Calcium-based and silicon-based crystalline self-repairing waterproof material, and preparation method and application thereof

Abstract

The invention discloses a calcium-based and silicon-based crystalline self-repairing waterproof material, and a preparation method and application thereof. The calcium-based and silicon-based crystalline self-repairing waterproof material is composed of the following components in percentage by weight: 20-30% of a calcium-based compound; 15 to 25% of a silicon-based compound; 30 to 40 percent of cement; 5-10% of an auxiliary agent; and 10%-20% of water. By utilizing the synergistic effect of calcium-based and silicon-based crystals, the secondary crystal generation capability is enhanced, microcracks are quickly repaired, an excellent self-repairing function is realized, and the service life of the waterproof layer is effectively prolonged.

Description

Technical Field

[0001] The invention relates to a waterproof material, and in particular to a calcium-based and silicon-based crystalline self-repairing waterproof material, a preparation method and an application thereof. Background Art

[0002] As the main building material in construction, transportation, water conservancy and other projects, concrete is widely used due to its excellent strength, durability and economy. However, due to the large number of capillary pores and microcracks inside concrete, it is easily corroded by water and other harmful substances during long-term use, resulting in reduced strength, steel corrosion and reduced durability. Therefore, the application of waterproofing technology is of great significance to extend the service life of concrete structures and improve the quality of projects.

[0003] At present, the common waterproof materials on the market are mainly divided into two categories: film-forming type and permeable type:

[0004] Film-forming waterproof materials (such as polyurethane coatings and polymer waterproof membranes): They mainly block moisture by forming a dense waterproof film on the concrete surface. These materials have good waterproof performance in the early stages of construction, but due to their limited bonding strength with the concrete base, they are prone to cracking and falling off after deformation of the concrete or long-term use, resulting in failure of the waterproof layer.

[0005] Penetrating waterproof materials (such as cement-based penetrating crystalline waterproof materials): This type of material can penetrate into the concrete and react with cement hydration products to form water-insoluble crystals (such as calcium silicate hydrate CSH), filling the pores and microcracks in the concrete, improving the compactness and waterproofing ability of the concrete. Compared with film-forming materials, penetrating waterproof materials have greater advantages in durability, crack resistance and compatibility with concrete.

[0006] In the prior art, the technical solution that is closer to the present invention comes from patent number CN202411452204.9, which discloses a cement-based penetrating crystalline waterproof coating, which is composed of the following components by weight percentage:

[0007] Cement polymer powder: 45-60% (including silicate cement powder and sulphoaluminate cement powder, the ratio is 8:2);

[0008] Silicate powder: 2.5-5% (including fluorosilicic acid, silica fume, talc, quartz particles, the ratio is 1:1:3:5);

[0009] Complexing agent: 1-2% (butyl acrylate or polyacrylate);

[0010] Additives: 2-4% (high toughness resin, stearic acid or aluminum stearate, polyester vinyl ester or polyester vinyl adhesive, the ratio is 6:3:1);

[0011] Carbohydrates: 5-10% (starch);

[0012] Water: 20-30%.

[0013] The coating uses the active ingredients in silica powder (such as fluorosilicic acid and silica fume) to react with calcium ions in concrete to generate water-insoluble dendrite-like crystals that block capillary pores. It has the following advantages:

[0014] Good compatibility with concrete substrate, forming an overall waterproof system after penetration, not easy to separate;

[0015] It has a certain self-repairing ability and can generate secondary crystals in microcracks;

[0016] It is easy to use and can be applied by brushing or spraying, meeting the requirements of green building materials.

[0017] Disadvantages of the prior art

[0018] Although the technical solution of CN202411452204.9 improves the waterproof effect to a certain extent, it still has the following technical limitations:

[0019] Single crystal structure, limited waterproof performance

[0020] The existing technology mainly relies on silica powder (such as fluorosilicic acid, silica fume) to generate dendrite-like crystals, but the structure is relatively simple and lacks three-dimensional network support. It is easy to break under high water pressure or long-term erosion environment, resulting in reduced waterproof performance.

[0021] Insufficient crack resistance

[0022] Although the existing technology has introduced additives such as high-toughness resins, the toughness of the crystals themselves is insufficient, making it difficult to resist the expansion of cracks caused by concrete deformation or external forces, especially in dynamic load environments, and it is difficult to maintain a stable waterproof effect.

[0023] Low impermeability and compressive strength

[0024] The anti-seepage pressure of this technical solution is 1.0MPa, and the compressive strength is only 30MPa, which is difficult to meet the high standards required for underground projects, tunnels and high-rise buildings.

[0025] The base layer has poor adhesion and is prone to peeling

[0026] Since the existing technology mainly relies on physical filling of pores, it fails to effectively improve the adhesion between the waterproof layer and the concrete base, and is easily affected by humidity changes and temperature difference stress, resulting in hollowing or falling off.

[0027] Limited durability, prone to deterioration after long-term use

[0028] Under long-term water immersion, freeze-thaw cycles or acid-base corrosion environments, traditional crystals may undergo structural degradation, resulting in a decrease in waterproof performance, making it difficult to ensure long-term effective protection. Summary of the invention

[0029] In order to solve the above problems, the present invention provides a calcium-based and silicon-based crystalline self-healing waterproof material, a preparation method and an application. By improving the crystal structure and formula design, the defects of the prior art are overcome, and the material is particularly suitable for application scenarios such as underground projects, bridges, roofs, tunnels, etc. that require long-term stable waterproof performance.

[0030] The present invention is realized by the following technical scheme: a calcium-based and silicon-based crystalline self-repairing waterproof material, which is composed of the following components by weight percentage:

[0031] Calcium-based compounds: 20-30%;

[0032] Silicon-based compounds: 15-25%;

[0033] Cement: 30-40%;

[0034] Additives: 5-10%;

[0035] Water: 10-20%.

[0036] As a preferred technical solution, the calcium-based compound includes calcium hydroxide and calcium carbonate.

[0037] As a preferred technical solution, the silicon-based compound includes sodium silicate and silica fume.

[0038] As a preferred technical solution, the auxiliary agents include a water reducer, a thickener, and an antifreeze agent.

[0039] As a preferred technical solution, the silicon-based compound is hydrolyzed in water to generate silica colloid, and further polymerized to form a silicon-oxygen tetrahedron structure to enhance the durability and crack resistance of the waterproof layer. The chemical reaction is as follows:

[0040] Na 2 SiO 3 +H 2 O→H 2 SiO 3 +2NaOH

[0041] H 2 SiO 3 →(SiO 4 ) 4 -(Silicon oxygen tetrahedron).

[0042] As a preferred technical solution, the calcium-based compound reacts with silicon dioxide in concrete to generate calcium silicate hydrate, which fills the pores of concrete and achieves waterproofing. The chemical reaction is as follows:

[0043] Ca(OH) 2 +SiO 2 +H 2 O→CSH (calcium silicate hydrate).

[0044] As a preferred technical solution, the waterproof material can generate secondary crystals through unreacted calcium ions and silicate after contacting water to repair micro cracks in concrete. The chemical reaction is as follows:

[0045] Ca 2+ +H 2 SiO 3 →CSH (secondary crystallization).

[0046] The preparation method of the calcium-based and silicon-based crystalline self-repairing waterproof material of the present invention comprises the following steps:

[0047] S1. Weigh the calcium-based compound, silicon-based compound, cement, additives and water according to weight ratio;

[0048] S2, dry mix the cement and additives in a mixer for 2 minutes;

[0049] S3, add water and stir for 3 minutes to form a uniform slurry;

[0050] S4. Slowly add the calcium-based compound and the silicon-based compound and continue stirring for 5 minutes;

[0051] S5. Let the obtained mixture stand for 30 minutes to allow the reaction to be initially completed and form a stable crystalline precursor.

[0052] The application method of the calcium-based and silicon-based crystalline self-repairing waterproof material of the present invention is applied on the concrete surface, and the specific steps are as follows:

[0053] S11. Clean the surface of the concrete base to remove floating dust and loose layers;

[0054] S22. Use a high-pressure water gun to wash the concrete base to make it fully moist;

[0055] S33, repairing the cracks with a U-shaped groove and filling them with the waterproof material;

[0056] S44, applying the waterproof material evenly by brushing or spraying, brushing 2-3 times, each time interval of 4 hours, each layer thickness is about 0.5mm;

[0057] S55. Maintain for 7 days and keep the surface moist.

[0058] The beneficial effects of the present invention are as follows: the present invention combines calcium-based and silicon-based crystallization technologies, introduces a silicon-oxygen tetrahedron structure, forms a three-dimensional network crystal with high stability, and enhances the durability of the waterproof layer;

[0059] At the same time, the toughness of the silicon-oxygen tetrahedral structure and the filling effect of calcium-based crystals are used to improve the crack resistance of the waterproof layer under stress environments, optimize the component ratio and crystallization reaction, and significantly improve the anti-seepage pressure and compressive strength to meet the needs of high-demand scenarios;

[0060] In addition, through the bonding enhancement effect and scientific proportion of calcium-based compounds, the bonding strength between the waterproof layer and the concrete base is improved to avoid falling off or hollowing;

[0061] More importantly, the present invention utilizes the synergistic effect of calcium-based and silicon-based crystals to enhance the secondary crystal generation capability, quickly repair microcracks, achieve excellent self-repairing function, and effectively extend the service life of the waterproof layer;

[0062] Compared with the prior art of patent number CN202411452204.9, the advantages of the present invention are as follows:

[0063] The crystal structure is more stable: the silicon-oxygen tetrahedral network provides three-dimensional support, which is superior to the single dendrite crystal of the existing technology, and the durability is improved by more than 20%;

[0064] Strong crack resistance: The toughness of silicon-based crystals makes the waterproof layer less likely to break under stress, and the crack expansion rate is reduced by 25%;

[0065] High anti-seepage pressure and compressive strength: the anti-seepage pressure is increased to 1.2MPa, and the compressive strength is 40MPa;

[0066] Excellent self-repairing function: Calcium-based and silicon-based synergy can completely repair 0.4mm cracks within 7 days, and the repair rate is 20% higher than the existing technology;

[0067] The base layer has good adhesion: the bonding strength reaches 1.5MPa, and no hollowing phenomenon is found. DETAILED DESCRIPTION

[0068] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0069] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0070] The calcium-based and silicon-based crystalline self-repairing waterproof material of the present invention is composed of a calcium-based compound, a silicon-based compound, cement, an additive and water. The material adopts a permeable crystallization waterproofing technology, and the calcium-based crystals fill the capillary channels and the silicon-based crystals form a silicon-oxygen tetrahedron network structure, which effectively improves the impermeability, crack resistance and durability of the concrete.

[0071] The main ingredients and their functions are as follows:

[0072] Calcium compounds (Ca(OH) 2 、CaCO 3 ): Provide calcium ions to react with cement hydration products and silicate ions to form calcium silicate hydrate (CSH), which fills the internal pores of concrete and improves bonding strength.

[0073] Silicon-based compounds (Na 2 SiO 3 , silica fume): provides silicate ions, hydrolyzes to form silica colloid, and further polymerizes into silicon-oxygen tetrahedron (SiO 4 ), enhance the density and crack resistance of the waterproof layer.

[0074] Cement (Portland cement): acts as a base material, synergistically with calcium-based and silicon-based compounds to improve the strength and durability of the waterproofing layer.

[0075] Additives (thickener, water reducer, antifreeze agent): optimize construction performance, improve the adhesion, construction adaptability and durability of the waterproof layer.

[0076] Main ingredients and ratio (mass percentage)

[0077]

[0078] The preparation process of the waterproof material of the present invention is as follows:

[0079] Raw material preparation: weigh calcium-based compounds, silicon-based compounds, cement, additives and water according to weight proportion to ensure that the content of each component meets the formula requirements.

[0080] Dry mixing: Place cement, additives and calcium-based compounds into a high-speed mixer and dry mix for 2 minutes until uniform to ensure that all powder components are evenly dispersed.

[0081] Add water and stir: gradually add water and continue stirring for 3 minutes to form a uniform slurry, ensuring that water and cement fully react to form an early hydration reaction.

[0082] Add silicon-based compounds: Slowly add sodium silicate and silica fume and continue stirring for 5 minutes to ensure that the silicon-based compounds are fully dissolved and dispersed.

[0083] Aging treatment: Let the obtained slurry stand for 30 minutes to allow the initial formation of crystals to improve the stability and waterproof effect of the material.

[0084] Final Stir: Stir again for 2 minutes to obtain an evenly dispersed, workable waterproofing material.

[0085] Chemical reaction mechanism of waterproof materials

[0086] Calcium-based crystallization reaction

[0087] Calcium hydroxide (Ca(OH) 2 ) and silicon dioxide (SiO 2 ) reacts to form calcium silicate hydrate (CSH), which fills the pores in the concrete and improves its waterproof performance.

[0088] Ca(OH) 2 +SiO 2 +H 2 O→CSH.

[0089] Silicon-based crystallization reaction

[0090] Sodium silicate (Na 2 SiO 3 ) is hydrolyzed in water to form silica colloid (H 2 SiO 3 ), further polymerized to form silicon-oxygen tetrahedron (SiO 4 ), enhancing durability and crack resistance.

[0091] N a2 SiO 3 +H 2 O→H 2 SiO 3 +2NaOH

[0092] H 2 SiO 3 →(SiO 4 ) 4- (Silicon oxygen tetrahedral structure).

[0093] Secondary crystallization self-repair

[0094] Unreacted calcium ions (Ca 2+ ) and silicate (SiO 3 2- ) reacts at the micro-cracks to generate new crystals, thus realizing the self-repair function of the waterproof layer.

[0095] Ca 2+ +H 2 SiO 3 →CSH.

[0096] Construction method of waterproof material:

[0097] Wall waterproofing construction

[0098] Base treatment: Clean the concrete surface and remove floating dust, oil stains and loose layers.

[0099] Wet the base: Use a high-pressure water gun to rinse the wall to fully wet the concrete base.

[0100] Crack repair: For concrete cracks, use chiseled U-shaped grooves to treat and fill them with the waterproof material of the present invention.

[0101] Apply waterproof material: Use a brush or sprayer to apply evenly 2-3 times, with an interval of 4 hours between each coat. The thickness of a single layer is 0.5mm.

[0102] Maintenance: After the coating is applied, wet maintenance is performed for 7 days to ensure that the crystals are fully formed.

[0103] Ground waterproofing construction

[0104] Base preparation: Clean the ground to a solid concrete base and rinse it clean.

[0105] Repair defects: For crack areas, use U-shaped groove treatment and fill with waterproofing material.

[0106] Negative water pressure treatment: In high water pressure areas, apply two coats of waterproof material and lay a wire mesh reinforcement layer.

[0107] Waterproof mortar pouring: the waterproof material of the present invention is mixed with cement, sand and gravel in a ratio of 1:2:3:2 to pour a waterproof layer of 3 to 5 cm thick.

[0108] Maintenance: Keep moist for 7 days to improve the strength of the waterproof layer.

[0109] Experimental data:

[0110]

[0111]

[0112] The present invention combines calcium-based and silicon-based crystallization technologies, introduces a silicon-oxygen tetrahedron structure, forms a highly stable three-dimensional network crystal, and enhances the durability of the waterproof layer;

[0113] At the same time, the toughness of the silicon-oxygen tetrahedral structure and the filling effect of calcium-based crystals are used to improve the crack resistance of the waterproof layer under stress environments, optimize the component ratio and crystallization reaction, and significantly improve the anti-seepage pressure and compressive strength to meet the needs of high-demand scenarios;

[0114] In addition, through the bonding enhancement effect and scientific proportion of calcium-based compounds, the bonding strength between the waterproof layer and the concrete base is improved to avoid falling off or hollowing;

[0115] More importantly, the present invention utilizes the synergistic effect of calcium-based and silicon-based crystals to enhance the secondary crystal generation capability, quickly repair microcracks, achieve excellent self-repairing function, and effectively extend the service life of the waterproof layer.

[0116] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A calcium-based and silicon-based crystalline self-repairing waterproof material, characterized in that: The following components are used in percentage by weight composition: Calcium-based compounds: 20-30%; Silicon-based compounds: 15-25%; Cement: 30-40%; Additives: 5-10%; Water: 10-20%.

2. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: The calcium-based compounds include calcium hydroxide and calcium carbonate.

3. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: The silicon-based compounds include sodium silicate and silica fume.

4. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: The auxiliary agents include water reducing agent, thickening agent and antifreeze agent.

5. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: The silicon-based compound is hydrolyzed in water to generate silica colloid, which is further polymerized to form a silicon-oxygen tetrahedron structure to enhance the durability and crack resistance of the waterproof layer. The chemical reaction is as follows: Na2SiO3+H2O→H2SiO3+2NaOH H2SiO3→(SiO4) 4 -(Silicon oxygen tetrahedron).

6. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: The calcium-based compound reacts with silicon dioxide in concrete to generate calcium silicate hydrate, which fills the pores in the concrete and achieves waterproofing. The chemical reaction is as follows: Ca(OH)2+SiO2+H2O→CSH (calcium silicate hydrate).

7. The calcium-based and silicon-based crystalline self-repairing waterproof material according to claim 1, characterized in that: When waterproof materials come into contact with water, they can generate secondary crystals through unreacted calcium ions and silicate ions to repair micro cracks in concrete. The chemical reaction is as follows: Ca 2+ +H2SiO3→CSH (secondary crystallization).

8. A method for preparing a calcium-based and silicon-based crystalline self-repairing waterproof material according to any one of claims 1 to 6, characterized in that: It includes the following steps: S1. Weigh the calcium-based compound, silicon-based compound, cement, additives and water according to weight ratio; S2, dry mix the cement and additives in a mixer for 2 minutes; S3, add water and stir for 3 minutes to form a uniform slurry; S4. Slowly add the calcium-based compound and the silicon-based compound and continue stirring for 5 minutes; S5. Let the obtained mixture stand for 30 minutes to allow the reaction to be initially completed and form a stable crystalline precursor.

9. A method for applying the calcium-based and silicon-based crystalline self-repairing waterproof material according to any one of claims 1 to 7, characterized in that: Apply to the concrete surface, the specific steps are as follows: S11. Clean the surface of the concrete base to remove floating dust and loose layers; S22. Use a high-pressure water gun to wash the concrete base to make it fully moist; S33, repairing the cracks with a U-shaped groove and filling them with the waterproof material; S44, applying the waterproof material evenly by brushing or spraying, brushing 2-3 times, each time interval of 4 hours, each layer thickness is about 0.5mm; S55. Maintain for 7 days and keep the surface moist.

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