Interface treatment agent, and preparation method and application thereof

Abstract

The application provides an interface treatment agent, which comprises liquid material A, liquid material B and liquid material C; raw materials and mass ratios of the liquid material A are as follows: 40-80% of biphosphate, 8-12% of migration type rust-preventing component, 0.01-2% of suspension stabilizer and 8-50% of water; raw materials and mass ratios of the liquid material B are as follows: 60-70% of heavy-burned magnesia, 10-20% of superfine mineral admixture, 1-5% of waterproof component, 0.5-2% of anti-sagging agent, 0.01-2% of dispersing agent, 1-5% of nano calcium carbonate and 10-20% of water; raw materials and mass ratios of the liquid material C are as follows: 40-80% of biphosphate, 4-8% of composite retarder, 0.01-2% of suspension stabilizer and 12-55% of water. The application further provides a preparation method and an application method of the interface treatment agent. The application can meet the construction requirement of the high-speed railway bridge pier leakage reinforcement repair, has the advantages of fast coagulation and solidification, excellent reinforcement protection performance, good bonding performance and waterproof and anti-permeation performance, can effectively resist the adverse influence of the intermittent high-frequency disturbance of the normal operation of the high-speed train on the bridge on the repair construction, guarantees the construction quality and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of maintenance and upkeep technology for concrete structures such as high-speed railway bridge piers, and specifically relates to an interface treatment agent, its preparation method, and its application. Background Technology

[0002] With rapid economic and social development, cement concrete has become one of the most widely used building materials globally. Its advantages, including convenient construction, strong applicability, superior performance, and low cost, make it indispensable in many infrastructure projects and large-scale structural engineering projects in my country. Among the many properties of cement concrete, durability is crucial for the safety and stability of building structures during service, and it also determines the service life of the structure. As the environmental conditions for cement concrete in high-speed railway projects become increasingly harsh, the durability of concrete bridge piers along high-speed railway lines has significantly decreased and severe damage has occurred under the combined effects of physical erosion and chemical corrosion. This damage is mainly manifested in large-area spalling and exposed reinforcement, which negatively impacts the safety of the concrete structure and the operational safety of trains.

[0003] Currently, conventional repair materials for exposed rebar defects in high-speed railway concrete bridge piers mainly include inorganic cement-based repair mortar and organic epoxy repair mortar. However, due to the high price, poor durability, and color variation of epoxy mortar, most high-speed railway concrete bridge pier exposed rebar repair projects use inorganic cement-based repair mortar. Compared with organic epoxy mortar, cement-based repair mortar has advantages such as high strength, good durability, and low price. However, in actual use, cement-based repair mortar has poor adhesion, especially to exposed rebar, and poor reinforcement performance, easily leading to voids at the exposed rebar. Even when using conventional organic interface agents with cement-based repair mortar, although the adhesion between the cement-based repair mortar and the base concrete can be improved, the problem of poor adhesion to exposed rebar still exists. Furthermore, organic interface agents also have problems during use, such as excessively long drying time, poor reinforcement performance, slow or difficult film formation at low temperatures, which can easily cause the reinforcing steel in the repair area to be corroded and damaged again, thus significantly weakening the overall repair effect. Finally, from the perspective of the construction environment, for the repair of concrete bridge piers on operating lines, the normal operation of high-speed trains will bring intermittent high-frequency disturbances, thus placing higher demands on the bonding performance of cement-based repair mortar.

[0004] Based on this, developing an interface treatment agent to solve various problems between cement-based repair mortar and the base concrete and exposed steel bars in the area to be repaired is of great practical significance and is also a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an interface treatment agent, its preparation method, and its application, aiming to solve the following problems existing in current methods of repairing exposed rebar in buildings:

[0006] (1) Areas repaired with cement-based repair mortar have poor adhesion, poor bond with exposed steel bars, poor reinforcement performance, and are prone to voids at exposed steel bars;

[0007] (2) The process of repairing with organic interface agents has problems such as long drying time, poor reinforcement performance, slow film formation at low temperature or difficulty in film formation, which can easily cause the reinforcement in the repair area to be corroded and damaged again, thus greatly weakening the overall repair effect.

[0008] (3) For the repair of concrete bridge piers on operating lines, the normal operation of high-speed trains will bring intermittent high-frequency disturbances, which will place higher demands on the bonding performance of cement-based repair mortar.

[0009] To solve the above-mentioned technical problems, the present invention provides an interface treatment agent, comprising liquid A, liquid B and liquid C;

[0010] By mass percentage, the raw materials of liquid A include: 40-80% dihydrogen phosphate, 8-12% migratory rust inhibitor, 0.01-2% suspension stabilizer, and 8-50% water;

[0011] By mass percentage, the raw materials of liquid material B include: 60-70% recalcined magnesium oxide, 10-20% ultrafine mineral admixture, 1-5% waterproofing component, 0.5-2% anti-sagging agent, 0.01-2% dispersant, 1-5% nano calcium carbonate, and 10-20% water;

[0012] The raw materials and their mass ratios of the liquid material C, by mass percentage, include: 40-80% dihydrogen phosphate, 4-8% composite retarder, 0.01-2% suspension stabilizer, and 12-55% water;

[0013] The dihydrogen phosphate salt is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0014] Optionally, the particle size of the recalcined magnesium oxide is no greater than 0.075 mm, and the particle size of the nano-calcium carbonate is 60-80 nm. The particles are finer and have higher surface activity, which improves the density of the bonding interface and increases the bonding strength between new and old concrete.

[0015] Optionally, the migratory rust-inhibiting component is a combination of at least two of triethanolamine, triisopropanolamine, and sodium dodecylbenzenesulfonate, which improves the rust-inhibiting effect of liquid A on exposed steel bars in the exposed bar area. The suspension stabilizer is methyl cellulose ether or Brunei gum, which increases the viscosity of liquid A and liquid C, which is beneficial to improving the overall bonding performance of the interface treatment agent.

[0016] Optionally, the ultrafine mineral admixture is a combination of at least two of microsphere powder, metakaolin, and silica fume.

[0017] Optionally, the waterproof component is a copolymer latex powder of vinyl chloride, ethylene and vinyl lauryl ester.

[0018] Optionally, the anti-sagging agent is polyethylene oxide, the polyethylene oxide has a purity greater than 96%, and the polyethylene oxide has a molecular weight of 2 to 3 million, which increases the viscosity of liquid B.

[0019] Optionally, the dispersant is a nonionic branched fatty alcohol alkoxy surfactant that uniformly disperses the particles in liquid B, allowing them to fully react with both liquid A and liquid C to produce a dense, double-layered vertical magnesium phosphate hydration reaction layer.

[0020] Optionally, the composite retarder is selected from one or more combinations of borax, sucrose, sodium tripolyphosphate and boric acid, which can affect the formation and structure of the magnesium phosphate hydration reaction layer, thereby controlling the setting time of the material, enabling the interface agent to solidify and connect in the liquid phase, improving the compressive strength of the repaired area, and avoiding the formation of a loose magnesium phosphate hydration reaction layer.

[0021] This invention also provides a method for preparing the above-mentioned interface treatment agent, comprising: preparing liquid A, liquid B and liquid C respectively, and storing them respectively, wherein:

[0022] (1) Preparation of liquid A: Weigh out the dihydrogen phosphate, migratory rust inhibitor, suspension stabilizer and water according to the proportion, mix them together, stir evenly with a mixer, make a suspension and seal it for storage;

[0023] (2) Preparation of liquid material B: Obtain calcined magnesium oxide, weigh out calcined magnesium oxide, ultrafine mineral admixture, waterproof component, anti-sagging agent, dispersant, nano calcium carbonate and water according to the proportion, mix them together, stir evenly with a mixer, then disperse them, and then continue to stir evenly to make a suspension and seal it for storage.

[0024] (3) Preparation of liquid material C: Weigh out the dihydrogen phosphate, composite retarder, suspension stabilizer and water according to the proportion, mix them together, use a high-speed mixer to stir evenly, make a suspension and seal it for storage.

[0025] This invention also provides an application method for repairing exposed rebar in buildings, comprising the following steps:

[0026] S1. Determine the area of ​​exposed rebar to be repaired on the bridge pier, and perform surface pretreatment on the area to be repaired.

[0027] S2. Three interface layers are applied sequentially to the pretreated surface. The raw materials used for the three interface layers are liquid material A, liquid material B and liquid material C, respectively.

[0028] By mass percentage, the raw materials of liquid A include: 40-80% dihydrogen phosphate, 8-12% migratory rust inhibitor, 0.01-2% suspension stabilizer, and 8-50% water;

[0029] By mass percentage, the raw materials of liquid material B include: 60-70% recalcined magnesium oxide, 10-20% ultrafine mineral admixture, 1-5% waterproofing component, 0.5-2% anti-sagging agent, 0.01-2% dispersant, 1-5% nano calcium carbonate, and 10-20% water;

[0030] The raw materials of liquid C, by mass percentage, include: 40-80% dihydrogen phosphate, 4-8% composite retarder, 0.01-2% suspension stabilizer, and 12-55% water;

[0031] The dihydrogen phosphate salt is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0032] S3. After the liquid material C is applied, the repair mortar will be applied.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. By setting liquid materials A, B, and C, and utilizing the in-situ reaction of magnesium phosphate cement between liquid materials A and B, a dense first transition zone is formed on the surface of the exposed rebar. Utilizing the in-situ reaction of magnesium phosphate cement between liquid materials B and C, a second transition zone is formed on the surface of the first transition zone and the surface of the base concrete in the exposed rebar area, enabling strong adhesion to the repair mortar. The first and second transition zones work together to create a double-layer transition zone on the exposed rebar surface, improving the adhesion between the cement-based repair mortar and the base concrete and exposed rebar, enhancing bonding performance, effectively improving the problem of weak adhesion between the cement-based repair mortar and the rebar, preventing voids between the rebar and the repair mortar, and avoiding weakening of the connection strength of the interface layer under dynamic disturbance conditions.

[0035] 2. By sequentially spraying liquid A, liquid B, and liquid C, the in-situ reaction of magnesium phosphate cement between liquid A and liquid B, and between liquid B and liquid C, forms a double-layer magnesium phosphate hydration reaction layer on the facade. Based on the construction sequence and function of the three liquids, different auxiliary components are added to the formula to effectively solve the problems of excessive drying time and poor reinforcement performance in the repair of exposed rebar areas. It is suitable for use in low-temperature environments, improves the overall structural strength of the repair area and the bonding effect with the exposed rebar area, and the repair mortar can be applied immediately after the liquid is sprayed, which improves the construction speed and effectively extends the service life of the repair area.

[0036] 3. The repair method of the interface treatment agent provided by the present invention is applicable to the repair of exposed rebar areas in buildings. Since the interface treatment agent provided by the present invention has the characteristics of high adhesion and rapid solidification, the repair area formed by the repair method provided by the present invention can effectively resist the adverse effects of intermittent high-frequency disturbances brought to the bridge by the normal operation of high-speed trains on the repair construction. It is particularly suitable for the construction needs of exposed rebar repair of high-speed railway bridge piers, ensuring construction quality and having broad application prospects.

[0037] 4. The preparation method of the interface treatment agent provided by the present invention is simple and has low production cost. Attached Figure Description

[0038] Figure 1 A schematic diagram of a concrete bridge pier structure repaired using the interface treatment agent provided in this invention.

[0039] Figure 2 for Figure 1 Enlarged view of point A;

[0040] Among them, 1. Bridge pier; 2. Bridge pier exposed rebar defect area; 3. Repair area; 31. First transition area; 32. Second transition area; 33. Repair mortar layer. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0043] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0044] This invention provides an interface treatment agent, comprising liquid A, liquid B, and liquid C, wherein liquid A, liquid B, and liquid C are separately prepared and sealed and stored separately, and are not mixed with each other before use;

[0045] By mass percentage, the raw materials of liquid component A include: 40-80% dihydrogen phosphate, 8-12% migratory rust inhibitor, 0.01-2% suspension stabilizer, and 8-50% water;

[0046] By mass percentage, the raw materials of liquid material B include: 60-70% recalcined magnesium oxide, 10-20% ultrafine mineral admixtures, 1-5% waterproofing components, 0.5-2% anti-sagging agent, 0.01-2% dispersant, 1-5% nano calcium carbonate, and 10-20% water;

[0047] By mass percentage, the raw materials and mass ratio of liquid C include: 40-80% dihydrogen phosphate, 4-8% composite retarder, 0.01-2% suspension stabilizer, and 12-55% water;

[0048] The dihydrogen phosphate salt is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0049] To enhance the reaction of liquid component B with the other two liquid components to form a denser magnesium phosphate hydration reaction layer, the particle size of the recalcined magnesium oxide is no greater than 0.075 mm, and the particle size of nano-calcium carbonate is 60-80 nm. The finer particles have higher surface activity, which improves the density of the bonding interface and enhances the bond strength between new and old concrete.

[0050] To achieve the ability of liquid component A to protect exposed steel bars in exposed bar areas, the migratory rust-inhibiting component is a combination of at least two of triethanolamine, triisopropanolamine, and sodium dodecylbenzenesulfonate to enhance the rust-inhibiting effect on the steel bars. The suspension stabilizer is methyl cellulose ether or Brunei gum to increase the viscosity of liquid components A and C, which is beneficial to improving the overall bonding performance of the interface treatment agent.

[0051] To further enhance the density and bonding ability of the magnesium phosphate hydration reaction layer, the ultrafine mineral admixture is a combination of at least two of the following: microsphere powder, metakaolin, and silica fume.

[0052] Optionally, the waterproofing component is a copolymer latex powder of vinyl chloride, ethylene and vinyl lauryl ester.

[0053] To further enhance the viscosity of liquid component B, the anti-sagging agent is polyethylene oxide with a purity greater than 96% and a molecular weight of 2 to 3 million.

[0054] Optionally, the dispersant is a nonionic branched fatty alcohol alkoxy surfactant, which uniformly disperses the particles in liquid B, allowing them to fully react with both liquid A and liquid C to produce a dense, double-layered vertical magnesium phosphate hydration reaction layer.

[0055] Optionally, the composite retarder is selected from one or more combinations of borax, sucrose, sodium tripolyphosphate and boric acid, which can affect the formation and structure of the magnesium phosphate hydration reaction layer, thereby controlling the setting time of the material, enabling the interface agent to solidify and connect in the liquid phase, improving the compressive strength of the repaired area, and avoiding the formation of a loose magnesium phosphate hydration reaction layer.

[0056] This invention also provides a method for preparing the above-mentioned interface treatment agent, comprising: preparing liquid A, liquid B and liquid C respectively, and storing them respectively, wherein:

[0057] (1) Preparation of liquid A: Weigh out the dihydrogen phosphate, migratory rust inhibitor, suspension stabilizer and water according to the proportion, mix them together, stir evenly with a mixer, make a suspension and seal it for storage;

[0058] (2) Preparation of liquid material B: Obtain calcined magnesium oxide, weigh out calcined magnesium oxide, ultrafine mineral admixture, waterproof component, anti-sagging agent, dispersant, nano calcium carbonate and water according to the proportion, mix them together, stir evenly with a mixer, then disperse them, and then continue to stir evenly to make a suspension and seal it for storage.

[0059] (3) Preparation of liquid material C: Weigh out the dihydrogen phosphate, composite retarder, suspension stabilizer and water according to the proportion, mix them together, use a high-speed mixer to stir evenly, make a suspension and seal it for storage.

[0060] In step (2), an appropriate amount of magnesite is obtained, calcined at a high temperature above 1500℃, and then ground until it passes through a 0.075mm square hole sieve to obtain recalcined magnesium oxide;

[0061] In step (2), after the raw materials are mixed, a high-speed mixer is used to stir them evenly at high speed, then they are dispersed. Then the speed of the high-speed mixer is adjusted to medium speed, and then the mixture is stirred evenly to form a suspension and sealed for storage.

[0062] In step (2), ultrasonic waves are used for dispersion.

[0063] In steps (1) and (3), a high-speed mixer is used to mix the mixture at high speed until it is homogeneous.

[0064] This invention also provides an application method for repairing exposed rebar in buildings, comprising the following steps:

[0065] S1. Determine the area of ​​exposed rebar to be repaired on the bridge pier, and perform surface pretreatment on the area to be repaired.

[0066] S2. Three interface layers are applied sequentially to the pretreated surface. The raw materials used for the three interface layers are liquid material A, liquid material B and liquid material C, respectively.

[0067] By mass percentage, the raw materials of liquid A include: 40-80% dihydrogen phosphate, 8-12% migratory rust inhibitor, 0.01-2% suspension stabilizer, and 8-50% water;

[0068] By mass percentage, the raw materials of liquid material B include: 60-70% recalcined magnesium oxide, 10-20% ultrafine mineral admixture, 1-5% waterproofing component, 0.5-2% anti-sagging agent, 0.01-2% dispersant, 1-5% nano calcium carbonate, and 10-20% water;

[0069] The raw materials of liquid C, by mass percentage, include: 40-80% dihydrogen phosphate, 4-8% composite retarder, 0.01-2% suspension stabilizer, and 12-55% water;

[0070] The dihydrogen phosphate salt is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0071] S3. After the liquid material C is applied, the repair mortar will be applied.

[0072] In S1, the steps for surface pretreatment of the exposed rebar area to be repaired include: chiseling away the loose concrete of the base layer in the repair area, cleaning the surface of the base concrete, and removing rust from the exposed rebar.

[0073] Furthermore, in S1, a handheld electric pick is used for chiseling, then cleans the surface of the base concrete with water to remove impurities, dust, and oil, and then uses an angle grinder to grind the exposed steel bars for rust removal.

[0074] In S2, the application is carried out by spraying. The spraying thickness of liquid A and liquid C is 1 mm, and the spraying thickness of liquid B is 2-3 mm. The application interval between liquid A and liquid B, and between liquid B and liquid C is less than 1 minute.

[0075] The main raw materials and their amounts involved in Examples 1-3 of this invention are shown in Table 1 (wt.%):

[0076] Table 1

[0077]

[0078]

[0079] Example 1

[0080] An interface treatment agent is composed of liquid component A, liquid component B, and liquid component C. Liquid component A contains the following raw materials and mass percentages: 50% ammonium dihydrogen phosphate, 30% potassium dihydrogen phosphate, 5% triethanolamine, 3.5% triisopropanolamine, 1.5% sodium dodecylbenzenesulfonate, 0.1% Brunei gum, and 9.9% water. Liquid component B contains the following raw materials and mass percentages: 70% calcined magnesium oxide, 5% microsphere powder, 5% metakaolin, 3% latex powder, 1% polyethylene oxide, 0.5% dispersant, 2.5% nano-calcium carbonate, and 13% water. Liquid component C contains the following raw materials and mass percentages: 50% ammonium dihydrogen phosphate, 30% potassium dihydrogen phosphate, 3% borax, 3% sucrose, 0.1% Brunei gum, and 13.9% water.

[0081] The preparation method of the interface treatment agent is as follows:

[0082] (1) Preparation of liquid material A: First, weigh all raw materials according to the ratio. Then, add dihydrogen phosphate, migratory rust inhibitor and suspension stabilizer to water and stir at low speed to obtain pre-made slurry. Finally, use a high-speed mixer to stir the pre-made slurry at high speed until it is uniform and a stable suspension is made, thus obtaining liquid material A.

[0083] (2) Preparation of liquid material B: First, weigh all raw materials according to the proportion. Then, add calcined magnesium oxide, ultrafine mineral admixture, waterproof component, polyethylene oxide, dispersant, and nano calcium carbonate to water and stir at low speed to obtain a pre-made slurry. Then, use a high-speed mixer to stir the pre-made slurry at high speed. After stirring evenly, place it in an ultrasonic sonochemical device and disperse it ultrasonically for 25 minutes. Finally, stir at medium speed until a stable suspension is formed, thus obtaining liquid material B.

[0084] (3) Preparation of liquid material C: First, weigh all raw materials according to the ratio, then add dihydrogen phosphate, composite retarder and suspension stabilizer to water, stir at low speed to mix evenly to obtain pre-made slurry, and finally use a high-speed mixer to stir the pre-made slurry at high speed until it is evenly mixed to form a stable suspension, thus obtaining liquid material C.

[0085] The above liquid materials A, B and C are sealed and stored separately to obtain the interface treatment agent.

[0086] The method for repairing exposed rebar areas of bridge piers using the interface treatment agent prepared above includes the following steps:

[0087] Step 1: Determine the area of ​​the exposed rebar repair area of ​​the bridge pier, and use a handheld electric pick to remove the loose concrete of the base layer in the repair area. Then, use clean water to clean the impurities, dust and oil stains on the surface of the base concrete. For exposed rebar, use an angle grinder to grind and remove rust.

[0088] Step 2: First, evenly spray a layer of liquid material A with a thickness of about 1 mm on the exposed steel bars and base concrete surface of the area to be repaired. Then, evenly spray a layer of liquid material B with a thickness of about 2 to 3 mm. Finally, evenly spray a layer of liquid material C with a thickness of about 1 mm. The construction interval between layers should not exceed 1 minute.

[0089] Step 3: Cement-based repair mortar construction. After the liquid material C is sprayed, the repair mortar can be applied.

[0090] Example 2

[0091] An interface treatment agent is composed of liquid A, liquid B and liquid C.

[0092] Based on Example 1, the mass percentage of dihydrogen phosphate in liquid A is changed to: 35% ammonium dihydrogen phosphate and 25% potassium dihydrogen phosphate, and the mass percentage of water in liquid A is changed to 29.9%.

[0093] The mass percentage of calcined magnesium oxide in liquid feed B is changed to 65%, and the mass percentage of water in liquid feed A is changed to 18%.

[0094] The mass percentage of dihydrogen phosphate in liquid C is changed to: 35% ammonium dihydrogen phosphate and 25% potassium dihydrogen phosphate, and the mass percentage of water in liquid A is changed to 33.9%.

[0095] The preparation method of the interface treatment agent is the same as in Example 1.

[0096] The method for repairing exposed reinforcement areas of bridge piers using the interface treatment agent prepared above is the same as in Example 1.

[0097] Example 3

[0098] An interface treatment agent is composed of liquid A, liquid B and liquid C.

[0099] Based on Example 1, the mass percentage of dihydrogen phosphate in liquid A is changed to: 25% ammonium dihydrogen phosphate and 15% potassium dihydrogen phosphate, and the mass percentage of water in liquid A is changed to 49.9%.

[0100] The mass percentage of recalcined magnesium oxide in liquid feed B is changed to 60%, and the mass percentage of water in liquid feed A is changed to 18%.

[0101] The mass percentage of dihydrogen phosphate in liquid C is changed to: 25% ammonium dihydrogen phosphate and 15% potassium dihydrogen phosphate, and the mass percentage of water in liquid A is changed to 53.9%.

[0102] The preparation method of the interface treatment agent is the same as in Example 1.

[0103] The method for repairing exposed reinforcement areas of bridge piers using the interface treatment agent prepared above is the same as in Example 1.

[0104] Comparative Example 1

[0105] Repairing exposed rebar areas on bridge piers without applying an interface treatment agent involves the following steps:

[0106] Step 1: Determine the area of ​​the exposed rebar repair area of ​​the bridge pier, and use a handheld electric pick to remove the loose concrete of the base layer in the repair area. Then, use clean water to clean the impurities, dust and oil stains on the surface of the base concrete. For exposed rebar, use an angle grinder to grind and remove rust.

[0107] Step 2: Apply cement-based repair mortar to the surface of the area to be repaired.

[0108] Comparative Example 2

[0109] The interface treatment agent used in this comparative example differs from that in Example 1 in that it does not contain liquid component A. The composition and preparation method of liquid components B and C are the same as in Example 1.

[0110] The method for repairing exposed rebar areas of bridge piers using the aforementioned interface treatment agent includes the following steps:

[0111] Step 1: Determine the area of ​​the exposed rebar repair area of ​​the bridge pier, and use a handheld electric pick to remove the loose concrete of the base layer in the repair area. Then, use clean water to clean the impurities, dust and oil stains on the surface of the base concrete. For exposed rebar, use an angle grinder to grind and remove rust.

[0112] Step 2: First, evenly spray a liquid material B layer with a thickness of about 2-3 mm on the exposed steel bars and base concrete surface of the area to be repaired, and then evenly spray a liquid material C layer with a thickness of about 1 mm. The construction interval between layers should not exceed 1 minute.

[0113] Step 3: Cement-based repair mortar construction. After the liquid material C is sprayed, the repair mortar can be applied.

[0114] Comparative Example 3

[0115] The interface treatment agent used in Comparative Example 3 differs from that in Example 1 in that it does not contain liquid component C. The composition and preparation method of liquid components A and B are the same as in Example 1.

[0116] The method for repairing exposed rebar areas of bridge piers using the interface treatment agent prepared above includes the following steps:

[0117] Step 1: Determine the area of ​​the exposed rebar repair area of ​​the bridge pier, and use a handheld electric pick to remove the loose concrete of the base layer in the repair area. Then, use clean water to clean the impurities, dust and oil stains on the surface of the base concrete. For exposed rebar, use an angle grinder to grind and remove rust.

[0118] Step 2: First, evenly spray a layer of liquid material A with a thickness of about 1 mm on the exposed steel bars and base concrete surface of the area to be repaired, and then evenly spray a layer of liquid material B with a thickness of about 2 to 3 mm. The construction interval between layers should not exceed 1 minute.

[0119] Step 3: Cement-based repair mortar construction. After liquid material B is sprayed, the repair mortar can be applied.

[0120] After the repair work in Examples 1-3 and Comparative Examples 1-3 is completed, a tensile bond strength test is performed on the surface of the repair mortar at the connection with the reinforcing steel. The test method refers to JGJ / T 70-2009 "Standard for Test Methods of Basic Performance of Building Mortar".

[0121] Exposed annular stirrups from bridge piers at the construction site were cut, polished smooth, and prepared to the dimensions required for the salt water immersion test. The novel surface treatment agents of Examples 1-3 and Comparative Examples 2 and 3 were sprayed onto the surface of the round steel (comparative Example 1 was not sprayed with any surface treatment agent). Then, the percentage of steel corrosion area in the salt water immersion environment was tested in accordance with JGJ / T 192 "Technical Specification for Application of Corrosion Inhibitors for Steel Reinforcing Bars".

[0122] The test results of bond strength and rust-preventing effect of steel bars are shown in Table 2.

[0123] Table 2

[0124]

[0125]

[0126] As can be seen from the above table,

[0127] Compared with Comparative Example 1, Examples 1-3 exhibit superior bonding and reinforcing properties, with the interface treatment agent prepared in Example 2 showing the best overall performance. However, compared to Comparative Examples 2 and 3, the absence of liquid component A or liquid component C in the interface treatment agent significantly negatively impacts the overall rust-inhibiting effect and bonding strength of the interface treatment agent.

[0128] The above performance test results show that the novel interface treatment agent prepared by the present invention can significantly improve the bond strength between the repair mortar and the reinforcing steel and the base concrete when applied to the repair of exposed rebar in bridge piers. At the same time, it has excellent performance in protecting the reinforcing steel, making it very suitable for bridge pier exposed rebar repair projects. It is also suitable for other parts with concrete defects, significantly improving the service life of the repair area.

[0129] Figure 1 and Figure 2 The diagram shows the practical application of the interface treatment agent provided by this invention.

[0130] like Figure 1 and Figure 2 As shown, the interface treatment agent provided by the present invention is applied between the repair mortar layer 33 and the exposed rebar defect area 2 of the bridge pier.

[0131] During construction, liquid material A is first applied to the exposed steel bars in the exposed steel bar defect area 2 of the bridge pier and the surface of the base concrete of the bridge pier 1 around it. The migratory rust inhibitor component in its composition can achieve the repair function of the steel bars inside the repair area.

[0132] Then, liquid B is coated on the surface of liquid A, and a first transition zone 31 with dense protective function is formed by the reaction between recalcined magnesium oxide and dihydrogen phosphate.

[0133] Then, liquid material C is coated on the surface of liquid material B. The dihydrogen phosphate in liquid material C reacts with the remaining calcined magnesium oxide in liquid material B to form a second transition zone 32 with a strong bonding function with the repair mortar. At the same time, the composite retarder in liquid material C can achieve the liquid phase solidification and connection of the interface agent, further increasing the interfacial bonding force between the repair mortar layer 33 and the base concrete and steel reinforcement.

[0134] In summary, the interface treatment agent, its preparation method, and its application provided by this invention can meet the construction requirements for repairing exposed reinforcement bars in high-speed railway bridge piers. It has advantages such as fast setting and curing, excellent reinforcement protection performance, good adhesion performance, and good waterproof and seepage-proof performance. It can effectively resist the adverse effects of intermittent high-frequency disturbances to the bridge caused by the normal operation of high-speed trains on the repair construction, ensure construction quality, and has broad application prospects.

[0135] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. An interface treatment agent, characterized by, The liquid material A, the liquid material B and the liquid material C are prepared respectively and stored separately. The raw materials of the liquid material A include, in percentage by mass, 40-80% of dihydrogen phosphate, 8-12% of migration type rust-proof component, 0.01-2% of suspension stabilizer and 8-50% of water; The raw materials of the liquid material B include, in percentage by mass, 60-70% of heavy-burned magnesium oxide, 10-20% of superfine mineral admixture, 1-5% of waterproof component, 0.5-2% of anti-sagging agent, 0.01-2% of dispersant, 1-5% of nano calcium carbonate and 10-20% of water; the superfine mineral admixture is a combination of at least two of microsphere powder, metakaolin and silica fume; The raw materials of the liquid material C include, in percentage by mass, 40-80% of dihydrogen phosphate, 4-8% of composite retarder, 0.01-2% of suspension stabilizer and 12-55% of water; The dihydrogen phosphate is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate and sodium dihydrogen phosphate. The liquid material A, the liquid material B and the liquid material C are stored separately, and are sequentially applied as the three interface layers during construction.

2. The interface treatment of claim 1, wherein, The particle size of the heavy-burned magnesium oxide is not greater than 0.075 mm, and the particle size of the nano calcium carbonate is 60-80 nm.

3. The interface treatment of claim 1, wherein, The migration type rust-proof component is a combination of at least two of triethanolamine, triisopropanolamine and sodium dodecyl benzene sulfonate, and the suspension stabilizer is methyl cellulose ether or Wray gel.

4. The interface treatment of claim 1, wherein, The waterproof component is a copolymer latex powder of vinyl chloride, ethylene and vinyl laurate.

5. The interface treatment of claim 1, wherein, The anti-sagging agent is polyethylene oxide, the purity of the polyethylene oxide is greater than 96%, and the molecular weight of the polyethylene oxide is 2-3 million.

6. The interface treatment of claim 1, wherein, The dispersant is a non-ionic branched fatty alcohol alkoxy surfactant.

7. The interface treatment of claim 1, wherein The composite retarder is selected from at least two of borax, sucrose, sodium tripolyphosphate and boric acid.

8. A method of producing the interface treatment agent according to any one of claims 1 to 7, characterized by, The liquid material A, the liquid material B and the liquid material C are prepared respectively and stored separately. The liquid material A, the liquid material B and the liquid material C are prepared respectively and stored separately. (1) Preparation of the liquid material A: the dihydrogen phosphate, the migration type rust-proof component, the suspension stabilizer and water weighed in proportion are mixed together, uniformly stirred by a stirrer, and stored as a suspension; (2) Preparation of the liquid material B: the heavy-burned magnesium oxide is obtained, the heavy-burned magnesium oxide, the superfine mineral admixture, the waterproof component, the anti-sagging agent, the dispersant, the nano calcium carbonate and water weighed in proportion are mixed together, uniformly stirred by a stirrer, then dispersed, and uniformly stirred again to prepare a suspension which is stored; (3) Preparation of the liquid material C: the dihydrogen phosphate, the composite retarder, the suspension stabilizer and water weighed in proportion are mixed together, uniformly stirred by a high-speed stirrer, and stored as a suspension.

9. A method of applying a repair to a building exposed reinforcing portion, characterised in that, The steps include: S1, determining the area of the bridge pier leakage reinforcement repair area, and pre-treating the surface of the exposed reinforcement to be repaired; S2, sequentially applying three interface layers on the pretreated surface, and the raw materials of the three interface layers are the liquid material A, the liquid material B and the liquid material C respectively; The raw materials of the liquid material A include, in percentage by mass, 40-80% of dihydrogen phosphate, 8-12% of migration type rust-proof component, 0.01-2% of suspension stabilizer and 8-50% of water; The raw materials of the liquid material B include, in percentage by mass, heavy-burned magnesium oxide 60-70%, super-fine mineral admixture 10-20%, waterproof component 1-5%, anti-sagging agent 0.5-2%, dispersing agent 0.01-2%, nano calcium carbonate 1-5% and water 10-20%; The raw materials of the liquid material C include, in percentage by mass, dihydrogen phosphate salt 40-80%, composite retarder 4-8%, suspension stabilizer 0.01-2% and water 12-55%; The dihydrogen phosphate salt is a combination of at least two of ammonium dihydrogen phosphate, potassium dihydrogen phosphate and sodium dihydrogen phosphate; S3, after the liquid material C is constructed, plastering construction of the repair mortar is performed.

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