Concrete repair material suitable for low temperature environment, preparation method and construction method

Abstract

This invention discloses a concrete repair material suitable for low-temperature environments, its preparation method, and its construction method. The composite material consists of polyurethane mortar and a two-component exothermic material. The construction method includes the following steps: Step 1, pre-treating the concrete substrate to be repaired; Step 2, applying the two-component exothermic material to the pre-treated concrete substrate in Step 1; Step 3, before the two-component exothermic material is fully cured, laying the polyurethane mortar on top of the applied material in Step 2; Step 4, after the application in Step 3 is completed, covering the polyurethane mortar surface with a plastic film, and then covering the plastic film with an insulating cloth. The composite material of this invention can cure normally in low-temperature environments after construction.

Description

Technical Field

[0001] This invention belongs to the field of concrete repair materials technology, specifically relating to concrete repair materials suitable for low-temperature environments, a preparation method for concrete repair materials suitable for low-temperature environments, and a construction method for concrete repair materials suitable for low-temperature environments. Background Technology

[0002] During long-term service, concrete structures are prone to damage such as cracks and spalling due to loads and environmental erosion, requiring timely repair. However, concrete repair work in the low-temperature environment of winter often faces the challenge of the low temperature affecting the curing of repair materials. For example, traditional cement-based mortar cures slowly or not at all in low-temperature environments, resulting in poor repair effects and even quality problems such as cracking and detachment.

[0003] In recent years, polyurethane mortar has been widely used in concrete repair due to its excellent adhesion, durability, and waterproofing properties. However, the curing performance of polyurethane mortar at low temperatures remains poor, failing to meet the needs of winter construction. Therefore, there is a need to develop a repair material that can cure rapidly at low temperatures. Summary of the Invention

[0004] The first objective of this invention is to provide a concrete repair material suitable for low-temperature environments, thereby solving the problem of slow curing of existing repair materials at low temperatures.

[0005] A second objective of this invention is to provide a method for preparing concrete repair materials suitable for low-temperature environments.

[0006] A third objective of this invention is to provide a method for constructing concrete repair materials suitable for low-temperature environments.

[0007] The first technical solution adopted in this invention is a concrete repair material suitable for low-temperature environments, which is composed of polyurethane mortar and a two-component exothermic material.

[0008] The invention is further characterized by:

[0009] Polyurethane mortar is composed of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier; The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8. The modifier consists of a low-temperature catalyst, a low-temperature activator, a viscosity reducer, a toughening agent, and a bonding promoter; The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100.

[0010] The two-component exothermic material consists of component A and component B, with a mass ratio of component A to component B of 4:1. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler A. Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B.

[0011] The second technical solution adopted in this invention is a method for preparing concrete repair materials suitable for low-temperature environments, the specific steps of which are as follows: Step 1: Prepare polyurethane mortar; Step 2: Prepare a two-component exothermic material.

[0012] The invention is further characterized by: The specific process of step 1 is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at a speed of 300 rpm to 400 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8.

[0013] The specific process of step 2 is as follows: Step 2.1: Using the bonding resin as the base material, elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler are added in sequence. Then, high-speed dispersion is carried out, and the viscosity is adjusted with deionized water after dispersion to obtain component A. The weight parts of each raw material in component A are as follows: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low temperature activator, and 15-20 parts of filler A. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B. The mass ratio of component A to component B is 4:1.

[0014] The third technical solution adopted in this invention is a construction method for concrete repair materials suitable for low-temperature environments, the specific steps of which are as follows: Step 1: Pre-treat the concrete base layer to be repaired; Step 2: Apply the two-component exothermic material to the concrete substrate to be repaired after the pretreatment in Step 1. Step 3: Before the two-component heat-releasing material is fully cured, lay the polyurethane mortar on the two-component heat-releasing material coated in Step 2. Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth.

[0015] The invention is further characterized by: The specific process of step 1 is as follows: the concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry. The specific process of step 2 is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of component A to component B of 4:1. Component A and component B are mixed and stirred until the color is uniform. The concrete base layer to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.1kg / m²~0.15kg / m², and the interval between the two coatings is 20min. The amount of the two-component heat-releasing material used in the second coating is 0.15kg / m²~0.2kg / m², and the total thickness of the two coatings is 1mm~3mm. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler A. Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B. The specific process of step 3 is as follows: Before the two-component heat-releasing material is completely cured, the pre-mixed polyurethane mortar is spread on the two-component heat-releasing material, and then the polyurethane mortar is spread and compacted according to the design thickness using a scraper, so that it is fully bonded with the two-component heat-releasing material without gaps. The spreading thickness is 5mm~10mm. Polyurethane mortar is composed of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier; The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8; the mass ratio of low-temperature catalyst to vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of low-temperature activator to vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of viscosity reducer to vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of toughening agent to vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of adhesion promoter to vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100.

[0016] The beneficial effects of this invention are: (1) The present invention is applicable to concrete repair materials in low-temperature environments. The two-component heat-releasing material can release heat during construction to provide temperature protection for its own curing and polyurethane mortar curing, ensuring that curing can proceed normally, thereby avoiding the problem of slow curing speed caused by low temperature. At the same time, polyurethane mortar and two-component heat-releasing material can form a dual interface of chemical bonding and physical interlocking, improving the interface bonding strength to ensure the repair effect. (2) The present invention is applicable to the construction method of concrete repair materials in low temperature environment. The two-component heat-releasing material is combined with the concrete base and polyurethane mortar through a three-step method of “base surface pretreatment ~ two-component heat-releasing material coating ~ polyurethane mortar repair”. During the curing process of polyurethane mortar, the temperature is maintained at ≥0℃ by the synergistic heat release of the two-component heat-releasing material. It can quickly cure to form a dual interface of chemical bonding and physical interlocking. Through the synergistic effect of material formulation and construction process, the efficient repair of concrete in low temperature environment in winter is achieved, avoiding the use of additional heating equipment and reducing construction costs and environmental impact. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the construction method of the present invention.

[0018] In the diagram, 1. The concrete base layer to be repaired, 2. The two-component heat-dissipating material layer, and 3. The polyurethane mortar layer. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] This invention relates to a concrete repair material suitable for low-temperature environments, which is composed of polyurethane mortar and a two-component exothermic material. Polyurethane mortar is composed of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8. The solid content concentration of the vegetable oil-modified polyether polyol aqueous dispersion is 40%~60%; The modifier consists of a low-temperature catalyst, a low-temperature activator, a viscosity reducer, a toughening agent, and a bonding accelerator. The low-temperature catalyst is bismuth isooctanoate, the low-temperature activator is polyetheramine, the viscosity reducer is polyether-modified polysiloxane, the toughening agent is polysulfide rubber, and the bonding accelerator is silane coupling agent (KH-560). The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100. The two-component exothermic material consists of component A and component B, with a mass ratio of component A to component B of 4:1. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler A. The bonding resin is an aqueous acrylic resin dispersion, the elastomer modifier is an aqueous acrylic ester emulsion, the accelerator is zirconium acetylacetonate, the metal powder is aluminum powder, the oxidant is manganese dioxide, the polymerization inhibitor is N,N-diethylhydroxylamine (DEHA), the catalyst is cuprous chloride, the low-temperature activator is lithium nitrate, and the filler A is light calcium carbonate. The solid content concentration of the waterborne acrylic resin dispersion is 45%~55%; Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B. The interface reinforcing agent is a silane coupling agent (KH-570), the initiator is cumene hydroperoxide (CHP) aqueous emulsion, the binder is a polyurethane prepolymer, and filler B is silica powder. The concentration of cumene hydroperoxide (CHP) aqueous emulsion is 8%~12%.

[0021] The present invention relates to a method for preparing concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Prepare polyurethane mortar; The specific process is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at a speed of 300 rpm to 400 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8. Step 2: Prepare a two-component exothermic material; The specific process is as follows: Step 2.1: Using the bonding resin as the base material, add the elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler in sequence. Then, disperse at high speed for 20 minutes. After dispersion, adjust the viscosity to 5 Pa·s~15 Pa·s with deionized water to obtain component A. The high-speed dispersion speed is 1000 rpm to 1500 rpm; The weight parts of each raw material in component A are as follows: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low temperature activator, and 15-20 parts of filler A. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B. The mass ratio of component A to component B is 4:1.

[0022] This invention relates to a construction method for concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: like Figure 1 As shown, step 1 involves pre-treating the concrete base layer 1 to be repaired; The specific process is as follows: The concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry. Step 2: Apply the two-component heat-releasing material to the concrete substrate to be repaired after the pretreatment in Step 1 to form the two-component heat-releasing material layer 2. The specific process is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of 4:1. Component A and component B are mixed and stirred until the color is uniform. The concrete substrate to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.1 kg / m² to 0.15 kg / m², and the interval between the two coatings is 20 min. The amount of the two-component heat-releasing material used in the second coating is 0.15 kg / m² to 0.2 kg / m², and the total thickness of the two coatings is 1 mm to 3 mm. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler A. Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B. Step 3: Before the two-component heat-releasing material is completely cured, the polyurethane mortar is laid on the two-component heat-releasing material coated in Step 2 to form polyurethane mortar layer 3. The specific process is as follows: Before the two-component heat-releasing material is fully cured, spread the pre-mixed polyurethane mortar on the two-component heat-releasing material, and then use a scraper to spread and compact the polyurethane mortar to the designed thickness so that it is fully bonded to the two-component heat-releasing material without gaps. The spreading thickness is 5mm~10mm. Polyurethane mortar is composed of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier; The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8; the mass ratio of low-temperature catalyst to vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of low-temperature activator to vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of viscosity reducer to vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of toughening agent to vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of adhesion promoter to vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100. Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth to ensure continuous heating.

[0023] After construction, the relationship between the three layers—1. the concrete base layer to be repaired, 2. the two-component heat-dissipating material layer, and 3. the polyurethane mortar layer—is as follows: Figure 1 As shown.

[0024] The specific principle of maintaining a temperature ≥0℃ during the curing process of polyurethane mortar using a two-component exothermic material is as follows: When components A and B of the two-component exothermic material are mixed, the redox system composed of the initiator cumene hydroperoxide and the accelerator zirconium acetylacetonate first triggers the aluminothermic reaction between the aluminum powder and the oxidant manganese dioxide, releasing a large amount of heat. Then, this heat simultaneously activates the cross-linking curing exothermic reaction of the elastomer modifier waterborne acrylate and the binder polyurethane prepolymer and other resins, forming a continuous heat source. The filler A (calcium carbonate), filler B (silica powder), and water in the system act as a heat buffer medium, absorbing the peak heat and releasing it slowly, thereby dynamically and stably maintaining the ambient temperature at the interface above 0℃ during the critical curing period of the polyurethane mortar.

[0025] This invention repairs concrete substrates using polyurethane mortar and a two-component exothermic material, forming a dual-bonded interface of chemical bonding and physical interlocking, thus improving interfacial adhesion strength. The principle is as follows: First, the concrete substrate is sandblasted or ground to create a rough, porous surface, providing a foundation for physical interlocking. Then, a two-component exothermic material is coated onto the surface, allowing its low-viscosity slurry to fully penetrate the substrate pores. Simultaneously, the silane coupling agent it contains undergoes a dehydration condensation reaction with the minerals on the concrete surface, forming preliminary chemical bonds. Finally, polyurethane mortar is laid while the two-component exothermic material is in a gel state. The system's exothermic effect activates the curing process of the polyurethane mortar, achieving a chemical bond between the two-component exothermic material and the upper polyurethane mortar. Simultaneously, the penetrating slurry solidifies to form microscopic mechanical anchors, ultimately creating a composite interface of chemical bonding and physical interlocking that extends from the interior of the concrete to the repaired body.

[0026] The method of this invention creates a suitable curing environment for polyurethane mortar by chemically coupling the two-component exothermic material with the polyurethane mortar, effectively solving the technical problems of its inability to cure normally at low temperatures and poor adhesion. It has the advantages of convenient construction, energy saving and high efficiency, and reliable repair quality.

[0027] Example 1 The present invention relates to a method for preparing concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Prepare polyurethane mortar; The specific process is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at 300 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8:100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71:1:8:0.5. Step 2: Prepare a two-component exothermic material; The specific process is as follows: Step 2.1: Using the bonding resin as the base material, elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler are added in sequence. Then, high-speed dispersion is carried out, and the viscosity is adjusted after dispersion to obtain component A. The weight proportions of each raw material in component A are as follows: 70 parts of bonding resin, 10 parts of elastomer modifier, 5 parts of accelerator, 10 parts of metal powder, 20 parts of oxidant, 1 part of polymerization inhibitor, 1 part of catalyst, 2 parts of low-temperature activator, and 15 parts of filler A. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 2 parts of interface reinforcing agent, 3 parts of initiator, 10 parts of binder component, and 10 parts of filler B. The mass ratio of component A to component B is 4:1.

[0028] Example 2 The present invention relates to a method for preparing concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Prepare polyurethane mortar; The specific process is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at 350 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 5:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.5:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 10:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 1.2:100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.85:1:8.5:0.6. Step 2: Prepare a two-component exothermic material; The specific process is as follows: Step 2.1: Using the bonding resin as the base material, elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler are added in sequence. Then, high-speed dispersion is carried out, and the viscosity is adjusted after dispersion to obtain component A. The weight proportions of each raw material in component A are as follows: 80 parts of bonding resin, 15 parts of elastomer modifier, 8 parts of accelerator, 12 parts of metal powder, 25 parts of oxidant, 3 parts of polymerization inhibitor, 2 parts of catalyst, 3 parts of low-temperature activator, and 18 parts of filler A. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 3 parts of interface reinforcing agent, 4 parts of initiator, 15 parts of binder component, and 15 parts of filler B. The mass ratio of component A to component B is 4:1.

[0029] Example 3 The present invention relates to a method for preparing concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Prepare polyurethane mortar; The specific process is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at 400 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.35:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8:100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.95:1:9:0.7. Step 2: Prepare a two-component exothermic material; The specific process is as follows: Step 2.1: Using the bonding resin as the base material, elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler are added in sequence. Then, high-speed dispersion is carried out, and the viscosity is adjusted after dispersion to obtain component A. The weight parts of each raw material in component A are as follows: 100 parts of adhesive resin, 20 parts of elastomer modifier, 10 parts of accelerator, 15 parts of metal powder, 30 parts of oxidant, 5 parts of polymerization inhibitor, 3 parts of catalyst, 5 parts of low temperature activator, and 20 parts of filler A. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 4 parts of interface reinforcing agent, 5 parts of initiator, 20 parts of binder, and 20 parts of filler B. The mass ratio of component A to component B is 4:1.

[0030] Example 4 The difference from Example 3 is that the mass ratio of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 1:1:9.5:0.8. Example 5 This invention relates to a construction method for concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Pre-treat the concrete base layer to be repaired; The specific process is as follows: The concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry. Step 2: Apply the two-component exothermic material to the concrete substrate to be repaired after the pretreatment in Step 1. The specific process is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of 4:1. Component A and component B are mixed and stirred until the color is uniform. The concrete base layer to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.1 kg / m², and the interval between the two coatings is 20 min. The amount of the two-component heat-releasing material used in the second coating is 0.15 kg / m², and the total thickness of the two coatings is 1 mm. The composition and weight percentage of components A and B are the same as in Example 1; Step 3: Before the two-component heat-releasing material is fully cured, lay the polyurethane mortar on the two-component heat-releasing material coated in Step 2. The specific process is as follows: Before the two-component heat-releasing material is fully cured, spread the pre-mixed polyurethane mortar on the two-component heat-releasing material, and then use a scraper to spread and compact the polyurethane mortar to the designed thickness, so that it is fully bonded with the two-component heat-releasing material without gaps. The spreading thickness is 5mm. The composition and mass ratio of the polyurethane mortar are the same as in Example 1; Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth to ensure continuous heating.

[0031] During the curing process of polyurethane mortar, the temperature is maintained at ≥0℃ through the synergistic release of heat by two-component exothermic materials, forming a dual interface of chemical bonding and physical interlocking.

[0032] Example 6 This invention relates to a construction method for concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Pre-treat the concrete base layer to be repaired; The specific process is as follows: The concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry. Step 2: Apply the two-component exothermic material to the concrete substrate to be repaired after the pretreatment in Step 1. The specific process is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of 4:1. Component A and component B are mixed and stirred until the color is uniform. The concrete base layer to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.12 kg / m², and the interval between the two coatings is 20 min. The amount of the two-component heat-releasing material used in the second coating is 0.18 kg / m², and the total thickness of the two coatings is 2 mm. The composition and weight percentage of components A and B are the same as in Example 2; Step 3: Before the two-component heat-releasing material is fully cured, lay the polyurethane mortar on the two-component heat-releasing material coated in Step 2. The specific process is as follows: Before the two-component heat-releasing material is fully cured, spread the pre-mixed polyurethane mortar on the two-component heat-releasing material, and then use a scraper to spread and compact the polyurethane mortar to the designed thickness, so that it is fully bonded with the two-component heat-releasing material without gaps. The spreading thickness is 8mm. The composition and mass ratio of the polyurethane mortar are the same as in Example 2; Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth to ensure continuous heating.

[0033] During the curing process of polyurethane mortar, the temperature is maintained at ≥0℃ through the synergistic release of heat by two-component exothermic materials, forming a dual interface of chemical bonding and physical interlocking.

[0034] Example 7 This invention relates to a construction method for concrete repair materials applicable to low-temperature environments, the specific steps of which are as follows: Step 1: Pre-treat the concrete base layer to be repaired; The specific process is as follows: The concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry. Step 2: Apply the two-component exothermic material to the concrete substrate to be repaired after the pretreatment in Step 1. The specific process is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of 4:1. Component A and component B are mixed and stirred until the color is uniform. The concrete substrate to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.15 kg / m², and the interval between the two coatings is 20 min. The amount of the two-component heat-releasing material used in the second coating is 0.2 kg / m², and the total thickness of the two coatings is 3 mm. The composition and weight percentage of components A and B are the same as in Example 3; Step 3: Before the two-component heat-releasing material is fully cured, lay the polyurethane mortar on the two-component heat-releasing material coated in Step 2. The specific process is as follows: Before the two-component heat-releasing material is fully cured, spread the pre-mixed polyurethane mortar on the two-component heat-releasing material, and then use a scraper to spread and compact the polyurethane mortar to the designed thickness, so that it is fully bonded with the two-component heat-releasing material without gaps. The spreading thickness is 10mm. The composition and mass ratio of the polyurethane mortar are the same as in Example 3; Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth to ensure continuous heating.

[0035] During the curing process of polyurethane mortar, the temperature is maintained at ≥0℃ through the synergistic release of heat by two-component exothermic materials, forming a dual interface of chemical bonding and physical interlocking.

[0036] Comparative Example 1 The repair material used in Comparative Example 1 differs from that in Example 1 in that it consists only of polyurethane mortar, and the modifier is removed from the polyurethane mortar components. It consists of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste. The rest is exactly the same as in Example 1.

[0037] Comparative Example 2 The repair material used in Comparative Example 2 differs from that in Example 2 in that it consists only of polyurethane mortar, and the modifier is removed from the polyurethane mortar components. It consists of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste. The rest is exactly the same as in Example 12.

[0038] Comparative Example 3 The repair material used in Comparative Example 3 differs from that in Example 3 in that it consists only of polyurethane mortar, and the modifier is removed from the polyurethane mortar components. It consists of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste. The rest is exactly the same as in Example 1.

[0039] The composite materials obtained in Examples 1, 2, and 3, as well as the mixed repair materials obtained in Comparative Examples 1, 2, and 3, were respectively made into specimens with concrete. The preparation time and methods were completely consistent. The specimens were used to measure the shear strength of the interface between the repair layer and the concrete. The specific test data are shown in Table 1.

[0040] Table 1

[0041] As can be seen from Table 1, the cross-sectional shear strength of Examples 1, 2, and 3 is greater than that of Comparative Examples 1, 2, and 3. This indicates that adding a modifier to the polyurethane mortar and coating a two-component exothermic material between the polyurethane mortar and the concrete substrate to be repaired can ensure the interfacial shear strength after low-temperature curing.

Claims

1. A concrete repair material suitable for low-temperature environments, characterized in that, It is composed of polyurethane mortar and a two-component heat-dissipating material.

2. The concrete repair material suitable for low-temperature environments according to claim 1, characterized in that, The polyurethane mortar is composed of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier; The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.

8. The modifier consists of a low-temperature catalyst, a low-temperature activator, a viscosity reducer, a toughening agent, and a bonding promoter; The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:

100.

3. The concrete repair material suitable for low-temperature environments according to claim 1, characterized in that, The bicomponent exothermic material is composed of component A and component B, with a mass ratio of component A to component B of 4:

1. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler. Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler.

4. A method for preparing concrete repair materials suitable for low-temperature environments, characterized in that, The specific steps are as follows: Step 1: Prepare polyurethane mortar; Step 2: Prepare a two-component exothermic material.

5. The method for preparing concrete repair material suitable for low-temperature environments according to claim 4, characterized in that, The specific process of step 1 is as follows: Step 1.1: Add vegetable oil modified polyether polyol aqueous dispersion to the reactor and stir at a speed of 300 rpm to 400 rpm. While stirring, add viscosity reducer, adhesion promoter, toughening agent, low temperature activator and low temperature catalyst in sequence. After mixing evenly, the component containing the modifier is obtained. The mass ratio of the low-temperature catalyst to the vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of the low-temperature activator to the vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of the viscosity reducer to the vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of the toughening agent to the vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of the adhesion promoter to the vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:

100. Step 1.2: Dry the inorganic active aggregate until the moisture content is no more than 0.5%, then put the dried inorganic active aggregate into a mixer and mix it in a closed container until uniform to obtain the mixed inorganic active aggregate. Step 1.3: The component containing the modifier obtained in Step 1.1, the inorganic active aggregate, diisocyanate, and color paste obtained in Step 1.2 are mixed and mixed evenly to obtain polyurethane mortar. The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.

8.

6. The method for preparing concrete repair material suitable for low-temperature environments according to claim 4, characterized in that, The specific process of step 2 is as follows: Step 2.1: Using the bonding resin as the base material, elastomer modifier, accelerator, metal powder, oxidant, polymerization inhibitor, catalyst, low-temperature activator, and filler are added in sequence. Then, high-speed dispersion is carried out, and the viscosity is adjusted with deionized water after dispersion to obtain component A. The weight parts of each raw material in component A are as follows: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low temperature activator, and 15-20 parts of filler. Step 2.2: Mix and emulsify the initiator, interface reinforcing agent, binder, and filler to obtain component B; The weight proportions of each raw material in component B are as follows: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler. The mass ratio of component A to component B is 4:

1.

7. A construction method for concrete repair materials suitable for low-temperature environments, characterized in that, The specific steps are as follows: Step 1: Pre-treat the concrete base layer to be repaired; Step 2: Apply the two-component exothermic material to the concrete substrate to be repaired after the pretreatment in Step 1. Step 3: Before the two-component heat-releasing material is fully cured, lay the polyurethane mortar on the two-component heat-releasing material coated in Step 2. Step 4: After the laying in step 3 is completed, cover the surface of the polyurethane mortar with a layer of plastic film, and then cover the plastic film with insulation cloth.

8. The construction method of the concrete repair material suitable for low-temperature environments according to claim 7, characterized in that, The specific process of step 1 is as follows: the concrete base layer to be repaired is sandblasted or ground to expose a clean aggregate surface, forming a rough and uniform bonding surface. Then, a high-pressure air machine is used to remove impurities from the base layer surface, making the base layer surface clean and dry.

9. The construction method of the concrete repair material suitable for low-temperature environments according to claim 7, characterized in that, The specific process of step 2 is as follows: The two-component heat-releasing material consists of component A and component B, with a mass ratio of component A to component B of 4:

1. Component A and component B are mixed and stirred until the color is uniform. The concrete base layer to be repaired after the pretreatment in step 1.1 is coated twice. The amount of the two-component heat-releasing material used in the first coating is 0.1kg / m²~0.15kg / m², and the interval between the two coatings is 20min. The amount of the two-component heat-releasing material used in the second coating is 0.15kg / m²~0.2kg / m², and the total thickness of the two coatings is 1mm~3mm. Component A consists of the following components by weight: 70-100 parts of bonding resin, 10-20 parts of elastomer modifier, 5-10 parts of accelerator, 10-15 parts of metal powder, 20-30 parts of oxidant, 1-5 parts of polymerization inhibitor, 1-3 parts of catalyst, 2-5 parts of low-temperature activator, and 15-20 parts of filler A. Component B consists of the following components by weight: 2 to 4 parts of interface reinforcing agent, 3 to 5 parts of initiator, 10 to 20 parts of binder, and 10 to 20 parts of filler B.

10. The construction method of the concrete repair material suitable for low-temperature environments according to claim 7, characterized in that, The specific process of step 3 is as follows: Before the two-component heat-releasing material is completely cured, the pre-mixed polyurethane mortar is spread on the two-component heat-releasing material, and then the polyurethane mortar is spread and compacted according to the design thickness using a scraper, so that it is fully bonded with the two-component heat-releasing material without gaps. The spreading thickness is 5mm~10mm. Polyurethane mortar is composed of vegetable oil modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, color paste, and modifier; The mass ratio of vegetable oil-modified polyether polyol aqueous dispersion, diisocyanate, inorganic active aggregate, and color paste is 0.71~1:1:8~9.5:0.5~0.8; the mass ratio of low-temperature catalyst to vegetable oil-modified polyether polyol aqueous dispersion is 0.2~0.5:100; the mass ratio of low-temperature activator to vegetable oil-modified polyether polyol aqueous dispersion is 3~8:100; the mass ratio of viscosity reducer to vegetable oil-modified polyether polyol aqueous dispersion is 0.3~0.8:100; the mass ratio of toughening agent to vegetable oil-modified polyether polyol aqueous dispersion is 5~15:100; and the mass ratio of adhesion promoter to vegetable oil-modified polyether polyol aqueous dispersion is 0.8~1.5:100.

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