Micro-expansive grouting material with cement replaced by superfine powder and preparation method of micro-expansive grouting material

Abstract

The invention relates to the technical field of grouting materials, in particular to a micro-expansive grouting material with superfine powder replacing cement and a preparation method thereof.The micro-expansive grouting material is at least prepared from, by weight, 10-50 parts of cement, 25-85 parts of river sand, 18-70 parts of solid waste superfine powder, 2-15 parts of water-borne epoxy resin, 0.5-8 parts of curing agent, 15-60 parts of modified sepiolite and 5-30 parts of water, the preparation raw materials of the modified sepiolite at least comprise acidified sepiolite, a functional compound and cellulose ether, the micro-expansive grouting material prepared according to the formula has the characteristics of micro-expansion, controllable dry shrinkage degree and excellent mechanical strength, and meanwhile, the solid waste superfine powder is used for replacing part of cement, so that the micro-expansive grouting material is more environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of grouting materials, in particular to a micro-expansion grouting material using ultrafine powder to replace cement and a preparation method thereof. Background Art

[0002] Grouting is the process of injecting materials with specific properties or slurry prepared with paint into the foundation rock and soil at a certain pressure to make it penetrate, fill or replace. After gelling or solidification, it improves the physical and mechanical properties of the soil to achieve the purpose of reinforcement, anti-seepage, and leak prevention.

[0003] The current grouting concrete is usually prepared with cement, fine sand, solid waste ultrafine powder and water as the main raw materials. The solid waste ultrafine powder includes mineral powder, silica fume, lime, kaolin, fly ash, etc., and some fibers or polymer materials are introduced to improve the performance of concrete. For example, a Chinese patent document (authorization announcement number is CN116535178B) discloses a foundation reinforcement material based on jet grouting and a preparation method thereof, which increases the crack resistance of the reinforcement material by adding methyl cellulose and sodium methyl silicate, and improves the durability and service life of the reinforcement material; a Chinese patent document (authorization announcement number is CN 112299765 B) discloses a grouting material prepared by steel slag and its preparation method and use, which uses steel slag powder as a hydraulic cementitious material instead of cement, and steel slag fine aggregate instead of sand and gravel aggregate, making full use of steel slag, while ensuring the fluidity and self-expansion and non-contraction of key materials. However, it still cannot effectively solve the durability of concrete caused by cracks caused by temperature changes. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement, the raw materials for preparing the micro-expansive grouting material include at least: cement, river sand, ultrafine powder of solid waste, water-based epoxy resin, curing agent, modified sepiolite, and water. The prepared micro-expansive grouting material has small expansion, controllable shrinkage, and excellent mechanical strength. The cracks in the later use process can be reduced by adjusting the humidity, thereby improving the durability of the grouting material.

[0005] On the one hand, the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder. The raw materials for preparing the micro-expansive grouting material include at least 10-50 parts of cement, 25-85 parts of river sand, 18-70 parts of solid waste ultrafine powder, 2-15 parts of water-based epoxy resin, 0.5-8 parts of curing agent, 15-60 parts of modified sepiolite and 5-30 parts of water, by weight.

[0006] In the grouting material formula of the present invention, ultrafine solid waste powder is used to replace a portion of high-carbon-emission cement, which is not only beneficial to the disposal of solid waste, but also helps to reduce carbon emissions and is more environmentally friendly.

[0007] Preferably, the micro-expansive grouting material in which ultrafine powder replaces cement comprises, by weight, at least 15-44 parts of cement, 28-82 parts of river sand, 22-64 parts of solid waste ultrafine powder, 4-12 parts of water-based epoxy resin, 1-5 parts of curing agent, 19-55 parts of modified sepiolite, and 9-26 parts of water.

[0008] As a preferred technical solution, the raw materials for preparing the modified sepiolite at least include acidified sepiolite, functional compounds, and cellulose ether.

[0009] Sepiolite is porous, has a large specific surface area, and is fibrous. It can not only play a certain role in binding the components in the grouting material, absorb external forces and reduce stress concentration, and improve the bearing capacity of the grouting material, but also the silicon hydroxyl group in sepiolite can improve the bonding strength of the new and old interfaces of concrete and optimize the mechanical properties of concrete.

[0010] As a preferred technical solution, the acidified sepiolite is sepiolite that has been acidified.

[0011] As a preferred technical solution, the preparation method of acidified sepiolite is: placing sepiolite in an acid solution, heating, stirring, filtering, and drying to obtain the acidified sepiolite.

[0012] Preferably, the preparation method of the acidified sepiolite is: soaking the sepiolite in a 0.5-2 mol / L hydrochloric acid aqueous solution, stirring at 40-80° C. for 3-10 h, filtering, and drying to obtain the acidified sepiolite.

[0013] Acidification of sepiolite with hydrochloric acid can not only wash away impurities in sepiolite, but also make H + Replacement of Mg in the sepiolite structure 2+ , acidified sepiolite is rich in more Si-OH active sites.

[0014] The present invention introduces functional compounds and cellulose ether to modify the acidified sepiolite, and the pore structure on the surface of the acidified sepiolite is optimized, and the adsorption and desorption of water molecules can be adjusted according to the ambient humidity, thereby reducing the generation of cracks in the grouting material caused by humidity changes.

[0015] Preferably, the raw materials for preparing the modified sepiolite include at least 10-55 parts of acidified sepiolite, 1-15 parts of functional compounds, and 0.5-7 parts of cellulose ether, by weight.

[0016] Further preferably, the raw materials for preparing the modified sepiolite include at least 20-50 parts of acidified sepiolite, 3-13 parts of functional compounds, and 1-4 parts of cellulose ether, by weight.

[0017] The active groups on the functional compounds and cellulose ethers can form chemical bonds with the silanol groups on the acidified sepiolite, and the two are in a competitive relationship and are alternately coated on the acidified sepiolite. On the one hand, the functional compounds and cellulose ethers are alternately coated on the acidified sepiolite, which improves the water resistance of cellulose ether and acidified sepiolite, reduces the water absorption and swelling degree of cellulose ether and acidified sepiolite, and avoids the serious shrinkage of the grouting material in the later stage due to the excessive expansion degree in the early stage. On the other hand, part of the coating can enter the pores on the surface of the acidified sepiolite, and then after heat treatment, the pore structure of the surface of the acidified sepiolite is optimized, and the absorption and desorption behavior of water molecules can be adjusted according to the environmental humidity, thereby reducing the cracks of the grouting material caused by humidity changes and improving the durability of the micro-expansion grouting material.

[0018] As a preferred technical solution, the functional compound is a compound with a carboxyl group.

[0019] As a preferred technical solution, the functional compound is at least one of C3-C17 alkanoic acids.

[0020] As a preferred technical solution, the functional compound is at least one of hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and heptadecanoic acid.

[0021] As a preferred technical solution, the functional compound is a compound with a terminal carboxyl group and a terminal double bond.

[0022] Preferably, the functional compound is at least one of acrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, 16-heptadecenoic acid, and vinylbenzoic acid.

[0023] More preferably, the functional compound is at least one of 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, and 16-heptadecenoic acid.

[0024] More preferably, the functional compound is at least one of 6-heptanoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, and 12-tridecenoic acid.

[0025] As a preferred technical solution, the cellulose ether is at least one of sodium carboxymethyl cellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, and carboxymethyl hydroxyethyl cellulose.

[0026] Cellulose ether emulsifies to form a viscous liquid, which can adjust the fluidity of the grouting material, increase its flexibility, bonding strength and other properties, and improve the mechanical properties of the grouting material.

[0027] As a preferred technical solution, the total mass of the functional compound and the cellulose ether accounts for 15-40% of the mass of the acidified sepiolite.

[0028] Preferably, the total mass of the functional compound and the cellulose ether accounts for 19-34% of the mass of the acidified sepiolite.

[0029] As a preferred technical solution, the mass ratio of the functional compound to the cellulose ether is 1:(0.1-1.0).

[0030] Preferably, the mass ratio of the functional compound to the cellulose ether is 1:(0.3-0.6).

[0031] As a preferred technical solution, the preparation method of modified sepiolite comprises the following steps:

[0032] 1) dissolving cellulose ether in a solvent and stirring until dissolved to obtain a cellulose ether solution;

[0033] 2) adding the functional compound and acidified sepiolite to the cellulose ether solution of step 1), stirring, filtering and drying to obtain modified sepiolite.

[0034] Preferably, the solvent in step 1) is an alcohol solution.

[0035] Preferably, the solvent in step 1) is an alcohol aqueous solution with a concentration of 30-50%.

[0036] Preferably, the preparation method of modified sepiolite comprises the following steps:

[0037] 1) dissolving cellulose ether in 30-50% ethanol aqueous solution, stirring until dissolved, to obtain a cellulose ether solution;

[0038] 2) adding the functional compound and acidified sepiolite to the cellulose ether solution of step 1), stirring for 2-5 hours, filtering, and drying at 160-250° C. for 1-4 hours to obtain modified sepiolite.

[0039] As a preferred technical solution, the cement is PO42.5 silicate cement.

[0040] As a preferred technical solution, the average particle size of the river sand is in the range of 0.5-2 mm.

[0041] As a preferred technical solution, the ultrafine solid waste powder is at least one of steel slag, fly ash, lime, silica fume and gypsum.

[0042] Preferably, the ultrafine solid waste powder is a mixture of steel slag, fly ash and silica fume.

[0043] As a preferred technical solution, the solid waste ultrafine powder includes: 5-30 parts of steel slag, 5-25 parts of fly ash, and 1-20 parts of silica fume.

[0044] Preferably, the solid waste ultrafine powder includes 10-27 parts of steel slag, 7-22 parts of fly ash, and 5-15 parts of silica fume.

[0045] As a preferred technical solution, the average particle size of steel slag is 50-100 μm; the average particle size of fly ash is 7-25 μm; the average specific surface area of ​​silica fume is 20000-35000m 2 / kg.

[0046] As a preferred technical solution, the water-based epoxy resin is a homemade product, and its preparation method is: add an emulsifier to the epoxy resin, heat it, stir it until it is mutually soluble, then add an appropriate amount of co-solvent, stir it until all the components are evenly mixed; then, under high-speed stirring conditions, slowly add deionized water, after the addition is completed, keep the temperature, and cool it naturally to obtain the water-based epoxy resin.

[0047] As a preferred technical solution, the epoxy resin is at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0048] Preferably, the epoxy resin is at least one of bisphenol A epoxy resins E20, E44, and E51.

[0049] As a preferred technical solution, the emulsifier is at least one of emulsifier 9107 and emulsifier 7201.

[0050] As a preferred technical solution, the co-solvent is at least one of ethylene glycol butyl ether, propylene glycol methyl ether, glycerol, benzyl alcohol, and mesityl oxide.

[0051] As a preferred technical solution, the epoxy resin accounts for 45-54 wt % of the system.

[0052] As a preferred technical solution, the emulsifier accounts for 4-7wt% of the system.

[0053] As a preferred technical solution, the co-solvent accounts for 1-4wt% of the system.

[0054] As a preferred technical solution, deionized water accounts for 35-50 wt % of the system.

[0055] As a preferred technical solution, the temperature in the preparation method is controlled at 80-100°C.

[0056] As a preferred technical solution, deionized water is added dropwise at a rotation speed of 1200-1600 rpm.

[0057] As a preferred technical solution, the insulation time is 0.5-1h.

[0058] As a preferred technical solution, the curing agent is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine, and diaminodiphenylmethane.

[0059] Modified sepiolite can also cooperate with water-based epoxy resin and curing agent to construct a polymer network in the grouting material system, making the modified sepiolite more evenly dispersed in the system. It is not only beneficial to maintain the moisture balance inside the micro-expansion grouting material, avoid shrinkage due to excessive water loss in the later stage, and alleviate the occurrence of cracks in the grouting material in the later stage, but also can play an external anti-seepage effect. The network can also absorb and disperse external stress in time to improve the mechanical properties of the grouting material.

[0060] In addition, the optimized micro-expansion grouting material system of the present invention contains a large amount of N + , can be effectively adsorbed on metal components, improve their corrosion resistance, and better meet practical application needs.

[0061] On the other hand, the present invention provides a method for preparing a micro-expansive grouting material using ultrafine powder to replace cement, which comprises at least the following steps: firstly, cement, river sand, ultrafine solid waste powder and modified sepiolite are uniformly mixed, and then water-based epoxy resin, curing agent and water are added and mixed uniformly to obtain a micro-expansive grouting material using ultrafine powder to replace cement.

[0062] Beneficial Effects

[0063] 1. The present invention provides a micro-expansive grouting material that uses ultrafine powder to replace cement. The acidified sepiolite is modified by functional compounds and cellulose ether to obtain modified sepiolite. Cement, river sand, solid waste ultrafine powder, water-based epoxy resin, curing agent, modified sepiolite and water are used as raw materials to prepare a micro-expansive grouting material with small expansion, controllable shrinkage and excellent mechanical strength, which is more environmentally friendly.

[0064] 2. The present invention introduces functional compounds and cellulose ether-modified acidified sepiolite, wherein the functional compounds and cellulose ether are interlacedly coated on the acidified sepiolite, and the modified sepiolite is obtained after heat treatment. The pore structure on the surface of the acidified sepiolite is optimized, and the adsorption and desorption of water molecules can be adjusted according to the ambient humidity, thereby reducing the generation of cracks in the micro-expansion grouting material caused by humidity changes.

[0065] 3. In the present invention, the modified sepiolite can cooperate with the water-based epoxy resin and the curing agent to construct a polymer network in the grouting material system, so that the modified sepiolite is dispersed more evenly in the system, which is beneficial to maintaining the internal moisture balance of the micro-expansion grouting material, avoiding shrinkage caused by excessive loss of water after removal, and alleviating the occurrence of cracks in the micro-expansion grouting material in the later stage. At the same time, it is also beneficial to improve the external anti-seepage effect of the grouting material; in addition, the network can also absorb and disperse external stress in time, and improve the mechanical properties of the grouting material.

[0066] 4. The optimized micro-expansion grouting material system of the present invention contains a large amount of N + , can be effectively adsorbed on metal components, improve their corrosion resistance, and better meet practical application needs. DETAILED DESCRIPTION

[0067] The invention provides a micro-expansion grouting material for replacing cement with superfine powder, and the preparation raw materials at least include: cement, river sand, solid waste superfine powder, water-based epoxy resin, curing agent, modified sepiolite and water.

[0068] In some embodiments, the raw materials include at least: 10-50 parts of cement, 25-85 parts of river sand, 18-70 parts of solid waste ultrafine powder, 2-15 parts of water-based epoxy resin, 0.5-8 parts of curing agent, 15-60 parts of modified sepiolite, and 5-30 parts of water.

[0069] In some embodiments, the prepared raw materials include at least: 15-44 parts of cement, 28-82 parts of river sand, 22-64 parts of solid waste ultrafine powder, 4-12 parts of water-based epoxy resin, 1-5 parts of curing agent, 19-55 parts of modified sepiolite, and 9-26 parts of water.

[0070] Specifically:

[0071] Raw material 1: cement

[0072] In some embodiments, the cement may be PO42.5 silicate cement.

[0073] Raw material 2: river sand

[0074] In some embodiments, the average particle size of the river sand is in the range of 0.5-2 mm.

[0075] Raw material three: solid waste ultrafine powder

[0076] In some embodiments, the ultrafine solid waste powder includes at least one of steel slag, fly ash, lime, silica fume, and gypsum.

[0077] In some embodiments, the ultrafine solid waste powder includes steel slag, fly ash and silica fume.

[0078] In some embodiments, the ultrafine solid waste powder includes: 5-30 parts of steel slag, 5-25 parts of fly ash, and 1-20 parts of silica fume.

[0079] In some embodiments, the ultrafine solid waste powder includes 10-27 parts of steel slag, 7-22 parts of fly ash, and 5-15 parts of silica fume.

[0080] In some embodiments, the average particle size of steel slag is 50-100 μm; the average particle size of fly ash is 7-25 μm; the average specific surface area of ​​silica fume is 20000-35000 m 2 / kg.

[0081] Raw material 4: water-based epoxy resin

[0082] In some embodiments, the water-based epoxy resin is a homemade product, and its preparation method is: add an emulsifier to the epoxy resin, increase the temperature, stir until they are mutually soluble, then add an appropriate amount of co-solvent, and continue heating until the components are evenly mixed; then, slowly add deionized water under high-speed stirring conditions, and after the addition is completed, keep the temperature and cool it naturally to obtain the water-based epoxy resin.

[0083] In some embodiments, the epoxy resin is at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0084] In some embodiments, the epoxy resin is at least one of bisphenol A epoxy resins E20, E44, and E51.

[0085] In some embodiments, the emulsifier is at least one of emulsifier 9107 and emulsifier 7201.

[0086] In some embodiments, the co-solvent is at least one of ethylene glycol butyl ether, propylene glycol methyl ether, glycerol, benzyl alcohol, and mesityl oxide.

[0087] In some embodiments, the epoxy resin comprises 45-54 wt % of the system.

[0088] In some embodiments, the emulsifier comprises 4-7 wt % of the system.

[0089] In some embodiments, the co-solvent comprises 1-4 wt % of the system.

[0090] In some embodiments, deionized water comprises 35-50 wt % of the system.

[0091] In some embodiments, the temperature during the preparation method is controlled at 80-100°C.

[0092] In some embodiments, deionized water is added dropwise at a rotation speed of 1200-1600 rpm.

[0093] In some embodiments, the incubation time is 0.5-1 h.

[0094] Raw material 5: curing agent

[0095] In some embodiments, the curing agent is selected from at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine, and diaminodiphenylmethane.

[0096] Raw material six: modified sepiolite

[0097] In some embodiments, the raw materials for preparing the modified sepiolite include at least acidified sepiolite, a functional compound, and a cellulose ether.

[0098] Sepiolite is porous, has a large specific surface area, and is fibrous. It can not only play a certain role in binding the components in the grouting material, absorb external forces and reduce stress concentration, and improve the bearing capacity of the grouting material, but also the silicon hydroxyl group in sepiolite can improve the bonding strength of the new and old interfaces of concrete and optimize the mechanical properties of concrete.

[0099] In some embodiments, the acidified sepiolite is sepiolite that has been treated with acid.

[0100] In some embodiments, the preparation method of acidified sepiolite is: placing sepiolite in an acid solution, heating, stirring, filtering, and drying to obtain the acidified sepiolite.

[0101] In some embodiments, the preparation method of acidified sepiolite is: soaking sepiolite in a 0.5-2 mol / L hydrochloric acid aqueous solution, stirring at 40-80° C. for 3-10 h, filtering, and drying to obtain the acidified sepiolite.

[0102] Acidification of sepiolite with hydrochloric acid can not only wash away impurities in sepiolite, but also make H + Replacement of Mg in the sepiolite structure 2+ , acidified sepiolite is rich in more Si-OH active sites.

[0103] The present invention introduces functional compounds and cellulose ether to modify the acidified sepiolite, and the pore structure on the surface of the acidified sepiolite is optimized, and the adsorption and desorption of water molecules can be adjusted according to the ambient humidity, thereby reducing the generation of cracks in the micro-expansion grouting material caused by humidity changes.

[0104] In some embodiments, the raw materials for preparing the modified sepiolite include at least 10-55 parts of acidified sepiolite, 1-15 parts of functional compounds, and 0.5-7 parts of cellulose ether, by weight.

[0105] In some embodiments, the raw materials for preparing the modified sepiolite include at least 20-50 parts of acidified sepiolite, 3-13 parts of functional compounds, and 1-4 parts of cellulose ether, by weight.

[0106] The active groups on the functional compounds and cellulose ethers can form chemical bonds with the silanol groups on the acidified sepiolite, and the two are in a competitive relationship and are alternately coated on the acidified sepiolite. On the one hand, the functional compounds and cellulose ethers are alternately coated on the acidified sepiolite, which improves the water resistance of cellulose ether and acidified sepiolite, reduces the water absorption and swelling degree of cellulose ether and acidified sepiolite, and avoids the serious shrinkage of the grouting material in the later stage due to the excessive expansion degree in the early stage. On the other hand, part of the coating can enter the pores on the surface of the acidified sepiolite, and then after heat treatment, the pore structure of the surface of the acidified sepiolite is optimized, and the absorption and desorption behavior of water molecules can be adjusted according to the environmental humidity, thereby reducing the cracks of the grouting material caused by humidity changes and improving the durability of the grouting material.

[0107] In some embodiments, the functional compound is a compound having a carboxyl group.

[0108] In some embodiments, the functional compound is at least one of a C3-C17 alkanoic acid.

[0109] In some embodiments, the functional compound is at least one of hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and heptadecanoic acid.

[0110] In some embodiments, the functional compound is a compound with a terminal carboxyl group and a terminal double bond.

[0111] In some embodiments, the functional compound is selected from at least one of acrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, 16-heptadecenoic acid, and vinylbenzoic acid.

[0112] In some embodiments, the functional compound is at least one of 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, and 16-heptadecenoic acid.

[0113] In some embodiments, the functional compound is at least one of 6-heptanoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, and 12-tridecenoic acid.

[0114] In some embodiments, the cellulose ether is at least one of sodium carboxymethyl cellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, and carboxymethyl hydroxyethyl cellulose.

[0115] Cellulose ether emulsifies to form a viscous liquid, which can adjust the fluidity of the grouting material, improve the construction performance, increase its flexibility, bonding strength and other properties, and improve the mechanical properties of the grouting material.

[0116] In some embodiments, the total mass of the functional compound and the cellulose ether accounts for 15-40% of the mass of the acidified sepiolite.

[0117] In some embodiments, the total mass of the functional compound and the cellulose ether is 19-34% of the mass of the acidified sepiolite.

[0118] In some embodiments, the mass ratio of the functional compound to the cellulose ether is 1:(0.1-1.0).

[0119] In some embodiments, the mass ratio of the functional compound to the cellulose ether is 1:(0.3-0.6).

[0120] In some embodiments, the preparation method of modified sepiolite comprises the following steps: 1) dissolving cellulose ether in a solvent and stirring until dissolved to obtain a cellulose ether solution; 2) adding a functional compound and acidified sepiolite to the cellulose ether solution of step 1), stirring, filtering, and drying to obtain modified sepiolite.

[0121] In some embodiments, the solvent in step 1) is an alcohol solution.

[0122] In some embodiments, the solvent in step 1) is an alcohol aqueous solution with a concentration of 30-50% (v / v).

[0123] In some embodiments, the preparation method of modified sepiolite comprises the following steps: 1) dissolving cellulose ether in 30-50% ethanol aqueous solution, stirring until dissolved, to obtain a cellulose ether solution; 2) adding functional compounds and acidified sepiolite to the cellulose ether solution of step 1), stirring for 2-5 hours, filtering, and drying at 160-250° C. for 1-4 hours to obtain modified sepiolite.

[0124] Modified sepiolite can also cooperate with water-based epoxy resin and curing agent to build a polymer network in the grouting material system, making the modified sepiolite more evenly dispersed in the system, locking water inside the grouting material and preventing external seepage, alleviating the occurrence of cracks in the grouting material in the later stage of work. The network can also absorb and disperse external stress in time, and improve the mechanical properties of the grouting material.

[0125] A method for preparing a micro-expansive grouting material using ultrafine powder to replace cement comprises at least the following steps: firstly, cement, river sand, ultrafine solid waste powder and modified sepiolite are uniformly mixed, and then water-based epoxy resin, curing agent and water are added and mixed uniformly to obtain the micro-expansive grouting material using ultrafine powder to replace cement.

[0126] The acidified sepiolite used in the examples of the present patent application is obtained by the following steps: soaking the sepiolite in an excess of 1 mol / L hydrochloric acid aqueous solution, stirring at 60° C. for 6 h, filtering, and drying to obtain the acidified sepiolite.

[0127] The water-based epoxy resins used in the embodiments of the present patent application are obtained by the following steps: adding 5 parts of emulsifier 9107 to 50 parts of epoxy resin E44, heating to 85°C, stirring until the two are mutually soluble, and then adding 3 parts of ethylene glycol butyl ether, stirring to mix the components evenly; then, adding 42 parts of deionized water at 1400 rpm, and after the addition is completed, keeping the temperature for 40 minutes, cooling naturally, and obtaining the water-based epoxy resin.

[0128] The curing agents used in the examples of this patent application are all diethylenetriamine.

[0129] Example 1

[0130] Embodiment 1 of the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder, and its preparation raw materials include, by weight: 30 parts of cement, 55.5 parts of river sand, 43.5 parts of solid waste ultrafine powder, 8.2 parts of water-based epoxy resin, 3.2 parts of diethylenetriamine curing agent, 37.6 parts of modified sepiolite, and 18 parts of water.

[0131] in:

[0132] The average particle size of river sand is 1 mm;

[0133] The solid waste ultrafine powder is 16 parts of steel slag (average particle size: 75μm), 17.5 parts of fly ash (average particle size: 16μm) and 10 parts of silica fume (average specific surface area: 27000m 2 / kg) mixture;

[0134] The raw materials for preparing the modified sepiolite include 35 parts of acidified sepiolite, 7 parts of 10-undecenoic acid and 2.5 parts of sodium carboxymethyl cellulose, and the preparation method is as follows: 1) dissolving sodium carboxymethyl cellulose in 100 parts of 40% (v / v) ethanol aqueous solution until it is dissolved to obtain a sodium carboxymethyl cellulose solution; 2) adding 10-undecenoic acid and acidified sepiolite to step 1), stirring for 3.5 hours, filtering, and drying at 210° C. for 2.5 hours to obtain the modified sepiolite.

[0135] The preparation method of the micro-expansion grouting material is as follows: firstly, cement, river sand, solid waste ultrafine powder and modified sepiolite are uniformly mixed, and then water-based epoxy resin, curing agent and water are added and mixed uniformly to obtain the micro-expansion grouting material.

[0136] Example 2

[0137] Embodiment 2 of the present invention provides a micro-expansive grouting material in which ultrafine powder replaces cement. The raw materials for its preparation include, by weight: 15 parts of cement, 28 parts of river sand, 22 parts of solid waste ultrafine powder, 4 parts of water-based epoxy resin, 1.5 parts of diethylenetriamine curing agent, 19 parts of modified sepiolite, and 9 parts of water.

[0138] in:

[0139] The average particle size of river sand is 0.7 mm;

[0140] The solid waste ultrafine powder is 10 parts of steel slag (average particle size: 100μm), 7 parts of fly ash (average particle size: 23μm) and 5 parts of silica fume (average specific surface area: 33000m 2 / kg) mixture;

[0141] The raw materials for preparing the modified sepiolite include 20 parts of acidified sepiolite, 3.1 parts of 8-nonenoic acid and 1.3 parts of sodium carboxymethyl cellulose, and the preparation method is as follows: 1) dissolving sodium carboxymethyl cellulose in 100 parts of 30% (v / v) ethanol aqueous solution until it is dissolved to obtain a sodium carboxymethyl cellulose solution; 2) adding 6-heptanoic acid and acidified sepiolite to step 1), stirring for 2 hours, filtering, and drying at 200° C. for 3 hours to obtain the modified sepiolite.

[0142] The preparation method of the micro-expansion grouting material is as follows: the preparation method is the same as that in Example 1.

[0143] Example 3

[0144] Embodiment 3 of the present invention provides a micro-expansive grouting material in which ultrafine powder replaces cement. The raw materials for its preparation include, by weight: 44 parts of cement, 82 parts of river sand, 64 parts of solid waste ultrafine powder, 12 parts of water-based epoxy resin, 4.5 parts of diethylenetriamine curing agent, 55 parts of modified sepiolite, and 26 parts of water.

[0145] in:

[0146] The average particle size of river sand is 1.5 mm;

[0147] The solid waste ultrafine powder is 27 parts of steel slag (average particle size: 50μm), 22 parts of fly ash (average particle size: 10μm) and 15 parts of silica fume (average specific surface area: 21000m 2 / kg) mixture;

[0148] The raw materials for preparing the modified sepiolite include 50 parts of acidified sepiolite, 13 parts of 12-tridecenoic acid and 4 parts of sodium carboxymethyl cellulose, and the preparation method is as follows: 1) dissolving sodium carboxymethyl cellulose in a sufficient amount of 50% (v / v) ethanol aqueous solution until it is dissolved to obtain a sodium carboxymethyl cellulose solution; 2) adding 12-tridecenoic acid and acidified sepiolite to step 1), stirring for 5 hours, filtering, and drying at 220° C. for 2 hours to obtain the modified sepiolite.

[0149] The preparation method of the micro-expansion grouting material is as follows: the preparation method is the same as that in Example 1.

[0150] Example 4

[0151] Example 4 of the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the 10-undecenoic acid is replaced by 3-butenoic acid.

[0152] Example 5

[0153] Example 5 of the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the 10-undecenoic acid is replaced by 16-heptadecenic acid.

[0154] Example 6

[0155] Example 6 of the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the 10-undecenoic acid is replaced by vinyl benzoic acid.

[0156] Example 7

[0157] Example 7 of the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder and a preparation method thereof. Its specific implementation method is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the modified sepiolite include: 35 parts of acidified sepiolite, 8.5 parts of 10-undecenoic acid, and 1 part of sodium carboxymethyl cellulose.

[0158] Example 8

[0159] Example 8 of the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder and a preparation method thereof. Its specific implementation method is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the modified sepiolite include: 35 parts of acidified sepiolite, 5 parts of 10-undecenoic acid, and 4.5 parts of sodium carboxymethyl cellulose.

[0160] Example 9

[0161] Example 9 of the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that 10-undecenoic acid is replaced by undecanoic acid.

[0162] Comparative Example 1

[0163] Comparative Example 1 of the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the modified sepiolite include: 35 parts of acidified sepiolite and 9.5 parts of sodium carboxymethyl cellulose.

[0164] Comparative Example 2

[0165] Comparative Example 2 of the present invention provides a micro-expansive grouting material for replacing cement with ultrafine powder and a preparation method thereof. Its specific implementation method is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the modified sepiolite include: 35 parts of acidified sepiolite and 9.5 parts of 10-undecenoic acid.

[0166] Comparative Example 3

[0167] Comparative Example 4 of the present invention provides a micro-expansive grouting material using ultrafine powder to replace cement and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the modified sepiolite is replaced by acidified sepiolite, and functional compounds and cellulose ether modification are not used.

[0168] Performance Testing

[0169] 1. With reference to GB / T 2419-2005 “Determination of fluidity of cement mortar”, the fluidity test was carried out on the samples of the embodiment and the comparative example. The test results are shown in Table 1.

[0170] 2. With reference to GB / T 17671-2021 “Test method for strength of cement mortar (ISO method)”, the compressive strength of the samples of the embodiment and the comparative example was tested. The test results are shown in Table 1.

[0171] 3. Referring to JC / T 603-2004 "Cement Mortar Shrinkage Test Method", shrinkage rate tests were performed on the examples and comparative examples. The test results are shown in Table 1.

[0172] The test results are shown in Table 1:

[0173] Table 1

[0174]

[0175] It can be seen from the table that the micro-expansion grouting materials obtained in Examples 1-3 have good fluidity, a compressive strength higher than 100.7 MPa, a 28-day shrinkage rate between -0.036% and 0%, and have micro-expansion.

[0176] Example 4 Compared with Example 1, 3-butenoic acid is used instead of 10-undecenoic acid. The reasons for the decrease in various properties of the micro-expansion grouting material may be: on the one hand, the alkyl chain length of 3-butenoic acid is shorter and the hydrophobicity is weaker, so water molecules are more easily able to enter the sodium carboxymethyl cellulose and acidified sepiolite, and the shorter chain length is not conducive to the overall interweaving and entanglement, affecting its overall inhibitory effect on the water absorption and swelling of sodium carboxymethyl cellulose and acidified sepiolite, so the product has a higher degree of expansion; on the other hand, due to the shorter chain length of 3-butenoic acid, it is not conducive to participating in the construction of the polymer network in the grouting material system, thereby affecting the overall strength, and therefore, the compressive strength of the obtained product is also deteriorated.

[0177] Example 5 is relative to Example 1: 16-heptadecenic acid replaces 10-undecenoic acid; theoretically, 16-heptadecenic acid has a higher hydrophobicity, and its use in compounding can better control the degree of water absorption and swelling of carboxymethyl cellulose and acidified sepiolite. However, from the data, the compressive strength and shrinkage rate of the micro-expansion grouting material in Example 5 are slightly worse than those in Example 1, but still maintain a high level. This may be because too long carbon chains are prone to entanglement, affecting the grafting efficiency and grafting uniformity.

[0178] Example 6 relative to Example 1: vinyl benzoic acid replaces 10-undecenoic acid; the benzene ring on the vinyl benzoic acid structure may help to improve the mechanical properties of the acidified sepiolite; but in the case of mutual matching with sodium carboxymethyl cellulose, its larger steric hindrance and shorter chain length may make it relatively difficult to graft the silanol groups on the acidified sepiolite, and the rigid benzene ring is difficult to entangle, and the expansion inhibition effect on the acidified sepiolite is reduced, so the compressive strength, shrinkage rate and other indicators of the product are deteriorated.

[0179] Example 7 relative to Example 1: functional compound: cellulose ether = 1:0.12; there is too little sodium carboxymethyl cellulose in the acidified sepiolite coating layer. Although the overall expansion degree is reduced and the shrinkage rate is reduced; however, the lack of cellulose ether makes the coating less optimized for the pore structure of the modified sepiolite, so the compressive strength is reduced.

[0180] Embodiment 8 Compared with Embodiment 1, the reasons for the decline in various properties of the micro-expansion grouting material may be that: functional compound: cellulose ether = 1: 0.9; there is more carboxymethyl cellulose ether in the acidified sepiolite coating layer, and the modified sepiolite swells to a greater extent after absorbing water, resulting in a higher degree of expansion of the product, and the pore structure of the modified sepiolite surface also deteriorates, resulting in its moisture regulation effect on the product deteriorating; at the same time, only a small number of functional compounds in the system are involved in constructing the polymer network, which not only leads to a decrease in the uniform dispersion of the modified sepiolite in the system, but also the simplification of the network structure makes the external stress dispersion ability of the grouting material worse, so the compressive strength of the micro-expansion grouting material deteriorates.

[0181] Example 9 relative to Example 1: undecanoic acid replaces 10-undecenoic acid; there is no double bond in the system and it cannot participate in building the polymer network. The force dispersion ability of the micro-expansion grouting material becomes worse, so the compressive strength decreases. From the data, the shrinkage rate does not change significantly.

[0182] Comparative Example 1 Compared with Example 1, the reasons for the deterioration of various properties of the micro-expansion grouting material may be that: no functional compound is used in the modification process of the acidified sepiolite, the hydrophobicity of the coating on the surface of the acidified sepiolite deteriorates, resulting in uninhibited water absorption and expansion of the modified sepiolite and deterioration of the moisture regulation effect; at the same time, the coating has no functional compound, which may also cause the pore structure of the surface of the modified sepiolite to deteriorate, and the ability to regulate the adsorption and desorption of water molecules according to the ambient humidity to deteriorate; in addition, there is no functional compound in the system that can participate in the construction of the polymer network, the network structure in the grouting material is simplified, and the stress dispersion path is reduced; therefore, the compressive strength and shrinkage rate of the micro-expansion grouting material are significantly deteriorated.

[0183] Comparative Example 2 relative to Example 1: No sodium carboxymethyl cellulose is added during the modification process of the acidified sepiolite, the optimization degree of the pore structure on the surface of the sepiolite becomes worse, the regulating effect on moisture is deteriorated, and the adhesion between the components of the grouting material system becomes worse, which will lead to a significant decrease in the strength of the micro-expansion grouting material; at the same time, the shrinkage rate is positive, which may be due to the excessive 10-undecenoic acid coating the acidified sepiolite, which greatly inhibits the expansion of the sepiolite and causes the material to shrink.

[0184] Comparative Example 3 Compared with Example 1, the unmodified acidified sepiolite was directly used, and the performance of the micro-expansion grouting material was relatively poor.

Claims

1. A micro-expansion grouting material for replacing cement with ultra-fine powder, characterized in that: The raw materials for its preparation include at least: 10-50 parts of cement, 25-85 parts of river sand, 18-70 parts of solid waste ultrafine powder, 2-15 parts of water-based epoxy resin, 0.5-8 parts of curing agent, 15-60 parts of modified sepiolite, and 5-30 parts of water; The raw materials for preparing the modified sepiolite at least include acidified sepiolite, functional compounds, and cellulose ether; The functional compound is a compound with a carboxyl group.

2. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The raw materials for preparing the modified sepiolite include at least 10-55 parts of acidified sepiolite, 1-15 parts of functional compounds, and 0.5-7 parts of cellulose ether in parts by weight.

3. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The acidified sepiolite is sepiolite that has been acidified; the total mass of the functional compound and the cellulose ether accounts for 15-40% of the mass of the acidified sepiolite, preferably 19-34%.

4. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The mass ratio of the functional compound to the cellulose ether is 1:(0.1-1.0), preferably 1:(0.3-0.6).

5. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The functional compound is a compound with a terminal carboxyl group and a terminal double bond; preferably, the functional compound is at least one of acrylic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, 16-heptadecenoic acid, and vinylbenzoic acid.

6. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The functional compound is at least one of 6-heptenoic acid, 7-octenoic acid, 8-nonenoic acid, 9-decenoic acid, 10-undecenoic acid, 11-dodecenoic acid, 12-tridecenoic acid, 15-hexadecenoic acid, and 16-heptadecenoic acid.

7. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The cellulose ether is at least one of sodium carboxymethyl cellulose, sodium hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose and carboxymethyl hydroxyethyl cellulose.

8. The micro-expansion grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The curing agent is at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine and diaminodiphenylmethane; the solid waste ultrafine powder is at least one of steel slag, fly ash, lime, silica fume and gypsum.

9. The micro-expansive grouting material for replacing cement with ultra-fine powder according to claim 1, characterized in that: The preparation method of the modified sepiolite comprises the following steps: 1) dissolving cellulose ether in a solvent and stirring until dissolved to obtain a cellulose ether solution; 2) adding the functional compound and acidified sepiolite to the cellulose ether solution of step 1), stirring, filtering and drying to obtain modified sepiolite.

10. A method for preparing a micro-expansive grouting material using ultrafine powder as a cement substitute according to any one of claims 1 to 9, characterized in that: The method comprises at least the following steps: firstly, cement, river sand, ultrafine solid waste powder and modified sepiolite are uniformly mixed, and then water, water-based epoxy resin and curing agent are added and mixed uniformly to obtain micro-expansion grouting material.

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