A low-cement-dosage cement-based penetrating crystalline waterproof coating and its preparation method

Abstract

The invention discloses a low-cement-dosage cement-based penetrating crystalline waterproof coating and a preparation method thereof, belonging to the technical field of building waterproof materials. The waterproof coating comprises, by weight, 18 to 22 parts of cement, 44 to 48 parts of a high-strength and dense skeleton component, 20 to 24 parts of a wear-resistant component, 2 to 4 parts of a solid sodium component, 3 to 5 parts of a solid chlorine component, 0.5 to 1.5 parts of a penetrant, 0.6 to 1.0 parts of a complexing agent, 2 to 4 parts of a calcium ion regulator, 0.03 to 0.07 parts of a water-retaining agent, and 26 to 30 parts of water. The preparation method of the high-strength and dense skeleton component comprises: mixing magnesium chloride and sodium methyl silicate in a mass ratio of (75 to 79):(23 to 27), and ball milling for 35 to 45 minutes to obtain modified magnesium chloride; then uniformly mixing the modified magnesium chloride, calcium carbonate, lithium carbonate, and light-burned magnesium oxide in a mass ratio of 100:(9 to 11):(1.6 to 2.4):(120 to 130) to obtain the high-strength and dense skeleton component. The low-cement-dosage cement-based penetrating crystallization waterproof coating of the present invention has low cement dosage, strong wear resistance, obvious waterproof effect, strong crack repairing ability, and the characteristics of sodium and chlorine solidification.

Description

Technical Field

[0001] The present invention relates to the technical field of building waterproof materials, and in particular to a low-cement-dosage cement-based penetrating crystalline waterproof coating and a preparation method thereof. Background Art

[0002] In recent years, safety incidents caused by poor waterproofing of underground structures and buildings have become commonplace. This not only negatively impacts the living environment of residents but also reduces the service life of underground structures and buildings. Concrete, an engineering composite material composed of aggregates bonded together by a cementitious material, contains numerous pores. After hardening, water evaporation leaves behind a porous structure. These pores and microcracks are the root cause of concrete leakage. Therefore, filling these pores and microcracks to prevent water penetration is crucial for improving concrete durability.

[0003] Cement-based penetrating crystalline waterproof coatings are a powdered material primarily composed of Portland cement and quartz sand, mixed with a certain amount of active chemicals. Upon reaction with water, the active chemicals in the material, using water as a carrier, penetrate the concrete and react with the cement hydration products to form water-insoluble needle-shaped crystals. These crystals fill capillary pores and micro-crevices, thereby improving the concrete's density and waterproofing. Cement-based penetrating crystalline waterproof coatings are now widely used in various buildings.

[0004] For example, Chinese patent CN114751697A discloses a cement-based penetrating crystallization waterproof coating, the raw materials of which include: 5-10 parts active ingredient, 3-5 parts surfactant, 0.3-0.8 parts nano-graphene oxide, 150-200 parts cement, and 180-200 parts water. The waterproof coating uses nano-graphene oxide and an active ingredient composed of sodium hexametaphosphate, alum, and citric acid to synergistically form continuous crystals, improving overall strength. It also prevents the energy generated by vibration from directly impacting the continuous crystals and forming new pores, effectively slowing or preventing the formation of new pores or small cracks. Another example is Chinese patent CN104876505A, which discloses a cement-based penetrating crystallization waterproof coating, the raw materials of which include: 50-75 parts of Portland cement, 15-30 parts of nano-silicon dioxide, 10-15 parts of nano-calcium carbonate, 2-4 parts of citric acid, 5-10 parts of silicone resin, and 5-10 parts of calcium chloride. The waterproof coating does not age and can heal even tiny cracks on its own, providing a self-repairing and waterproofing function. It also protects concrete, prevents cracking, enhances concrete strength, protects against steel corrosion, and resists chemical corrosion and impact, resulting in a permanent waterproof effect. While the aforementioned waterproof coatings can repair concrete cracks, they all suffer from the drawbacks of high cement usage and poor wear resistance. Summary of the Invention

[0005] In view of the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a cement-based penetrating crystallization waterproof coating with low cement dosage, which has low cement dosage, strong wear resistance, obvious waterproof effect, strong crack repair ability, and the characteristics of sodium and chlorine solidification.

[0006] In order to achieve the above objectives, the following technologies are specifically used:

[0007] A low-cement-dosage cement-based penetrating crystallization waterproof coating, comprising the following raw materials in parts by weight: 18 to 22 parts of cement, 44 to 48 parts of a high-strength dense skeleton component, 20 to 24 parts of a wear-resistant component, 2 to 4 parts of a solid sodium component, 3 to 5 parts of a solid chlorine component, 0.5 to 1.5 parts of a penetrant, 0.6 to 1.0 parts of a complexing agent, 2 to 4 parts of a calcium ion regulator, 0.03 to 0.07 parts of a water-retaining agent, and 26 to 30 parts of water;

[0008] The preparation method of the high-strength dense skeleton component is as follows:

[0009] Mixing magnesium chloride and sodium methyl silicate in a mass ratio of (75-79):(23-27), and ball milling for 35-45 minutes to obtain modified magnesium chloride;

[0010] The modified magnesium chloride, calcium carbonate, lithium carbonate and light-burned magnesium oxide are uniformly mixed in a mass ratio of 100:(9-11):(1.6-2.4):(120-130) to obtain a high-strength and dense skeleton component.

[0011] Light-burned magnesium oxide, magnesium chloride, and water react to form 3Mg(OH)2·MgCl2·8H2O (3.18 phase) and 5Mg(OH)2·MgCl2·8H2O (5.18 phase). These products can interlink to form a crystalline phase network structure with a very strong tower-jointed hinge system that can withstand extremely high pressure. However, since the 3.18 phase and the 5.18 phase are unstable in polar solvents, especially water, they are easily dissolve and hydrolyzed by the impact of polar water molecules with permanent dipoles. The present invention modifies magnesium chloride by adding sodium methyl silicate and magnesium chloride and ball milling to impart hydrophobic and water-repellent properties to the magnesium chloride. After the magnesium chloride, light-burned magnesium oxide, and water generate the 3.18 phase and the 5.18 phase, the sodium methyl silicate can crosslink with the 3.18 phase or the 5.18 phase to form an excellent hydrophobic layer, allowing the entire high-strength, dense skeleton component to maintain excellent water resistance. Calcium carbonate has high strength and can be used as a crystal nucleus to promote the construction of a high-strength dense skeleton. The final crystalline phase network structure tightly wraps the calcium carbonate to form a high-strength dense skeleton-like three-dimensional spatial structure. This structure can fill the capillary pores and tiny gaps in the concrete, greatly improving the waterproof performance of the concrete. The present invention significantly reduces the amount of cement by adding a high-strength dense skeleton component, and the resulting waterproof coating has good waterproof performance and strong crack repair ability. Lithium carbonate is conducive to the development of early strength. The mesh size of the light-burned magnesium oxide should not be too low. If it is too low, it is easy to react too slowly with magnesium chloride and the like, resulting in low overall strength. It is preferably 170 to 200 meshes.

[0012] Preferably, the cement is modified rapid-hardening cement, and the preparation method of the modified rapid-hardening cement is as follows: ferroaluminate cement and triisopropanolamine are mixed in a mass ratio of 1:(0.004-0.006), and ball-milled for 25-40 minutes to obtain the modified rapid-hardening cement. Rapid-hardening cement has a relatively fast early strength growth and relatively high later strength, which can shorten the cement hardening time and enable waterproof coatings to repair concrete cracks more quickly. On the one hand, triisopropanolamine can act as a grinding aid, reduce the particle size of ferroaluminate cement, accelerate the hydration rate, and increase the strength of cement after hardening; on the other hand, triisopropanolamine can also promote the dissolution of the iron phase in ferroaluminate cement, generate a stable and dense waterproof product, and improve the waterproof performance of concrete.

[0013] Preferably, the wear-resistant component comprises the following raw materials by weight: 33-37% biotite, 38-42% quartz diorite, and 23-27% diabase cast stone; the biotite has a mesh size of 120-150, the quartz diorite has a mesh size of 80-120, and the diabase cast stone has a mesh size of 40-80. Biotite, diorite, and diabase cast stone have high hardness, which can enhance the abrasion and erosion resistance of the waterproof coating and increase its lifespan. Furthermore, when these three materials are combined in specific proportions and mesh sizes, they can achieve a super-additive effect, resulting in better performance than a single wear-resistant material.

[0014] Preferably, the solid sodium component comprises the following raw materials by weight percentage: 26-30% high-calcium clinker, 13-17% high-aluminum clinker, 52-56% metakaolin, and 2-4% fluorite powder; the calcium oxide content in the high-calcium clinker is 55-60%; the aluminum oxide content in the high-aluminum clinker is 85-90%; the silicon dioxide content in the metakaolin is 52-58%, and the aluminum oxide content is 38-42%; and the CaF2 content in the fluorite powder is not less than 98%. Calcium oxide and other substances in the solid sodium component can provide an alkaline environment, promoting the hydration reaction of aluminum oxide, silicon dioxide, etc. to generate active silicon, active aluminum, and other substances. These substances can react with free sodium oxide and potassium oxide to generate stable sodium feldspar Na2O·Al2O3·6SiO2 and potassium feldspar K2O·Al2O3·6SiO2, fixing excess sodium and potassium ions in the system and preventing alkali-aggregate reaction. CaF2, as a co-solvent, can lower the melting temperature of the system and make the whole system form a highly active metastable state.

[0015] More preferably, the solid sodium component is prepared by uniformly mixing high-calcium clinker, high-aluminum clinker, metakaolin, and fluorite powder in a certain proportion, then maintaining the mixture at 550-650°C for 1-1.5 hours, and then rapidly cooling the mixture with air within 10-12 minutes to obtain a solid sodium stabilized material. Rapid cooling can maintain the particles within each substance in a high energy state, thereby improving activity.

[0016] Preferably, the chlorine-fixing component is prepared by dissolving magnesium-aluminum hydrotalcite in water to form a suspension, then adding sulfuric acid dropwise to the suspension to adjust the pH to 4-5, then adding calcium hydroxide (5-6% by weight of the magnesium-aluminum hydrotalcite), stirring thoroughly, and drying at 100-110°C to obtain the chlorine-fixing component. Modification of the magnesium-aluminum hydrotalcite with calcium hydroxide forms a layered structure that absorbs chloride ions in the system, preventing chloride ions from corroding steel bars in concrete.

[0017] Preferably, the penetrant comprises the following raw materials by weight: 43-47% sodium silicate, 10-14% sodium tripolyphosphate, 16-20% sodium hexametaphosphate, 13-17% fatty alcohol polyoxyethylene ether, and 8-12% polysiloxane. The penetrant is a composite of an inorganic penetrant and an organic penetrant, resulting in enhanced penetrability, reduced environmental impact, and excellent stability, thereby facilitating the migration of active chemical substances into the concrete.

[0018] Preferably, the complexing agent includes one or more of disodium EDTA, sodium gluconate, tartaric acid, or sodium ethylenediaminetetramethylenephosphonate. The complexing agent can complex metal ions such as calcium ions, iron ions, and aluminum ions in the coating system. After the metal ions are enriched to a certain extent, they can combine with silicate ions in the coating system to form a stable calcium silicate hydrate gel, which fills the cracks in the concrete and improves the waterproof performance of the concrete.

[0019] Preferably, the calcium ion regulator comprises one or more of calcium hydroxide, calcium formate, or calcium chloride. The calcium ion regulator can provide a sufficient source of calcium ions for the entire coating system, ensuring the smooth progress of the hydration reaction. Calcium hydroxide releases calcium ions by slow dissolution, while calcium formate and calcium chloride provide calcium ions by ionization.

[0020] Preferably, the water-retaining agent comprises one or more of lignin fiber, hydroxymethyl propyl cellulose ether, and polyethylene glycol. The water-retaining agent can improve the water-retaining performance of the waterproof coating, reduce pores, and improve density.

[0021] The object of the present invention is also to provide a method for preparing a low-cement-dosage cement-based penetrating crystalline waterproof coating as described in any of the above items, comprising the following steps: weighing each solid raw material according to a ratio, mixing them evenly to form a powder, then adding water according to a proportion, and stirring evenly to obtain a low-cement-dosage cement-based penetrating crystalline waterproof coating.

[0022] Compared with the prior art, the present invention is beneficial in that:

[0023] (1) The low-cement-dosage cement-based penetrating crystalline waterproof coating of the present invention forms a high-strength and dense three-dimensional structure with calcium carbonate as the core and a crystalline phase network structure wrapped around it by adding a high-strength and dense skeleton component. This structure can fill the capillary pores and tiny gaps in concrete, greatly improving the waterproof performance of concrete, significantly reducing the amount of cement used in the waterproof coating, and effectively saving resources.

[0024] (2) The low-cement-dosage cement-based penetrating crystallization waterproof coating of the present invention is added with high-hardness materials such as biotite, quartz diorite and diabase cast stone, which enhances the abrasion and erosion properties of the waterproof coating and increases the life of the waterproof coating; at the same time, the three materials are compounded in a specific proportion and mesh size to achieve a super-superposition effect, which has better performance than a single wear-resistant material.

[0025] (3) The low-cement-dosage cement-based penetrating crystalline waterproof coating of the present invention uses a composite of an organic penetrant and an inorganic penetrant, which has stronger penetrating ability, is less affected by the environment, has good stability, and helps active chemical substances migrate into the interior of the concrete, which is better than a single penetrant. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Any equivalent transformation or substitution made by those skilled in the art based on the following embodiments is within the scope of protection of the present invention.

[0027] In the following examples and comparative examples, unless otherwise specified, the modified rapid-hardening cement was prepared according to the following preparation method: ferroaluminate cement and triisopropanolamine were mixed in a mass ratio of 1:(0.004-0.006), and ball-milled in a ball mill for 25-40 minutes to obtain the modified rapid-hardening cement.

[0028] The high-strength and dense skeleton components are prepared according to the following preparation method: sodium methyl silicate and magnesium chloride are weighed in proportion, ball-milled and stirred in a ball mill for 35 to 45 minutes, and then lithium carbonate, calcium carbonate, and 170 to 200 mesh light-burned magnesium oxide powder are added in proportion and mixed evenly to obtain the high-strength and dense skeleton components.

[0029] The solid sodium components are all prepared according to the following preparation method: high calcium clinker, high aluminum clinker, metakaolin and fluorite powder are mixed evenly in proportion, kept in a hot furnace at 550-650° C. for 1-1.5 hours, and then rapidly cooled by air within 10-12 minutes to obtain a solid sodium stabilized material.

[0030] The solid chlorine components are prepared according to the following preparation method: magnesium aluminum hydrotalcite is dissolved in water to form a suspension, sulfuric acid is then added dropwise to the suspension to adjust the pH to 4-5, and then calcium hydroxide accounting for 5-6% of the mass of the magnesium aluminum hydrotalcite is added, and the mixture is thoroughly stirred and then dried at 100-110°C to obtain the solid chlorine component.

[0031] The waterproof coatings are prepared according to the following preparation method: solid raw materials are weighed according to the proportion, mixed evenly to form powder, and then water is added according to the proportion and stirred evenly to obtain a cement-based penetrating crystalline waterproof coating with low cement dosage.

[0032] Unless otherwise specified, all raw materials are commercially available, and the polysiloxane is 3168 silicone.

[0033] Example 1

[0034] This embodiment provides a low-cement-content modified cement-based penetrating crystalline waterproof coating, which specifically comprises the following raw materials in parts by weight: 18 parts of ordinary Portland cement, 46 parts of a high-strength dense skeleton component, 24 parts of a wear-resistant component, 4 parts of a sodium-solidifying component, 5 parts of a chlorine-solidifying component, 0.5 parts of a penetrant, 0.6 parts of a complexing agent, 2 parts of a calcium ion regulator, 0.03 parts of a water-retaining agent, and 26 parts of water;

[0035] The high-strength, dense skeleton component comprises magnesium chloride, light-burned magnesium oxide, sodium methyl silicate, calcium carbonate, and lithium carbonate in a mass ratio of 77:127:25:10:5:2, with the light-burned magnesium oxide having a mesh size of 180. The modified rapid-hardening cement comprises a mass ratio of ferroaluminate cement to triisopropanolamine of 1:0.005. The wear-resistant component comprises, by mass percentage, 33% biotite, 42% quartz diorite, and 25% diabase cast stone. The biotite has a mesh size of 130, the quartz diorite has a mesh size of 100, and the diabase cast stone has a mesh size of 60. The solid sodium components, by mass percentage, include: 28% high-calcium clinker, 15% high-aluminum clinker, 54% metakaolin, and 3% fluorite powder. The calcium oxide content in the high-calcium clinker is 57%; the aluminum oxide content in the high-aluminum clinker is 88%; the silicon dioxide content in the metakaolin is 55% and the aluminum oxide content is 40%; and the CaF2 content in the fluorite powder is 98%. The penetrant, by mass percentage, includes: 45% sodium silicate, 12% sodium tripolyphosphate, 18% sodium hexametaphosphate, 15% fatty alcohol polyoxyethylene ether, and 10% polysiloxane. The complexing agent is disodium EDTA. The calcium ion regulator is calcium hydroxide. The water-retaining agent is lignin fiber.

[0036] Example 2

[0037] This embodiment provides a low-cement-content modified cement-based penetrating crystallization waterproof coating, which specifically comprises the following raw materials in parts by weight: 18 parts of modified rapid-hardening cement, 46 parts of a high-strength dense skeleton component, 24 parts of a wear-resistant component, 4 parts of a sodium-solidifying component, 5 parts of a chlorine-solidifying component, 0.5 parts of a penetrant, 0.6 parts of a complexing agent, 2 parts of a calcium ion regulator, 0.03 parts of a water-retaining agent, and 26 parts of water;

[0038] The high-strength, dense skeleton component comprises magnesium chloride, light-burned magnesium oxide, sodium methyl silicate, calcium carbonate, and lithium carbonate in a mass ratio of 79:130:23:9:4:1.6, with the light-burned magnesium oxide having a mesh size of 170. The modified rapid-hardening cement comprises a mass ratio of ferroaluminate cement to triisopropanolamine of 1:0.006. The wear-resistant component comprises, by mass percentage, 35% biotite, 40% quartz diorite, and 25% diabase cast stone. The biotite has a mesh size of 120, the quartz diorite has a mesh size of 80, and the diabase cast stone has a mesh size of 40. The solid sodium components, by mass percentage, include: 27% high-calcium clinker, 13% high-aluminum clinker, 56% metakaolin, and 4% fluorite powder. The calcium oxide content in the high-calcium clinker is 60%; the aluminum oxide content in the high-aluminum clinker is 85%; the silicon dioxide content in the metakaolin is 58% and the aluminum oxide content is 38%; and the CaF2 content in the fluorite powder is 98%. The penetrant, by mass percentage, includes: 45% sodium silicate, 10% sodium tripolyphosphate, 20% sodium hexametaphosphate, 17% fatty alcohol polyoxyethylene ether, and 8% polysiloxane. The complexing agent is disodium EDTA. The calcium ion regulator is calcium hydroxide. The water-retaining agent is lignin fiber.

[0039] Example 3

[0040] This embodiment provides a low-cement-content modified cement-based penetrating crystallization waterproof coating, which specifically comprises the following raw materials in parts by weight: 22 parts of modified rapid-hardening cement, 47 parts of a high-strength dense skeleton component, 20 parts of a wear-resistant component, 2 parts of a solid sodium component, 3 parts of a solid chlorine component, 1.0 part of a penetrant, 1.0 part of a complexing agent, 4 parts of a calcium ion regulator, 0.03 parts of a water-retaining agent, and 28 parts of water;

[0041] The high-strength, dense skeleton component comprises magnesium chloride, light-burned magnesium oxide, sodium methyl silicate, calcium carbonate, and lithium carbonate in a mass ratio of 75:120:27:11:5.5:2.4, with the mesh size of the light-burned magnesium oxide being 200 mesh. The modified rapid-hardening cement comprises alumina-ferrocement and triisopropanolamine in a mass ratio of 1:0.004. The wear-resistant component comprises, by mass percentage, 37% biotite, 40% quartz diorite, and 23% diabase cast stone. The biotite has a mesh size of 150 mesh, the quartz diorite has a mesh size of 120 mesh, and the diabase cast stone has a mesh size of 80 mesh. The solid sodium components, by mass percentage, include: 29% high-calcium clinker, 17% high-aluminum clinker, 52% metakaolin, and 2% fluorite powder. The calcium oxide content in the high-calcium clinker is 55%; the aluminum oxide content in the high-aluminum clinker is 90%; the silicon dioxide content in the metakaolin is 52% and the aluminum oxide content is 41%; and the CaF2 content in the fluorite powder is 98%. The penetrant, by mass percentage, includes: 45% sodium silicate, 12% sodium tripolyphosphate, 18% sodium hexametaphosphate, 15% fatty alcohol polyoxyethylene ether, and 10% polysiloxane. The complexing agents are sodium gluconate and tartaric acid. The calcium ion regulators are calcium hydroxide, calcium formate, and calcium chloride. The water-retaining agent is hydroxymethylpropyl cellulose ether.

[0042] Comparative Example 1

[0043] This comparative example provides a cement-based penetrating crystallization waterproof coating. The raw materials and preparation method of the coating are basically the same as those in Example 1, except that the raw materials do not contain a high-strength dense skeleton component and are replaced by an equal amount of ordinary Portland cement.

[0044] Comparative Example 2

[0045] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those of Example 2, except that the high-strength dense skeleton component does not contain calcium carbonate.

[0046] Comparative Example 3

[0047] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those of Example 2, except that the high-strength dense skeleton component does not contain lithium carbonate.

[0048] Comparative Example 4

[0049] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those in Example 2, except that: in the preparation method of the high-strength dense skeleton component, the order of adding magnesium chloride and light-burned magnesium oxide is reversed, that is, light-burned magnesium oxide is first ground with sodium methyl silicate, and then mixed with lithium carbonate, potassium dihydrogen phosphate, calcium phosphate and magnesium chloride, and the amount of each substance used remains unchanged.

[0050] Comparative Example 5

[0051] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those in Example 2, except that the wear-resistant component is replaced by an equal amount of diabase cast stone with the same mesh size and grading.

[0052] Comparative Example 6

[0053] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those in Example 2, except that the penetrant does not contain sodium tripolyphosphate and sodium hexametaphosphate, and is replaced by an equal amount of fatty alcohol polyoxyethylene ether.

[0054] Comparative Example 7

[0055] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those in Example 2, except that the raw materials do not contain solid sodium components and are replaced by an equal amount of modified rapid-hardening cement.

[0056] Comparative Example 8

[0057] This comparative example provides a cement-based penetrating crystallization waterproof coating with low cement dosage. The raw materials and preparation method of the coating are basically the same as those in Example 2, except that the raw materials do not contain solid chlorine components and are replaced by an equal amount of modified rapid-hardening cement.

[0058] Performance Testing

[0059] The cement-based penetrating crystallization waterproof coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were respectively tested for the waterproof coatings and the concrete coated with the waterproof coatings according to GB18445 and JC / T2158 standards; the waterproof coating coating hardened for 28 days was crushed into small pieces, further ball-milled to 150 mesh, and sieved. 100 g of the powder was weighed and added to 500 g of distilled water. The mixture was stirred thoroughly for 30 minutes and allowed to stand for 24 hours. The upper clear liquid was taken and the alkali content and chloride ion content in the clear liquid were measured. The test results are shown in Table 1 below.

[0060] Table 1: Test results of waterproof coatings and concrete performance

[0061]

[0062] As can be seen from the data in Table 1, the wet base surface bond strength, 28d anti-seepage pressure (with coating and without coating), and 56d anti-seepage pressure (with coating) of the low-cement-dosage cement-based penetrating crystallization waterproof coatings prepared in each embodiment are significantly higher than the national standard GB18445, indicating that the waterproof coating of the present invention has a significant waterproof effect and strong crack repair ability, and the repaired concrete still has good waterproof performance for a long time; the wear resistance ratio of the waterproof coating prepared in each embodiment is also significantly higher than the JC / T2158 standard, indicating that the waterproof coating of the present invention has excellent wear resistance and can repair concrete cracks for a long time after application, with a long service life; the alkali content and chloride ion content of the clarified liquid of the waterproof coating prepared in each embodiment are extremely low, which avoids the effects of alkali-aggregate reaction and steel corrosion on concrete; comparing Examples 1 and 2, it can be seen that the high-strength dense skeleton component of the present invention can replace ordinary Portland cement and modified rapid-hardening cement, significantly reducing the amount of cement used.

[0063] By comparing the data of Comparative Example 1 and Example 1, it can be seen that after ordinary Portland cement is replaced by a high-strength dense skeleton component, the bonding strength, waterproof performance and wear resistance of the waterproof coating obtained are reduced, indicating that the high-strength dense skeleton material has a significant effect on improving the overall performance of the system, exceeding the effect of cement.

[0064] Comparing the data from Comparative Examples 2 and 3 with Example 2, it can be seen that without the addition of calcium carbonate or lithium carbonate to the raw materials for the high-strength, dense skeleton component, the resulting waterproof coating exhibited significantly reduced bond strength, waterproof performance, and abrasion resistance. This is because calcium carbonate acts as a crystal nucleus within the entire system, significantly promoting the growth and density of the three-dimensional structure. The lack of calcium carbonate in Comparative Example 2 prevented the formation of a dense three-dimensional structure, significantly reducing the overall performance of the waterproof coating. Furthermore, the lack of lithium carbonate in Comparative Example 3 resulted in slow early strength development, hindering the construction of the three-dimensional structure and significantly reducing the overall performance of the waterproof coating.

[0065] Comparing the data of Comparative Example 4 and Example 2, it can be seen that after the order of adding magnesium chloride and light-burned magnesium oxide is changed in the preparation method of the high-strength dense skeleton component, the bonding strength and waterproof performance of the waterproof coating obtained are significantly reduced. This is because magnesium oxide itself is difficult to dissolve in water, and after being modified and wrapped by sodium methyl silicate, it is more difficult to react, which has an adverse effect on the construction of the three-dimensional skeleton and the progress of the reaction.

[0066] By comparing the data of Comparative Example 5 and Example 2, it can be seen that after the wear-resistant component is replaced by an equal amount of diabase cast stone with the same mesh size grading, the wear resistance of the obtained waterproof coating is significantly reduced. This is because the materials of different particle sizes and hardnesses of quartz diorite, biotite, and diabase cast stone are compounded in a specific proportion to form a super-stacked pinning effect, which is higher than the hardness of single-component cast stone.

[0067] Comparing the data of Comparative Example 6 and Example 2, it can be seen that the waterproof performance of the waterproof coating obtained is significantly reduced when the penetrant does not contain sodium tripolyphosphate and sodium hexametaphosphate. This is because the lack of the enhancement of the inorganic penetrating component reduces the penetration crystallization ability of the system, reduces the density of the system, and reduces the waterproof performance.

[0068] By comparing the data of Comparative Examples 7 and 8 with that of Example 2, it can be seen that after the raw materials do not contain solid sodium components or solid chlorine components, the alkali content or chloride ion content in the prepared clear solution of the waterproof coating is significantly increased, resulting in an increase in alkali-aggregate reaction, and the anti-seepage pressure, wet base surface bonding strength and wear resistance ratio of the waterproof coating are all reduced to a certain extent.

[0069] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details of the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

Claims

1. A low-cement-dosage cement-based penetrating crystalline waterproof coating, characterized in that: The invention comprises the following raw materials in parts by weight: 18-22 parts of cement, 44-48 parts of high-strength dense skeleton component, 20-24 parts of wear-resistant component, 2-4 parts of solid sodium component, 3-5 parts of solid chlorine component, 0.5-1.5 parts of penetrant, 0.6-1.0 parts of complexing agent, 2-4 parts of calcium ion regulator, 0.03-0.07 parts of water retaining agent, and 26-30 parts of water; The preparation method of the high-strength dense skeleton component is as follows: Magnesium chloride and sodium methyl silicate are mixed in a mass ratio of (75-79):(23-27), and ball milled for 35-45 minutes to obtain modified magnesium chloride; The modified magnesium chloride and calcium carbonate, lithium carbonate, and light-burned magnesium oxide are uniformly mixed in a mass ratio of 100:(9-11):(1.6-2.4):(120-130) to obtain a high-strength and dense skeleton component; The solid sodium component comprises the following raw materials by weight percentage: 26-30% high calcium clinker, 13-17% high aluminum clinker, 52-56% metakaolin, and 2-4% fluorite powder; the calcium oxide content in the high calcium clinker is 55-60%; the aluminum oxide content in the high aluminum clinker is 85-90%; the silicon dioxide content in the metakaolin is 52-58%, and the aluminum oxide content is 38-42%; the CaF2 content in the fluorite powder is not less than 98%; The preparation method of the solid chlorine component is as follows: dissolving magnesium aluminum hydrotalcite in water to form a suspension, then adding sulfuric acid to the suspension to adjust the pH to 4-5, and then adding calcium hydroxide accounting for 5-6% of the mass of the suspension. After fully stirring, the suspension is dried at 100-110°C to obtain the solid chlorine component.

2. The low-cement-dosage cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The cement is modified rapid-hardening cement, and the preparation method of the modified rapid-hardening cement is as follows: ferroaluminate cement and triisopropanolamine are mixed in a mass ratio of 1:(0.004-0.006), and ball-milled for 25-40 minutes to obtain the modified rapid-hardening cement.

3. The low-cement-content cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The wear-resistant component includes the following raw materials in weight percentage: 33-37% biotite, 38-42% quartz diorite, and 23-27% diabase cast stone; the mesh number of the biotite is 120-150 mesh, the mesh number of the quartz diorite is 80-120 mesh, and the mesh number of the diabase cast stone is 40-80 mesh.

4. The low-cement-content cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The penetrant comprises the following raw materials by weight percentage: 43-47% sodium silicate, 10-14% sodium tripolyphosphate, 16-20% sodium hexametaphosphate, 13-17% fatty alcohol polyoxyethylene ether, and 8-12% polysiloxane.

5. The low-cement-dosage cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The complexing agent includes one or more of disodium EDTA, sodium gluconate, tartaric acid or sodium ethylenediaminetetramethylenephosphonate.

6. The low-cement-dosage cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The calcium ion regulator includes one or more of calcium hydroxide, calcium formate or calcium chloride.

7. The low-cement-content cement-based penetrating crystallization waterproof coating according to claim 1, characterized in that: The water-retaining agent comprises one or more of lignin fiber, hydroxymethylpropyl cellulose ether, and polyethylene glycol.

8. The method for preparing a low-cement-content cement-based penetrating crystallization waterproof coating according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: weighing various solid raw materials according to a proportion, mixing them evenly to form powder, then adding water according to a proportion, and stirring evenly to obtain a cement-based penetrating crystalline waterproof coating with low cement dosage.

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