Material for protecting and repairing wet earthen site and preparation method thereof

Abstract

The invention relates to a material for protecting and repairing a wet earthen site and a preparation method thereof, and belongs to the technical field of novel wall materials. The material is prepared from a light porous ceramsite powder filler, active metakaolin, over-fire red clay, a volcanic ash modified mineral polymer and a bio-based organic-inorganic hybrid binder. Tributyl citrate, diethyl phthalate, modified vermiculite powder and the like are used as raw materials, all the components are matched for use to prepare the composite material, and the composite material is applied to wall protection and repair of earthen ruins cracking, collapse and other diseases in a common environment or a humid environment and has the advantages of being good in compatibility, appropriate in strength, uniform in stress, durable and the like; and a good ruin repairing and protecting effect can be effectively realized.

Description

Technical Field

[0001] The invention belongs to the technical field of novel wall materials, and in particular relates to a material for protecting and repairing moist earthen ruins and a preparation method thereof. The novel wall material is used for repairing walls of ruins buildings. Background Art

[0002] Most of the earthen sites were unearthed through archaeological excavations. Most of them are exposed to the natural environment or covered with protective housing facilities. They are basically located in low-lying areas. The environment where the earthen sites are located is relatively humid. As the display time goes by, they have developed different degrees of disease problems, such as wall soil powdering, cracking, and peeling, which seriously damages the artistic expression value of the site architectural relics. In order to improve the durability of these site architectural relics, it is necessary to develop some new wall materials to protect and repair the main body of these site architectural relics, especially the walls, and improve their mechanical properties, moisture resistance, and freeze-thaw resistance.

[0003] According to the composition of the materials, repair and reinforcement materials can be divided into inorganic reinforcement materials and organic reinforcement materials. Among them, organic reinforcement materials (such as polyacrylic resin, epoxy resin, etc.) have good bonding properties and strong fluidity, and have certain advantages in the filling and reinforcement of small cracks, but their durability is low and they are prone to secondary damage to the walls of the ruins. Inorganic reinforcement materials have similar composition and structure to the wall and high compatibility, and have attracted the attention of researchers in recent years.

[0004] Common inorganic reinforcement materials include cement, lime, water glass, etc., which have been used on the walls of cultural relics. For example, Chinese patent CN114933461A discloses a nano-silicon ball-modified metakaolin-based composite material for crack grouting and its preparation and application. The composite material includes an inorganic gelling material and porous silica microspheres dispersed in the inorganic gelling material. The inorganic gelling material is a composite of metakaolin and natural hydraulic lime. However, inorganic materials also have certain disadvantages. They have poor integration with the walls of cultural relics at the site, are difficult to apply to moist soil, have a large difference in strength from the cultural relics at the site, and have uneven material stress, which causes damage to the cultural relics at the site.

[0005] Therefore, it is necessary to develop materials that are more suitable for the walls of site buildings to achieve better integration and protection and increase the lifespan of the overall site cultural relics. Summary of the invention

[0006] The existing materials have poor compatibility with the walls of ruins and cultural relics, are difficult to apply to moist soil, have a large difference in strength from the strength of ruins and cultural relics, and the materials cause uneven stress, which causes damage to the ruins and cultural relics. The present invention provides a material and preparation method for the protection and restoration of moist earthen ruins, using lightweight porous ceramsite powder filler, active kaolin, overfired red clay, volcanic ash-modified mineral polymers, bio-based organic-inorganic hybrid binders, tributyl citrate, diethyl phthalate, modified vermiculite powder, etc. as raw materials, and the various components are used in combination to prepare a composite material, which is applied to the protection and restoration of walls of earthen ruins with cracks, collapses and other diseases in ordinary environments or moist environments. It has the advantages of good compatibility, appropriate strength, uniform stress, durability, etc., and can effectively achieve a good effect of ruins restoration and protection. The specific technical scheme is as follows:

[0007] A material for the protection and restoration of wet earthen ruins comprises the following raw materials in parts by mass: 15 to 20 parts of lightweight porous ceramsite powder filler, 20 to 25 parts of active metakaolin, 10 to 15 parts of overfired red clay, 15 to 20 parts of natural hydraulic lime, 15 to 20 parts of volcanic ash modified mineral polymer, 10 to 15 parts of bio-based organic-inorganic hybrid binder, 3 to 5 parts of tributyl citrate, 1 to 3 parts of diethyl phthalate, 5 to 8 parts of modified vermiculite powder, 0 to 3 parts of pigment, 5 to 8 parts of liquid potassium silicate, 0.5 to 1 part of tartaric acid, 2 to 3 parts of silicone waterproofing agent, 0.1 to 0.5 parts of silicone defoaming agent, and the balance is water.

[0008] Among the above raw materials, the active metakaolin is obtained by calcining kaolin at 700° C. to 750° C. for 2 h to 2.5 h.

[0009] Among the above raw materials, the overfired red clay is obtained by calcining red clay at 500°C-550°C for 0.5h-1h, calcining at 600°C-650°C for 0.5h-1h, calcining at 700°C-750°C for 0.5h-1h, calcining at 800°C-850°C for 0.5h-1h and calcining at 900°C-950°C for 0.5h-1h.

[0010] Among the above raw materials, the particle size of the lightweight porous ceramsite powder filler is between 80 meshes and 150 meshes.

[0011] Among the above raw materials, the particle size of the activated metakaolin is below 1250 mesh sieve.

[0012] Among the above raw materials, the particle size of the fired red clay is between 460 mesh and 6000 mesh.

[0013] Among the above raw materials, the particle size of natural hydraulic lime is below 150 mesh sieve.

[0014] Among the above raw materials, the particle size of the volcanic ash modified mineral polymer is below 600 mesh sieve.

[0015] Among the above raw materials, the particle size of the bio-based organic-inorganic hybrid binder is below 100 mesh sieve.

[0016] Among the above raw materials, the particle size of the modified vermiculite powder is below 200 mesh sieve.

[0017] Among the above raw materials, the pigment is ferro-titanium ore powder, namely Fe 2 O 3 -TiO 2 Composite pigments.

[0018] Among the above raw materials, the preparation method of the volcanic ash modified mineral polymer includes reacting the volcanic ash with an alkaline activator, drying, and crushing to obtain the volcanic ash modified mineral polymer.

[0019] The mass ratio of volcanic ash to alkaline activator is 1:(4-6); the alkaline activator is a mixed aqueous solution of sodium hydroxide and sodium silicate, containing 15wt%-20wt% of sodium hydroxide and 22wt%-28wt% of sodium silicate; the reaction temperature is 50℃-60℃, the reaction time is 2h-3h, and the stirring speed of the reaction is 400r / min-600r / min; the particle size of the volcanic ash is below 600 mesh sieve.

[0020] Among the above raw materials, the preparation method of the bio-based organic-inorganic hybrid binder includes: adding pregelatinized starch and glutaraldehyde to water for cross-linking reaction to obtain a cross-linked biomaterial solution; ultrasonically dispersing nano titanium dioxide in ethanol to obtain a dispersion; mixing the dispersion with the cross-linked biomaterial solution, stirring for reaction, drying, and crushing to obtain a bio-based organic-inorganic hybrid binder.

[0021] The mass ratio of pregelatinized starch, glutaraldehyde and water is (1-1.2):(0.03-0.1):(6-8); the mass ratio of nano-titanium dioxide and ethanol is (1-1.5):(8-10); the volume ratio of the dispersion liquid to the cross-linked biomaterial solution is 1:(1.5-3); the temperature of the cross-linking reaction is 20°C-30°C, the time of the cross-linking reaction is 2h-3h, and the stirring speed of the cross-linking reaction is 150r / min-250r / min; the temperature of the stirring reaction is 40°C-50°C, the time of the stirring reaction is 4h-5h, and the speed of the stirring reaction is 200r / min-400r / min.

[0022] Among the above raw materials, the preparation method of modified vermiculite powder includes: uniformly dispersing the vermiculite powder in an ethanol aqueous solution by ultrasonication, adding hexadecyltrimethoxysilane, stirring for reaction, drying, and crushing to obtain the modified vermiculite powder.

[0023] The mass ratio of vermiculite powder, ethanol aqueous solution and hexadecyltrimethoxysilane is (1-1.5):(8-10):(0.3-0.8); the volume concentration of ethanol aqueous solution is 30%-50%; the stirring reaction temperature is 60°C-70°C, the stirring reaction time is 5h-6h, and the stirring reaction speed is 300r / min-500r / min; the particle size of the vermiculite powder is below 200 mesh sieve.

[0024] The method for preparing the material for the protection and restoration of wet earthen ruins comprises the following steps:

[0025] S1: Pour the lightweight porous ceramsite powder filler, active metakaolin, overfired red clay, natural hydraulic lime, volcanic ash modified mineral polymer, bio-based organic-inorganic hybrid binder, modified vermiculite powder, tartaric acid and pigment into a stirring container according to the mass proportions, stir and mix evenly to obtain a mixture A;

[0026] S2: adding tributyl citrate, diethyl phthalate, liquid potassium silicate, silicone waterproofing agent and silicone defoaming agent to mixture A, stirring and mixing evenly to obtain mixture B;

[0027] S3: Add water to mixture B, stir evenly, let stand for 10 to 15 minutes, and then mix evenly to obtain a uniform slurry.

[0028] The present invention provides a material and a preparation method for the protection and restoration of wet earthen ruins, and the beneficial effects are as follows:

[0029] 1. Active metakaolin is calcined from kaolin, with its crystal structure destroyed, specific surface area increased, and active points increased. Compared with kaolin, it can react with water and alkaline substances faster to generate more gelling products, significantly improving the early strength and later durability of the material, and can work better with other materials to improve overall performance.

[0030] 2. After multiple stages of calcination, the moisture and organic matter in the internal structure of over-fired red clay are removed, the crystal structure is changed, and the pore structure is more reasonable. Compared with red clay, it has better stability, stronger water resistance, less shrinkage, can maintain better performance in a humid environment, and can improve the overall stability and deformation resistance of the material when mixed with other ingredients.

[0031] 3. Volcanic ash modified mineral polymers are activated by alkaline activators to form a more stable three-dimensional network structure. Compared with pure volcanic ash, it has higher reactivity and can produce more gelling substances in a shorter time, greatly improving the strength and durability of the material, and significantly enhancing its impermeability and chemical corrosion resistance.

[0032] 4. Bio-based organic-inorganic hybrid binders combine the flexibility of organic materials and the rigidity and stability of inorganic materials through cross-linking reaction and introduction of nano-titanium dioxide. Compared with gelatinized corn starch, it has higher bonding strength, better water resistance, stronger anti-aging performance, can maintain good bonding effect in humid environments, and has better durability and resistance to microbial erosion.

[0033] 5. Tributyl citrate and diethyl phthalate are both plasticizers. When used together, they can play a role under different temperature and humidity conditions, more comprehensively reduce the glass transition temperature of the material, and make the material maintain good flexibility and plasticity in a wider temperature range. They can also effectively reduce the pores of the composite material, enhance the processing performance and use performance of the material, and improve the comprehensive performance of the material. The selection and addition ratio of the two components are designed according to the soil characteristics of the ruins, which can well blend the materials with the ruins. The use of the two in a certain proportion has a good synergistic effect on the repair material.

[0034] 6. Modified vermiculite powder introduces organic functional groups through surface modification, and the surface changes from hydrophilic to hydrophobic, which improves the compatibility with organic and inorganic materials. Compared with vermiculite powder, it can be better dispersed in the material, has stronger binding force with other components, and can more effectively improve the mechanical properties, thermal stability and waterproof properties of the material.

[0035] 7. Active metakaolin and over-fired red clay provide strength and stability; bio-based organic-inorganic hybrid binder enhances the bonding effect; modified vermiculite powder improves the comprehensive performance of the material; tributyl citrate and diethyl phthalate make the material flexible and plastic. They work together to enable the material to maintain good mechanical properties and stability in a humid environment, while also having appropriate flexibility and waterproof properties, good fusion, and improve the overall durability, impermeability and deformation resistance of the material, achieving a synergistic improvement of multiple properties.

[0036] In summary, materials such as active metakaolin and natural hydraulic lime have certain gelling properties and affinity, and can be well combined with the soil of earthen sites; bio-based organic-inorganic hybrid binders can also help enhance the bond with the soil and facilitate integration. Silicone waterproofing agents can effectively improve the waterproof performance of materials and can resist humid environments to a certain extent; the reasonable combination of various raw materials forms a dense material structure, which can reduce the impact of moisture on material properties and is suitable for humid soil. Lightweight porous ceramsite powder fillers and other materials work together to ensure a certain strength while matching the material performance with humid earthen sites and reducing strength differences. The material has certain fluidity and flexibility, high mixing uniformity, can make stress distribution uniform, reduce damage to the wall layer, and is durable.

[0037] The preparation method is simple, easy, fast and efficient, and has prospects for large-scale application; the operation process is environmentally friendly and safe, has little impact on operators and the environment, has good biocompatibility and is non-toxic and non-irritating; in addition, the inorganic reinforcement material has high durability and is more suitable for the long-term protection of earthen site cultural relics, and is suitable for the protection and restoration of wet earthen sites. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific implementation cases, but the present invention is not limited to these embodiments.

[0039] Example 1

[0040] A material for the protection and restoration of wet earthen ruins, comprising the following raw materials in parts by mass: 18 parts of lightweight porous ceramsite powder filler, 23 parts of active kaolin, 12 parts of overfired red clay, 18 parts of natural hydraulic lime, 18 parts of volcanic ash modified mineral polymer, 12 parts of bio-based organic-inorganic hybrid binder, 4 parts of tributyl citrate, 2 parts of diethyl phthalate, 6.5 parts of modified vermiculite powder, 6.5 parts of liquid potassium silicate, 0.8 parts of tartaric acid, 2.5 parts of silicone waterproofing agent, 0.3 parts of silicone defoaming agent, and the balance is water.

[0041] Among them, the particle size of the lightweight porous ceramsite powder filler is between 80 mesh and 150 mesh. The particle size of the active kaolin is below 1250 mesh. The particle size of the fired red clay is between 460 mesh and 6000 mesh. The particle size of the natural hydraulic lime is below 150 mesh. The particle size of the volcanic ash modified mineral polymer is below 600 mesh. The particle size of the bio-based organic-inorganic hybrid binder is below 100 mesh. The particle size of the modified vermiculite powder is below 200 mesh.

[0042] The active metakaolin is obtained by calcining kaolin at 750°C for 2 hours.

[0043] The overfired red clay is obtained by calcining red clay at 500°C for 0.5h, 600°C for 0.5h, 700°C for 0.5h, 800°C for 0.5h and 900°C for 0.5h in sequence.

[0044] The preparation method of volcanic ash modified mineral polymer includes: preparing an alkaline activator, which is a mixed aqueous solution of sodium hydroxide and sodium silicate, containing 18wt% of sodium hydroxide and 25wt% of sodium silicate; mixing the volcanic ash passed through a 600-mesh sieve with the alkaline activator at a mass ratio of 1:5, stirring and reacting at 55°C and 500r / min for 2.5h, drying to constant weight, crushing, passing through a 600-mesh sieve, taking the sieve material, and obtaining the volcanic ash modified mineral polymer.

[0045] Among them, the preparation method of the bio-based organic-inorganic hybrid binder includes: adding pregelatinized starch and glutaraldehyde to water at a mass ratio of 1.1:0.06:7, and carrying out a cross-linking reaction for 2.5 hours at 25°C and 200r / min stirring conditions to obtain a cross-linked biomaterial solution; ultrasonically dispersing nano-titanium dioxide in ethanol at a mass ratio of 1.2:9 to obtain a dispersion; mixing the dispersion with the cross-linked biomaterial solution at a volume ratio of 1:2.2, stirring and reacting at 45°C and 300r / min for 4.5 hours, drying to constant weight, crushing, passing through a 100-mesh sieve, taking the sieve under the sieve to obtain a bio-based organic-inorganic hybrid binder.

[0046] The preparation method of modified vermiculite powder includes: uniformly dispersing the vermiculite powder passing through a 200-mesh sieve in an ethanol aqueous solution with a volume concentration of 40% by ultrasonic method according to the mass ratio of vermiculite powder, ethanol aqueous solution and hexadecyltrimethoxysilane being 1.2:9:0.5, adding hexadecyltrimethoxysilane, stirring and reacting at 65°C and 400r / min for 5.5h, drying to constant weight, crushing, passing through a 200-mesh sieve, taking the sieved material, and obtaining modified vermiculite powder.

[0047] The method for preparing the material for the protection and restoration of wet earthen ruins comprises the following steps:

[0048] S1: Pour the lightweight porous ceramsite powder filler, active metakaolin, overfired red clay, natural hydraulic lime, volcanic ash modified mineral polymer, bio-based organic-inorganic hybrid binder, modified vermiculite powder and tartaric acid into a stirring container according to the mass proportion, stir at a speed of 120 r / min for 8 min, and mix evenly to obtain a mixture A;

[0049] S2: Add tributyl citrate, diethyl phthalate, liquid potassium silicate, silicone waterproofing agent and silicone defoaming agent to mixture A according to their mass fractions, stir at a speed of 250 r / min for 12 min, mix well, and obtain mixture B;

[0050] S3: Add 50% water of the mass of mixture B to mixture B, stir evenly, let stand for aging for 12 minutes, and then mix evenly to obtain a uniform slurry.

[0051] Example 2

[0052] A material for the protection and restoration of wet earth ruins, comprising the following raw materials in parts by mass: 15 parts of lightweight porous ceramsite powder filler, 20 parts of active kaolin, 10 parts of overfired red clay, 15 parts of natural hydraulic lime, 15 parts of volcanic ash modified mineral polymer, 10 parts of bio-based organic-inorganic hybrid binder, 3 parts of tributyl citrate, 1 part of diethyl phthalate, 5 parts of modified vermiculite powder, 1.5 parts of pigment, 5 parts of liquid potassium silicate, 0.5 parts of tartaric acid, 2 parts of silicone waterproofing agent, 0.1 parts of silicone defoaming agent, and the balance is water.

[0053] Among them, the particle size of the lightweight porous ceramsite powder filler is between 80 mesh and 150 mesh. The particle size of the active kaolin is below 1250 mesh. The particle size of the overfired red clay is between 460 mesh and 6000 mesh. The particle size of the natural hydraulic lime is below 150 mesh. The particle size of the volcanic ash modified mineral polymer is below 600 mesh. The particle size of the bio-based organic-inorganic hybrid binder is below 100 mesh. The particle size of the modified vermiculite powder is below 200 mesh. The pigment is ferro-titanium ore powder, that is, Fe 2 O 3 -TiO 2 Composite pigments.

[0054] The active metakaolin is obtained by calcining kaolin at 730°C for 2 hours.

[0055] The overfired red clay is obtained by calcining red clay at 520°C for 1 hour, 630°C for 1 hour, 720°C for 1 hour, 830°C for 1 hour and 920°C for 1 hour in sequence.

[0056] The preparation method of volcanic ash modified mineral polymer includes: preparing an alkaline activator, which is a mixed aqueous solution of sodium hydroxide and sodium silicate, containing 15wt% of sodium hydroxide and 22wt% of sodium silicate; mixing the volcanic ash passed through a 600-mesh sieve with the alkaline activator at a mass ratio of 1:4, stirring and reacting at 50°C and 400r / min for 2h, drying to constant weight, crushing, passing through a 600-mesh sieve, taking the sieve material, and obtaining the volcanic ash modified mineral polymer.

[0057] Among them, the preparation method of the bio-based organic-inorganic hybrid binder includes: adding pregelatinized starch and glutaraldehyde to water at a mass ratio of 1:0.03:6, and carrying out a cross-linking reaction for 2 hours at 20°C and 150r / min stirring conditions to obtain a cross-linked biomaterial solution; ultrasonically dispersing nano-titanium dioxide in ethanol at a mass ratio of 1:8 to ethanol to obtain a dispersion; mixing the dispersion with the cross-linked biomaterial solution at a volume ratio of the dispersion to the cross-linked biomaterial solution of 1:1.5, stirring and reacting at 40°C and 200r / min for 4 hours, drying to constant weight, crushing, passing through a 100-mesh sieve, taking the sieve under the sieve to obtain a bio-based organic-inorganic hybrid binder.

[0058] The preparation method of modified vermiculite powder includes: uniformly dispersing the vermiculite powder passing through a 200-mesh sieve in an ethanol aqueous solution with a volume concentration of 30% by ultrasonic according to the mass ratio of vermiculite powder, ethanol aqueous solution and hexadecyltrimethoxysilane being 1:8:0.3, adding hexadecyltrimethoxysilane, stirring and reacting at 60°C and 300r / min for 5h, drying to constant weight, crushing, passing through a 200-mesh sieve, taking the sieved material, and obtaining modified vermiculite powder.

[0059] The method for preparing the material for the protection and restoration of wet earthen ruins comprises the following steps:

[0060] S1: Pour the lightweight porous ceramsite powder filler, active metakaolin, overfired red clay, natural hydraulic lime, volcanic ash modified mineral polymer, bio-based organic-inorganic hybrid binder, modified vermiculite powder, tartaric acid and pigment into a stirring container according to the mass proportion, stir at a speed of 100 r / min for 5 min, mix evenly, and obtain a mixture A;

[0061] S2: Add tributyl citrate, diethyl phthalate, liquid potassium silicate, silicone waterproofing agent and silicone defoaming agent to mixture A according to their mass fractions, stir at a speed of 200 r / min for 10 min, mix well, and obtain mixture B;

[0062] S3: Add 45% of the mass of mixture B into mixture B, mix evenly, let stand for aging for 10 minutes, and then mix evenly to obtain a uniform slurry.

[0063] Example 3

[0064] A material for the protection and restoration of wet earth ruins, comprising the following raw materials in parts by mass: 20 parts of lightweight porous ceramsite powder filler, 25 parts of active kaolin, 15 parts of overfired red clay, 20 parts of natural hydraulic lime, 20 parts of volcanic ash modified mineral polymer, 15 parts of bio-based organic-inorganic hybrid binder, 5 parts of tributyl citrate, 3 parts of diethyl phthalate, 8 parts of modified vermiculite powder, 3 parts of pigment, 8 parts of liquid potassium silicate, 1 part of tartaric acid, 3 parts of silicone waterproofing agent, 0.5 parts of silicone defoaming agent, and the balance is water.

[0065] Among them, the particle size of the lightweight porous ceramsite powder filler is between 80 mesh and 150 mesh. The particle size of the active kaolin is below 1250 mesh. The particle size of the overfired red clay is between 460 mesh and 6000 mesh. The particle size of the natural hydraulic lime is below 150 mesh. The particle size of the volcanic ash modified mineral polymer is below 600 mesh. The particle size of the bio-based organic-inorganic hybrid binder is below 100 mesh. The particle size of the modified vermiculite powder is below 200 mesh. The pigment is ferro-titanium ore powder, that is, Fe 2 O 3 -TiO 2 Composite pigments.

[0066] The active metakaolin is obtained by calcining kaolin at 700°C for 2.5 hours.

[0067] The overfired red clay is obtained by calcining red clay at 550°C for 0.5h, 650°C for 0.5h, 750°C for 0.5h, 850°C for 0.5h and 950°C for 0.5h in sequence.

[0068] The preparation method of volcanic ash modified mineral polymer includes: preparing an alkaline activator, which is a mixed aqueous solution of sodium hydroxide and sodium silicate, containing 20wt% of sodium hydroxide and 28wt% of sodium silicate; mixing the volcanic ash passed through a 600-mesh sieve with the alkaline activator at a mass ratio of 1:6, stirring and reacting at 60°C and 600r / min for 3h, drying to constant weight, crushing, passing through a 600-mesh sieve, taking the sieve material, and obtaining the volcanic ash modified mineral polymer.

[0069] Among them, the preparation method of the bio-based organic-inorganic hybrid binder includes: adding pregelatinized starch and glutaraldehyde to water at a mass ratio of 1.2:0.1:8, and carrying out a cross-linking reaction for 3 hours at 30°C and 250r / min stirring conditions to obtain a cross-linked biomaterial solution; ultrasonically dispersing nano-titanium dioxide in ethanol at a mass ratio of 1.5:10 to obtain a dispersion; mixing the dispersion with the cross-linked biomaterial solution at a volume ratio of 1:3, stirring and reacting at 50°C and 400r / min for 5 hours, drying to constant weight, crushing, passing through a 100-mesh sieve, taking the sieve under the sieve to obtain a bio-based organic-inorganic hybrid binder.

[0070] The preparation method of modified vermiculite powder includes: uniformly dispersing the vermiculite powder passing through a 200-mesh sieve in an ethanol aqueous solution with a volume concentration of 50% by ultrasonic method according to the mass ratio of vermiculite powder, ethanol aqueous solution and hexadecyltrimethoxysilane being 1.5:10:0.8, adding hexadecyltrimethoxysilane, stirring and reacting at 70°C and a speed of 500r / min for 6h, drying to constant weight, crushing, passing through a 200-mesh sieve, taking the sieved material, and obtaining modified vermiculite powder.

[0071] The method for preparing the material for the protection and restoration of wet earthen ruins comprises the following steps:

[0072] S1: Pour the lightweight porous ceramsite powder filler, active metakaolin, overfired red clay, natural hydraulic lime, volcanic ash modified mineral polymer, bio-based organic-inorganic hybrid binder, modified vermiculite powder, tartaric acid and pigment into a stirring container according to the mass proportion, stir at a speed of 150 r / min for 10 min, mix evenly, and obtain a mixture A;

[0073] S2: Add tributyl citrate, diethyl phthalate, liquid potassium silicate, silicone waterproofing agent and silicone defoaming agent to mixture A according to their mass fractions, stir at a speed of 300 r / min for 15 min, mix well, and obtain mixture B;

[0074] S3: Add 55% of the mass of mixture B into mixture B, mix evenly, let stand for aging for 15 minutes, and then mix evenly to obtain a uniform slurry.

[0075] In the above embodiments, the material of the lightweight porous ceramsite powder filler is lightweight shale ceramsite, which comes from Anhui Kongshi Ceramsite Products Co., Ltd. The active kaolin comes from Lingshou County Jieling Mineral Products Trading Co., Ltd. The red clay comes from SL-05 red clay from Lingshou County Shuolong Mineral Products Processing Plant. The raw materials of natural hydraulic lime come from Shanghai Desaibao Building Materials Co., Ltd., model NHL2. Volcanic ash comes from Lingshou County Jiashuo Building Materials Processing Co., Ltd. Pregelatinized starch comes from Ningjin County Jiahe Energy Saving Materials Co., Ltd., model JH-001, containing cassava starch and corn starch. Vermiculite powder comes from Lingshou County Baofeng Mica Processing Co., Ltd. Hexadecyl trimethoxysilane comes from Guangzhou Shanghe Chemical Technology Co., Ltd., model 151. Tributyl citrate comes from Shandong Shuntai Chemical Co., Ltd., model 0711. Diethyl phthalate comes from Shandong Xinbaihe Chemical Technology Co., Ltd., model EYZ06. Liquid potassium silicate comes from Guangzhou Fuer Chemical Technology Co., Ltd., model WLK-2.8-P, 40 degrees Baume. Tartaric acid comes from Suzhou Kuangshi Chemical Co., Ltd., DL-tartaric acid powder. Silicone waterproofing agent comes from Shandong Pulisi New Energy Co., Ltd., model FSJ001. Silicone defoaming agent comes from Jinan Xinchen Chemical Co., Ltd., model YT-20A.

[0076] Comparative Example 1

[0077] Among the materials, active metakaolin was replaced by kaolin, that is, no calcination was performed; other parameters and methods were the same as in Example 1.

[0078] Comparative Example 2

[0079] Among the materials, the over-fired red clay was replaced by red clay, that is, no calcination was performed; other parameters and methods were the same as in Example 1.

[0080] Comparative Example 3

[0081] In the material, the volcanic ash-modified mineral polymer is replaced by volcanic ash, that is, no modification is performed; other parameters and methods are the same as in Example 1.

[0082] Comparative Example 4

[0083] In the material, the bio-based organic-inorganic hybrid binder is replaced by gelatinized corn starch; other parameters and methods are the same as in Example 1. The gelatinized corn starch comes from Henan Fengwei Biotechnology Co., Ltd.

[0084] Comparative Example 5

[0085] In the material, tributyl citrate was not added, and the amount of tributyl citrate was replaced by diethyl phthalate; other parameters and methods were the same as in Example 1.

[0086] Comparative Example 6

[0087] In the material, no diethyl phthalate was added, and the amount of diethyl phthalate was replaced by tributyl citrate; other parameters and methods were the same as in Example 1.

[0088] Comparative Example 7

[0089] In the material, tributyl citrate and diethyl phthalate were not added, and activated metakaolin was used instead; other parameters and methods were the same as in Example 1.

[0090] Comparative Example 8

[0091] In the material, the modified vermiculite powder is replaced by vermiculite powder; other parameters and methods are the same as in Example 1.

[0092] Comparative Example 9

[0093] The active metakaolin was replaced by kaolin, the over-fired red clay was replaced by red clay, the bio-based organic-inorganic hybrid binder was replaced by gelatinized corn starch, and the modified vermiculite powder was replaced by vermiculite powder; other parameters and methods were the same as in Example 1.

[0094] Comparative Example 10

[0095] Activated metakaolin was replaced by kaolin, over-fired red clay was replaced by red clay, the bio-based organic-inorganic hybrid binder was replaced by gelatinized corn starch, and the modified vermiculite powder was replaced by vermiculite powder; at the same time, tributyl citrate and diethyl phthalate were not added, and the amounts used were all replaced by activated metakaolin; other parameters and methods were the same as in Example 1.

[0096] The slurries prepared in the above-mentioned embodiments and comparative examples were tested for use.

[0097] 1. Fusion test: Take a small sample of the mixed wall of a Qing Dynasty building in a certain site (combining the characteristics of brick wall and rammed earth wall, with a compressive strength of about 15MPa) as the test matrix, and evenly apply the slurry on the surface of the sample, and the coating thickness is controlled to be 5mm. The curing process is carried out in a standard curing room, the temperature is maintained at 20±2℃, the relative humidity is maintained at above 95%, and the curing time is 28 days. After the curing period, 5 different locations are randomly selected, and the width of the interface transition zone is measured. The average value is taken to quantify the fusion. The smaller the width, the better the fusion. The test results are shown in Table 1 below.

[0098] 2. Compressive strength and wet soil applicability test: The material is made into 6 cylindrical specimens with a diameter of 50mm and a height of 50mm. After 28 days of standard curing, 3 specimens are taken to test the compressive strength, and the average value is taken as the compressive strength before the specimen is soaked. The remaining 3 specimens are used to simulate the wet soil environment. The specimens are placed in a constant temperature and humidity chamber with the humidity set to 95% and the temperature set to 25°C. The specimens are completely immersed in water below the simulated groundwater level, and the soaking time is strictly controlled to 3 months. After the soaking, the specimens are taken out and their compressive strength is tested using a universal material testing machine. The average value is taken as the compressive strength after the specimen is soaked; the compressive strength retention rate is calculated, and the formula is: compressive strength retention rate = compressive strength after specimen soaking / compressive strength before specimen soaking × 100%. The test results are shown in Table 1 below.

[0099] 3. Stress uniformity test: Prepare a material specimen with a size of 100mm×100mm×100mm, evenly paste 10 high-precision strain gauges on the surface of the material specimen, use a material testing machine to perform uniaxial compression loading on the specimen, and strictly control the loading rate to 0.05mm / min until the material specimen is destroyed. The strain data of the strain gauges at different positions are collected in real time through the data acquisition system, and the strain standard deviation is calculated; the smaller the standard deviation, the better the stress uniformity. The test results are shown in Table 1 below.

[0100] Table 1 Test data results

[0101]

[0102]

[0103] As can be seen from the above results, the materials of Example 1 to Example 3 have more suitable fusion after use, which means that the mechanical properties between the two materials change more slowly. When the external material is combined with the site cultural relic wall, if the transition zone is too large, a significant mechanical property gradient will be formed between the two. When subjected to external force, stress concentration is easily generated in this transition zone, resulting in cracks and falling off at the junction. In a moderate transition zone, the mechanical properties between the materials are closer, stress can be transmitted more evenly, the overall structure is more stable, and the fusion is better. If the transition zone is too large, it means that excessive chemical reactions or physical penetrations have occurred between the materials, which will change the original structure and performance of the site cultural relic wall, such as causing the composition of the wall material to be excessively diluted, the crystal structure to be destroyed, etc. The moderate transition zone shows that there can be a certain bonding force between the materials, and it will not cause too much interference to the original properties of the cultural relic wall, thereby ensuring good fusion. The compressive strength of the materials of each embodiment is moderate, fits the strength of the site wall, has good applicability to moist soil, has a high retention rate of compressive strength, and has uniform stress, which can play a good protective role.

[0104] In comparative example 1, active metakaolin is replaced by kaolin without calcination. Kaolin has a complete crystal structure and few active sites, and it is difficult to fully react chemically with the components in the wall material of the site cultural relics. In terms of fusion, it is impossible to form a tight chemical bond connection. In a humid environment, kaolin easily absorbs water and swells, destroying the internal structure of the material and reducing the retention rate of compressive strength. The unevenness of the internal structure leads to large differences in strain distribution when subjected to force, and the compressive strength is also reduced.

[0105] In comparative example 2, the over-fired red clay was replaced with red clay without calcination. The mineral structure of the uncalcined red clay has not changed, the bonding force between particles is weak, and it is not tightly bonded to other components and the walls of the ruins. It has poor fusion. In a humid environment, the soluble components in the red clay are easily dissolved and lost, resulting in structural damage and low retention rate of compressive strength. Its strength is different from that of the over-fired red clay that has been calcined and modified. The uncalcined red clay has large pores and good connectivity, which enhances permeability, poor overall uniformity of the material, and uneven stress distribution when subjected to force.

[0106] Comparative Example 3, the volcanic ash-modified mineral polymer is replaced by volcanic ash without modification. The unmodified volcanic ash has low activity and low degree of participation in the chemical reaction of the material, and cannot effectively fill the internal pores of the material and improve the structure. In terms of fusion, the degree of integration with the walls of the site cultural relics is average. In a humid environment, insufficient reaction leads to insufficient resistance of the material to environmental erosion and low retention rate of compressive strength. Unmodified materials have an insufficiently dense internal structure, more gas permeation paths, uneven internal structure, uneven stress distribution, and low overall strength.

[0107] In comparative example 4, the bio-based organic-inorganic hybrid binder is replaced by gelatinized corn starch. The main component of gelatinized corn starch is polysaccharide, and the bonding effect mainly relies on physical entanglement, and the bonding force is much lower than that of the bio-based organic-inorganic hybrid binder. In terms of fusion, it is impossible to make the material tightly combined with the wall of the site cultural relics. In a humid environment, gelatinized corn starch is easily decomposed by microorganisms, resulting in damage to the material structure and reduced compressive strength retention rate. The overall strength of the material cannot be effectively enhanced, the internal bonding of the material is not tight, there are many pore channels, and the unstable structure leads to extremely uneven stress distribution when subjected to force.

[0108] In comparative example 5, tributyl citrate is not added. Tributyl citrate, as a plasticizer, can reduce the intermolecular forces within the material and increase flexibility. When not added, the rigidity of the material is enhanced, and it is difficult to form a good microscopic bond with the wall of the site cultural relics during bonding. In a humid environment, the material becomes more brittle, its ability to resist volume changes caused by humidity changes decreases, and the retention rate of compressive strength decreases. Not adding tributyl citrate has a certain effect on the internal structure of the material, especially the internal porosity becomes larger, which reduces the strength, and the internal stress distribution is not uniform due to the change in flexibility.

[0109] In comparative example 6, diethyl phthalate is not added. Diethyl phthalate also has a plasticizing effect, and its absence reduces the flexibility of the material. In terms of fusion, the fusion effect with the wall of the site cultural relics is affected. In a humid environment, the ability to resist deformation caused by humidity decreases, and the retention rate of compressive strength decreases. The stress distribution is uneven due to the change in material flexibility, which affects the overall performance of the material.

[0110] Comparative Example 7, tributyl citrate and diethyl phthalate are not added at the same time. Both plasticizers are missing, the brittleness of the material is greatly increased, and the flexibility is almost lost. In terms of integration, the integration with the walls of the site cultural relics is even worse. In a humid environment, it is very easy to cause cracks and other damage due to humidity changes, and the compressive strength retention rate is extremely low. The structure is loose, the stress distribution is extremely uneven, and the strength characteristics change significantly.

[0111] In comparative example 8, modified vermiculite powder is replaced by vermiculite powder. Unmodified vermiculite powder has low surface activity and poor compatibility with other ingredients, and cannot be effectively dispersed in the material system. In terms of fusion, the combination effect with other ingredients and the walls of ruins and cultural relics is affected. In a humid environment, it cannot effectively play the role of strengthening and stabilizing the structure, and the retention rate of compressive strength is reduced. The effect on enhancing the strength of the material is limited, the overall uniformity of the material is affected, and the stress uniformity is poor.

[0112] In comparative example 9, multiple key components were not processed or replaced. The performance of multiple key components was poor, resulting in a chaotic overall structure of the material. In terms of integration, it was almost impossible to form an effective combination with the walls of the site cultural relics. In a humid environment, it was severely damaged and the compressive strength retention rate was extremely low. The internal structure was chaotic and the stress distribution was extremely uneven.

[0113] In comparative example 10, multiple key components were not processed or replaced and no plasticizer was added. Multiple unfavorable factors were superimposed, the internal structure of the material was disordered, the compatibility of the components was poor, the reaction was limited, and the water resistance was poor, and the material properties were seriously deteriorated.

Claims

1. A material for the protection and restoration of wet earth ruins, characterized in that: The invention comprises the following raw materials in parts by weight: 15 to 20 parts of lightweight porous expanded clay powder filler, 20 to 25 parts of active kaolin, 10 to 15 parts of overfired red clay, 15 to 20 parts of natural hydraulic lime, 15 to 20 parts of volcanic ash modified mineral polymer, 10 to 15 parts of bio-based organic-inorganic hybrid binder, 3 to 5 parts of tributyl citrate, 1 to 3 parts of diethyl phthalate, 5 to 8 parts of modified vermiculite powder, 0 to 3 parts of pigment, 5 to 8 parts of liquid potassium silicate, 0.5 to 1 part of tartaric acid, 2 to 3 parts of silicone waterproofing agent, 0.1 to 0.5 parts of silicone defoaming agent, and the balance is water.

2. A material for the protection and restoration of wet earth ruins according to claim 1, characterized in that: The active metakaolin is obtained by calcining kaolin at 700°C-750°C for 2h-2.5h; the overfired red clay is obtained by calcining red clay at 500°C-550°C for 0.5h-1h, at 600°C-650°C for 0.5h-1h, at 700°C-750°C for 0.5h-1h, at 800°C-850°C for 0.5h-1h and at 900°C-950°C for 0.5h-1h in sequence.

3. A material for the protection and restoration of wet earthen ruins according to claim 1 or 2, characterized in that: The particle size of the lightweight porous expanded clay powder filler is between 80 mesh and 150 mesh; the particle size of the activated kaolin is below 1250 mesh sieve; the particle size of the fired red clay is between 460 mesh and 6000 mesh; the particle size of the natural hydraulic lime is below 150 mesh sieve; the particle size of the volcanic ash modified mineral polymer is below 600 mesh sieve; the particle size of the bio-based organic-inorganic hybrid binder is below 100 mesh sieve; the particle size of the modified vermiculite powder is below 200 mesh sieve; the pigment is ferro-titanium ore powder, that is, Fe2O3-TiO2 composite pigment.

4. A material for the protection and restoration of wet earth ruins according to claim 1, characterized in that: The preparation method of volcanic ash modified mineral polymer comprises the steps of reacting volcanic ash with an alkaline activator, drying, and crushing to obtain volcanic ash modified mineral polymer.

5. A material for the protection and restoration of wet earth ruins according to claim 4, characterized in that: The mass ratio of volcanic ash to alkaline activator is 1:(4-6); the alkaline activator is a mixed aqueous solution of sodium hydroxide and sodium silicate, containing 15wt%-20wt% of sodium hydroxide and 22wt%-28wt% of sodium silicate; the reaction temperature is 50℃-60℃, the reaction time is 2h-3h, and the stirring speed of the reaction is 400r / min-600r / min; the particle size of the volcanic ash is below 600 mesh sieve.

6. A material for the protection and restoration of wet earth ruins according to claim 1, characterized in that: The preparation method of the bio-based organic-inorganic hybrid binder includes: adding pregelatinized starch and glutaraldehyde into water for cross-linking reaction to obtain a cross-linked biomaterial solution; ultrasonically dispersing nano-titanium dioxide in ethanol to obtain a dispersion; mixing the dispersion with the cross-linked biomaterial solution, stirring for reaction, drying, and crushing to obtain the bio-based organic-inorganic hybrid binder.

7. A material for the protection and restoration of wet earth ruins according to claim 6, characterized in that: The mass ratio of pregelatinized starch, glutaraldehyde and water is (1-1.2):(0.03-0.1):(6-8); the mass ratio of nano-titanium dioxide and ethanol is (1-1.5):(8-10); the volume ratio of the dispersion liquid to the cross-linked biomaterial solution is 1:(1.5-3); the temperature of the cross-linking reaction is 20°C-30°C, the time of the cross-linking reaction is 2h-3h, and the stirring speed of the cross-linking reaction is 150r / min-250r / min; the temperature of the stirring reaction is 40°C-50°C, the time of the stirring reaction is 4h-5h, and the speed of the stirring reaction is 200r / min-400r / min.

8. A material for the protection and restoration of wet earth ruins according to claim 1, characterized in that: The preparation method of modified vermiculite powder comprises the following steps: uniformly dispersing the vermiculite powder in an ethanol aqueous solution by ultrasonication, adding hexadecyltrimethoxysilane, stirring for reaction, drying, and crushing to obtain the modified vermiculite powder.

9. A material for the protection and restoration of wet earth ruins according to claim 8, characterized in that: The mass ratio of vermiculite powder, ethanol aqueous solution and hexadecyltrimethoxysilane is (1-1.5):(8-10):(0.3-0.8); the volume concentration of ethanol aqueous solution is 30%-50%; the stirring reaction temperature is 60°C-70°C, the stirring reaction time is 5h-6h, and the stirring reaction speed is 300r / min-500r / min; the particle size of the vermiculite powder is below 200 mesh sieve.

10. A method for preparing a material for the protection and restoration of moist earthen ruins, used for preparing the material for the protection and restoration of moist earthen ruins as claimed in claim 1, characterized in that: The preparation method comprises the following steps: S1: Pour the lightweight porous ceramsite powder filler, active metakaolin, overfired red clay, natural hydraulic lime, volcanic ash modified mineral polymer, bio-based organic-inorganic hybrid binder, modified vermiculite powder, tartaric acid and pigment into a stirring container according to the mass proportions, stir and mix evenly to obtain a mixture A; S2: adding tributyl citrate, diethyl phthalate, liquid potassium silicate, silicone waterproofing agent and silicone defoaming agent to mixture A, stirring and mixing evenly to obtain mixture B; S3: Add water to mixture B, stir evenly, let stand for 10 to 15 minutes, and then mix evenly to obtain a uniform slurry.

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