A semi-flexible pavement grouting material, a preparation method and use thereof

Abstract

The application belongs to the technical field of building materials, and particularly discloses a semi-flexible pavement grouting material, a preparation method and a use method thereof. The semi-flexible pavement grouting material comprises the following raw material components: high-free calcium belite sulphoaluminate clinker, gypsum, granulated blast furnace slag powder and fly ash cenospheres; wherein the high-free calcium belite sulphoaluminate clinker comprises the following mineral components: anhydrous calcium sulphoaluminate, free calcium sulphate, free calcium oxide, belite and iron phase. The application uses a large amount of industrial waste such as gypsum, granulated blast furnace slag powder, fly ash cenospheres and steel slag powder as main raw materials, and adds high-free calcium belite sulphoaluminate clinker, amorphous calcium aluminate and silica fume and the like, so as to utilize the synergistic effect of the components and prepare a high-strength semi-flexible pavement grouting material. The application effectively solves the problems of low strength, poor water resistance and poor durability of the grouting material under a large amount of gypsum.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, and in particular relates to a semi-flexible pavement grouting material, its preparation method and application method. Background Technology

[0002] Semi-flexible pavement is a new type of pavement structure that combines the advantages of asphalt and concrete pavements. It possesses excellent properties such as rutting resistance, wear resistance, oil resistance, and acid resistance, and is widely used in pavement construction. Semi-flexible pavement combines the flexibility of asphalt pavement with the rigidity of concrete pavement, and its rutting resistance is more than ten times that of ordinary asphalt pavement. It also has strong deformation resistance; by filling the pores of the asphalt mixture with grouting materials, its resistance to shoving deformation under high summer temperatures is improved. Furthermore, semi-flexible pavement has good durability, excellent resistance to water damage, and a long service life, reducing maintenance frequency. Although the initial construction cost is slightly higher than that of asphalt pavement alone, the significantly improved durability and reduced maintenance frequency result in a substantial decrease in the overall cost of use. This technology is now being used more and more widely.

[0003] Gypsum-based materials are increasingly used in construction projects due to their low cost and low carbon emission intensity, such as gypsum-based self-leveling mortar, gypsum-based plastering mortar, and machine-sprayed mortar. More importantly, with the rapid development of my country's chemical industry and the increasing environmental protection requirements, more and more industrial by-product gypsum is awaiting treatment, such as desulfurized gypsum, phosphogypsum, and fluorogypsum, which have accumulated for many years and are still being generated. However, the biggest drawback of gypsum-based materials is their poor water resistance and low strength, which greatly limits their development and application. Therefore, researching and developing building materials or other engineering materials that can utilize gypsum in large proportions, overcome the shortcomings of poor water resistance, and have high strength is a major scientific and technological challenge that urgently needs to be solved. Grouting materials for semi-flexible pavements are an important component of semi-flexible pavements, and their quality directly affects the performance and long-term durability of the semi-flexible pavement structure. Currently, a mixture of cement and fine sand is basically used as the basic material for grouting materials for semi-flexible pavements, and the proportion of cement by weight in the dry powder of the grouting material is generally not less than 45%. However, the production process of cement is energy-intensive, has a high carbon emission intensity, and produces a large amount of pollutants, which is environmentally unfriendly.

[0004] Therefore, developing a grouting material that can apply gypsum to semi-flexible pavements is of great practical significance for the development of grouting materials for semi-flexible pavements. Summary of the Invention

[0005] In view of this, the present invention provides a semi-flexible pavement grouting material, its preparation method, and its application method. The present invention uses a large amount of building gypsum, various industrial by-product gypsum, granulated blast furnace slag powder, fly ash microspheres, steel slag, and other industrial wastes, as well as fine sand, as the main raw materials. High-performance mineral-activated admixtures, calcium sulfoaluminate binders, inorganic mineral admixtures, and silica fume are incorporated, effectively solving the problems of low strength, poor water resistance, and poor durability of grouting materials with large gypsum usage.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] This invention provides a semi-flexible pavement grouting material, comprising the following raw material components by mass percentage: 3.65%~11% high free calcium belite sulfoaluminate clinker, 19%~40% gypsum, 31.57%~47.92% granulated blast furnace slag powder, and 8%~14% fly ash microspheres;

[0008] The high-free-calcium belite sulfoaluminate clinker comprises the following mineral components by mass percentage: anhydrous calcium sulfoaluminate 25.31%~33.27%, free calcium sulfate 6.55%~12.26%, free calcium oxide 14.82%~19.71%, belite 27.27%~33.87%, and iron phase 3.04%~6.08%.

[0009] Compared to existing technologies, the semi-flexible pavement grouting material provided by this invention utilizes high-free-calcium belite sulfoaluminate clinker to provide an excess of free calcium oxide. Due to the moderate content of free calcium sulfate in the clinker system, the free calcium oxide, amorphous / cubic anhydrous calcium sulfoaluminate, and free calcium sulfate in the clinker can react rapidly, generating a large amount of highly active AFm microcrystals in a short time. Because the above reactants are highly reactive, the generated AFm microcrystals are small in size, highly active, and in a metastable state. The inventors discovered that gypsum-based materials, due to the high solubility of their hydration product dihydrate gypsum and the absence of colloidal hydration products, exhibit poor water resistance and low strength. As the externally added gypsum gradually dissolves, the surrounding Ca... 2+ and SO4 2- The increased ion concentration induces the AFm reaction to generate a large number of AFt microcrystals around the dihydrate gypsum, a product of the gypsum hydration process. These AFt microcrystals gradually encapsulate the dihydrate gypsum crystals. The AFt microcrystals generated in this invention are small in size and have a good encapsulation effect, enabling the semi-flexible pavement grouting material to quickly form a skeleton, generate a dense microstructure, and produce high early strength.

[0010] This invention optimizes the types, crystal forms, and growth positions of hydration products generated in the early and later stages by incorporating specially designed high-free-calcium belite sulfoaluminate clinker, granulated blast furnace slag powder, and fly ash microspheres into gypsum-based materials. This promotes the directional growth of water-resistant hydration products around dihydrate gypsum. During this process, the dihydrate gypsum crystals formed by the external gypsum addition are densely coated by ettringite microcrystals and C-(A)-SH gel. Even with a high gypsum content, this invention effectively prevents the easily soluble dihydrate gypsum from dissolving in water, thus solving the problem of poor water resistance, significant strength reduction, and even collapse of gypsum-based materials caused by the high solubility of dihydrate gypsum. Furthermore, as the microstructure of the gypsum-based material gradually densifies, its internal porosity gradually decreases, and its strength is significantly improved. Simultaneously, it prevents external water from dissolving the dihydrate gypsum, solving the problem of poor water resistance in existing semi-flexible pavement grouting materials and effectively improving the mechanical properties and durability of semi-flexible pavement grouting materials.

[0011] The semi-flexible pavement grouting material of the present invention has the largest proportion of building gypsum and granulated blast furnace slag powder as its main components. Both of these raw materials are very inexpensive, thereby effectively reducing the production cost of high-strength semi-flexible pavement grouting material powder.

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

[0013] Preferably, the iron phase comprises tetracalcium aluminoferrite (C4AF).

[0014] Preferably, the high free calcium belite sulfoaluminate clinker further includes 4.95% to 7.66% mixed mineral components.

[0015] For example, based on a mass content of 100% of high free calcium belite sulfoaluminate clinker, the mixed mineral components include 2%~4% periclase (main component is MgO), 0.85%~2.55% perovskite (main component is CaTiO3), and 0.5%~1.5% alkali metal sulfates.

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

[0017] More preferably, the high-free-calcium belite sulfoaluminate clinker further includes 4% to 6.7% mixed oxides.

[0018] For example, the hybrid oxides include at least one of MgO, TiO2, Na2O or K2O.

[0019] Preferably, the specific surface area of ​​the high free calcium belite sulfoaluminate clinker is ≥500 m². 2 / kg.

[0020] More preferably, the specific surface area of ​​the high free calcium belite sulfoaluminate clinker is 510 m². 2 / kg-550m 2 / kg.

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

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

[0023] The raw material is calcined at 1200℃~1300℃ to obtain the high free calcium berite sulfoaluminate clinker.

[0024] The present invention provides a method for preparing high-free-calcium belite sulfoaluminate clinker. The method designs the amount of raw materials based on the mineral composition of the clinker, thereby calculating the proportion of each oxide in the clinker. Through extensive experimentation, the present invention has found that the optimal firing temperature range for this type of clinker is 1200℃ to 1300℃. Temperatures that are too high or too low will not allow for the formation of the target mineral composition. If the calcination temperature is too low, the mineral composition of the clinker will not be fully formed; if the calcination temperature is too high, some mineral components will decompose, and neither method will achieve the desired mineral composition range.

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

[0026] ([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%;

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

[0028] It should be noted that in this invention, [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.

[0029] This invention ensures that the content of free calcium oxide in the clinker meets the requirements by limiting ([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%. Similarly, by limiting (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal) = 6.55%~12.26%, the content of free calcium sulfate in the clinker meets the requirements.

[0030] Preferably, the mass ratio of limestone, bauxite and gypsum is (60~71):(17~23):(12~19).

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

[0032] For example, calcination is carried out in a rotary kiln, and the time from entering the kiln to exiting it is 30 to 60 minutes. The specific calcination time can be adjusted according to the specific conditions of different rotary kilns.

[0033] For example, after calcination, the process also includes cooling and grinding to obtain powdered high-free-calcium belite sulfoaluminate clinker.

[0034] The high-free-calcium belite sulfoaluminate clinker (hereinafter referred to as clinker) provided by this invention introduces a specific amount of free calcium sulfate into the clinker. Anhydrous calcium sulfoaluminate can be dissolved in the liquid phase of free calcium sulfate (the free calcium sulfate forms a liquid phase during high-temperature calcination), generating a mixture of amorphous anhydrous calcium sulfoaluminate and cubic anhydrous calcium sulfoaluminate. In the presence of free calcium sulfate, the activity of cubic anhydrous calcium sulfoaluminate is much higher than that of orthorhombic anhydrous calcium sulfoaluminate in conventional sulfoaluminate cement clinker. A specific amount of free calcium oxide is also introduced into the clinker. Free calcium oxide has high hydration activity and can react rapidly when it comes into contact with water. Therefore, a higher amount of free calcium and a suitable amount of free calcium sulfate will significantly enhance the activity of other minerals in the clinker and the clinker as a whole.

[0035] Preferably, the semi-flexible pavement grouting material further includes the following raw material components by mass percentage: 0%~0.6% amorphous calcium aluminate, 0%~26% inorganic mineral admixture, 0%~1% ordinary silica fume, 0%~0.6% high zirconium silica fume, 0%~0.18% defoamer, 0%~0.02% cellulose, 0%~0.6% water-reducing agent, 0%~1% adhesive powder, and 0%~0.26% retarder.

[0036] The present invention further limits the amount of each component in the semi-flexible pavement grouting material. The preferred amount is conducive to further exerting the synergistic effect between the components, thereby improving the unconfined compressive strength of the semi-flexible pavement grouting material.

[0037] More preferably, the amorphous content of the amorphous calcium aluminate is ≥99.0%; the specific surface area of ​​the amorphous calcium aluminate is ≥500 m². 2 / kg.

[0038] The selected amorphous calcium aluminate exhibits extremely high hydration activity, reacting completely within 5 minutes. Furthermore, the inventors' research revealed that the highly active amorphous calcium aluminate reacts rapidly with sufficient free calcium oxide and added gypsum in the clinker minerals, quickly generating small-sized, well-encapsulated ettringite microcrystals. The highly active amorphous calcium aluminate synergistically activates and stimulates the glassy structure in the granulated blast furnace slag with the clinker, and the generated ettringite microcrystals induce the dissolution of substances within the glassy structure; on the one hand, under the induction of the ettringite microcrystals, [AlO2] dissolves. ~ and Ca 2+ It reacts with externally added gypsum to continue forming ettringite, which fills the pores; the remaining Ca in the granulated blast furnace slag powder 2+ and SiO3 2- It also gradually dissolves, and the ettringite microcrystals formed in the early clinker reaction are Ca... 2+ and SiO3 2- The reaction generates C-(A)-SH gel, providing growth sites and accelerating its formation. Furthermore, the C-(A)-SH gel forms around the existing gypsum dihydrate crystals, creating an encapsulation effect. Because these C-(A)-SH gels have a low calcium-to-silica ratio and a denser microstructure, they provide better encapsulation of the gypsum dihydrate. Through the above hydration reaction and product formation process, even with a high gypsum content in this invention, the gypsum dihydrate crystals formed by the external gypsum are densely encapsulated by both ettringite microcrystals and C-(A)-SH gel. This prevents the easily water-soluble gypsum dihydrate from dissolving in water, solving the problem of poor water resistance and significantly reduced strength of gypsum-based materials caused by the high solubility of gypsum dihydrate.

[0039] 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, fluorogypsum, anhydrite, or dihydrate gypsum.

[0040] Preferably, desulfurized gypsum-based building gypsum and phosphogypsum-based building gypsum should meet the requirements of GB / T 9776-2022 "Building Gypsum"; desulfurized gypsum, phosphogypsum, and fluorogypsum should meet the requirements of GB / T 21371-2019 "Industrial By-product Gypsum Used in Cement", and phosphogypsum should also meet the requirements of GB / T 23456-2018 "Phosphogypsum"; α-high-strength gypsum should meet the requirements of JC / T2038-2010 "α-type High-strength Gypsum"; and anhydrite and dihydrate gypsum should meet the requirements of GB / T 5483-2024 "Natural Gypsum".

[0041] It should be further noted that when this invention uses two or more types of gypsum in a compound, there are no requirements on the amount of different types of gypsum used.

[0042] The fluorinated gypsum, phosphogypsum, and desulfurized gypsum in the gypsum described in this invention are all solid wastes that have been stockpiled in large quantities and are constantly being generated. The resource utilization of these solid wastes not only solves the problem of solid waste disposal, but also further reduces the cost of the grouting material described in this invention.

[0043] Preferably, the granulated blast furnace slag powder should meet the requirements of GB / T 18046-2017 "Granulated Blast Furnace Slag Powder for Cement, Mortar and Concrete" for granulated blast furnace slag powder of grade not lower than S75, and more preferably S95 grade.

[0044] More preferably, the inorganic mineral admixture is one or more of quartz powder, silica powder, fly ash, or steel slag powder.

[0045] More preferably, the particle size of the quartz powder is 100-300 mesh.

[0046] More preferably, the particle size of the silicon powder is 100-300 mesh.

[0047] More preferably, the particle size of the fly ash is 100-300 mesh.

[0048] More preferably, the particle size of the steel slag powder is 100-300 mesh.

[0049] While ensuring product performance, the semi-flexible road grouting material provided by this invention utilizes fly ash and steel slag powder, enabling the resource utilization of these two solid wastes.

[0050] More preferably, the water-reducing agent is at least one of polycarboxylate-based water-reducing agents, naphthalene-based high-efficiency water-reducing agents, melamine-based high-efficiency water-reducing agents, aminosulfonate-based high-efficiency water-reducing agents, aliphatic-based high-efficiency water-reducing agents, or lignin sulfonate-based water-reducing agents.

[0051] High fluidity is an essential property of grouting materials. The purpose of adding water-reducing agents is to enable the grouting material to have high fluidity at a low water-to-material ratio, thereby ensuring that the grouting material has both good construction convenience and high strength.

[0052] More preferably, the retarder is at least one of citric acid, sodium citrate, gluconate retarder, sugar retarder, tartrate retarder, phosphate retarder, or gypsum retarder.

[0053] More preferably, the defoamer is at least one of a polyether defoamer, an organosilicone oil defoamer, or a tributyl phosphate defoamer.

[0054] More preferably, the cellulose is hydroxyethyl methyl cellulose or hydroxypropyl methyl cellulose.

[0055] More preferably, the ordinary silica fume is 920 silica fume.

[0056] More preferably, the high-zirconium silica fume is a mixture of silica fume and zirconium oxide.

[0057] More preferably, the zirconium oxide content in the high-zirconium silica fume is ≥15%.

[0058] The fly ash microspheres are tiny, hollow or solid spherical glass particles with a specific physical morphology found in fly ash.

[0059] More preferably, the adhesive powder is at least one of vinyl acetate-ethylene copolymer adhesive powder, acrylic polymer adhesive powder, styrene-acrylic adhesive powder, or styrene-butadiene adhesive powder.

[0060] The second aspect of the present invention provides a method for preparing the semi-flexible pavement grouting material, comprising the following steps: weighing each raw material component according to the designed ratio, mixing them evenly to obtain the semi-flexible pavement grouting material.

[0061] The third aspect of the present invention provides a method for using the semi-flexible pavement grouting material, comprising the following steps: mixing water and the semi-flexible pavement grouting material evenly at a water-to-material ratio of 0.27 to 0.35.

[0062] The water-material ratio described in this invention is the mass ratio of water to the semi-flexible pavement grouting material, both in kg.

[0063] Preferably, the initial flowability of the semi-flexible pavement grouting material after mixing with water is ≥330mm, and the Marshall viscosity is 11.3~13.8s; the flowability after mixing with water for 30min is ≥305mm, and the Marshall viscosity is 12~17.5s; the grout stone rate is ≥98%.

[0064] Preferably, the 28-day compressive strength of the grout formed by adding water to the semi-flexible pavement grouting material is 55.1~81.8 MPa.

[0065] In summary, this invention provides a semi-flexible pavement grouting material. It utilizes high-free-calcium belite sulfoaluminate clinker combined with different types of gypsum or mixtures thereof, granulated blast furnace slag powder, and fly ash microspheres. The properties are finely tuned using auxiliary materials such as amorphous calcium aluminate, inorganic mineral admixtures, water-reducing agents, retarders, cellulose, adhesive powder, silica fume, and defoamers. Under the action of the highly active components in the high-free-calcium belite sulfoaluminate clinker, rapid hydration forms a large amount of microcrystalline ettringite and calcium silicate gel, fully coating the dihydrate gypsum generated during hydration, resulting in a high-strength semi-flexible pavement grouting material. This high-strength semi-flexible pavement grouting material possesses excellent mechanical properties, water resistance, and durability, and its preparation cost is low and the process is simple, providing a new design concept for the development of semi-flexible pavement grouting materials. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0067] In this invention, amorphous calcium aluminate was purchased from Anhui Qiming New Materials Co., Ltd., and it has no crystalline phase and a specific surface area of ​​561 m². 2 / kg; Desulfurized gypsum-based building gypsum was purchased from Luanxian Fuyou Renewable Resources Co., Ltd. or Shijiazhuang Rongqiang New Building Materials Co., Ltd.; phosphogypsum-based building gypsum was purchased from Shandong Shantian Chemical Technology Co., Ltd.; fluorogypsum was purchased from Anhui Jinyang Fluorochemical Co., Ltd.; anhydrite was purchased from Anhui Huantai New Materials Co., Ltd.; desulfurized gypsum was purchased from Luanxian Fuyou Renewable Resources Co., Ltd.; α-high-strength gypsum was purchased from Pingyi Yuantong Gypsum Products Co., Ltd.; S95 grade granulated blast furnace slag powder was purchased from Qian'an Shengjiu Building Materials Co., Ltd.; desulfurized gypsum was purchased from Qian'an Yangang; phosphogypsum was purchased from Qinhuangdao Huaying Phosphoric Acid Co., Ltd.; fly ash was purchased from Kaiping District Huashan Fly Ash Distribution Center; limestone powder was purchased from Tangshan Guoxin Shengmei Trading Co., Ltd. The sand, silica fume, silica powder, fly ash microspheres, water-reducing agent, retarder, accelerator, defoamer, adhesive powder, cellulose, water-repellent agent, and defoamer used without a specified manufacturer are all conventional products that can be obtained through commercial purchase. The zirconium oxide content in the high-zirconium silica fume used is 16.5%.

[0068] To better illustrate the present invention, further examples are provided below.

[0069] Example 1

[0070] This embodiment provides a high-free-calcium belite sulfoaluminate clinker, comprising the following mineral components by mass percentage: anhydrous calcium sulfoaluminate 31.92%, free calcium sulfate 6.55%, free calcium oxide 19.71%, belite 32.14%, iron phase 4.56%, and mixed mineral components 5.12%. The high-free-calcium belite sulfoaluminate clinker also comprises the following oxides by mass percentage: SiO2 11.20%, Al2O3 17.00%, CaO 58.00%, SO3 8.00%, Fe2O3 1.50%, and mixed oxides 4.30%.

[0071] The preparation method of the above-mentioned high free calcium berit sulfoaluminate clinker includes the following steps:

[0072] S100. According to the chemical composition design, limestone, bauxite and gypsum in a mass ratio of 66.4:19.3:14.3 are weighed, mixed and ground, and after passing through a 0.08mm square hole sieve, 13% residue is obtained to obtain raw material.

[0073] The chemical components in the raw meal satisfy the following:

[0074] ([CaO]-1.87×[SiO2]-1.05×[Fe2O3]-0.7×[TiO2]-0.55×[Al2O3]-0.7×[SO3]) / (100%-Loss on ignition of raw meal)=19.71%

[0075] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal)=6.55%.

[0076] S200: The raw material is calcined in a rotary kiln at 1250℃ and then ground to obtain a specific surface area of ​​525m². 2 / kg of high free calcium belite sulfoaluminate clinker.

[0077] Example 2

[0078] This embodiment provides a high-free-calcium belite sulfoaluminate clinker, comprising the following mineral components by weight percentage: anhydrous calcium sulfoaluminate 25.31%, free calcium sulfate 12.26%, free calcium oxide 14.82%, belite 33.87%, iron phase 6.08%, and mixed mineral components 7.66%. The high-free-calcium belite sulfoaluminate clinker also comprises the following oxides by weight percentage: SiO2 11.80%, Al2O3 14.00%, CaO 55.00%, SO3 10.50%, Fe2O3 2.00%, and mixed oxides 6.70%.

[0079] The preparation method of the above-mentioned high free calcium berit sulfoaluminate clinker includes the following steps:

[0080] S100. According to the chemical composition ratio, limestone, bauxite and gypsum are weighed in a mass ratio of 60.0:21.3:18.7, mixed and ground, and after passing through a 0.08mm square hole sieve, 12% residue is obtained to obtain raw material.

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

[0082] ([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%

[0083] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal)=12.26%.

[0084] S200: The raw material is calcined in a rotary kiln at 1200℃ and then ground to obtain a specific surface area of ​​520m². 2 / kg of high free calcium belite sulfoaluminate clinker.

[0085] Example 3

[0086] This embodiment provides a high-free-calcium belite sulfoaluminate clinker, comprising the following mineral components by mass percentage: anhydrous calcium sulfoaluminate 32.87%, free calcium sulfate 11.09%, free calcium oxide 17.12%, belite 27.84%, iron phase 6.08%, and mixed mineral components 4.99%. The high-free-calcium belite sulfoaluminate clinker also comprises the following oxides by mass percentage: SiO2 9.70%, Al2O3 17.80%, CaO 55.60%, SO3 10.80%, Fe2O3 2.00%, and mixed oxides 4.10%.

[0087] The preparation method of the above-mentioned high free calcium berit sulfoaluminate clinker includes the following steps:

[0088] S100. According to the chemical composition ratio, limestone, bauxite and gypsum are weighed in a mass ratio of 62.5:19.5:18.0, mixed and ground, and after passing through a 0.08mm square hole sieve, 13% residue is obtained to obtain raw material.

[0089] The chemical components in the raw meal satisfy the following:

[0090] ([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%

[0091] (1.7×[SO3]-0.45×[Al2O3]+0.28×[Fe2O3]) / (100%-loss on ignition of raw meal)=11.09%.

[0092] S200: The raw material is calcined in a rotary kiln at 1250℃ and then ground to obtain a specific surface area of ​​530m². 2 / kg of high free calcium belite sulfoaluminate clinker.

[0093] Example 4

[0094] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0095] Example 1 contains 3.65% high free calcium belite sulfoaluminate clinker, 0.5% amorphous calcium aluminate, 12% fly ash microspheres, 25% desulfurized gypsum-based building gypsum, 40% S95 grade granulated blast furnace slag powder, 17.09% silica fume, 0.3% 920 silica fume, 0.14% P803 defoamer, 0.12% XDD water-reducing agent, 0.02% 400PFV cellulose, 1.0% 328 adhesive powder, and 0.18% sodium gluconate; wherein the silica fume has a particle size of 180-200 mesh.

[0096] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0097] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.35 before use.

[0098] Example 5

[0099] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0100] The high free calcium belite sulfoaluminate clinker of Example 1 contains 3.75%, amorphous calcium aluminate 0.40%, fly ash microspheres 10%, desulfurized gypsum-based building gypsum 40%, S95 grade granulated blast furnace slag powder 44.06%, high zirconium silicate 0.3%, P803 defoamer 0.14%, XDD water-reducing agent 0.28%, 400PFV cellulose 0.02%, 328 adhesive powder 1.0%, and AG-46 gypsum retarder 0.05%.

[0101] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0102] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0103] Example 6

[0104] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0105] The high free calcium belite sulfoaluminate clinker described in Example 1 consists of 3.80% high free calcium belite sulfoaluminate clinker, 0.35% amorphous calcium aluminate, 10% fly ash microspheres, 40% anhydrite, 44.23% S95 grade granulated blast furnace slag powder, 0.3% high zirconium silicate fume, 0.14% P803 defoamer, 0.16% XDD water-reducing agent, 0.02% 400PFV cellulose, and 1.0% 328 adhesive powder.

[0106] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0107] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0108] Example 7

[0109] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0110] The high free calcium belite sulfoaluminate clinker of Example 1 contains 3.8%, amorphous calcium aluminate 0.35%, fly ash microspheres 10%, α-high-strength gypsum 40%, S95 grade granulated blast furnace slag powder 44.14%, high zirconium silicate 0.3%, P803 defoamer 0.14%, XDD water-reducing agent 0.2%, 400PFV cellulose 0.02%, 328 adhesive powder 1.0%, and AG-46 gypsum retarder 0.05%.

[0111] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0112] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0113] Example 8

[0114] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0115] The high free calcium belite sulfoaluminate clinker described in Example 1 consists of 3.9%, amorphous calcium aluminate 0.25%, fly ash microspheres 10%, fluorogypsum 40%, S95 grade granulated blast furnace slag powder 44.21%, high zirconium silicate 0.3%, P803 defoamer 0.14%, XDD water-reducing agent 0.18%, 400PFV cellulose 0.02%, and 328 adhesive powder 1.0%.

[0116] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0117] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0118] Example 9

[0119] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0120] The high free calcium belite sulfoaluminate clinker of Example 1 consists of 4.0%, amorphous calcium aluminate 0.15%, fly ash microspheres 10%, dried desulfurized gypsum 40%, S95 grade granulated blast furnace slag powder 44.05%, high zirconium silicate 0.3%, P803 defoamer 0.14%, XDD water-reducing agent 0.27%, 400PFV cellulose 0.02%, 328 adhesive powder 1.0%, and AG-46 gypsum retarder 0.07%.

[0121] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0122] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0123] Example 10

[0124] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0125] The high free calcium belite sulfoaluminate clinker of Example 1 consists of 4.15%, fly ash microspheres 10%, dried phosphogypsum 40%, S95 grade granulated blast furnace slag powder 44.06%, high zirconium silicate 0.3%, P803 defoamer 0.14%, XDD water-reducing agent 0.28%, 400PFV cellulose 0.02%, 328 adhesive powder 1.0%, and AG-46 gypsum retarder 0.05%.

[0126] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0127] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0128] Example 11

[0129] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0130] Example 2 contains 8.5% high free calcium belite sulfoaluminate clinker, 0.6% amorphous calcium aluminate, 12% fly ash microspheres, 19% phosphogypsum-based building gypsum, 47.92% S95 grade granulated blast furnace slag powder, 10% silica fume, 0.8% 920 silica fume, 0.14% P803 defoamer, 0.18% XDD water-reducing agent, 1.0% 328 adhesive powder, 0.06% citric acid, and 0.2% sodium gluconate; wherein the silica fume has a particle size of 180-200 mesh.

[0131] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0132] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0133] Example 12

[0134] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0135] Example 2 contains 8.9% high-free-calcium belite sulfoaluminate clinker, 0.3% amorphous calcium aluminate, 12% fly ash microspheres, 19% phosphogypsum-based building gypsum, 31.57% S95 grade granulated blast furnace slag powder, 26% silica fume, 0.8% 920 silica fume, 0.14% P803 defoamer, 0.18% XDD water-reducing agent, 0.02% 400PFV cellulose, 1.0% 328 adhesive powder, 0.06% sodium citrate, and 0.05% AG-46 gypsum retarder. The silica fume has a particle size of 180-200 mesh.

[0136] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0137] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0138] Example 13

[0139] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0140] Example 2 contains 9.0% high free calcium belite sulfoaluminate clinker, 0.2% amorphous calcium aluminate, 12% fly ash microspheres, 19% phosphogypsum-based building gypsum, 31.97% S95 grade granulated blast furnace slag powder, 26% fly ash, 0.3% 920 silica fume, 0.14% P803 defoamer, 0.18% XDD water-reducing agent, 1.0% 328 adhesive powder, 0.06% sodium citrate, and 0.05% AG-46 gypsum retarder.

[0141] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0142] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.34 before use.

[0143] Example 14

[0144] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0145] Example 2 contains 9.0% high-free-calcium belite sulfoaluminate clinker, 0.2% amorphous calcium aluminate, 12% fly ash microspheres, 19% desulfurized gypsum-based building gypsum, 31.57% S95 grade granulated blast furnace slag powder, 26% quartz powder, 0.8% 920 silica fume, 0.14% P803 defoamer, 0.18% XDD water-reducing agent, 1.0% 328 adhesive powder, 0.06% sodium citrate, and 0.05% AG-46 gypsum retarder. The quartz powder has a particle size of 120-200 mesh.

[0146] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0147] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0148] Example 15

[0149] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0150] Example 2 contains 8.7% high free calcium belite sulfoaluminate clinker, 0.5% amorphous calcium aluminate, 12% fly ash microspheres, 19% desulfurized gypsum-based building gypsum, 31.59% S95 grade granulated blast furnace slag powder, 26% steel slag powder, 0.8% 920 silica fume, 0.14% P803 defoamer, 0.16% XDD water-reducing agent, 0.02% 400PFV cellulose, 1.0% 328 adhesive powder, 0.06% sodium citrate, and 0.05% AG-46 gypsum retarder.

[0151] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0152] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.32 before use.

[0153] Example 16

[0154] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0155] Example 3 contains 9.5% high free calcium belite sulfoaluminate clinker, 0.15% amorphous calcium aluminate, 14% fly ash microspheres, 35% desulfurized gypsum-based building gypsum, 39.48% S95 grade granulated blast furnace slag powder, 26% silica fume, 0.3% 920 silica fume, 0.14% P803 defoamer, 0.26% XDD water-reducing agent, 0.02% Fangdakang 400 cellulose, 1.0% 7400 adhesive powder, and 0.2% sodium gluconate; wherein the silica fume has a particle size of 120-200 mesh.

[0156] Weigh each raw material component according to the design ratio, add water and mix evenly to obtain the semi-flexible road grouting material, wherein the water-to-material ratio is 0.33.

[0157] Example 17

[0158] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0159] Example 3 contains 11% high free calcium belite sulfoaluminate clinker, 0.4% amorphous calcium aluminate, 12% fly ash microspheres, 28% desulfurized gypsum-based building gypsum, 46.02% S95 grade granulated blast furnace slag powder, 0.6% high zirconium silicate fume, 0.14% P803 defoamer, 0.36% C900 water-reducing agent, 0.3% XDD water-reducing agent, 0.1% 328 adhesive powder, and 0.14% sodium gluconate.

[0160] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0161] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.30 before use.

[0162] Example 18

[0163] This embodiment provides a semi-flexible pavement grouting material and its preparation and application methods, comprising the following raw material components in weight percentage:

[0164] Example 3 contains 9.65% high free calcium belite sulfoaluminate clinker, 12% fly ash microspheres, 35% desulfurized gypsum-based building gypsum, 33.74% S95 grade granulated blast furnace slag powder, 8% silica fume, 0.5% 920 silica fume, 0.18% P8850 defoamer, 0.36% FL51 water-reducing agent, 0.02% 400PFV cellulose, 0.05% 328 adhesive powder, and 0.05% AG-36 gypsum retarder.

[0165] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0166] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.29 before use.

[0167] Comparative Example 1

[0168] This comparative example provides a road grouting material and its preparation and application methods, comprising the following raw material components in mass percentage:

[0169] The high-belite sulfoaluminate cement clinker comprises 9.65% fly ash microspheres, 12% desulfurized gypsum-based building gypsum, 35% S95 grade granulated blast furnace slag powder, 33.74% silica fume, 8% silica fume, 0.5% silica fume, 0.18% P8850 defoamer, 0.36% FL51 water-reducing agent, 0.02% 400PFV cellulose, 0.05% 328 adhesive powder, and 0.05% AG~36 gypsum retarder. The high-belite sulfoaluminate cement clinker includes the following mineral components by mass percentage: anhydrous calcium sulfoaluminate 28%, free calcium sulfate 16%, free calcium oxide 3%, belite 45%, iron phase 6%, and mixed mineral components 2%.

[0170] Weigh each raw material component according to the design ratio, mix them evenly, and obtain the semi-flexible pavement grouting material.

[0171] The semi-flexible pavement grouting material is mixed with water at a water-to-material ratio of 0.29 before use.

[0172] Verification test

[0173] The performance of the road grouting materials provided in Examples 4-18 and Comparative Example 1 was tested, and the specific test results are shown in Tables 1-2.

[0174] The test methods, specifications, and product standards used were GB / T 17671-1999 "Test Method for Strength of Cement Mortar" and JTG3420:T0508 "Test Methods for Cement and Concrete in Highway Engineering". The compressive strength, flexural strength, and Marvin viscosity of the pavement grouting materials obtained in each example and comparative example were tested.

[0175] Table 1 Test results of the examples and comparative examples

[0176]

[0177] Table 2 Test results of the examples and comparative examples

[0178]

[0179] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A semi-flexible pavement grouting material, characterized in that, The raw material components include the following percentages by weight: high free calcium belite sulfoaluminate clinker 3.65%~11%, gypsum 19%~40%, granulated blast furnace slag powder 31.57%~47.92%, and fly ash microspheres 8%~14%; The high-free-calcium belite sulfoaluminate clinker comprises the following mineral components by mass percentage: anhydrous calcium sulfoaluminate 25.31%~33.27%, free calcium sulfate 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 berit sulfoaluminate clinker comprises the following oxides in mass percentage: SiO2 9.5%~11.8%, Al2O3 14%~18%, CaO 55%~58%, SO3 8%~11% and Fe2O3 1%~2%.

2. The semi-flexible pavement grouting material as described in claim 1, characterized in that, The preparation method of the high free calcium belite sulfoaluminate clinker includes the following steps: Limestone, bauxite, and gypsum are mixed and ground to obtain raw material; The raw material is calcined at 1200℃~1300℃ to obtain the high free calcium berite sulfoaluminate clinker.

3. The semi-flexible pavement grouting material as described in claim 2, characterized in that, The chemical components in the raw meal satisfy the following: ([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%.

4. The semi-flexible pavement grouting material according to any one of claims 1-3, characterized in that, It also includes the following raw material components by mass percentage: amorphous calcium aluminate 0%~0.6%, inorganic mineral admixtures 0~26%, ordinary silica fume 0~1%, high zirconium silica fume 0~0.6%, defoamer 0~0.18%, cellulose 0~0.02%, water-reducing agent 0~0.6%, adhesive powder 0~1%, and retarder 0~0.26%.

5. The semi-flexible pavement grouting material as described in claim 4, characterized in that, The inorganic mineral admixture is one or more of the following: quartz powder, silica powder, fly ash, or steel slag powder. The water-reducing agent is at least one of the following: polycarboxylate water-reducing agent, naphthalene-based high-efficiency water-reducing agent, melamine-based high-efficiency water-reducing agent, aminosulfonate-based high-efficiency water-reducing agent, aliphatic-based high-efficiency water-reducing agent, or lignin sulfonate water-reducing agent. The retarder is at least one of citric acid, sodium citrate, gluconate retarder, sugar retarder, tartrate retarder, phosphate retarder, or gypsum retarder. The defoamer is at least one of polyether defoamer, silicone oil defoamer, or tributyl phosphate defoamer; The cellulose is hydroxyethyl methyl cellulose or hydroxypropyl methyl cellulose; The high-zirconium silica fume is a mixture of silica fume and zirconium oxide; The adhesive powder is at least one of vinyl acetate-ethylene copolymer adhesive powder, acrylic polymer adhesive powder, styrene-acrylic adhesive powder, or styrene-butadiene adhesive powder.

6. A method for preparing a semi-flexible pavement grouting material as described in any one of claims 1 to 5, characterized in that, The process includes the following steps: weigh each raw material component according to the design ratio, mix them evenly, and obtain a semi-flexible pavement grouting material.

7. A method of using the semi-flexible pavement grouting material as described in any one of claims 1 to 5, characterized in that, The process includes the following steps: mixing water and semi-flexible pavement grouting material at a water-to-material ratio of 0.27 to 0.35 until homogeneous before use.

8. The method of using the semi-flexible pavement grouting material as described in claim 7, characterized in that, The initial flowability of the semi-flexible pavement grouting material after mixing with water is ≥330mm, and the Marshall viscosity is 11.3~13.8s; the flowability after mixing with water for 30min is ≥305mm, and the Marshall viscosity is 12~17.5s; the grout stone rate is ≥98%.

9. The method of using the semi-flexible pavement grouting material as described in claim 8, characterized in that, The 28-day compressive strength of the grout formed by adding water to the semi-flexible pavement grouting material is 43.5~81.8 MPa.

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