A high-toughness, abrasion-resistant concrete protective coating and its preparation method

Abstract

This invention discloses a high-toughness, impact-resistant, and abrasion-resistant concrete protective coating and its preparation method. The coating comprises, from the inside out, an epoxy-penetrating adhesive underlayer, a toughened epoxy impact-resistant intermediate layer, and a weather-resistant, dense epoxy top layer. Using epoxy-terminated polysiloxane grafting modification technology, flexible Si-O bonds are introduced into the epoxy resin crosslinking network to construct a rigid-tough synergistic composite crosslinking system. This effectively improves the shortcomings of traditional epoxy resins, such as high rigidity, low toughness, and weak impact and cavitation resistance, significantly enhancing the coating's resistance to fatigue erosion, high-speed impact, and cavitation damage. A nano-ultrafine-hard three-gradient activated wear-resistant filler system is employed, resulting in dense filler packing, low coating porosity, and good structural uniformity, greatly improving the coating's density and resistance to silt and sand erosion. This allows for long-term adaptability to high-speed, clear water, and high-sand-fluid-content composite erosion conditions, demonstrating excellent long-term service stability.

Description

Technical Field

[0001] This invention belongs to the technical field of hydraulic concrete protective materials, specifically relating to a high-toughness, abrasion-resistant concrete protective coating and its preparation method. Background Technology

[0002] A large number of hydraulic concrete flow structures are in a complex service environment with high water head, large flow rate, and high sediment coupling effect for a long time. The structural surface is continuously subjected to multiple effects such as high-speed water flow scouring (flow velocity can reach 30-50m / s), negative pressure cavitation impact, alternating wet and dry cycles (the number of cycles can reach hundreds of times per year), temperature stress changes (temperature difference can reach more than 80℃) and trace media erosion.

[0003] To improve the abrasion resistance of concrete, the industry mainly adopts two technical approaches: one is to optimize the mix proportion of the concrete matrix, such as by adding silica fume and steel fiber to improve the wear resistance of the matrix. However, this method is only suitable for new construction projects. For the repair and renovation of existing structures, the workload is large, the construction period is long, and the overall cost is high. In addition, water and water supply need to be stopped during construction, which affects the normal operation of the project. The other approach is to apply a protective coating to the concrete surface. Due to its convenient construction, strong adaptability, and significant protective effect, it can meet the needs of both new construction and repair projects and has become the mainstream technical solution for long-term protection of hydraulic concrete.

[0004] Epoxy resin materials possess excellent mechanical strength, interfacial adhesion, dense impermeability, and chemical stability, making them the most widely used matrix resin material in current hydraulic engineering anti-erosion protection systems. However, existing commercial epoxy protective coatings still have significant technical limitations, making them difficult to adapt to harsh working conditions such as high water head, strong abrasion, and frequent cavitation. Furthermore, traditional epoxy resin curing systems have high crosslinking density, high rigidity, but insufficient toughness. Conventional epoxy coating filler systems are often singular with unreasonable particle size distribution, frequently using single quartz powder or calcium carbonate fillers, resulting in insufficient overall density. Summary of the Invention

[0005] The purpose of this invention is to provide a high-toughness, abrasion-resistant concrete protective coating and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-toughness, impact-resistant concrete protective coating, comprising, from the inside out, an epoxy penetrating bonding underlayer, a toughened epoxy impact-resistant intermediate layer, and a weather-resistant dense epoxy top layer; The epoxy penetrating adhesive underlayer has a thickness of 0.2mm to 0.4mm, the toughened epoxy impact-resistant intermediate layer has a thickness of 1.2mm to 1.8mm, and the weather-resistant dense epoxy top layer has a thickness of 0.3mm to 0.6mm.

[0007] In a preferred embodiment, the epoxy penetrating adhesive underlayer is a two-component system of component A and component B. By weight, component A includes 40 to 50 parts of bisphenol A epoxy resin, 8 to 15 parts of reactive diluent, and 0.3 to 0.8 parts of silane coupling agent, and component B is 30 to 40 parts of modified amine curing agent. The mixing ratio of component A to component B is 3:1.

[0008] In a preferred embodiment, the toughened epoxy impact-resistant intermediate layer is a two-component system consisting of A and B. By weight, component A comprises 45 to 55 parts of modified epoxy resin, 5 to 10 parts of epoxy-based polysiloxane toughening modifier, 10 to 18 parts of active solvent, 0.2 to 0.5 parts of dispersant, and 33 to 47 parts of multi-stage wear-resistant filler; component B comprises 35 to 42 parts of modified polyamide and alicyclic amine compound curing agent.

[0009] In a preferred embodiment, the multi-stage wear-resistant filler is composed of 8 to 12 parts by weight of nano-activated calcium carbonate, 15 to 20 parts by weight of ultrafine quartz powder, and 10 to 15 parts by weight of corundum wear-resistant particles; the multi-stage wear-resistant filler is pre-dried at high temperature to remove water, and surface activation modification is completed by using a silane coupling agent.

[0010] In one preferred embodiment, the weather-resistant dense epoxy surface layer comprises, by weight, 50 to 60 parts of modified weather-resistant epoxy resin, 1 to 2 parts of UV-resistant additive, 0.5 to 1 part of hydrophobic modifier, 10 to 15 parts of ultrafine wear-resistant filler, and 32 to 38 parts of compound curing agent.

[0011] In a preferred embodiment, the adhesion strength of the coating to a damp substrate is not less than 2.5 MPa.

[0012] This invention also discloses a method for preparing a high-toughness, impact-resistant concrete protective coating, comprising the following steps: S1. Pretreatment of filler: The multi-level wear-resistant filler composed of nano-activated calcium carbonate, ultrafine quartz powder and corundum wear-resistant particles is dried at high temperature to remove water, and then the filler is surface activated and modified by silane coupling agent. S2. Resin premixing: Stir the modified epoxy resin at low speed and heat it up, then add the epoxy polysiloxane toughening modifier, active solvent and dispersant in sequence, and continue to stir at a uniform speed until the materials are mixed evenly. S3. Graded feeding and dispersion: First, add nano-active calcium carbonate to the premixed resin system and disperse it at high speed until it is completely mixed. Then, add ultrafine quartz powder and corundum wear-resistant particles at low speed to avoid the hard particles from breaking. S4. Post-processing to prepare component A: The dispersed mixture is subjected to vacuum defoaming and filtration to remove impurities, thus obtaining toughened epoxy impact-resistant intermediate layer component A. S5. Preparation of component B: Mix and stir the corresponding curing agent raw materials according to the ratio to prepare epoxy penetrating bonding underlayer component B, toughened epoxy impact and wear resistant intermediate layer component B, and weather-resistant dense epoxy top layer compound curing agent. Each component is independently sealed and packaged.

[0013] As a preferred embodiment, the multi-stage wear-resistant filler that is dried at high temperature in step S1 is sealed and stored for later use after surface activation modification.

[0014] In a preferred embodiment, when adding ultrafine quartz powder and corundum wear-resistant particles in step S2, the stirring speed is lower than the high-speed dispersion speed of nano-active calcium carbonate.

[0015] In a preferred embodiment, vacuum defoaming and filtration are performed continuously in step S4.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention employs epoxy-terminated polysiloxane grafting modification technology to introduce flexible Si-O bonds into the epoxy resin crosslinking network, constructing a rigid-tough composite crosslinking system that effectively improves the defects of traditional epoxy resins, such as high rigidity, low toughness, and weak impact and cavitation resistance, significantly enhancing the coating's resistance to fatigue erosion, high-speed impact, and cavitation damage.

[0017] The system adopts a three-stage activated wear-resistant filler system of nano-ultrafine-hard material, which has dense filler packing, low coating porosity, and good structural uniformity. This greatly improves the coating's density and resistance to erosion and wear from mud and sand. It can be adapted to high-speed clean water and high-sand water flow composite erosion conditions for a long time, and has excellent long-term service stability.

[0018] The design adopts a three-layer functional gradient composite structure, with the mechanical parameters, shrinkage performance and thermal stability of each functional layer matched layer by layer. It has good interlayer compatibility and high interfacial bonding strength, effectively alleviating the problem of interfacial stress concentration under temperature difference alternation and dry-wet cycle conditions, avoiding failure phenomena such as interlayer peeling, hollow cracking and so on, and significantly improving the stability of the overall protection system.

[0019] Adopting a moisture-adaptive compound curing system, the coating can be stably cured and anchored in conditions of damp concrete, slight seepage, and no standing water. This greatly relaxes the restrictions on on-site construction environment for hydraulic engineering projects. It has strong construction adaptability and a wide range of applications, and can meet the needs of various projects such as new construction, repair, and emergency protection.

[0020] The coating of this invention integrates multiple functions such as impact and abrasion resistance, cavitation resistance, seepage and waterproofing, weather resistance and aging resistance, and resistance to media corrosion. It has a low rate of mechanical property decay and excellent structural durability, which can significantly extend the service life of hydraulic concrete structures, reduce the cost of engineering operation and maintenance and renovation, and has good engineering application prospects and promotion value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the steps in the preparation method of the high-toughness, impact-resistant, and abrasion-resistant concrete protective coating of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments.

[0023] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0024] Please see Figure 1 The present invention provides a high-toughness impact-resistant concrete protective coating, which consists of an epoxy penetrating bonding underlayer, a toughened epoxy impact-resistant intermediate layer, and a weather-resistant dense epoxy top layer arranged sequentially from the inside to the outside. The epoxy penetrating adhesive underlayer has a thickness of 0.2mm to 0.4mm, the toughened epoxy impact-resistant intermediate layer has a thickness of 1.2mm to 1.8mm, and the weather-resistant dense epoxy top layer has a thickness of 0.3mm to 0.6mm.

[0025] The epoxy penetrating adhesive underlayer is a two-component system consisting of components A and B. By weight, component A includes 40 to 50 parts of bisphenol A epoxy resin, 8 to 15 parts of reactive diluent, and 0.3 to 0.8 parts of silane coupling agent. Component B is 30 to 40 parts of modified amine curing agent. The mixing ratio of component A to component B is 3:1.

[0026] The toughened epoxy impact and wear-resistant intermediate layer is a two-component system consisting of A and B. By weight, component A consists of 45 to 55 parts of modified epoxy resin, 5 to 10 parts of epoxy-based polysiloxane toughening modifier, 10 to 18 parts of active solvent, 0.2 to 0.5 parts of dispersant, and 33 to 47 parts of multi-grade wear-resistant filler; component B consists of 35 to 42 parts of modified polyamide and alicyclic amine compound curing agent.

[0027] The multi-stage wear-resistant filler is composed of 8 to 12 parts by weight of nano-activated calcium carbonate, 15 to 20 parts by weight of ultrafine quartz powder, and 10 to 15 parts by weight of corundum wear-resistant particles. The multi-stage wear-resistant filler is pre-dried at high temperature to remove water, and surface activation modification is completed by using a silane coupling agent.

[0028] The weather-resistant dense epoxy surface layer comprises, by weight, 50 to 60 parts of modified weather-resistant epoxy resin, 1 to 2 parts of UV-resistant additive, 0.5 to 1 part of hydrophobic modifier, 10 to 15 parts of ultrafine wear-resistant filler, and 32 to 38 parts of compound curing agent.

[0029] The adhesion strength of the coating to a damp substrate is not less than 2.5 MPa.

[0030] This invention also discloses a method for preparing a high-toughness, impact-resistant concrete protective coating, comprising the following steps: S1. Pretreatment of filler: The multi-level wear-resistant filler composed of nano-activated calcium carbonate, ultrafine quartz powder and corundum wear-resistant particles is dried at high temperature to remove water, and then the filler is surface activated and modified by silane coupling agent. S2. Resin premixing: Stir the modified epoxy resin at low speed and heat it up, then add the epoxy polysiloxane toughening modifier, active solvent and dispersant in sequence, and continue to stir at a uniform speed until the materials are mixed evenly. S3. Graded feeding and dispersion: First, add nano-active calcium carbonate to the premixed resin system and disperse it at high speed until it is completely mixed. Then, add ultrafine quartz powder and corundum wear-resistant particles at low speed to avoid the hard particles from breaking. S4. Post-processing to prepare component A: The dispersed mixture is subjected to vacuum defoaming and filtration to remove impurities, thus obtaining toughened epoxy impact-resistant intermediate layer component A. S5. Preparation of component B: Mix and stir the corresponding curing agent raw materials according to the ratio to prepare epoxy penetrating bonding underlayer component B, toughened epoxy impact and wear resistant intermediate layer component B, and weather-resistant dense epoxy top layer compound curing agent. Each component is independently sealed and packaged.

[0031] In step S1, the multi-stage wear-resistant filler that has been dried at high temperature and dehydrated is sealed and stored for later use after surface activation and modification. In step S2, when ultrafine quartz powder and corundum wear-resistant particles are added, the stirring speed is lower than the high-speed dispersion speed of nano-activated calcium carbonate. In step S4, vacuum defoaming and filtration are carried out continuously.

[0032] This invention also discloses a process for constructing and molding a high-toughness, impact-resistant concrete protective coating, comprising the following steps: S1 Base surface pretreatment: Grind away the laitance, sand, debris and aged coating on the concrete base surface. Clean the base surface with high pressure. After treatment, keep the base surface moist but without standing water. S2 Base Layer Construction: Mix components A and B of the epoxy penetrating adhesive base layer according to the mixing ratio, and apply it to the pretreated concrete substrate by roller or trowel, and wait for the coating to dry to the touch. S3 Intermediate Layer Construction: After the epoxy penetration bonding base layer is surface dry, mix the toughened epoxy impact and abrasion resistant intermediate layer components A and B evenly, and apply them evenly in two coats. Control the coating thickness to be uniform, without sagging, hollowing, or pinhole defects. When applying the toughened epoxy impact and abrasion resistant intermediate layer, the thickness of each coat should be evenly stacked, and the overall thickness should be controlled within the range of 1.2 to 1.8 mm. S4 Topcoat Construction: After the toughened epoxy impact-resistant intermediate layer has fully cured, grind the surface smooth and roll-apply weather-resistant dense epoxy topcoat material to complete the surface sealing. S5 Curing and Shaping: Place the completed coating in a normal temperature environment for 7 days to cure, and complete the construction after curing.

[0033] Example 1 (Optimal Example) Penetrating primer: Component A consists of 45 parts bisphenol A type epoxy resin, 12 parts reactive diluent, and 0.5 parts silane coupling agent; Component B consists of 35 parts modified amine curing agent, with a mixing ratio of 3:1; Impact and abrasion resistant intermediate coat: Component A consists of 50 parts modified epoxy resin, 8 parts epoxy polysiloxane modifier, 15 parts reactive solvent, 0.3 parts dispersant, 10 parts nano-activated calcium carbonate, 18 parts ultrafine quartz powder, and 12 parts corundum wear-resistant particles; Component B consists of 38 parts compound curing agent; Weather-resistant topcoat: 55 parts modified weather-resistant epoxy resin, 1.5 parts UV resistant additive, 0.8 parts hydrophobic modifier, 12 parts ultrafine wear-resistant filler, and 35 parts compound curing agent; The total coating thickness is 2.2 mm, of which the primer is 0.3 mm, the intermediate coat is 1.5 mm, and the topcoat is 0.4 mm.

[0034] Example 2 (suitable for mild scouring conditions) Only the components of the anti-abrasion intermediate coating are adjusted: the epoxy polysiloxane modifier is adjusted to 5 parts, the corundum wear-resistant particles are adjusted to 10 parts, and the remaining components, proportions, and thickness parameters remain the same as in Example 1. It is suitable for protection projects in ordinary water conveyance channels and mild abrasion conditions.

[0035] Example 3 (Adapted for high head and strong scouring conditions) Adjust the composition and thickness of the anti-impact and abrasion intermediate coating: adjust the epoxy polysiloxane modifier to 10 parts, the corundum abrasion-resistant particles to 15 parts, and increase the intermediate coating thickness to 1.8 mm; the remaining parameters are the same as in Example 1, which is suitable for high water head, strong impact and abrasion and strong cavitation conditions such as spillway tunnels and overflow dams.

[0036] Scale settings Comparative Example 1: Ordinary pure epoxy resin coating, without the addition of polysiloxane toughening components, without the use of multi-stage hard wear-resistant fillers, using only conventional single powder; Comparative Example 2: Commercially available conventional hydraulic epoxy wear-resistant mortar coating. (Table 1 is a performance test comparison data table)

[0037] Table 1 Performance Test Comparison Data Through multiple comparative tests, this invention, through the toughening modification of polysiloxane, the compounding of three-graded wear-resistant fillers, and the synergistic optimization of a three-layer gradient structure, has achieved significant improvements in adhesion performance on wet substrates, mechanical toughness, impact and abrasion resistance, cavitation stability, and aging resistance compared to existing traditional epoxy protective materials, effectively overcoming many inherent defects of existing technologies.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-toughness, impact-resistant, and abrasion-resistant concrete protective coating, characterized in that, From the inside out, the epoxy penetrating adhesive underlayer, the toughened epoxy impact-resistant intermediate layer, and the weather-resistant dense epoxy top layer are sequentially arranged. The epoxy penetrating adhesive underlayer has a thickness of 0.2mm to 0.4mm, the toughened epoxy impact-resistant intermediate layer has a thickness of 1.2mm to 1.8mm, and the weather-resistant dense epoxy top layer has a thickness of 0.3mm to 0.6mm.

2. The high-toughness, impact-resistant concrete protective coating according to claim 1, characterized in that: The epoxy penetrating adhesive underlayer is a two-component system consisting of components A and B. By weight, component A includes 40 to 50 parts of bisphenol A epoxy resin, 8 to 15 parts of reactive diluent, and 0.3 to 0.8 parts of silane coupling agent. Component B is 30 to 40 parts of modified amine curing agent. The mixing ratio of component A to component B is 3:

1.

3. The high-toughness, impact-resistant concrete protective coating according to claim 1, characterized in that: The toughened epoxy impact-resistant intermediate layer is a two-component system consisting of A and B. By weight, component A consists of 45 to 55 parts of modified epoxy resin, 5 to 10 parts of epoxy-based polysiloxane toughening modifier, 10 to 18 parts of active solvent, 0.2 to 0.5 parts of dispersant, and 33 to 47 parts of multi-grade wear-resistant filler. Component B consists of 35 to 42 parts of modified polyamide and alicyclic amine compound curing agent.

4. The high-toughness, impact-resistant concrete protective coating according to claim 1, characterized in that: The multi-level wear-resistant filler is composed of 8 to 12 parts by weight of nano-active calcium carbonate, 15 to 20 parts by weight of ultrafine quartz powder, and 10 to 15 parts by weight of corundum wear-resistant particles. The multi-stage wear-resistant filler is pre-dried at high temperature to remove water, and surface activation modification is completed using a silane coupling agent.

5. The high-toughness, impact-resistant concrete protective coating according to claim 1, characterized in that: The weather-resistant dense epoxy surface layer comprises, by weight, 50 to 60 parts of modified weather-resistant epoxy resin, 1 to 2 parts of UV-resistant additive, 0.5 to 1 part of hydrophobic modifier, 10 to 15 parts of ultrafine wear-resistant filler, and 32 to 38 parts of compound curing agent.

6. The high-toughness, impact-resistant concrete protective coating according to claim 1, characterized in that: The adhesion strength of the coating to a damp substrate is not less than 2.5 MPa.

7. A method for preparing a high-toughness, impact-resistant concrete protective coating, comprising the high-toughness, impact-resistant concrete protective coating as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Pretreatment of filler: The multi-level wear-resistant filler composed of nano-activated calcium carbonate, ultrafine quartz powder and corundum wear-resistant particles is dried at high temperature to remove water, and then the filler is surface activated and modified by silane coupling agent. S2. Resin premixing: Stir the modified epoxy resin at low speed and heat it up, then add the epoxy polysiloxane toughening modifier, active solvent and dispersant in sequence, and continue to stir at a uniform speed until the materials are mixed evenly. S3. Graded feeding and dispersion: First, add nano-active calcium carbonate to the premixed resin system and disperse it at high speed until it is completely mixed. Then, add ultrafine quartz powder and corundum wear-resistant particles at low speed to avoid the hard particles from breaking. S4. Post-processing to prepare component A: The dispersed mixture is subjected to vacuum defoaming and filtration to remove impurities, thus obtaining toughened epoxy impact-resistant intermediate layer component A. S5. Preparation of component B: Mix and stir the corresponding curing agent raw materials according to the ratio to prepare epoxy penetrating bonding underlayer component B, toughened epoxy impact and abrasion resistant intermediate layer component B, and weather-resistant dense epoxy top layer compound curing agent. Each component is independently sealed and packaged.

8. The method for preparing a high-toughness, impact-resistant, and abrasion-resistant concrete protective coating according to claim 7, characterized in that: The multi-stage wear-resistant filler that was dried at high temperature in step S1 is then sealed and stored for later use after surface activation modification.

9. The method for preparing a high-toughness, impact-resistant, and abrasion-resistant concrete protective coating according to claim 7, characterized in that: When adding ultrafine quartz powder and corundum wear-resistant particles in step S2, the stirring speed is lower than the high-speed dispersion speed of nano-active calcium carbonate.

10. The method for preparing a high-toughness, impact-resistant, and abrasion-resistant concrete protective coating according to claim 7, characterized in that: In step S4, vacuum defoaming and filtration are carried out continuously.

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