cementitious powder material, 1200-1400 parts of quartz sand, 65-80 parts of silica fume, 10-60 parts of mineral powder, 20-60 parts of fly ash, 25-50 parts of composite retarder, 0.5-2 parts of water-reducing agent, 2-8 parts of early-strength agent, 0.1-0.6 parts of water-retaining agent, and 200-270 parts of water.

[0010] Optimally, as a further feasible option, the mixture comprises 100 parts of sulfoaluminate cement, 35 parts of aluminate cement, 310 parts of recycled cementitious powder material, 1300 parts of quartz sand, 70 parts of silica fume, 30 parts of mineral powder, 50 parts of fly ash, 40 parts of composite retarder, 1.5 parts of water-reducing agent, 4 parts of early-strength agent, 0.4 parts of water-retaining agent, and 210 parts of water.

[0011] To further optimize the mass ratio of each component, it is best to further optimize the compatibility of each component according to the above proportions. A better proportion of each substance can improve the stability of the grouting material and its early strength and rapid setting effect.

[0012] The addition of quartz sand is to effectively improve fluidity, ensure excellent mechanical properties, and enhance crack resistance. 70-120 mesh quartz sand with excellent uniform dispersion is preferred.

[0013] Preferably, as a further feasible option, the recycled cementitious powder material is mainly prepared from the following raw materials: by mass parts, 20-40 parts of concrete construction waste with a particle size ≤4.75mm after one-time crushing, 10-20 parts of solid waste steel slag, 6-10 parts of burnt coal gangue, 2-4 parts of magnesium slag, 3-5 parts of lithium slag, 5-10 parts of desulfurized gypsum, 2-7 parts of active activator, and 0.1-3 parts of grinding aid.

[0014] Preferably, as a further feasible option, the active activator is formed by compounding sodium silicate, sodium oxalate, calcium hydroxide and diethanolamine.

[0015] Preferably, the mass ratio of sodium silicate:calcium hydroxide:sodium oxalate:diethanolamine is (20~40):(40:70):(5~25):(5~30), and more preferably, the mass ratio of sodium silicate:calcium hydroxide:sodium oxalate:diethanolamine is 26:50:12:12. The sodium silicate-calcium hydroxide combination and the diethanolamine-sodium oxalate combination have a synergistic effect. Calcium hydroxide provides an alkaline environment, promotes the release of siloxane groups from sodium silicate, and accelerates the formation of CSH gel. The dispersing effect of diethanolamine and the calcium ion regulation effect of sodium oxalate have a synergistic effect, reducing particle agglomeration and optimizing grinding efficiency. Sodium oxalate can also inhibit the excessive consumption of diethanolamine and prolong the effect time. In addition, the combination of sodium silicate and calcium hydroxide plays the leading role in the hydration reaction pathway in the composite active activator, while diethanolamine and sodium oxalate improve the grinding environment through physical dispersion, forming a dual-effect mechanism of chemical enhancement + physical dispersion.

[0016] Preferably, as a further feasible option, the grinding aid is formed by compounding diethanol monoisopropanolamine and aminosulfonic acid. Preferably, the mass ratio of diethanol monoisopropanolamine to aminosulfonic acid is (60:90):(5~40), more preferably, the mass ratio of diethanol monoisopropanolamine to aminosulfonic acid is 80:20.

[0017] On one hand, aminosulfonic acid reacts with the alkaline components in the composite powder to neutralize them, forming soluble salts that reduce the surface energy of the particles and the bonding force between them, thus promoting crack propagation. In short, aminosulfonic acid alters the crystal structure of the particle surface through a chemical reaction with the alkaline components in the composite powder, reducing particle hardness and making the material easier to grind and crush. Secondly, the sulfonic acid groups in aminosulfonic acid are highly hydrophilic, allowing them to adsorb onto the particle surface to form a lubricating film, reducing the solid-gas interfacial tension and making it easier for liquids to penetrate the particle gaps. This reduces the stress required for grinding and crushing through a "wedge effect." Meanwhile, the amino groups in diethanolamine can adsorb onto the particle surface, providing a positive charge that disperses the particles due to electrostatic repulsion, preventing agglomeration. Simultaneously, the hydroxyl groups in its molecules enhance the bonding with other particle surfaces through hydrogen bonding, forming a stable adsorption layer that provides steric hindrance, effectively improving particle flowability and reducing over-grinding.

[0018] In the recycled cementitious powder material of this invention, the incorporation of solid waste steel slag can effectively improve the fluidity of cement paste and has a certain effect on activation and retarding regulation. It also has a synergistic enhancement effect with lithium slag compound grinding. The incorporation of lithium slag can also optimize the particle size distribution, reduce the porosity of cement paste, and reduce the hydration activation energy, so that the prepared recycled cementitious powder material has excellent low-temperature adaptability. CaF2 in magnesium slag can be used as minerals and seed crystals. When combined with the above-mentioned powders, an early-strength recycled cementitious powder material with strong low-temperature adaptability can be prepared. Therefore, due to the synergistic effect of each component, the recycled cementitious powder material prepared after compounding can play its due role.

[0019] In terms of specific dosage, the main additives are concrete construction waste with a primary crushing particle size of ≤4.75mm and solid waste steel slag. This is because the primary crushing particle size of ≤4.75mm maintains the basic strength of the cement paste. Then, by adding a corresponding amount of steel slag, the fluidity is improved, and the active activation and retarding regulation effects are effectively exerted. Therefore, the amount of steel slag added is also relatively large. Of course, in order to improve the synergistic enhancement effect, steel slag alone is not enough, so lithium slag and magnesium slag are also added. Of course, the amount added does not need to be too large. It can be seen that each component has a specific reason for its dosage, and it cannot be added arbitrarily.

[0020] Preferably, as a further feasible option, the composite retarder mainly comprises: a specific surface area of ​​410~450 m² by mass. 2 / kg of desulfurized gypsum 20-60 parts, borax 5-10 parts, sodium p-aminobenzenesulfonate 2-3 parts, sodium pyrophosphate 1-3 parts and potassium tartrate 1-2 parts.

[0021] The function of the composite retarder is to alter the double-layer structure on the surface of cement particles, thereby inhibiting the process of water adsorption and hydration reaction. The composite retarder of this invention mainly employs a combination of inorganic and organic retarders. Its primary purpose is to optimize the balance and controllability of retarding time and performance through a multi-mechanism combination of organic and inorganic retarders, ensuring stable expression and inhibiting fluidity loss. Sodium pyrophosphate and potassium tartrate inhibit Ca²⁺ through complexation and precipitation mechanisms; borax and sodium p-aminobenzenesulfonate delay the reaction through adsorption and surface covering; desulfurized gypsum, through the formation of ettringite, delays the intense early hydration reaction, thus indirectly prolonging and pH-regulating the retarding process. Furthermore, desulfurized gypsum, based on its micro-expansion characteristics after hydration, can also provide volume stability for the grouting material system. The reversible complexation of Ca²⁺ by sodium pyrophosphate allows subsequent hydration to continue, avoiding strength loss. The high adsorption properties of sodium pyrophosphate and sodium p-aminobenzenesulfonate can maintain the fluidity of the slurry, while the cooling effect of borax reduces the viscosity increase of hydration products, and the synergistic effect reduces the loss of fluidity over time.

[0022] Preferably, as a further feasible option, the water-retaining agent is a compound of hydroxypropyl methylcellulose with a viscosity of 400 cps, xanthan gum with a viscosity of 1200 cps, and sodium caseinate, in a compound mass ratio of (7-9):1:(1-3). More preferably, the compound mass ratio is 8:1:1.

[0023] The water-retaining agent of the present invention uses hydroxypropyl methylcellulose as the main agent, which associates with water molecules through hydroxyl and ether bonds on the molecular chain to form hydrogen bonds, converting free water into bound water, thereby reducing water evaporation. Then, xanthan gum and sodium caseinate are used to compound it.

[0024] In terms of dosage, the hydroxypropyl methylcellulose and xanthan gum polymers in this compound ratio can organically complement each other in terms of molecular structure and performance, and exhibit good chemical stability. Their respective properties demonstrate high stability under varying temperatures, pH levels, and salt solutions. The compound also exhibits better compatibility with the adsorption of free water and more uniform dispersion in the slurry, ensuring excellent thickening and water retention properties, fluidity, slurry stability, and low shrinkage while maintaining the fluidity of the grouting material. This effectively balances the conflicting demands of low viscosity and high water retention. Sodium caseinate exhibits excellent thickening and emulsifying properties under alkaline conditions and possesses certain foaming properties, significantly improving the workability of the grouting material mixture. Therefore, the addition of sodium caseinate can have a synergistic effect.

[0025] Preferably, as a further feasible option, the early strength agent is diethanol monoisopropanolamine, lithium carbonate, zinc fluorosilicate, and potassium formate, and the mass ratio of the compound is (2-4):(1-2):(0-1):(0-1). More preferably, the mass ratio of the compound is 3:1.5:0.7:0.5.

[0026] The early-strength agent of this invention mainly uses diethanol monoisopropanolamine and lithium carbonate. The reason for choosing these components for compounding is to utilize both organic and inorganic components, especially the combination of organic compounds, represented by diethanol monoisopropanolamine, and inorganic compounds, represented by lithium carbonate, which can better exert the early-strength effect. The organic component, diethanol monoisopropanolamine, can effectively shorten the induction period, accelerate the dissolution and hydration reaction of silicate minerals, promote the rapid formation of CSH gel, and improve early strength. Lithium carbonate accelerates the hydration reaction of C3A and C3S by increasing the liquid phase pH, accelerates the formation of hydrated calcium sulfoaluminate (AFt) and calcium aluminum hydrotalcite (AFm), and has low-temperature adaptability, enabling the repair grouting material to have excellent low-temperature performance. A preferred approach is to add zinc fluorosilicate and potassium formate to the above two components. The purpose is to further improve the low-temperature adaptability by adding these two substances, expanding the application range of the grouting material; therefore, it is best to add zinc fluorosilicate and potassium formate. The fluoride ions released during the hydration of zinc fluorosilicate can react with tricalcium aluminate in cement clinker to form calcium fluoroaluminate, while the released silicate ions react with calcium hydroxide to form calcium silicate CSH gel. These two products can act as crystal nuclei, lowering the nucleation barrier of hydration products and accelerating the hydration reaction rate. Furthermore, pH adjustment promotes early hydration of tricalcium silicate, activating the surface of cementitious particles and accelerating the formation of CSH gel. The formate ions in calcium formate have a complexing effect, forming complexes with calcium ions, iron ions, and tricalcium aluminate, promoting the hydration of C4AF, tricalcium silicate, dicalcium silicate, and the formation of ettringite. They can also crosslink with hydroxyl groups, forming more CSH gel to fill voids, improving early density and strength. The synergistic effect of zinc fluorosilicate and calcium formate can comprehensively accelerate the hydration process of cementitious materials and optimize the structure of hydration products.

[0027] The water-reducing agent of this invention is specifically selected as C6 polycarboxylate-based high-performance water-reducing agent powder. It is a powder or solid high-performance water-reducing agent product prepared by conventional and mature spray drying method from C6 polycarboxylate-based high-performance water-reducing agent liquid with many related compounding ingredients. It can also be customized with related functional excipients to give the water-reducing agent product corresponding functions according to performance requirements.

[0028] Specifically, the C6 polycarboxylate-based high-performance water-reducing agent is prepared by mechanically mixing a C6 polycarboxylate-based fast-release mother liquor and a C6 polycarboxylate-based slow-release mother liquor, with a mass ratio of (1-5):1. After being mixed with other components, the water-reducing agent can improve the workability of grouting materials, reduce the water-cement ratio, and thus increase the strength of the grouting material's solidified body.

[0029] In summary, the grouting material of this invention works synergistically by combining recycled cementitious powder with a specific formulation of early-strength agent, water-reducing agent, water-retaining agent, and composite retarder. This not only improves the working stability of the grouting material but also enhances its early-strength and rapid-setting effect, making it more suitable for use in harsh weather conditions and expanding its application range. Of course, the excellent application effect is closely related to the specific formulation of the recycled cementitious powder selected in this invention, as well as the specific formulations of the water-reducing agent, water-retaining agent, and composite retarder. Practice has proven that only by rationally proportioning the various components according to the scheme of this invention can the excellent performance effect claimed by this invention be achieved.

[0030] This invention also provides a method for preparing the above-mentioned early-strength rapid repair grouting material, comprising the following steps:

[0031] The main material mixture is obtained by mixing sulfoaluminate cement, aluminate cement, silica fume, quartz sand, mineral powder, fly ash and recycled cementitious powder materials at 300~600 rpm.

[0032] Add the composite retarder, early strength agent, water-retaining agent, water-reducing agent, and water to the main material mixture, and stir at 300~600 rpm for 1 minute until uniform.

[0033] Preferably, as a further feasible option, after stirring for 1 minute, the rotation speed is increased to 1000~1500 rpm, and stirring is continued for 2 minutes.

[0034] The preparation method of the present invention, by controlling the various operating conditions in the preparation process within a relatively excellent range, enables the prepared grouting material to have the best performance. Detailed Implementation

[0035] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0036] Example 1

[0037] The preparation method of early-strength rapid repair grouting material is carried out according to the following steps:

[0038] 1) The following proportions by weight are used to prepare a mixture of: 20 parts of crushed concrete construction waste with a particle size ≤4.75mm, 20 parts of solid waste steel slag, 6 parts of burnt coal gangue, 4 parts of magnesium slag, 3 parts of lithium slag, 10 parts of desulfurized gypsum, 2 parts of an active activator (a mixture of sodium silicate, sodium oxalate, calcium hydroxide, and diethanolamine in a mass ratio of 20:70:5:5), and 3 parts of a grinding aid (a mixture of diethanolamine monoisopropanolamine and aminosulfonic acid in a mass ratio of 6:4). All are ground together to prepare a mixture with a specific surface area of ​​330 m². 2 / kg~350m 2 / kg of recycled gel powder material.

[0039] 2) Mix according to the following mass proportions: 410m 2 A composite retarder was obtained by mixing 20 parts of desulfurized gypsum ( / kg) with 10 parts of borax, 2 parts of sodium p-aminobenzenesulfonate, 3 parts of sodium pyrophosphate, and 1 part of potassium tartrate at 900 rpm.

[0040] 3) Prepare the early strength agent by mixing 2 parts of diethanol monoisopropanolamine, 2 parts of lithium carbonate, and 1 part of zinc fluorosilicate at 600 rpm.

[0041] 4) Mix the following proportions by weight: 7 parts of hydroxypropyl methylcellulose with a viscosity of 400 cps, 1 part of xanthan gum with a viscosity of 1200 cps, and 1 part of sodium caseinate, and stir evenly at 900 rpm to obtain a water-retaining agent.

[0042] 5) According to the mixing ratio requirements, 50 kg of sulfoaluminate cement, 150 kg of aluminate cement, 50 kg of silica fume, 150 kg of mineral powder, 1200 kg of quartz sand, 100 kg of fly ash and 200 kg of recycled powder cementitious material are mixed evenly at 300 rpm to obtain the main material mixture.

[0043] 6) According to the specific construction requirements, add 1 kg of water-retaining agent, 0.1 kg of water-reducing agent, 10 kg of early strength agent, 15 kg of composite retarder and 300 kg of water to the main material mixture in step 5) according to the mixing ratio, and stir at 600 rpm for 1 min until uniform.

[0044] 7) Increase the rotation speed to 1000 rpm and stir for 2 minutes to obtain a high-solid-waste resource recycling powder early-strength rapid repair grouting material.

[0045] Example 2

[0046] The preparation method of early-strength rapid repair grouting material is carried out according to the following steps:

[0047] 1) The following proportions by weight are used to prepare a mixture of: 40 parts of crushed concrete construction waste with a particle size ≤4.75mm, 10 parts of solid waste steel slag, 10 parts of burnt coal gangue, 2 parts of magnesium slag, 5 parts of lithium slag, 5 parts of desulfurized gypsum, 7 parts of an active activator (a mixture of sodium silicate, sodium oxalate, calcium hydroxide, and diethanolamine in a mass ratio of 40:40:25:30), and 0.1 parts of a grinding aid (a mixture of diethanolamine monoisopropanolamine and aminosulfonic acid in a mass ratio of 90:5). All these components are then ground together to prepare a mixture with a specific surface area of ​​330 m². 2 / kg~350m 2 / kg of recycled gel powder material.

[0048] 2) Mix according to the following mass proportions: 450m 2 A composite retarder was obtained by mixing 60 parts of desulfurized gypsum (at a concentration of 60 kg / m³), 5 parts of borax, 3 parts of sodium p-aminobenzenesulfonate, 1 part of sodium pyrophosphate, and 2 parts of potassium tartrate at 600 rpm.

[0049] 3) Prepare the mixture according to the following proportions by weight: Mix 4 parts of diethanol monoisopropanolamine, 1 part of lithium carbonate, and 1 part of potassium formate at 600 rpm until homogeneous to obtain the early strength agent.

[0050] 4) Mix the following proportions by weight: 9 parts of hydroxypropyl methylcellulose with a viscosity of 400 cps, 1 part of xanthan gum with a viscosity of 1200 cps, and 3 parts of sodium caseinate, and stir evenly at 900 rpm to obtain a water-retaining agent.

[0051] 5) According to the mixing ratio requirements, 150 kg of sulfoaluminate cement, 10 kg of aluminate cement, 100 kg of silica fume, 10 kg of mineral powder, 1400 kg of quartz sand, 10 kg of fly ash and 350 kg of recycled powder cementitious material are mixed evenly at 600 rpm to obtain the main material mixture.

[0052] 6) According to the specific construction requirements, add 0.01 kg of water-retaining agent, 2 kg of water-reducing agent, 1 kg of early strength agent, 50 kg of composite retarder and 200 kg of water to the main material mixture in step 5) according to the mixing ratio, and stir at 300 rpm for 1 min until uniform.

[0053] 7) Increase the rotation speed to 1500 rpm and stir for 2 minutes to obtain a high-solid-waste resource recycling powder with early strength and rapid repair grouting material.

[0054] Example 3

[0055] The preparation method of early-strength rapid repair grouting material is carried out according to the following steps:

[0056] 1) The following proportions by weight are used to prepare a mixture of: 30 parts of crushed concrete construction waste with a particle size ≤4.75mm, 15 parts of solid waste steel slag, 7 parts of burnt coal gangue, 3 parts of magnesium slag, 3 parts of lithium slag, 8 parts of desulfurized gypsum, 4 parts of an active activator (a mixture of sodium silicate, sodium oxalate, calcium hydroxide, and diethanolamine in a mass ratio of 26:50:12:12), and 2 parts of a grinding aid (a mixture of diethanolamine monoisopropanolamine and aminosulfonic acid in a mass ratio of 80:20). All these components are then ground together to prepare a mixture with a specific surface area of ​​330 m². 2 / kg~350m 2 / kg of recycled gel powder material.

[0057] 2) Mix according to the following mass proportions: 410m 2 A composite retarder was obtained by mixing 30 parts of desulfurized gypsum (per kg), 7 parts of borax, 2 parts of sodium p-aminobenzenesulfonate, 3 parts of sodium pyrophosphate, and 1 part of potassium tartrate at 900 rpm.

[0058] 3) Prepare the early strength agent by mixing 2 parts of diethanol monoisopropanolamine, 2 parts of lithium carbonate, 0 parts of zinc fluorosilicate and 1 part of potassium formate at 600 rpm.

[0059] 4) Mix the following proportions by weight: 8 parts of hydroxypropyl methylcellulose with a viscosity of 400 cps, 1 part of xanthan gum with a viscosity of 1200 cps, and 2 parts of sodium caseinate, and stir evenly at 900 rpm to obtain a water-retaining agent.

[0060] 5) According to the mixing ratio requirements, 80 kg of sulfoaluminate cement, 150 kg of aluminate cement, 10 kg of mineral powder, 80 kg of silica fume, 1200 kg of quartz sand, 60 kg of fly ash and 230 kg of recycled powder cementitious material are mixed evenly at 300 rpm to obtain the main material mixture.

[0061] 6) According to the specific construction requirements, add 8kg of early strength agent, 25kg of composite retarder, 0.6kg of water retention agent, 0.5kg of water reducing agent and 270kg of water to the main material mixture in step 5) according to the mixing ratio, and stir at 600rpm for 1min until uniform.

[0062] 7) Increase the rotation speed to 1000 rpm and stir for 2 minutes to obtain a high-solid-waste resource recycling powder early-strength rapid repair grouting material.

[0063] Example 4

[0064] The preparation method of early-strength rapid repair grouting material is carried out according to the following steps:

[0065] 1) The following proportions by weight are used to prepare a mixture of: 35 parts of crushed concrete construction waste with a particle size ≤4.75mm, 12 parts of solid waste steel slag, 8 parts of burnt coal gangue, 2 parts of magnesium slag, 5 parts of lithium slag, 7 parts of desulfurized gypsum, 5 parts of an active activator (a mixture of sodium silicate, sodium oxalate, calcium hydroxide, and diethanolamine in a mass ratio of 26:50:12:12), and 1 part of a grinding aid (a mixture of diethanolamine monoisopropanolamine and aminosulfonic acid in a mass ratio of 80:20). All are ground together to prepare a mixture with a specific surface area of ​​330m². 2 / kg~350m 2 / kg of recycled gel powder material.

[0066] 2) Mix according to the following mass proportions: 450m 2 A composite retarder was obtained by mixing 35 parts of desulfurized gypsum ( / kg), 8 parts of borax, 3 parts of sodium p-aminobenzenesulfonate, 1 part of sodium pyrophosphate, and 2 parts of potassium tartrate at 600 rpm.

[0067] 3) Prepare the early strength agent by mixing 4 parts of diethanol monoisopropanolamine, 1 part of lithium carbonate, and 1 part of zinc fluorosilicate at 600 rpm.

[0068] 4) Mix the following proportions by weight: 9 parts of hydroxypropyl methylcellulose with a viscosity of 400 cps, 1 part of xanthan gum with a viscosity of 1200 cps, and 1 part of sodium caseinate, and stir evenly at 900 rpm to obtain a water-retaining agent.

[0069] 5) According to the mixing ratio requirements, 120 kg of sulfoaluminate cement, 30 kg of aluminate cement, 60 kg of mineral powder, 65 kg of silica fume, 1400 kg of quartz sand, 20 kg of fly ash and 350 kg of recycled powder cementitious material are mixed evenly at 600 rpm to obtain the main material mixture.

[0070] 6) According to the specific construction requirements, add 50kg of composite retarder, 2kg of water-reducing agent, 2kg of early strength agent, 0.1kg of water-retaining agent and 200kg of water to the main material mixture in step 5) according to the mixing ratio, and stir at 300rpm for 1min until uniform.

[0071] 7) Increase the rotation speed to 1500 rpm and stir for 2 minutes to obtain a high-solid-waste resource recycling powder with early strength and rapid repair grouting material.

[0072] Example 5

[0073] The specific operating steps are the same as in Example 4, except that:

[0074] 5) According to the mixing ratio requirements, 100 kg of sulfoaluminate cement, 35 kg of aluminate cement, 70 kg of silica fume, 30 kg of mineral powder, 1300 kg of quartz sand, 50 kg of fly ash and 310 kg of recycled powder cementitious material are mixed evenly at 400 rpm to obtain the main material mixture.

[0075] 6) According to the specific construction requirements, add 40kg of composite retarder, 1.5kg of water-reducing agent, 4kg of early strength agent, 0.4kg of water-retaining agent and 210kg of water to the main material mixture in step 5) according to the mixing ratio, and stir at 400rpm for 1min until uniform.

[0076] Example 6

[0077] The specific operating steps are the same as in Example 5, except that lithium carbonate, zinc fluorosilicate, and potassium formate are not added to the early strength agent.

[0078] Example 7

[0079] The specific operating steps are the same as in Example 5, except that the mass fraction of diethanol monoisopropanolamine is 7 parts.

[0080] Example 8

[0081] The specific operating steps are the same as in Example 5, except that sodium caseinate is not added to the water-retaining agent.

[0082] Example 9

[0083] The specific operating steps are the same as in Example 5, except that the 400cps viscosity hydroxypropyl methylcellulose in the water-retaining agent is replaced with methylcellulose.

[0084] Example 10

[0085] The specific operating steps are the same as in Example 5, except that lithium slag is not added during the formulation of the recycled cementitious powder material in step 1).

[0086] Example 11

[0087] The specific operating steps are the same as in Example 5, except that no active activator is added during the formulation of the recycled gel powder material in step 1).

[0088] Example 12

[0089] The specific operation steps are the same as in Example 5, except that in step 1), 70 parts of concrete construction waste with a particle size ≤4.75mm are crushed at one time during the process of mixing the recycled cementitious powder material.

[0090] Example 13

[0091] The specific operating steps are the same as in Example 5, except that sodium oxalate is not added to the active activator in step 1).

[0092] Example 14

[0093] The specific operating steps are the same as in Example 5, except that in step 1), the mass ratio of the grinding aid diethanol monoisopropanolamine and aminosulfonic acid is 5:1.

[0094] Example 15

[0095] The specific operating steps are the same as in Example 5, except that 30 kg of recycled powder cementitious material is used.

[0096] Example 16

[0097] The specific operating steps are the same as in Example 5, except that no quartz sand is added.

[0098] Comparative Example 1

[0099] Jiangsu Subote New Material Co., Ltd., a leading domestic admixture manufacturer, produces the product SBTJK. ® -Ⅰ Ultra-early strength repair mortar, specific parameters are as follows:

[0100]

[0101] Experimental Example 1

[0102] Water inflow occurred at the bottom of the tunnel in the section under the Liangshuijing Bridge of the Guiyang Metro Line S1 Phase I project. Curtain grouting was implemented within 3 meters below the tunnel invert and bottom excavation surface to stop the water seepage. However, water leakage was severe in the backfill section beneath the bridge, requiring vertical surface grouting for water plugging during construction. The grouting material used in the aforementioned examples and comparative examples was employed, and the construction was carried out according to the following steps:

[0103] 1. Preparations:

[0104] 1) Drilling arrangement: Grouting holes are arranged in a quincunx or straight line pattern in the area to be repaired. The drilling depth must penetrate the crack or void.

[0105] 2) Equipment inspection: Inspect the grouting pump, pipes, pressure gauges, production mixers, and other equipment to ensure they are functioning properly and meet the requirements for grouting production;

[0106] 3) Prepare the grouting repair material according to the design mix ratio.

[0107] 2. Grouting construction

[0108] 1) Arrangement of grouting equipment and conduits: Arrange grouting equipment and grouting pipelines reasonably according to the on-site working environment, insert the grouting conduits into the borehole, and seal the pipe openings to prevent leakage;

[0109] 2) Grouting operation: Start the grouting pump and slowly inject the grout, controlling the pressure. Generally, the pressure is set at 0.6~1.0MPa. The grouting pressure needs to be gradually increased to avoid sudden increases that could damage the structure. During the grouting process, carefully observe the grout seepage. Stop grouting when the grout overflows from the surface of the adjacent hole or crack.

[0110] 3) Grouting hole treatment: After pulling out the grouting pipe, immediately seal the hole opening with cement mortar or anchoring agent.

[0111] 3. Maintenance measures

[0112] 1) After grouting is completed, cover with plastic film or damp burlap, spray water regularly to keep it moist, and cure for at least 7 days;

[0113] 2) Insulation measures must be taken if the ambient temperature is below 5 degrees Celsius;

[0114] 3) In high-temperature environments, the spraying frequency needs to be increased;

[0115] 4) During the curing period, the repaired area must not be disturbed to ensure that the slurry aggregate is fully hydrated;

[0116] 5) After the curing period, check whether the density and strength of the repaired area meet the standards.

[0117] The performance of the grouting material cured according to the above steps was then tested, and the test results are shown in Table 1 below.

[0118]

[0119] As can be seen from the results in Table 1 above, the best grouting material performance for the present invention is Example 5. Compared with Example 5, Examples 1-4 also achieve good results in terms of setting time, mechanical properties and impermeability.

[0120] However, compared with Example 5, Examples 6-7 have an impact on the early strength and later strength of the grouting material because the formulation of the early strength agent and the dosage of a certain component are not within the optimal dosage range. In particular, the early strength is more significantly affected, while the later strength only decreases slightly. The reason for this is that Example 6 mainly relies on the synergistic effect of lithium carbonate, zinc fluorosilicate and calcium formate to improve the hydration process and the types of hydration products, thereby improving the strength of the grouting material. Therefore, without the addition of these three, it is impossible to achieve the mechanical properties of early strength and high strength. In addition, in Example 7, the addition of diethanol monoisopropanolamine is too large, which disrupts the balance of synergistic expression between organic and inorganic early strength agents, thus failing to achieve the ideal early strength effect. Therefore, the strength is actually affected to a certain extent.

[0121] Compared to Example 5, Examples 8-9 show poorer mechanical properties. This is because if the water-retaining agent is not formulated according to the present invention, it will reduce the rheological homogeneity of the grouting material, leading to bleeding and thus affecting its mechanical properties. In Example 8, the absence of sodium caseinate in the water-retaining agent prevents it from synergistically combining with other components, resulting in suboptimal mechanical properties. In Example 9, replacing the cellulose type with methylcellulose affects mechanical properties. MC has poorer temperature resistance than HPMC, a slower cold water solubility, and lower salt and enzymatic stability, making it unsuitable for high-temperature construction environments. MC also lacks hydroxypropoxy groups compared to HPMC, resulting in poorer water retention. Therefore, the choice of cellulose type is crucial. Furthermore, the present invention also requires a specific viscosity; 400 cps hydroxypropyl methylcellulose can balance water retention and the working rheological properties of the grout mixture in this gelling system. Lower viscosity hydroxypropyl methylcellulose has poor water retention, while higher viscosity hydroxypropyl methylcellulose mixtures have poor working rheological properties and are not easy to use for grouting operations. Therefore, its viscosity is best controlled within a certain range.

[0122] Examples 10-12 were designed to verify the impact of changes in the formulation of recycled cementitious powder materials on the performance of grouting materials. It was found that unreasonable formulation design resulted in generally prolonged setting time, and varying degrees of deterioration in mechanical properties and impermeability. The reasons for this are as follows: Example 10, without the addition of lithium slag, could not achieve optimal particle size distribution, reduce hydration activation energy, and improve low-temperature adaptability; Example 11, without the addition of an activation activator, failed to effectively activate and improve the cementitious activity of the low-cementing-activity powder material. Therefore, the addition of an activation activator is essential. In Example 12, the addition of 70 parts of construction waste with a single-stage crushing particle size ≤4.75mm was too large. Excessive addition would disrupt the optimal compatibility between the components, thus affecting the performance of the final grouting material.

[0123] Example 13 is an experimental verification of the formulation of the active activator itself. It can be found that the performance of the grouting material is also affected when sodium oxalate is not added to the formulation. This is because the absence of sodium oxalate increases particle agglomeration, reduces grinding efficiency, and cannot inhibit the rapid consumption of diethanolamine, resulting in a shorter effective time of the grinding aid. Therefore, the absence of sodium oxalate prevents the active activator from exerting its due effect. It is evident that the formulation needs to be reasonably matched according to the components specifically designed in this invention.

[0124] In Example 14, the mass ratio of diethanol monoisopropanolamine and aminosulfonic acid in the grinding aid was not within the optimal dosage range. As a result, the compatibility between the two was unbalanced, and they could not exert their best effect. Therefore, the performance of the final grouting material was also affected.

[0125] Examples 15-16 are comparative experiments on the formulation of the grouting material itself. It was found that when the amount of recycled powder cementitious material added is too small, or when no quartz sand is added, the performance of the grouting material will be affected, especially the later strength. Finally, Comparative Example 1 is a grouting material of the prior art. Some of its performance parameters, especially the later strength, are far different from the performance of the grouting material of the present invention.

[0126] Although the invention has been illustrated and described with reference to specific embodiments, it should be understood that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such variations and modifications falling within the scope of the invention be included in the appended claims.

Claims

1. A rapid-strength, early-strength repair grouting material, characterized in that, It is mainly made from the following raw materials: By weight, the following components are used: 50-150 parts of sulfoaluminate cement, 10-150 parts of aluminate cement, 200-350 parts of recycled cementitious powder material, 1200-1400 parts of quartz sand, 50-100 parts of silica fume, 10-150 parts of mineral powder, 10-100 parts of fly ash, 15-50 parts of composite retarder, 0.1-2 parts of water-reducing agent, 1-10 parts of early-strength agent, 0.01-1 parts of water-retaining agent, and 200-300 parts of water. The recycled cementitious powder material is mainly prepared from particles with a particle size ≤4.75mm from primary crushing of concrete construction waste, solid waste steel slag, overburned coal gangue, magnesium slag, lithium slag, active activator, and grinding aid. The recycled cementitious powder material is mainly prepared from the following raw materials: by mass parts, 20-40 parts of concrete construction waste with a particle size ≤4.75mm after one-time crushing, 10-20 parts of solid waste steel slag, 6-10 parts of overburned coal gangue, 5-10 parts of desulfurized gypsum, 2-4 parts of magnesium slag, 3-5 parts of lithium slag, 2-7 parts of active activator, and 0.1-3 parts of grinding aid; The active activator is formed by combining sodium silicate, sodium oxalate, calcium hydroxide and diethanolamine; The grinding aid is formed by compounding diethanol monoisopropanolamine and aminosulfonic acid. The composite retarder mainly comprises: by mass parts, a specific surface area of ​​410~450m². 2 / kg of desulfurized gypsum 20-60 parts, borax 5-10 parts, sodium p-aminobenzenesulfonate 2-3 parts, sodium pyrophosphate 1-3 parts and potassium tartrate 1-2 parts. The water-retaining agent is a compound of hydroxypropyl methylcellulose with a viscosity of 400 cps, xanthan gum with a viscosity of 1200 cps, and sodium caseinate, with a compound mass ratio of (7-9):1:(1-3).

2. The early-strength rapid repair grouting material according to claim 1, characterized in that, The early strength agent is diethanol monoisopropanolamine, lithium carbonate, zinc fluorosilicate and potassium formate, and the mass ratio of the compound is (2-4):(1-2):(0-1):(0-1).

3. The early-strength rapid repair grouting material according to claim 1, characterized in that, By weight, the composition includes 80-120 parts of sulfoaluminate cement, 30-150 parts of aluminate cement, 230-350 parts of recycled cementitious powder material, 1200-1400 parts of quartz sand, 65-80 parts of silica fume, 10-60 parts of mineral powder, 20-60 parts of fly ash, 25-50 parts of composite retarder, 0.5-2 parts of water-reducing agent, 2-8 parts of early-strength agent, 0.1-0.6 parts of water-retaining agent, and 200-270 parts of water.

4. The preparation method of the early-strength rapid repair grouting material according to any one of claims 1-3, characterized in that, Includes the following steps: The main material mixture is obtained by mixing sulfoaluminate cement, aluminate cement, silica fume, quartz sand, mineral powder, fly ash and recycled cementitious powder materials at 300~600 rpm. Add the composite retarder, early strength agent, water-retaining agent, water-reducing agent, and water to the main material mixture, and stir at 300~600 rpm for 1 minute until uniform.

5. The preparation method according to claim 4, characterized in that, After stirring for 1 minute, increase the speed to 1000~1500 rpm and stir for 2 minutes.

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