Temperature-sensitive self-repairing phosphogypsum composite base material and preparation method thereof

Abstract

The invention relates to the technical field of preparation of ardealite base materials, in particular to a temperature-sensitive self-repairing ardealite composite base material and a preparation method thereof. The base layer material is prepared from the following raw materials in parts by mass: 80 to 110 parts of phosphogypsum, 4 to 6 parts of alkali activator, 150 to 180 parts of graded broken stone, 5 to 10 parts of temperature-sensitive hydrogel microspheres and 10 to 15 parts of water. The base material prepared by the invention contains the temperature-sensitive hydrogel microspheres, the composite repairing agent is contained in the temperature-sensitive hydrogel microspheres, and the composite repairing agent is composed of modified nano-silica and modified wollastonite whiskers, so that under the condition that the base material has cracks, the composite repairing agent can be released to prevent the cracks of the base material from further expanding; the strength of the base material is effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of phosphogypsum base material preparation technology, specifically a thermosensitive self-healing phosphogypsum composite base material and its preparation method. Background Technology

[0002] Phosphogypsum composite base course material is a mixture mainly composed of phosphogypsum, combined with a certain proportion of crushed stone, cement, and curing agent. Its strength, durability, and water stability meet the relevant road specifications for base and subbase courses. It is a strip structure constructed according to route location and specific technical requirements, serving as the foundation of the pavement and bearing the traffic loads transmitted from the pavement. It can be a primary load-bearing layer directly beneath the asphalt pavement surface layer, or a structural layer directly beneath the cement concrete slab. It can also be a secondary load-bearing layer paved under the asphalt pavement base course or an auxiliary layer paved under the cement concrete pavement base course.

[0003] When phosphogypsum composite base materials are used in the field, factors such as temperature and pressure can sometimes cause micro-cracks to appear in the base material. If not addressed promptly, these cracks can widen, leading to damage to the base material. Traditional methods typically involve waiting until the cracks enlarge to the point of affecting normal use before manually repairing them. This approach is not only slow and inefficient but also requires significant manpower and is quite cumbersome. To address these technical problems, those skilled in the art have designed a self-healing base material for phosphogypsum base materials. Summary of the Invention

[0004] The purpose of this invention is to provide a thermosensitive self-healing phosphogypsum composite base material and its preparation method, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A temperature-sensitive self-healing phosphogypsum composite base material, comprising the following raw materials by weight: 80-110 parts phosphogypsum, 4-6 parts alkali activator, 150-180 parts graded crushed stone, 5-10 parts thermosensitive hydrogel microspheres, and 10-15 parts water; The method for preparing the temperature-sensitive hydrogel microspheres includes the following steps: S1. Add the composite repair agent, calcium chloride, sodium alginate, N-isopropylacrylamide and N,N-methylenebisacrylamide to deionized water and stir until homogeneous to obtain the aqueous phase; S2. Add fatty acid glycerides to cyclohexane and stir until homogeneous to obtain the oil phase; S3. Mix the aqueous phase and oil phase together and stir at 500-800 r / min for 20-40 min. Then heat to 40-60℃ and react continuously for 2-4 h. After that, filter and wash the filtered product with sufficient deionized water. Then vacuum dry to constant weight to obtain temperature-sensitive hydrogel microspheres. The preparation method of the composite repair agent includes the following steps: S101. Disperse nano-silica ultrasonically into a mixed solution of ethanol and deionized water containing γ-methacryloxypropyltrimethoxysilane, and soak at 60-80℃ for 4-8 hours to obtain a mixed solution. S102. Add poly(N-isopropylacrylamide) and 3-aminopropyltriethoxysilane to the mixed solution obtained in step S101, heat to 90-100℃, continue the reaction for 5-12 hours, then filter, wash the filtered product with sufficient deionized water and dry to constant weight to obtain modified nano-silica. S103. Immerse wollastonite whiskers in 0.1-0.5wt% hydrochloric acid solution and continuously sonicate for 1-5 hours. Then filter, wash the filtered product with sufficient deionized water and vacuum dry to constant weight to obtain modified wollastonite whiskers. S104. The modified nano-silica obtained in step S102 and the wollastonite whiskers obtained in step S103 are ultrasonically dispersed in deionized water and continuously stirred and mixed for 3-5 hours to obtain a mixture. S105. Add 2-4 wt% sodium alginate solution to the mixed solution in step S104, then add 0.5-1 wt% calcium chloride solution, and react continuously for 2-3 hours. After filtration, the product is washed with deionized water and vacuum dried to constant weight to obtain the composite repair agent.

[0006] Furthermore, in step S1, the mass ratio of the composite repair agent, sodium alginate, N-isopropylacrylamide, N,N-methylenebisacrylamide, and deionized water is (6-10):1:(4-8):(12-20):(0.2-1):(200-240).

[0007] Furthermore, the mass ratio between fatty acid glycerides in step S2 and N-isopropylacrylamide in step S1 is 1:(4-5), and the mass ratio between the oil phase in step S2 and the aqueous phase in step S1 is 1:(4-6).

[0008] Furthermore, in step S101, the mass ratio of γ-methacryloxypropyltrimethoxysilane, ethanol, and deionized water is 1:(20-30):(5-8), and the mass ratio of nano-silica to γ-methacryloxypropyltrimethoxysilane is 3:1.

[0009] Furthermore, in step S102, the mass ratio of poly(N-isopropylacrylamide) and 3-aminopropyltriethoxysilane to nano-silica in step S101 is (2-5):1:(10-30).

[0010] Furthermore, in step S103, the mass ratio between wollastonite whiskers and hydrochloric acid solution is 1:15.

[0011] Furthermore, in step S104, the mass ratio of modified nano-silica, modified wollastonite whiskers and deionized water is 1:(2-4):(15-20).

[0012] Furthermore, the mass ratio of sodium alginate solution, calcium chloride solution and deionized water in step S105 is (2-4):1:(5-10).

[0013] A method for preparing a thermosensitive self-healing phosphogypsum composite base material, the method comprising the following steps: Z1. Add phosphogypsum, graded crushed stone, and thermosensitive hydrogel microspheres to water according to the mass ratio, and stir to mix evenly to obtain a mixture; Z2. Add alkali activator to the mixture obtained in step S1 according to the mass fraction, and continue to stir and mix evenly to obtain a slurry; Z3. Add the slurry obtained in step S2 into the mold, cure and demold to obtain the temperature-sensitive self-healing phosphogypsum composite base material.

[0014] Furthermore, the alkali activator in step S2 is a mixture of lime and cement, with a mass ratio of lime to cement of 1:2.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The core of the interaction in this system lies in the functional symbiotic relationship established between the thermosensitive hydrogel and the hydration environment and products of phosphogypsum. The highly alkaline environment generated after the hydration of the phosphogypsum-alkali activator system provides a stable working background for the thermosensitive hydrogel, and its ionic strength helps to maintain the stability and reversibility of the swelling-shrinkage behavior of the hydrogel. 2. More importantly, the intelligent behavior of the hydrogel generates multiple positive feedbacks on the phosphogypsum matrix. First, when the ambient temperature exceeds its critical dissolution temperature (LCST), the hydrogel shrinks and releases a nanocomposite repair agent, which includes nano-silica and wollastonite whiskers. The nano-silica can immediately react with phosphogypsum and Ca(OH)2 to generate additional CSH gel, which is the chemical basis for the self-repair of microcracks. The wollastonite whiskers bridge and pull out of the cracks, consuming energy and restoring the strength of the base material. Second, the hydrogel itself acts as an "intelligent moisture manager": during the low-temperature mixing and curing stage, its swelling behavior can absorb some free water and reduce bleeding; during the high-temperature use stage, the water released by its shrinkage can be used to promote the continuous hydration of unhydrated particles, playing an internal curing role, thereby improving the density and strength of the matrix in the later stage; in addition, the propagation of cracks, which causes the hydrogel to rupture, can also promote the formation of this mechanism. 3. The composite repair agent in this invention includes nano-silica and wollastonite whiskers. The wollastonite whiskers act as a framework, and the nano-silica combined with them forms countless repair sites on a repair framework. The nano-silica is like a rivet on the wollastonite whiskers. Through this synergistic effect, the repair effect of the composite repair agent is more three-dimensional and has a better repair effect on base layer cracks. Attached Figure Description

[0016] Figure 1 This is a process flow diagram for preparing temperature-sensitive hydrogel microspheres in this invention; Figure 2 This is a process flow diagram for preparing the composite repair agent in this invention; Figure 3 This is a process flow diagram for preparing the composite substrate layer in this invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figures 1 to 3 The present invention provides: Example 1 A temperature-sensitive self-healing phosphogypsum composite base material, comprising the following raw materials by weight: 100 parts phosphogypsum, 5 parts alkali activator, 160 parts graded crushed stone, 8 parts thermosensitive hydrogel microspheres and 12 parts water.

[0019] The preparation method of the above-mentioned thermosensitive hydrogel microspheres includes the following steps: S1. Add 8 parts of composite repair agent, 1 part of calcium chloride, 6 parts of sodium alginate, 18 parts of N-isopropylacrylamide and 0.6 parts of N,N-methylenebisacrylamide to 220 parts of deionized water and stir evenly to obtain an aqueous phase. S2. Add 4 parts of fatty acid glycerides to 40 parts of cyclohexane and stir until homogeneous to obtain the oil phase; S3. Mix the aqueous phase and oil phase together and stir at 600 r / min for 30 min. Then heat to 55℃ and react continuously for 3 h. After filtration, wash the filtered product with sufficient deionized water and vacuum dry to constant weight to obtain temperature-sensitive hydrogel microspheres.

[0020] The preparation method of the above-mentioned composite repair agent includes the following steps: S101. Six parts of nano-silica were ultrasonically dispersed into a mixed solution of ethanol and deionized water containing γ-methacryloxypropyltrimethoxysilane. The amounts of γ-methacryloxypropyltrimethoxysilane, ethanol and deionized water were 2 parts, 50 parts and 12 parts, respectively. The solution was soaked at 75°C for 6 hours to obtain a mixed solution. S102. Add 1.2 parts of poly-N-isopropylacrylamide and 0.3 parts of 3-aminopropyltriethoxysilane to the mixed solution obtained in step S101, heat to 95°C, continue the reaction for 10 hours, then filter, wash the filtered product with sufficient deionized water and dry to constant weight to obtain modified nano silica. S103. 24 parts of wollastonite whiskers were soaked in 360 parts of hydrochloric acid solution with a concentration of 0.4wt% and continuously sonicated for 4 hours at a frequency of 40kHz. After filtration, the filtered product was washed with sufficient deionized water and then vacuum dried to constant weight to obtain modified wollastonite whiskers. S104. The 5 parts of modified nano-silica obtained in step S102 and the 15 parts of wollastonite whiskers obtained in step S103 are ultrasonically dispersed into 80 parts of deionized water and continuously stirred and mixed for 4 hours to obtain a mixture. S105. Add 30 parts of 3wt% sodium alginate solution to the mixed solution in step S104, then add 10 parts of 0.8wt% calcium chloride solution, and react continuously for 2.5 hours. After filtration, the product is washed with deionized water and vacuum dried to constant weight to obtain the composite repair agent.

[0021] Example 2 A temperature-sensitive self-healing phosphogypsum composite base material, comprising the following raw materials by weight: 80 parts phosphogypsum, 4 parts alkali activator, 150 parts graded crushed stone, 5 parts thermosensitive hydrogel microspheres and 10 parts water.

[0022] The preparation method of the above-mentioned thermosensitive hydrogel microspheres includes the following steps: S1. Add 6 parts of composite repair agent, 1 part of calcium chloride, 4 parts of sodium alginate, 12 parts of N-isopropylacrylamide and 0.2 parts of N,N-methylenebisacrylamide to 200 parts of deionized water and stir evenly to obtain an aqueous phase. S2. Add 3 parts of fatty acid glycerides to 52.8 parts of cyclohexane and stir until homogeneous to obtain the oil phase; S3. Mix the aqueous phase and oil phase together and stir at 500 r / min for 20 min. Then heat to 40℃ and react continuously for 2 h. After filtration, wash the filtered product with sufficient deionized water and vacuum dry to constant weight to obtain temperature-sensitive hydrogel microspheres.

[0023] The preparation method of the above-mentioned composite repair agent includes the following steps: S101. Six parts of nano-silica were ultrasonically dispersed into a mixed solution of ethanol and deionized water containing γ-methacryloxypropyltrimethoxysilane. The amounts of γ-methacryloxypropyltrimethoxysilane, ethanol and deionized water were 2 parts, 40 parts and 10 parts, respectively. The solution was soaked at 60°C for 4 hours to obtain a mixed solution. S102. Add 1.2 parts of N-isopropylacrylamide and 0.6 parts of 3-aminopropyltriethoxysilane to the mixed solution obtained in step S101, heat to 90°C, continue the reaction for 5 hours, then filter, wash the filtered product with sufficient deionized water and dry to constant weight to obtain modified nano silica. S103. 24 parts of wollastonite whiskers were soaked in 360 parts of hydrochloric acid solution with a concentration of 0.1wt% and continuously sonicated for 1 hour. After filtration, the filtered product was washed with sufficient deionized water and then vacuum dried to constant weight to obtain modified wollastonite whiskers. S104. The 4 parts of modified nano-silica obtained in step S102 and the 8 parts of wollastonite whiskers obtained in step S103 are ultrasonically dispersed into 60 parts of deionized water and continuously stirred and mixed for 3 hours to obtain a mixture. S105. Add 24 parts of 2wt% sodium alginate solution to the mixed solution in step S104, then add 12 parts of 0.5wt% calcium chloride solution, react continuously for 2 hours, then filter, and the product is washed with deionized water and vacuum dried to constant weight to obtain the composite repair agent.

[0024] Example 3 A temperature-sensitive self-healing phosphogypsum composite base material, comprising the following raw materials by weight: 110 parts phosphogypsum, 6 parts alkali activator, 180 parts graded crushed stone, 10 parts thermosensitive hydrogel microspheres and 15 parts water.

[0025] The preparation method of the above-mentioned thermosensitive hydrogel microspheres includes the following steps: S1. Add 10 parts of composite repair agent, 1 part of calcium chloride, 8 parts of sodium alginate, 20 parts of N-isopropylacrylamide and 1 part of N,N-methylenebisacrylamide to 240 parts of deionized water and stir evenly to obtain an aqueous phase. S2. Add 4 parts of fatty acid glycerides to 42.6 parts of cyclohexane and stir until homogeneous to obtain the oil phase; S3. Mix the aqueous phase and oil phase together and stir at 800 r / min for 40 min. Then heat to 60℃ and react continuously for 4 h. After filtration, wash the filtered product with sufficient deionized water and vacuum dry to constant weight to obtain temperature-sensitive hydrogel microspheres.

[0026] The preparation method of the above-mentioned composite repair agent includes the following steps: S101. Six parts of nano-silica were ultrasonically dispersed into a mixed solution of ethanol and deionized water containing γ-methacryloxypropyltrimethoxysilane. The amounts of γ-methacryloxypropyltrimethoxysilane, ethanol and deionized water were 2 parts, 60 parts and 16 parts, respectively. The solution was soaked at 80°C for 8 hours to obtain a mixed solution. S102. Add 1 part of N-isopropylacrylamide and 0.2 parts of 3-aminopropyltriethoxysilane to the mixed solution obtained in step S101, heat to 100°C, continue to react for 12 hours, then filter, wash the filtered product with sufficient deionized water and dry to constant weight to obtain modified nano silica. S103. 24 parts of wollastonite whiskers were soaked in 360 parts of hydrochloric acid solution with a concentration of 0.5wt% and subjected to continuous ultrasonic treatment for 5 hours. After filtration, the filtered product was washed with sufficient deionized water and then vacuum dried to constant weight to obtain modified wollastonite whiskers. S104. The 4 parts of modified nano-silica obtained in step S102 and the 16 parts of wollastonite whiskers obtained in step S103 are ultrasonically dispersed into 80 parts of deionized water and continuously stirred and mixed for 5 hours to obtain a mixture. S105. Add 32 parts of 4wt% sodium alginate solution to the mixed solution in step S104, then add 8 parts of 1wt% calcium chloride solution, react continuously for 3 hours, then filter, and the product is washed with deionized water and vacuum dried to constant weight to obtain the composite repair agent.

[0027] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that steps S101 and S102 were omitted, and unmodified nano-silica was added in step S104. The remaining steps are exactly the same as in Example 1.

[0028] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that step S103 was omitted, and unmodified wollastonite whiskers were added in step S104. The remaining steps are exactly the same as in Example 1.

[0029] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that step S105 is omitted, while the remaining steps are exactly the same as in Example 1.

[0030] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the composite repair agent in S1 of the raw materials was replaced with 2 parts modified nano-silica and 6 parts modified wollastonite whiskers, while the rest of the steps were exactly the same as in Example 1.

[0031] The thermosensitive self-healing phosphogypsum composite base materials obtained in Examples 1-3 and Comparative Examples 1-4 above were prepared according to the following method: Z1. Add phosphogypsum, graded crushed stone, and thermosensitive hydrogel microspheres to water according to the mass ratio, and stir to mix evenly to obtain a mixture; Z2. Add alkali activator to the mixture obtained in step S1 according to the mass fraction, and continue to stir and mix evenly to obtain a slurry; Z3. Add the slurry obtained in step S2 into the mold, cure and demold to obtain the temperature-sensitive self-healing phosphogypsum composite base material. The curing temperature is set at 22℃ and the relative humidity is 95%.

[0032] The specific dosage for each of the above Examples 1-3 and Comparative Examples 1-4 is 10g. For example, Example 1 uses 100 parts phosphogypsum, 5 parts alkali activator, 160 parts graded crushed stone, 8 parts thermosensitive hydrogel microspheres and 12 parts water. The specific dosage is 1000g phosphogypsum, 50g alkali activator, 1600g graded crushed stone, 80g thermosensitive hydrogel microspheres and 120g water. The other implementation methods are the same.

[0033] The base materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to strength tests. The testing standards were in accordance with GB / T50081-2019 "Standard for Test Methods of Mechanical Properties of Concrete". The size of the base materials tested was 100mm×100mm×100mm. The experiment consisted of three groups, each containing seven portions of base materials prepared in Examples 1-3 and Comparative Examples 1-4. The first group tested the compressive strength after 7 days of curing, the second group tested the compressive strength after 28 days of curing, and the third group tested the pressure after 7 days of curing. The pressure used was 80% of that in the first group (the 80% pressure applied in the third group corresponds to that in the first group; that is, if the compressive strength of Example 1 in the first group was 20.6MPa, then the pressure applied in Example 1 in the third group was 0.8×20.6MPa). After the pressure test, a 28-day compressive strength test was conducted. The experimental results are shown in Table 1 below.

[0034] As can be seen from the data in Table 1 above, the 7-day and 28-day compressive strengths of Comparative Examples 1-4 in this invention are not significantly different from those of Example 1. However, after the compressive strength test, due to the formation of microcracks in the base material, the repair ability of Comparative Examples 1-4 is insufficient compared to Example 1, resulting in a significant reduction in the 28-day compressive strength in subsequent tests. From the comparison between Comparative Examples 1-2 and Example 1, further modification of nano-silica and wollastonite whiskers is beneficial to improving the compatibility between nano-silica and wollastonite whiskers. Steps S10 and S105 further composite the two materials, and the composite repair material formed by them constitutes a three-dimensional repair system, which greatly improves the repair effect of the repair material on the base material.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A temperature-sensitive self-healing phosphogypsum composite base material, characterized in that, Raw materials comprising the following components by weight: 80-110 parts phosphogypsum, 4-6 parts alkali activator, 150-180 parts graded crushed stone, 5-10 parts thermosensitive hydrogel microspheres, and 10-15 parts water; The preparation method of the temperature-sensitive hydrogel microspheres includes the following steps: S1. Add the composite repair agent, calcium chloride, sodium alginate, N-isopropylacrylamide and N,N-methylenebisacrylamide to deionized water and stir until homogeneous to obtain the aqueous phase; S2. Add fatty acid glycerides to cyclohexane and stir until homogeneous to obtain the oil phase; S3. Mix the aqueous phase and oil phase together and stir at 500-800 r / min for 20-40 min. Then heat to 40-60℃ and react continuously for 2-4 h. After that, filter and wash the filtered product with sufficient deionized water. Then vacuum dry to constant weight to obtain temperature-sensitive hydrogel microspheres. The preparation method of the composite repair agent includes the following steps: S101. Disperse nano-silica ultrasonically into a mixed solution of ethanol and deionized water containing γ-methacryloxypropyltrimethoxysilane, and soak at 60-80℃ for 4-8 hours to obtain a mixed solution. S102. Add poly(N-isopropylacrylamide) and 3-aminopropyltriethoxysilane to the mixed solution obtained in step S101, heat to 90-100℃, continue the reaction for 5-12 hours, then filter, wash the filtered product with sufficient deionized water and dry to constant weight to obtain modified nano-silica. S103. Immerse wollastonite whiskers in 0.1-0.5wt% hydrochloric acid solution and continuously sonicate for 1-5 hours. Then filter, wash the filtered product with sufficient deionized water and vacuum dry to constant weight to obtain modified wollastonite whiskers. S104. The modified nano-silica obtained in step S102 and the wollastonite whiskers obtained in step S103 are ultrasonically dispersed in deionized water and continuously stirred and mixed for 3-5 hours to obtain a mixture. S105. Add 2-4 wt% sodium alginate solution to the mixed solution in step S104, then add 0.5-1 wt% calcium chloride solution, and react continuously for 2-3 hours. After filtration, the product is washed with deionized water and vacuum dried to constant weight to obtain the composite repair agent.

2. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, In step S1, the mass ratio of the composite repair agent, sodium alginate, N-isopropylacrylamide, N,N-methylenebisacrylamide, and deionized water is (6-10):1:(4-8):(12-20):(0.2-1):(200-240).

3. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, The mass ratio between fatty acid glycerides in step S2 and N-isopropylacrylamide in step S1 is 1:(4-5), and the mass ratio between the oil phase in step S2 and the aqueous phase in step S1 is 1:(4-6).

4. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, In step S101, the mass ratio of γ-methacryloxypropyltrimethoxysilane, ethanol, and deionized water is 1:(20-30):(5-8), and the mass ratio of nano-silica to γ-methacryloxypropyltrimethoxysilane is 3:

1.

5. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, In step S102, the mass ratio of poly(N-isopropylacrylamide) and 3-aminopropyltriethoxysilane to nano-silica in step S101 is (2-5):1:(10-30).

6. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, In step S103, the mass ratio of wollastonite whiskers to hydrochloric acid solution is 1:

15.

7. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, In step S104, the mass ratio of modified nano-silica, modified wollastonite whiskers and deionized water is 1:(2-4):(15-20).

8. The thermosensitive self-healing phosphogypsum composite base material according to claim 1, characterized in that, The mass ratio of sodium alginate solution, calcium chloride solution and deionized water in step S105 is (2-4):1:(5-10).

9. The preparation method of the thermosensitive self-healing phosphogypsum composite base material according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: Z1. Add phosphogypsum, graded crushed stone, and thermosensitive hydrogel microspheres to water according to the mass ratio, and stir to mix evenly to obtain a mixture; Z2. Add alkali activator to the mixture obtained in step S1 according to the mass fraction, and continue to stir and mix evenly to obtain a slurry; Z3. Add the slurry obtained in step S2 into the mold, cure and demold to obtain the temperature-sensitive self-healing phosphogypsum composite base material.

10. The preparation method of the thermosensitive self-healing phosphogypsum composite base material according to claim 9, characterized in that, The alkali activator in step S2 is a mixture of lime and cement, with a mass ratio of lime to cement of 1:2.

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