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

Abstract

The application belongs to the technical field of building materials, and particularly discloses 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 provided by the application 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 application comprises the following mineral components: anhydrous calcium sulphoaluminate, free calcium sulphate, free calcium oxide, belite and iron phase. The application optimizes the mineral components of the high-free calcium belite sulphoaluminate clinker and the raw material composition of the high-strength inorganic soil solidifying agent, so that the high-strength inorganic soil solidifying agent can be used to prepare engineering materials with excellent unconfined compressive strength after solidifying soil. The application effectively solves the problems of low compressive strength and environmental unfriendliness of the existing soil solidifying material.

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 can react with soil to generate cementitious material 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:

[0008] The application provides a high-strength inorganic soil solidifying agent, 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%.

[0009] 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%.

[0010] 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.

[0011] The present application also finds that the present application takes gypsum and granulated blast furnace slag powder as main raw materials, and mixes special designed high free calcium belite sulphoaluminate clinker, so that the dihydrate gypsum crystals formed by the mixed gypsum are double densely coated by AFt microcrystals and C-(A)-S-H gel, even in the case of high gypsum content, the water-soluble dihydrate gypsum can be avoided from dissolving in water, the problems of poor water resistance, large strength reduction and poor freeze-thaw resistance of soil consolidation agent caused by high solubility of dihydrate gypsum are solved, and the compressive strength and durability of the soil consolidation agent are effectively improved. More importantly, since the cost of gypsum and granulated blast furnace slag powder is low, the production cost of the inorganic soil consolidation agent is also effectively reduced, which provides a new design idea for the development of soil consolidation agent.

[0012] Preferably, the belite includes dicalcium silicate (C2S).

[0013] Preferably, the ferrite phase includes tetracalcium aluminoferrite (C4AF).

[0014] Preferably, the high free calcium belite sulphoaluminate clinker further includes a hybrid mineral component of 4.95% to 7.66%.

[0015] Illustratively, the hybrid mineral component includes periclase (MgO) 2% to 4%, perovskite (CaTiO3) 0.85% to 2.55%, and alkali sulfate 0.5% to 1.5%.

[0016] Preferably, the high free calcium belite sulphoaluminate clinker includes oxides in the following mass percentage: SiO2 9.5% to 11.8%, Al2O3 14% to 18%, CaO 55% to 58%, SO3 8% to 11%, and Fe2O3 1% to 2%.

[0017] Further preferably, the high free calcium belite sulphoaluminate clinker further includes a hybrid oxide of 4% to 6.7%.

[0018] Illustratively, the hybrid oxide includes at least one of MgO, TiO2, Na2O, or K2O.

[0019] Preferably, the high free calcium belite sulphoaluminate clinker has a specific surface area of ≥500 m 2 / kg.

[0020] Further preferably, the high free calcium belite sulphoaluminate clinker has a specific surface area of 510 m 2 / kg to 550 m 2 / kg.

[0021] Preferably, the preparation method of the high free calcium belite sulphoaluminate clinker includes the following steps:

[0022] The limestone, bauxite and gypsum are mixed and ground to obtain raw material;

[0023] The raw material is calcined at 1200-1300 DEG C to obtain the high free calcium belite sulfoaluminate clinker.

[0024] The preparation method of the high free calcium belite sulfoaluminate clinker provided by the application is as follows: the amount of the raw material is designed according to the mineral composition of the clinker, so that the proportion of each oxide in the raw material is calculated. It is found through a large number of experiments that the temperature range of 1200-1300 DEG C is the best firing temperature of the clinker, and the mineral composition of the target clinker cannot be formed if the calcination temperature is too high or too low. If the calcination temperature is too low, the mineral composition of the clinker is not fully formed, and if the calcination temperature is too high, some mineral compositions are decomposed, and the mineral compositions in the required content range cannot be achieved.

[0025] Preferably, the chemical components in the raw material satisfy:

[0026] ([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%;

[0027] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw material)=6.55%-12.26%.

[0028] It should be noted that [CaO] in the application 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.

[0029] 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%.

[0030] Preferably, the mass ratio of the limestone, bauxite and gypsum is (61-71):(17-23):(12-19).

[0031] Preferably, the particle size of the raw material is 15% or less after being sieved through a 0.08mm square hole sieve.

[0032] Preferably, the calcination is performed in a rotary kiln, and the time from entering the kiln to exiting the kiln is 30-60min. The specific calcination time can be adjusted according to the specific conditions of different rotary kilns.

[0033] Preferably, the calcination further comprises cooling and grinding, to obtain a powdery high-free calcium belite-sulphoaluminate clinker.

[0034] The high-free calcium belite-sulphoaluminate clinker provided by the present application introduces a specific amount of free calcium sulphate into the clinker, and anhydrous calcium sulphoaluminate can be solid-solubilized in the liquid phase of the free calcium sulphate (free calcium sulphate 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 conventional sulphoaluminate cement clinker in the presence of free calcium sulphate. The introduction of a specific amount of free calcium oxide into the clinker has high hydration activity and can react rapidly in the presence of water. Therefore, a higher free calcium and suitable free calcium sulphate can significantly improve the activity of other minerals in the clinker and the overall activity of the clinker.

[0035] 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.

[0036] 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 rapidly generated, and the performance of the high-strength inorganic soil stabilizer can be improved. The preferred dosage of each raw material component is beneficial to further exert the synergistic effect between the components, and thus the unconfined compressive strength of the high-strength inorganic soil stabilizer can be improved.

[0037] Preferably, the gypsum comprises at least one of desulphurization gypsum-based building gypsum, phosphogypsum-based building gypsum, dried desulphurization gypsum, dried phosphogypsum, wet desulphurization gypsum, wet phosphogypsum, alpha high-strength gypsum, fluorogypsum, hard gypsum or dihydrate gypsum.

[0038] 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".

[0039] 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.

[0040] 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.

[0041] The processing difficulty of different gypsums in the art varies greatly, 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.

[0042] 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.

[0043] 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.

[0044] Further preferably, the amorphous calcium aluminate has an amorphous proportion of ≥99.0%; and a specific surface area of ≥500 m 2 / kg.

[0045] Preferably, the amorphous calcium aluminate has extremely high hydration activity and can completely react within 5 minutes.

[0046] 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.

[0047] Preferably, the silica fume has a SiO2 content of ≥90%.

[0048] 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.

[0049] Preferably, the retarder is at least one of citric acid, sodium citrate, sodium gluconate, zinc carbonate, tartaric acid, or a gypsum retarder.

[0050] 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 mixing uniformly to obtain the high-strength inorganic soil solidifying agent.

[0051] The third aspect of the present application provides a high-strength soil solidifying material, which comprises the high-strength inorganic soil solidifying agent.

[0052] Preferably, the 7d unconfined compressive strength of the high-strength soil solidifying material can reach 25-27 MPa.

[0053] Preferably, the 28d unconfined compressive strength of the high-strength soil solidifying material can reach 34-36 MPa.

[0054] 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.

[0055] 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 relatively high 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.

[0056] Furthermore, the high-strength inorganic soil solidifying agent is mixed with soil at a certain ratio, and is formed and cured according to JTG3441-2024 'Highway Engineering Inorganic Binder Stabilized Material Test Procedures', and it is tested that 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.

[0057] Preferably, the soil is giant particle soil, coarse-grained soil, fine-grained soil, clay, loam, silt, sandy soil, silt, silt soil, dredged soil, engineering excavation soil. DETAILED DESCRIPTION

[0058] 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 not to limit the present application.

[0059] 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.

[0060] Five kinds of soil are used in the examples and comparative examples, and the specific indexes include the following contents:

[0061] 1# The natural bulk density of the fine-grained soil is 1320kg / m 3 , the liquid limit is 20%, the plastic limit is 9.3%, and the plasticity index is 10.7;

[0062] 2# The natural bulk density of the fine-grained soil is 1189kg / m 3 , the liquid limit is 36.4%, the plastic limit is 14%, and the plasticity index is 11.92;

[0063] 3# The natural bulk density of the fine-grained soil is 1282kg / m 3 , the liquid limit is 27.5%, the plastic limit is 15%, and the plasticity index is 12.5;

[0064] The natural bulk density of the clay is 1697kg / m 3 , the liquid limit is 46.6%, the plastic limit is 23.1%, and the plasticity index is 22.5;

[0065] The natural bulk density of the silt soil is 1512kg / m 3 , the liquid limit is 65.7%, the plastic limit is 33.2%, and the plasticity index is 37.6.

[0066] In order to better illustrate the present application, the following examples are further illustrated.

[0067] Example 1

[0068] The present example provides a high free calcium belite sulphoaluminate clinker, which comprises the following mineral components in mass percentage: calcium sulphoaluminate anhydrate 32.08%, free calcium sulphate 9.57%, free calcium oxide 16.92%, belite 29.27%, iron phase 6.08%, and miscellaneous mineral components 6.08%.

[0069] The high free calcium high belite sulphoaluminate clinker comprises the following oxides in mass percentage: SiO2 10.20%, Al2O3 17.40%, CaO 55.20%, SO3 9.80%, Fe2O3 2.00%, and miscellaneous oxides 5.40%.

[0070] The preparation method of the above high free calcium belite sulphoaluminate clinker comprises the following steps:

[0071] S100, limestone, bauxite and gypsum with mass ratio of 61.9:20.6:17.5 according to the chemical component proportioning design are weighed and mixed, then ground, and after passing through a 0.08mm square hole screen, the residue is 13%, to obtain raw material.

[0072] The chemical components in the raw meal satisfy:

[0073] ([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)=16.92%;

[0074] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw meal)=9.57%.

[0075] S200, calcining the raw meal in a rotary kiln at 1250℃, grinding, to obtain a high free calcium belite sulphoaluminate clinker with a specific surface area of 530m 2 / kg.

[0076] Example 2

[0077] The present example provides a high free calcium belite sulphoaluminate clinker, comprising mineral components in mass percentage: calcium sulphoaluminate 32.87%, free calcium sulphate 11.09%, free calcium oxide 17.12%, belite 27.84%, iron phase 6.08%, and miscellaneous mineral components 4.99%.

[0078] The high free calcium high belite sulphoaluminate clinker comprises oxides in mass percentage: SiO2 9.70%, Al2O3 17.80%, CaO 55.60%, SO3 10.80%, Fe2O3 2.00%, and miscellaneous oxides 4.10%.

[0079] The preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps:

[0080] S100, according to the chemical component proportioning design, limestone, bauxite and gypsum with a mass ratio of 62.5:19.5:18 are weighed and mixed, and then ground, and the sieve residue is 13% after passing through a 0.08mm square hole sieve, to obtain a raw meal.

[0081] The chemical components in the raw meal satisfy:

[0082] ([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)=17.12%;

[0083] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw meal)=11.09%.

[0084] S200, calcining the raw meal in a rotary kiln at 1250℃, grinding, to obtain a high free calcium belite sulphoaluminate clinker with a specific surface area of 530m 2 / kg.

[0085] Example 3

[0086] The present example provides a high free calcium belite sulphoaluminate clinker, comprising mineral components in mass percentage of: 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%.

[0087] The high free calcium high belite sulphoaluminate clinker comprises oxides in mass percentage of: SiO211.20%, Al2O317.00%, CaO 58.00%, SO38.00%, and Fe2O31.50%, and miscellaneous oxides 4.30%.

[0088] The preparation method of the high free calcium belite sulphoaluminate clinker comprises the following steps:

[0089] S100, according to the chemical component proportioning design, limestone, bauxite and gypsum with mass ratio of 66.4:19.3:14.3 are weighed and mixed, and then ground, and the sieve residue is 13% after passing through a 0.08mm square hole sieve, to obtain a raw meal.

[0090] The chemical components in the raw meal satisfy:

[0091] ([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%;

[0092] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-the loss on ignition of the raw meal)=6.55%.

[0093] S200, calcining the raw meal in a rotary kiln at 1250℃, grinding, to obtain a high free calcium belite sulphoaluminate clinker with a specific surface area of 530m 2 / kg.

[0094] Examples 4-14

[0095] Examples 4-14 provide high-strength inorganic soil solidifying agents using the high free calcium belite sulphoaluminate clinker described in Example 1, desulfurized gypsum and S95 grade granulated blast furnace slag powder as raw materials, and the raw material composition of the high-strength inorganic soil solidifying agents is shown in Table 1.

[0096] The high-strength inorganic soil solidifying agent provided in Examples 4-14 is mixed with 1# fine-grained soil to prepare high-strength soil solidifying materials, and the mixing ratio is shown in Table 1. The unconfined compressive strength of the high-strength soil solidifying materials obtained in Examples 4-14 is tested according to JTG3441-2024 "Test Code for Inorganic Binding Material Stabilized Materials in Highway Engineering", and the size of the test piece is Φ50*50mm. The test results are shown in Table 1.

[0097] Table 1 Raw material ratio and performance of Examples 4-14

[0098]

[0099] By analyzing the composition and performance of the high-strength inorganic soil solidifying agent of Examples 4-14, it is found that the high-strength inorganic soil solidifying agent prepared from 15%-40% high-free calcium belite sulphoaluminate clinker, 18%-50% desulfurization gypsum and 30%-62% granulated blast furnace slag powder, when mixed with 1# fine-grained soil at a mass ratio of 0.03-0.2:1, can prepare high-strength soil solidifying materials with excellent performance. The 7d unconfined compressive strength of the obtained high-strength soil solidifying materials can be 1.6-18.3MPa, and the 28d unconfined compressive strength can be 3.5-30.9MPa.

[0100] Examples 15-18

[0101] Examples 15-18 provide high-strength inorganic soil solidifying agents with high-free calcium belite sulphoaluminate clinker 20%, gypsum 25% and S95 grade granulated blast furnace slag powder 55% as raw materials, and 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.

[0102] 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 solidifying materials, and the unconfined compressive strength of the high-strength soil solidifying materials obtained in Examples 15-18 is tested according to JTG3441-2024 "Test Code for Inorganic Binding Material Stabilized Materials in Highway Engineering", and the size of the test piece is Φ50*50mm.

[0103] The raw material composition of the soil solidifying agent and the performance of the high-strength soil solidifying materials prepared therefrom are shown in Table 2.

[0104] Table 2 Raw material ratio and performance of Examples 15-18

[0105]

[0106] By analyzing the composition and performance of the high-strength inorganic soil stabilizer of examples 15-18, it is found that using multiple gypsums and adopting the raw material ratio provided by the present application, a high-strength soil consolidation material with excellent performance can be prepared, with 7d unconfined compressive strength of 3.9-5.1MPa and 28d unconfined compressive strength of 7.3-8.7MPa.

[0107] Examples 19-26

[0108] Examples 19-26 provide high-strength inorganic soil stabilizers using high-free calcium belite-sulphoaluminate clinker, desulfurized gypsum, S95 grade granulated blast furnace slag powder, amorphous calcium aluminate and silica fume as raw materials, and the raw material composition of the high-strength inorganic soil stabilizer is shown in Table 3.

[0109] The high-strength inorganic soil stabilizer provided by examples 19-26 is mixed with 1# fine-grained soil to prepare a soil consolidation material, and the mixing ratio is shown in Table 3. According to JTG3441-2024 "Test Code for Inorganic Stabilized Materials in Highway Engineering", the unconfined compressive strength test is performed on the high-strength soil consolidation material obtained from examples 19-26, and the size of the test piece used is Φ50*50mm.

[0110] Table 3 Raw material ratio and performance of examples 19-26

[0111]

[0112] It is found by analysis that as the dosage of amorphous calcium aluminate in the soil stabilizer increases from 1.5% to 3.9%, the unconfined compressive strength of the soil consolidation material increases, and a high-strength soil consolidation material with excellent performance can be prepared, with 7d unconfined compressive strength increasing from 4.8MPa to 5.7MPa and 28d unconfined compressive strength increasing from 8.3MPa to 9.0MPa;

[0113] As the dosage of silica fume added to the soil stabilizer increases from 1% to 5%, the 7d unconfined compressive strength of the soil consolidation material slightly decreases, and the 28d unconfined compressive strength significantly increases, and a high-strength soil consolidation material with excellent performance can be prepared, with 7d unconfined compressive strength of 3.7-4.5MPa and 28d unconfined compressive strength of 8.2-9.5MPa;

[0114] The complex 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.

[0115] Examples 27 and 28

[0116] Embodiments 27 and 28 provide two high-strength inorganic soil solidifying agents with raw materials of 20% high-free calcium belite sulphoaluminate clinker, 25% desulfurized gypsum and 55% S95 grade granulated blast furnace slag powder 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 contents are shown in Table 4; and, according to JTG3441-2024 “Highway Engineering Inorganic Binder Stabilized Material Test Procedures”, the high-strength soil solidifying materials obtained in Embodiments 27-28 are tested for unconfined compressive strength, and the size of the test piece used is Φ50*50mm.

[0117] Table 4: Proportioning and performance of Embodiments 27 and 28

[0118]

[0119] It is found through analysis that the high-strength inorganic soil solidifying agents produced by different clinkers provided in Embodiments 27 and 28 can be used to consolidate soil, and high-strength soil solidifying materials with excellent performance are prepared, with 7d unconfined compressive strength of 4.7 and 5.1 MPa, and 28d unconfined compressive strength of 7.6 and 7.3 MPa.

[0120] Embodiments 29-32

[0121] Embodiments 29-32 provide high-strength inorganic soil solidifying agents with raw materials of 20% high-free calcium belite sulphoaluminate clinker, 25% gypsum and 55% S95 grade granulated blast furnace slag powder as described in Embodiment 1. The high-strength inorganic soil solidifying agents provided in Embodiments 29-32 are mixed with 2# fine-grained soil, 3# fine-grained soil, clay and silt soil in a suitable ratio to prepare soil solidifying materials; the specific contents are shown in Table 5; and, according to JTG3441-2024 “Highway Engineering Inorganic Binder Stabilized Material Test Procedures”, the high-strength soil solidifying materials obtained in Embodiments 29-32 are tested for unconfined compressive strength, and the size of the test piece used is Φ50*50mm.

[0122] Table 5: Proportioning and performance of Embodiments 29-32

[0123]

[0124] It is found through analysis that the high-strength inorganic soil solidifying agents provided in Embodiments 29-32 can be used to consolidate various soils, and high-strength soil solidifying materials with excellent performance are prepared, with 7d unconfined compressive strength of 4.1-6.6 MPa, and 28d unconfined compressive strength of 7.5-14.2 MPa.

[0125] Embodiments 33-47

[0126] Embodiments 33-47 provide high-strength inorganic soil solidifying agents using the high-free calcium belite sulphoaluminate clinker, gypsum and S95 grade granulated blast furnace slag powder as described in Embodiment 1 as raw materials; and the high-strength inorganic soil solidifying agents provided in Embodiments 33-47 are mixed with 1# fine-grained soil, 2# fine-grained soil and 3# fine-grained soil respectively at a suitable ratio to prepare soil solidifying materials, and the specific contents are shown in Table 6.

[0127] According to the JTG3441-2024 “Highway Engineering Inorganic Binder Stabilized Material Test Procedures”, the unconfined compressive strength test is performed on the high-strength soil solidifying materials obtained in Embodiments 33-47, and the size of the test piece used is Φ50*50mm, and the results are shown in Table 7.

[0128] Table 6 Raw material composition of soil solidifying agents in Embodiments 33-47

[0129]

[0130] Table 7 Composition and performance of soil solidifying materials in Embodiments 33-47

[0131]

[0132] It is found through analysis that the high-strength inorganic soil solidifying agents provided in Embodiments 33-47 can be used to consolidate various soils, and high-strength soil solidifying materials with excellent performance are prepared.

[0133] Comparative Examples 1-7

[0134] Comparative Examples 1-7 provide high-strength inorganic soil solidifying agents using Jidong cement, building gypsum, S95 grade granulated blast furnace slag powder and steel slag as raw materials, which are mixed with 1# fine-grained soil, 2# fine-grained soil and 3# fine-grained soil respectively at a suitable ratio to prepare soil solidifying materials. According to the JTG3441-2024 “Highway Engineering Inorganic Binder Stabilized Material Test Procedures”, the unconfined compressive strength test is performed on the high-strength soil solidifying materials obtained in Embodiments 1-7, and the size of the test piece used is Φ50*50mm.

[0135] The raw material composition of the soil solidifying agents provided in Comparative Examples 1-7 and the performance of the high-strength soil solidifying materials prepared therefrom are shown in Table 8.

[0136] Table 8 Raw material ratio and performance of Comparative Examples 1-7

[0137]

[0138] Comparative Example 8

[0139] The comparative example 8 provides an inorganic soil stabilizer, and the ratio is: high belite sulphoaluminate cement clinker 20%, desulfurized gypsum 25% and S95 grade granulated blast furnace slag powder 55% (comparative examples 4, 27 and 28). The high belite sulphoaluminate cement clinker includes the following mineral components: anhydrous calcium sulphoaluminate 28%, free calcium sulfate 16%, free calcium oxide 3%, belite 45%, iron phase 6% and miscellaneous mineral components 2%. The inorganic soil stabilizer provided by the comparative example 8 is mixed with the 1# fine-grained soil to prepare a soil stabilizing material, and the mass ratio of the inorganic soil stabilizer to the soil is 0.1. According to the “Highway Engineering Inorganic Binder Stabilized Material Test Procedure” (JTG3441-2024), the unconfined compressive strength of the obtained soil stabilizing material is tested. The size of the test piece is Φ50*50mm, and the performance results are shown in Table 9.

[0140] Table 9 Performance of comparative example 8

[0141]

[0142] It can be seen from the comparison that the 7d unconfined compressive strength of the high-strength soil stabilizing material provided by the embodiments of the present application can reach 25.2MPa at most, and the unconfined compressive strength of the soil stabilizing material after 28d curing can reach more than 34.6MPa at most, which is much higher than the strength of the soil stabilizing material provided by the comparative example under the same soil stabilizer content. The high-strength soil stabilizing material provided by the present application has a significant advantage.

[0143] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-strength inorganic soil stabilizer, characterized by comprising: a calcium compound; a magnesium compound; a sodium compound; a potassium compound; a sulfate compound; and a silicate compound. The raw material components include the following mass percentages: high free calcium belite sulphoaluminate clinker 15-40%, gypsum 18-50%, and granulated blast furnace slag powder 25-62%. The high free calcium high belite calcium sulphoaluminate clinker includes the following mass percentages of mineral components: 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%. The high free calcium belite sulphoaluminate clinker includes the following mass percentages of oxides: SiO2 9.5-11.8%, Al2O3 14-18%, CaO 55-58%, SO3 8-11%, and Fe2O3 1-2%.

2. The high-strength inorganic soil stabilizer according to claim 1, wherein The preparation method of the high free calcium belite sulphoaluminate clinker includes the following steps: The limestone, bauxite and gypsum are mixed and ground to obtain raw material; The raw material is calcined at 1200-1300°C, and after cooling, the high free calcium belite sulphoaluminate clinker is obtained by grinding.

3. The high strength inorganic soil stabilizer of claim 2, wherein the calcium sulfate is anhydrite. In the preparation method of the high free calcium belite sulphoaluminate clinker, the chemical components of the raw material satisfy: ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-loss on ignition of the raw material)=14.82-19.71%; (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of the raw material)=6.55-12.26%.

4. The high-strength inorganic soil stabilizer according to any one of claims 1 to 3, wherein The raw material components also include the following mass percentages: amorphous calcium aluminate 0-3.9%, silica fume 0-5%, water reducing agent 0-1.5%, and retarder 0-0.3%.

5. The high strength inorganic soil stabilizer of claim 4, wherein the calcium sulfate is anhydrite. The content of sulfur trioxide in the gypsum is ≥35%.

6. The high strength inorganic soil stabilizer of claim 5, wherein the calcium sulfate is anhydrite. The amorphous proportion of the amorphous calcium aluminate is ≥ 99.0%; the specific surface area of the amorphous calcium aluminate is ≥ 500 m 2 / kg; The SiO2 content of the silica fume is ≥90%; The water reducing agent is at least one of polycarboxylic acid water reducing agent, melamine water reducing agent, melamine-based efficient water reducing agent, FL51 water reducing agent or naphthalene-based water reducing agent; The retarder is at least one of citric acid, sodium citrate, sodium gluconate, zinc carbonate, tartaric acid or gypsum retarder.

7. A method of producing the high-strength inorganic soil solidifying agent according to any one of claims 1 to 6, characterized by, The method includes the following steps: each raw material component is weighed according to the design ratio of the high-strength inorganic soil solidifying agent, and is uniformly mixed to obtain the high-strength inorganic soil solidifying agent.

8. A high-strength soil stabilizing material, characterized by, The high-strength inorganic soil solidifying agent of any one of claims 1-6 is included.

9. The high-strength soil stabilizing material of claim 8, wherein, The 7d unconfined compressive strength of the high-strength soil solidifying material can reach 25-27MPa. The 28d unconfined compressive strength of the high-strength soil solidifying material can reach 34-36MPa.

10. A method of producing a high-strength soil stabilizing material as claimed in claim 8 or 9, characterized in that, The high-strength inorganic soil solidifying agent of any one of claims 1-6 is mixed with soil in a mass ratio of 0.03-0.20, is uniformly shaped, is maintained, and the high-strength soil solidifying material is obtained.

11. The method for preparing the high-strength soil consolidation material as described in claim 10, characterized in that, The soil is at least one of giant particle soil, coarse-grained soil, fine-grained soil, clay, loam, silt, sandy soil, silt, silt soil, dredged soil or engineering excavation soil.

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