High-strength inorganic soil stabilizer, preparation method thereof and high-strength soil consolidation material

Abstract

The invention belongs to the technical field of building materials, and particularly discloses a high-strength inorganic soil stabilizer, a preparation method thereof and a high-strength soil consolidation material. The high-strength inorganic soil stabilizer provided by the invention takes high-free-calcium belite sulphoaluminate clinker, gypsum and granulated blast-furnace slag powder as main raw materials. The high free calcium belite sulphoaluminate clinker provided by the invention comprises the following mineral components: anhydrous calcium sulphoaluminate, free calcium sulfate, free calcium oxide, belite and an iron phase. According to the high-strength inorganic soil stabilizer, mineral components of the high-free-calcium belite sulphoaluminate clinker and raw material compositions of the high-strength inorganic soil stabilizer are optimally designed, so that the high-strength inorganic soil stabilizer can be used for consolidating soil to prepare an engineering material with excellent unconfined compressive strength; the problems that an existing soil consolidation material is low in compressive strength and not environmentally friendly are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building materials, and particularly relates to a high-strength inorganic soil solidifying agent, a preparation method thereof, and a high-strength soil solidifying material. BACKGROUND

[0002] Soil has the advantages of wide raw material sources and low cost, and is widely used in the fields of road engineering, municipal construction, and hydraulic structures. However, due to the low strength and poor water stability of natural soil, the application range of soil is very limited. In order to meet the requirements of engineering construction, a high-strength soil solidifying material which can directly cement the surface of soil particles in soil or generate cementitious substances by mineral reaction with soil at room temperature has become a main research topic in the field.

[0003] According to the action mechanism, soil solidifying materials are divided into four types: inorganic soil solidifying materials, organic soil solidifying materials, ionic soil solidifying materials, and biological enzyme soil solidifying materials. Among them, inorganic soil solidifying materials have the characteristics of reliable and stable performance, low price, and the like, and are most widely used. The commonly used inorganic soil solidifying materials on the market mainly include cement, lime, industrial solid waste such as fly ash and slag, and the like. The action mechanism is to solidify soil through hydration reaction, ion exchange, and crystalline cementation. The hydration products of the solidifying material, such as hydrated calcium silicate, hydrated calcium sulfate, and hydrated calcium aluminate, can form a high-strength gel structure system. Part of the gel binds soil particles to form a network, and the combination of the two can achieve the purpose of solidifying soil.

[0004] At present, although inorganic soil solidifying materials mainly represented by cement and lime have good strength, water stability, and frost resistance, and have been widely used in many road engineering projects, such materials have defects such as large shrinkage after solidification, high risk of cracking, low early strength, and slow development of strength. Moreover, the unconfined compressive strength of the soil solidified by such solidifying materials is also relatively low, and the late strength is difficult to develop continuously, so the bearing capacity is limited when used as a road base. Moreover, due to the large amount of lime, the alkalinity of the system is high when the ecological solidified soil is prepared using such inorganic soil solidifying materials, which is not conducive to the germination and growth of plants. In addition, the gases and particulate matters discharged in the production process of cement and lime will pollute the environment and are not environmentally friendly.

[0005] Therefore, it is of important practical significance for the development of soil materials to develop a high-strength low-carbon soil solidifying material. SUMMARY

[0006] In view of this, the application provides a high-strength inorganic soil solidifying agent, a preparation method thereof and a high-strength soil solidifying material. The high-strength inorganic soil solidifying agent takes high-free calcium belite sulphoaluminate clinker, gypsum and granulated blast furnace slag powder as main raw materials, and successfully prepares a high-strength inorganic soil solidifying agent through reasonable design of the mineral composition of the high-free calcium belite sulphoaluminate clinker and the content of the raw material components. The soil material prepared by using the high-strength inorganic soil solidifying agent not only has high compressive strength, but also has simple composition and is friendly to the environment. The technical scheme of the application effectively solves the problems of low compressive strength and unfriendliness to the environment of the existing soil solidifying material.

[0007] To solve the above technical problems, the technical scheme provided by the application is: The application provides a high-strength inorganic soil solidifying agent in a first aspect, which comprises the following raw material components in mass percentage: high-free calcium belite sulphoaluminate clinker 15-40%, gypsum 18-50% and granulated blast furnace slag powder 25-62%. The high-free calcium belite sulphoaluminate clinker comprises the following mineral components in mass percentage: anhydrous calcium sulphoaluminate 25.31-33.27%, free calcium sulphate 6.55-12.26%, free calcium oxide 14.82-19.71%, belite 27.27-33.87% and iron phase 3.04-6.08%.

[0008] Compared with the prior art, in the high-strength inorganic soil solidifying agent provided by the application, the high-free calcium belite sulphoaluminate clinker and the granulated blast furnace slag can improve the types, composition and microstructure of the gypsum hydration products, and grow the hydration products with excellent water resistance around the dihydrate gypsum, thereby avoiding the dissolution of the dihydrate gypsum by external water, and significantly improving the water resistance and mechanical strength of the soil solidifying agent. The inventors have found through a large number of researches that the introduction of a proper amount of free calcium sulphate and more free calcium oxide into the cement clinker minerals can make the free calcium sulphate form a liquid phase at high temperature, the anhydrous sulphoaluminate reacts with the free calcium sulphate to generate a mixture of amorphous anhydrous sulphoaluminate and cubic anhydrous sulphoaluminate, and the activity of the cubic anhydrous sulphoaluminate is much higher than that of the orthorhombic anhydrous sulphoaluminate in the conventional sulphoaluminate cement clinker in the presence of the free calcium sulphate. Moreover, sufficient free calcium reacts with the amorphous / cubic anhydrous sulphoaluminate and the free calcium sulphate to generate a large amount of high-activity AFm microcrystals, the AFm microcrystals directly react with the added gypsum to generate ettringite microcrystals, and the ettringite microcrystals gradually wrap the dihydrate gypsum generated by the hydration of the added gypsum. Due to the high activity of the above-mentioned reaction products, the generated AFm microcrystals have small size and better wrapping effect, so that the soil solidifying agent material rapidly forms a skeleton and generates a dense microstructure, thereby producing high early strength.

[0009] The present inventors also discovered that the present invention uses gypsum and granulated blast furnace slag powder as the main raw materials, and incorporates a specially designed high-free calcium belite sulfoaluminate clinker. This allows the dihydrate gypsum crystals formed by the external gypsum to be double-densely coated with AFt microcrystals and C-(A)-SH gel. Even with high gypsum dosages, the water-soluble dihydrate gypsum can be prevented from dissolving in water. This solves the problems of poor water resistance, significantly reduced strength, and poor freeze-thaw resistance of soil consolidators caused by the high solubility of dihydrate gypsum, thereby effectively improving the compressive strength and durability of the soil consolidator. More importantly, the low cost of gypsum and granulated blast furnace slag powder also effectively reduces the production cost of the inorganic soil consolidator, providing a new design concept for the development of soil consolidators.

[0010] Preferably, the belite comprises dicalcium silicate (C2S).

[0011] Preferably, the iron phase comprises tetracalcium aluminoferrite (C4AF).

[0012] Preferably, the high free calcium belite sulphoaluminate clinker further comprises 4.95% to 7.66% of mixed mineral components.

[0013] For example, the mixed mineral components include 2% to 4% of periclase (MgO), 0.85% to 2.55% of perovskite (CaTiO3), and 0.5% to 1.5% of alkali metal sulfate.

[0014] Preferably, the high free calcium belite sulphoaluminate clinker comprises the following oxides in percentage by mass: SiO2 9.5% to 11.8%, Al2O3 14% to 18%, CaO 55% to 58%, SO3 8% to 11% and Fe2O3 1% to 2%.

[0015] Further preferably, the high free calcium belite sulphoaluminate clinker further comprises 4% to 6.7% of mixed oxides.

[0016] Illustratively, the mixed oxide includes at least one of MgO, TiO2, Na2O, or K2O.

[0017] Preferably, the specific surface area of ​​the high free calcium belite sulphoaluminate clinker is ≥500m 2 / kg.

[0018] Further preferably, the specific surface area of ​​the high free calcium belite sulphoaluminate clinker is 510m 2 / kg-550m 2 / kg.

[0019] Preferably, the preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps: Mixing, grinding limestone, bauxite and gypsum to obtain raw material; The raw material is calcined at 1200-1300 DEG C to obtain the high free calcium belite sulfoaluminate clinker.

[0020] The application provides a preparation method of high free calcium belite sulfoaluminate clinker, the amount of raw material is designed according to the mineral composition of the clinker, and the component proportion of each oxide in the raw material is calculated. A large number of experiments show that the temperature range of 1200-1300 DEG C is the best sintering temperature of the clinker, and the mineral composition of the target clinker cannot be formed when the sintering temperature is too high or too low. If the sintering temperature is too low, the mineral composition of the clinker is not fully formed, and if the sintering temperature is too high, some mineral compositions are decomposed, and the mineral compositions cannot reach the required content range.

[0021] Preferably, the chemical components in the raw material satisfy: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-the loss on ignition of the raw material)=14.82%-19.71%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw material)=6.55%-12.26%.

[0022] It should be noted that in the application, [CaO] represents the mass percentage of CaO in the raw material, [SiO2] represents the mass percentage of SiO2 in the raw material, [Fe2O3] represents the mass percentage of Fe2O3 in the raw material, [TiO2] represents the mass percentage of TiO2 in the raw material, [Al2O3] represents the mass percentage of Al2O3 in the raw material, and [SO3] represents the mass percentage of SO3 in the raw material.

[0023] The application can ensure that the content of free calcium oxide in the prepared clinker meets the requirements through the limitation of ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-the loss on ignition of the raw material)=14.82%-19.71%, and can ensure that the content of free calcium sulfate in the prepared clinker meets the requirements through the limitation of (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw material)=6.55%-12.26%.

[0024] Preferably, the mass ratio of the limestone, bauxite and gypsum is (61-71):(17-23):(12-19).

[0025] Preferably, the particle size of the raw material is 15% or less after being sieved through a 0.08mm square hole sieve.

[0026] The calcination is preferably performed in a rotary kiln, and the time from entering the kiln to exiting the kiln is 30min~60min. The specific calcination time can be adjusted according to the specific conditions of different rotary kilns.

[0027] The calcination further includes cooling and grinding, to obtain a powdery high-free calcium belite sulphoaluminate clinker.

[0028] The high-free calcium belite sulphoaluminate clinker provided by the present application introduces a specific amount of free calcium sulfate into the clinker, and the anhydrous calcium sulphoaluminate can be solid-soluted in the liquid phase of the free calcium sulfate (the free calcium sulfate forms a liquid phase when calcined at high temperature), to generate a mixture of amorphous anhydrous calcium sulphoaluminate and cubic anhydrous calcium sulphoaluminate. The activity of the cubic anhydrous calcium sulphoaluminate is much higher than that of the orthorhombic anhydrous calcium sulphoaluminate in the conventional sulphoaluminate cement clinker when the free calcium sulfate is present. The introduction of a specific amount of free calcium oxide into the clinker has a high hydration activity and can react rapidly with water. Therefore, a higher free calcium and suitable free calcium sulfate can significantly improve the activity of other minerals in the clinker and the overall activity of the clinker.

[0029] Preferably, the high-strength inorganic soil stabilizer further comprises the following raw material components in the following mass percentages: 0~3.9% of amorphous calcium aluminate, 0~5% of silica fume, 0~1.5% of water reducing agent, and 0~0.3% of retarder.

[0030] The present application further limits the dosage range of the high-free calcium belite sulphoaluminate clinker and the amorphous calcium aluminate. By reasonably designing the dosage, the size of the ettringite microcrystals can be quickly generated, the encapsulation effect is good, and the performance of the high-strength inorganic soil stabilizer is improved. Preferably, the dosage of each raw material component is beneficial to further exert the synergistic effect between the components, and the unconfined compressive strength of the high-strength inorganic soil stabilizer is improved.

[0031] Preferably, the gypsum includes at least one of desulfurization gypsum-based building gypsum, phosphogypsum-based building gypsum, dried desulfurization gypsum, dried phosphogypsum, wet desulfurization gypsum, wet phosphogypsum, alpha high-strength gypsum, fluorogypsum, hard gypsum, or dihydrate gypsum.

[0032] Preferably, the desulfurization gypsum-based building gypsum and the phosphogypsum-based building gypsum meet the requirements of GB / T 9776-2022 "Building Gypsum"; the desulfurization gypsum, the phosphogypsum and the fluorogypsum meet the requirements of GB / T 21371-2019 "Industrial By-Product Gypsum for Use in Cement", and the phosphogypsum also meets the requirements of GB / T 23456-2018 "Phosphogypsum"; the alpha high-strength gypsum meets the requirements of JC / T2038-2010 "Alpha High-Strength Gypsum"; and the anhydrite and the dihydrate gypsum meet the requirements of GB / T 5483-2024 "Natural Gypsum".

[0033] It should be further explained that when two or more kinds of gypsum are selected for compounding, there is no requirement for the amount of different gypsums.

[0034] For example, the desulfurization gypsum includes at least one of desulfurization gypsum-based building gypsum, wet desulfurization gypsum or dried desulfurization gypsum, and the phosphogypsum includes at least one of phosphogypsum-based building gypsum, wet phosphogypsum or dried phosphogypsum.

[0035] The processing difficulty of different gypsums in the art is quite different, and the processing of phosphogypsum is a big problem in China. Therefore, many current gypsum processing technologies are mainly for processing a single type of gypsum. The present application can be applied to almost all types of gypsum, especially industrial by-product gypsum, without special limitation on the type of gypsum, and has the characteristics of high efficiency, energy saving and wide applicability.

[0036] The fluorogypsum, the phosphogypsum and the desulfurization gypsum in the gypsum described in the present application all belong to solid waste that has been stored in large quantities and is continuously generated. The resource utilization of these solid waste not only solves the problem of solid waste disposal, but also further reduces the cost of the soil stabilizer described in the present application.

[0037] Preferably, the granulated blast furnace slag powder meets the requirements of GB / T 18046-2017 "Granulated Blast Furnace Slag for Use in Cement, Mortar and Concrete" for not less than S75 grade granulated blast furnace slag powder, and is further preferably S95 grade.

[0038] Further preferably, the amorphous calcium aluminate has an amorphous proportion of ≥99.0%; and a specific surface area of ≥500 m 2 / kg.

[0039] Preferably, the amorphous calcium aluminate has extremely high hydration activity and can completely react within 5 minutes.

[0040] The present application discloses a high-strength inorganic soil solidifying agent and a preparation method thereof. - and Ca 2+ , which continue to generate AFt by reacting with the added gypsum and fill in the pores; the remaining Ca 2+ and SiO3 2- in the GGBFS are also gradually dissolved, and the AFt microcrystals generated by the early clinker reaction provide growth sites for the C-(A)-S-H gel by reacting with Ca 2+ and SiO3 2- , thereby accelerating the formation of the C-(A)-S-H gel, and the C-(A)-S-H gel can form a wrapping effect outside the dihydrate gypsum crystals; in addition, the C-(A)-S-H gel has a low calcium-silicon ratio, a more compact microstructure, and better wrapping properties for dihydrate gypsum.

[0041] Preferably, the silica fume has a SiO2 content of ≥90%.

[0042] Preferably, the water reducing agent is at least one of a polycarboxylic acid water reducing agent, a melamine water reducing agent, a melamine-based high-efficiency water reducing agent, an FL51 water reducing agent, or a naphthalene-based water reducing agent.

[0043] Preferably, the retarder is at least one of citric acid, sodium citrate, sodium gluconate, zinc carbonate, tartaric acid, or a gypsum retarder.

[0044] The second aspect of the present application provides a preparation method of the high-strength inorganic soil solidifying agent, which comprises the following steps: weighing each raw material component according to the design ratio of the high-strength inorganic soil solidifying agent, and uniformly mixing to obtain the high-strength inorganic soil solidifying agent.

[0045] The third aspect of the present application provides a high-strength soil solidifying material, which comprises the high-strength inorganic soil solidifying agent.

[0046] Preferably, the 7d unconfined compressive strength of the high-strength soil solidifying material can reach 25-27 MPa.

[0047] Preferably, the 28d unconfined compressive strength of the high-strength soil solidifying material can reach 34-36 MPa.

[0048] The fourth aspect of the present application provides a preparation method of the high-strength soil solidifying material, which comprises the following steps: uniformly mixing the high-strength inorganic soil solidifying agent with soil at a mass ratio of 0.03-0.20, shaping, curing, and obtaining the high-strength soil solidifying material.

[0049] The high-strength inorganic soil solidifying agent is mixed with a large amount of soil, and under the action of a high-activity component in the high-strength inorganic soil solidifying agent, a hydration reaction occurs, a large amount of microcrystalline ettringite and C-A-S-H gel are quickly formed, the dihydrate gypsum generated in the hydration reaction is fully coated, the soil particles are cemented together, and a high-strength soil solidified material is prepared. It is also found that the dihydrate gypsum crystals formed by adding gypsum are double-densely coated by AFt microcrystals and C-(A)-S-H gel, even in the case of a higher amount of gypsum, the dihydrate gypsum which is easily soluble in water can be avoided from dissolving in water, and the problems of poor water resistance, large reduction in strength and poor freeze-thaw resistance of the high-strength soil solidified material caused by the high solubility of dihydrate gypsum are solved. With the gradual densification of the microstructure, the porosity of the soil solidified material gradually decreases, thereby the mechanical strength gradually increases.

[0050] In addition, the high-strength inorganic soil solidifying agent is mixed with soil in a certain proportion, and is formed and maintained according to JTG3441-2024 'Highway Engineering Inorganic Binder Stabilized Material Test Procedures', and through testing, the high-strength soil solidified material prepared by using the high-strength inorganic soil solidifying agent has a standard water curing strength greater than a standard dry air curing strength.

[0051] Preferably, the soil is giant particle soil, coarse-grained soil, fine-grained soil, clay, loam, silt, sandy soil, silt, silt soil, dredged soil, and engineering excavated soil. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application.

[0053] In the present application, the amorphous calcium aluminate is purchased from Anhui Qiming New Material Co., Ltd., and the specific surface area is 561 m 2 / kg; S95 grade granulated blast furnace slag powder is purchased from Qian'an Shengjiu Building Material Co., Ltd.; desulfurization gypsum and desulfurization gypsum-based building gypsum (i.e. hemihydrate gypsum) are purchased from Luanxian Fuyou Renewable Resources Co., Ltd., alpha high-strength gypsum is purchased from Pingyi County Yuantong Gypsum Products Co., Ltd., anhydrous gypsum is purchased from Anhui Huantai New Material Co., Ltd., wet phosphorus gypsum and phosphorus gypsum-based building gypsum (i.e. hemihydrate gypsum) are purchased from Tangshan Beizixiong Building Material Co., Ltd.; silica ash is purchased from Aiken International Trade (Shanghai) Co., Ltd.; the gypsum retarder is AG-46 gypsum retarder purchased from Hubei Zhaojia Material Co., Ltd., sodium gluconate is purchased from Xiwang Group Co., Ltd.; C900 polycarboxylic acid water reducer is purchased from Suzhou Fuke Technology Co., Ltd., and XDD polycarboxylic acid water reducer is purchased from Shandong Xindadi Industrial Group Co., Ltd. Other manufacturers not specified are all conventional products that can be obtained by purchase.

[0054] Five kinds of soil were used in the examples and comparative examples, and their specific indicators included the following: The natural bulk density of 1# fine-grained soil is 1320kg / m 3 , liquid limit is 20%, plastic limit is 9.3%, and plasticity index is 10.7; The natural bulk density of 2# fine-grained soil is 1189kg / m 3 , liquid limit is 36.4%, plastic limit is 14%, and plasticity index is 11.92; The natural bulk density of 3# fine-grained soil is 1282kg / m 3 , liquid limit is 27.5%, plastic limit is 15%, and plasticity index is 12.5; The natural bulk density of clay is 1697 kg / m 3 , liquid limit is 46.6%, plastic limit is 23.1%, and plasticity index is 22.5; The natural bulk density of silt soil is 1512 kg / m 3 , the liquid limit is 65.7%, the plastic limit is 33.2%, and the plasticity index is 37.6.

[0055] In order to better illustrate the present invention, further examples are given below.

[0056] Example 1 This embodiment provides a high-free calcium belite sulphoaluminate clinker, comprising the following mineral components in percentage by weight: 32.08% anhydrous calcium sulphoaluminate, 9.57% free calcium sulfate, 16.92% free calcium oxide, 29.27% ​​belite, 6.08% iron phase, and 6.08% miscellaneous mineral components.

[0057] The high-free calcium and high-belite calcium sulfoaluminate clinker comprises the following oxides in percentage by mass: SiO2 10.20%, Al2O3 17.40%, CaO 55.20%, SO3 9.80%, Fe2O3 2.00% and mixed oxides 5.40%.

[0058] The preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps: S100. According to the designed chemical composition ratio, limestone, bauxite and gypsum are weighed in a mass ratio of 61.9:20.6:17.5, mixed and ground, and the residue after screening through a 0.08 mm square hole sieve is 13%, thereby obtaining the raw meal.

[0059] The chemical components in the raw material meet the following requirements: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-loss on ignition of raw meal) = 16.92%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal)=9.57%.

[0060] S200, the raw material was calcined in a rotary kiln at 1250 ° C and ground to obtain a specific surface area of ​​530m 2 / kg high free calcium belite sulphoaluminate clinker.

[0061] Example 2 This embodiment provides a high-free calcium belite sulphoaluminate clinker, comprising the following mineral components by weight: 32.87% anhydrous calcium sulphoaluminate, 11.09% free calcium sulfate, 17.12% free calcium oxide, 27.84% belite, 6.08% iron phase, and 4.99% miscellaneous mineral components.

[0062] The high-free calcium and high-belite calcium sulfoaluminate clinker comprises the following oxides in percentage by mass: SiO2 9.70%, Al2O3 17.80%, CaO 55.60%, SO3 10.80%, Fe2O3 2.00% and mixed oxides 4.10%.

[0063] The preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps: S100. According to the designed chemical composition ratio, limestone, bauxite and gypsum are weighed in a mass ratio of 62.5:19.5:18, mixed and ground, and the residue after screening through a 0.08 mm square hole sieve is 13%, thereby obtaining the raw meal.

[0064] The chemical components in the raw material meet the following requirements: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-loss on ignition of raw meal) = 17.12%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal) = 11.09%.

[0065] S200, the raw material was calcined in a rotary kiln at 1250 ° C and ground to obtain a specific surface area of ​​530m 2 / kg high free calcium belite sulphoaluminate clinker.

[0066] Example 3 The embodiment provides a high-free calcium belite sulphoaluminate clinker, which comprises the following mineral components in mass percentage: anhydrous calcium sulphoaluminate 31.92%, free calcium sulphate 6.55%, free calcium oxide 19.71%, belite 32.14%, iron phase 4.56% and miscellaneous mineral components 5.12%.

[0067] The high-free calcium high-belite sulphoaluminate clinker comprises the following oxides in mass percentage: SiO211.20%, Al2O317.00%, CaO 58.00%, SO38.00% and Fe2O31.50% and miscellaneous oxides 4.30%.

[0068] The preparation method of the high-free calcium belite sulphoaluminate clinker comprises the following steps: S100, limestone, bauxite and gypsum are weighed according to the chemical component proportioning design, the mass ratio is 66.4:19.3:14.3, mixed, ground, and screened through a 0.08mm square hole screen, the sieve residue is 13%, and the raw meal is obtained.

[0069] The chemical components in the raw meal meet the following conditions: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-the loss on ignition of the raw meal)=19.71%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw meal)=6.55%.

[0070] S200, the raw meal is calcined in a rotary kiln at 1250 DEG C, and ground, and the high-free calcium belite sulphoaluminate clinker with a specific surface area of 530m 2 / kg is obtained.

[0071] Embodiments 4-14 Embodiments 4-14 provide high-strength inorganic soil solidifying agents prepared from the high-free calcium belite sulphoaluminate clinker, desulfurized gypsum and S95 grade granulated blast furnace slag powder described in embodiment 1, and the raw material composition of the high-strength inorganic soil solidifying agents is shown in Table 1.

[0072] The high-strength inorganic soil solidifying agents provided in embodiments 4-14 are mixed with 1# fine-grained soil to prepare high-strength soil solidifying materials, the mixing ratio is shown in Table 1, and the unconfined compressive strength test is carried out on the high-strength soil solidifying materials obtained in embodiments 4-14 according to JTG3441-2024 'Highway Engineering Inorganic Binder Stabilized Material Test Procedures', and the size of the test sample is Φ50*50mm, and the test results are shown in Table 1.

[0073] Table 1 Raw material ratio and performance of examples 4~14

[0074] By analyzing the composition and performance of high-strength inorganic soil solidifying agent of examples 4~14, it is found that the high-strength inorganic soil solidifying agent prepared by 15%~40% of high free calcium belite sulphoaluminate clinker, 18%~50% of desulfurization gypsum and 30%~62% of granulated blast furnace slag powder can be mixed with 1# fine-grained soil at a mass ratio of 0.03~0.2:1 to prepare high-strength soil solidified material with excellent performance, and the 7d unconfined compressive strength of the obtained high-strength soil solidified material can be 1.6~18.3MPa, and the 28d unconfined compressive strength can be 3.5~30.9MPa.

[0075] Examples 15~18 Examples 15~18 provide high-strength inorganic soil solidifying agent with 20% of high free calcium belite sulphoaluminate clinker, 25% of gypsum and 55% of S95 grade granulated blast furnace slag powder as raw materials, wherein the types of gypsum are hard gypsum, wet phosphogypsum, alpha high-strength gypsum and desulfurization gypsum-based building gypsum respectively; the raw material composition of the high-strength inorganic soil solidifying agent is shown in Table 2.

[0076] The high-strength inorganic soil solidifying agent provided in examples 15~18 is mixed with 1# fine-grained soil at a mass ratio of 0.10 to prepare high-strength soil solidified material, and the unconfined compressive strength test of the high-strength soil solidified material obtained in examples 15~18 is carried out according to JTG3441-2024 "Highway Engineering Inorganic Binder Stabilized Material Test Procedures", and the size of the test piece used is Φ50*50mm.

[0077] The raw material composition of the soil solidifying agent and the performance of the high-strength soil solidified material prepared therefrom are shown in Table 2.

[0078] Table 2 Raw material ratio and performance of examples 15~18

[0079] By analyzing the composition and performance of high-strength inorganic soil solidifying agent of examples 15~18, it is found that using various types of gypsum and adopting the raw material ratio provided in the application can prepare high-strength soil solidified material with excellent performance, and the 7d unconfined compressive strength is 3.9~5.1MPa, and the 28d unconfined compressive strength is 7.3~8.7MPa.

[0080] Examples 19~26 Embodiments 19-26 provide high-strength inorganic soil solidifying agents with raw materials of high free calcium belite sulphoaluminate clinker, desulfurized gypsum, S95 grade granulated blast furnace slag powder, amorphous calcium aluminate and silica fume as described in Embodiment 1, and the raw material composition of the high-strength inorganic soil solidifying agents is shown in Table 3.

[0081] The high-strength inorganic soil solidifying agents provided in Embodiments 19-26 are mixed with 1# fine-grained soil to prepare soil solidifying materials, and the mixing ratio is shown in Table 3. According to the “Test Code for Inorganic Stabilizing Materials in Highway Engineering” (JTG3441-2024), the unconfined compressive strength of the high-strength soil solidifying materials obtained in Embodiments 19-26 is tested, and the size of the test piece is Φ50*50mm.

[0082] Table 3 Raw material ratio and performance of Embodiments 19-26

[0083] It is found through analysis that, as the dosage of amorphous calcium aluminate in the soil solidifying agent increases from 1.5% to 3.9%, the unconfined compressive strength of the soil solidifying material increases, and a high-strength soil solidifying material with excellent performance can be prepared, with the 7d unconfined compressive strength increasing from 4.8MPa to 5.7MPa, and the 28d unconfined compressive strength increasing from 8.3MPa to 9.0MPa; As the dosage of silica fume in the soil solidifying agent increases from 1% to 5%, the 7d unconfined compressive strength of the soil solidifying material slightly decreases, and the 28d unconfined compressive strength significantly increases, and a high-strength soil solidifying material with excellent performance can be prepared, with the 7d unconfined compressive strength being 3.7-4.5MPa, and the 28d unconfined compressive strength being 8.2-9.5MPa; The combined addition of amorphous calcium aluminate and silica fume is more obvious in improving the later mechanical properties, and the 28d unconfined compressive strength is as high as 9.5MPa.

[0084] Embodiments 27 and 28 Embodiments 27 and 28 provide two high-strength inorganic soil solidifying agents with 20% of high free calcium belite sulphoaluminate clinker, 25% of desulfurized gypsum and 55% of S95 grade granulated blast furnace slag powder as raw materials, as described in Embodiments 2 and 3, respectively, and the two high-strength inorganic soil solidifying agents are mixed with 1# fine-grained soil to prepare soil solidifying materials, and the specific content is shown in Table 4. According to the “Test Code for Inorganic Stabilizing Materials in Highway Engineering” (JTG3441-2024), the unconfined compressive strength of the high-strength soil solidifying materials obtained in Embodiments 27-28 is tested, and the size of the test piece is Φ50*50mm.

[0085] Table 4 Ratio and performance of Embodiments 27 and 28

[0086] Through analysis, it was found that the high-strength inorganic soil solidifiers produced from different clinkers provided in Examples 27 and 28 of the present invention can be used to consolidate soil to prepare high-strength soil consolidation materials with excellent performance, with 7d unconfined compressive strength of 4.7 and 5.1 MPa, and 28d unconfined compressive strength of 7.6 and 7.3 MPa.

[0087] Examples 29-32 Examples 29-32 provide high-strength inorganic soil solidifiers using 20% ​​of the high-free-calcium belite sulfoaluminate clinker described in Example 1, 25% of gypsum, and 55% of S95-grade granulated blast furnace slag powder as raw materials. The high-strength inorganic soil solidifiers provided in Examples 29-32 were mixed with 2# fine-grained soil, 3# fine-grained soil, clay, and silt soil in appropriate proportions to produce soil solidification materials; the specific contents are shown in Table 5. Furthermore, in accordance with JTG3441-2024, "Testing Procedures for Inorganic Binder Stabilized Materials for Highway Engineering," the high-strength soil solidification materials obtained in Examples 29-32 were subjected to unconfined compressive strength testing using specimens measuring 50 x 50 mm.

[0088] Table 5 Proportions and properties of Examples 29 to 32

[0089] Through analysis, it was found that the high-strength inorganic soil solidifier provided by Examples 29 to 32 of the present invention can be used to consolidate a variety of soils to prepare high-strength soil consolidation materials with excellent performance, with a 7-day unconfined compressive strength of 4.1 to 6.6 MPa and a 28-day unconfined compressive strength of 7.5 to 14.2 MPa.

[0090] Examples 33 to 47 Examples 33 to 47 provide high-strength inorganic soil solidifiers using the high-free calcium belite sulfoaluminate clinker, gypsum, and S95-grade granulated blast furnace slag powder described in Example 1 as raw materials. The high-strength inorganic soil solidifiers provided in Examples 33 to 47 are mixed with 1# fine-grained soil, 2# fine-grained soil, and 3# fine-grained soil in appropriate proportions to produce soil solidification materials. The specific contents are shown in Table 6.

[0091] In accordance with JTG3441-2024 "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering", the high-strength soil consolidation materials obtained in Examples 33 to 47 were subjected to unconfined compressive strength tests. The size of the specimens used was Φ50*50 mm. The results are shown in Table 7.

[0092] Table 6 Raw material composition of soil solidifying agent in Examples 33 to 47

[0093] Table 7 Composition and properties of soil consolidation materials in Examples 33 to 47

[0094] Through analysis, it was found that the high-strength inorganic soil solidifier provided by Examples 33 to 47 of the present invention can be used to consolidate a variety of soils to prepare high-strength soil consolidation materials with excellent performance.

[0095] Comparative Examples 1 to 7 Comparative Examples 1-7 provide high-strength inorganic soil solidifiers made from Jidong cement, building gypsum, S95-grade granulated blast furnace slag powder, and steel slag. These are mixed with 1# fine-grained soil, 2# fine-grained soil, and 3# fine-grained soil in appropriate proportions to produce soil solidification materials. The high-strength soil solidification materials obtained in Examples 1-7 were subjected to unconfined compressive strength testing in accordance with JTG3441-2024, "Testing Procedure for Inorganic Binder Stabilized Materials for Highway Engineering," using specimens measuring 50 x 50 mm.

[0096] Comparative Examples 1 to 7 provide the raw material composition of the soil solidifier and the performance of the high-strength soil consolidation material made from the soil as shown in Table 8.

[0097] Table 8 Raw material ratios and properties of comparative examples 1 to 7

[0098] Comparative Example 8 Comparative Example 8 provides an inorganic soil solidifier with the following proportions: 20% high-belite sulphoaluminate cement clinker, 25% desulfurized gypsum, and 55% S95-grade granulated blast furnace slag powder (similar to Examples 4, 27, and 28). The high-belite sulphoaluminate cement clinker includes the following mineral components by weight: 28% anhydrous calcium sulphoaluminate, 16% free calcium sulfate, 3% free calcium oxide, 45% belite, 6% iron phase, and 2% miscellaneous mineral components. The inorganic soil solidifier provided in Comparative Example 8 was mixed with No. 1 fine-grained soil to produce a soil solidification material. The mass ratio of soil solidifier to soil was 0.1. The resulting soil solidification material was subjected to unconfined compressive strength testing in accordance with JTG3441-2024, "Testing Procedures for Inorganic Binder Stabilized Materials for Highway Engineering." The test specimens used were Φ50*50 mm in size. The performance results are shown in Table 9.

[0099] Table 9 Performance of Comparative Example 8

[0100] It can be seen that the 7d unconfined compressive strength of the high-strength soil consolidation material provided by the embodiment of the application can reach 25.2MPa at most, and the unconfined compressive strength of the soil consolidation material after 28d curing can reach more than 34.6MPa at most, which is much higher than the strength of the soil consolidation material provided by the comparative example under the same soil stabilizer content, and the high-strength soil consolidation material provided by the application has a significant advantage.

[0101] The above merely describes preferred embodiments of the application and is not intended to limit the application, and any modification, equivalent replacement or improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A high-strength inorganic soil solidifier, characterized in that: The raw material components include the following percentages by weight: 15% to 40% of high free calcium belite sulphoaluminate clinker, 18% to 50% of gypsum and 25% to 62% of granulated blast furnace slag powder; The high-free calcium and high-belite calcium sulfoaluminate clinker includes the following mineral components in percentage by mass: 25.31% to 33.27% of anhydrous calcium sulfoaluminate, 6.55% to 12.26% of free calcium sulfate, 14.82% to 19.71% of free calcium oxide, 27.27% to 33.87% of belite, and 3.04% to 6.08% of iron phase.

2. The high-strength inorganic soil solidifier according to claim 1, characterized in that: The high-free calcium belite sulphoaluminate clinker comprises the following oxides in percentage by mass: SiO2 9.5%-11.8%, Al2O3 14%-18%, CaO 55%-58%, SO3 8%-11% and Fe2O3 1%-2%.

3. The high-strength inorganic soil solidifier according to claim 1, characterized in that The preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps: Mix limestone, bauxite and gypsum and grind them to obtain raw material; The raw material is calcined at 1200° C. to 1300° C., and ground after cooling to obtain the high-free calcium belite sulphoaluminate clinker.

4. The high-strength inorganic soil solidifying agent according to claim 3, characterized in that: In the method for preparing high-free-calcium belite sulphoaluminate clinker, the chemical components of the raw material meet the following requirements: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-loss on ignition of raw meal) = 14.82%~19.71%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal)=6.55%~12.26%.

5. The high-strength inorganic soil solidifier according to any one of claims 1 to 4, characterized in that: The invention also includes the following raw material components in percentage by mass: 0-3.9% amorphous calcium aluminate, 0-5% silica fume, 0-1.5% water reducer and 0-0.3% retarder.

6. The high-strength inorganic soil solidifying agent according to claim 5, characterized in that: The content of sulfur trioxide in the gypsum is ≥35%.

7. The high-strength inorganic soil solidifying agent according to claim 6, characterized in that: The gypsum includes at least one of desulfurized gypsum-based building gypsum, phosphogypsum-based building gypsum, dried desulfurized gypsum, dried phosphogypsum, wet desulfurized gypsum, wet phosphogypsum, α high-strength gypsum, fluorinated gypsum, anhydrite or dihydrate gypsum; The amorphous ratio of the amorphous calcium aluminate is ≥99.0%; the specific surface area of ​​the amorphous calcium aluminate is ≥500m 2 / kg; The SiO2 content of the silica fume is ≥90%; The water reducer is at least one of a polycarboxylate water reducer, a melamine water reducer, a melamine-based high-efficiency water reducer, a FL51 water reducer or a naphthalene-based water reducer; The retarder is at least one of citric acid, sodium citrate, sodium gluconate, zinc carbonate, tartaric acid or gypsum retarder.

8. A method for preparing the high-strength inorganic soil solidifier according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: weighing various raw material components according to the designed proportion of the high-strength inorganic soil solidifier, mixing them evenly, and obtaining the high-strength inorganic soil solidifier.

9. A high-strength soil consolidation material, characterized in that: The invention comprises the high-strength inorganic soil solidifying agent according to any one of claims 1 to 7.

10. The high-strength soil consolidation material according to claim 9, wherein: The 7d unconfined compressive strength of the high-strength soil consolidation material can reach 25-27 MPa; The 28d unconfined compressive strength of the high-strength soil consolidation material can reach 34-36 MPa.

11. A method for preparing the high-strength soil consolidation material according to claim 9 or 10, characterized in that: The high-strength inorganic soil solidifying agent according to any one of claims 1 to 7 is uniformly mixed with soil in a mass ratio of 0.03 to 0.20, molded, and cured to obtain the high-strength soil consolidation material.

12. The method for preparing a high-strength soil consolidation material according to claim 11, wherein: The soil is at least one of coarse-grained soil, coarse-grained soil, fine-grained soil, clay, loam, silt, sandy soil, silt, muddy soil, dredged soil or engineering excavated soil.

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