New and old concrete interface treating agent for concrete structure repair and preparation method thereof

Abstract

The present invention discloses a new and old concrete interface treatment agent for concrete structure repair and a preparation method thereof, and belongs to the technical field of building materials. The interface agent of the present invention is mainly composed of 2-acrylamide-2-methylpropane sodium sulfonate, lactic acid, allyl polyoxyethylene ether and high-grade cement paste. Organic and inorganic materials work together to effectively bond the new and old concrete interfaces into one, so that the mechanical properties of the bonding surface are better than the mechanical properties of the concrete body, and the weak surface of the new and old concrete interface is eliminated to achieve the purpose of reinforcement. The interface agent of the present invention has the advantages of simple construction and good operability, and can be widely used in the bonding and repair of the new and old concrete interfaces in water conservancy and hydropower projects, road projects, houses and bridges, and other projects, as well as the fields of steel bar anchoring, crack repair, and chromatic aberration repair of pores on the surface of clear water concrete.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a new-old concrete interface treating agent for repairing concrete structures and a preparation method thereof. Background Art

[0002] The interface between the concrete poured successively at the construction joint of reinforced concrete structure or the interface between the new and old concrete when repairing the civil engineering concrete structure usually becomes the weak link of the overall concrete structure. In production practice, the interfacial bonding strength between the new and old concrete is often the weak link of concrete repair and reinforcement. If it is not handled properly, it will easily lead to the reduction of the integrity, impermeability and durability of the concrete structure. Usually, the splitting tensile strength of the concrete at the construction interface of the new and old concrete is only 30%-80% of the splitting tensile strength of the integrally poured concrete. In order to avoid the adverse effects of the low interfacial bonding strength of the new and old concrete on the integrity and durability of the concrete, it is necessary to effectively pretreat the interface between the new and old concrete. Usually, the method of machine spraying or manual brushing of the interface treatment agent is used to improve the integrity and durability of the concrete structure.

[0003] GB50204 "Concrete Structure Engineering Construction Quality Acceptance Code" requires that the construction joints or the interface between new and old concrete should be treated, and measures should be taken to make the new and old concrete tightly bonded; JTG / T3650 "Highway Bridge and Culvert Construction Technical Code" requires that after the concrete construction joints are roughened, 10-20mm 1:2 cement mortar should be poured, or a layer of concrete about 300mm thick should be laid, and the coarse aggregate should be reduced by 10% compared with the newly poured concrete, as an interface agent to improve the interface bonding strength. The method recommended by the above specifications is cumbersome and consumes a lot of raw materials. In order to reduce construction costs, many projects usually only perform roughening treatment without pouring mortar or concrete interface agents, which makes the interface between new and old concrete become the weak link of the overall concrete structure and causes construction quality problems.

[0004] At present, in order to improve the bonding strength of the interface between new and old concrete, engineering and technical personnel have developed a variety of concrete interface treatment agents. For example: using organic materials such as vinyl acetate-ethylene emulsion, thickener, defoamer, etc. to prepare concrete interface treatment agents to improve the interface bonding strength between new and old concrete; using liquid bisphenol epoxy resin, nano-SiO2, active silicon powder, calcium sulfate whiskers, etc. as treatment agents to improve the interface bonding between new and old concrete; using inorganic materials such as nano-scale microcrystalline silicon, SiO2, calcium carbonate, etc. as treatment agents to improve the interface bonding between new and old concrete, etc. Polymer emulsion can improve the interfacial bonding strength of new and old concrete, but there are many types of polymer emulsions, and the effect of improving the interfacial bonding strength by only using a single polymer emulsion is limited; the use of inorganic materials such as epoxy resin, nano-SiO2, active silicon powder, calcium sulfate whiskers, etc. as a composite to improve the interfacial bonding strength has a particularly complex production process and is difficult to operate in practice; the use of inorganic materials such as nano-scale microcrystalline silicon, SiO2, and calcium carbonate as treatment agents to improve the interfacial bonding between new and old concrete requires the hydration product of calcium hydroxide in the new and old concrete to participate in the reaction. Today's high-performance concrete is mixed with a large amount of fly ash and slag powder, and the free calcium hydroxide in the hydration product is relatively small due to the secondary reaction itself. Therefore, it is relatively difficult to rely on the hydration products of new and old concrete to stimulate the reaction of inorganic materials such as nano-scale microcrystalline silicon, silicon dioxide, and calcium carbonate, and it is difficult to achieve a good effect of improving the interfacial bonding between new and old concrete.

[0005] Therefore, developing a new concrete interface treatment agent that can significantly improve the bonding strength of the interface between new and old concrete and has a relatively simple construction process so that it can effectively improve the interface bonding strength between new and old concrete has become a technical problem that needs to be urgently solved in this field. Summary of the invention

[0006] The present invention aims at the problems existing in the prior art and provides a novel concrete interface treating agent, which can effectively enhance the mechanical properties and impermeability of concrete and enhance the interface adhesion, and has a simple preparation and use method, low cost and high efficiency, and has broad application prospects.

[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0008] A new-old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 1-4 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 1-4 parts of lactic acid, 1-4 parts of allyl polyoxyethylene ether solution, 0.01-0.03 parts of defoaming agent, 50-70 parts of silicate cement, 0.7-1.2 parts of steel bar rust inhibitor, 0.3-0.8 parts of water reducing agent and 17-45 parts of water.

[0009] Furthermore, the mass concentration of the sodium 2-acrylamide-2-methylpropane sulfonate solution is 50-53%, and the density is 1.20-1.23 g / cm 3 .

[0010] Furthermore, the mass concentration of the allyl polyoxyethylene ether solution is 50-75%.

[0011] Furthermore, the defoamer is a polyether surfactant with a solid content of 50-52%, a pH of 4-7, and a density of 0.97-1.01 g / cm 3 .

[0012] Furthermore, the silicate cement is 52.5 grade ordinary silicate cement.

[0013] Furthermore, the steel bar rust inhibitor is obtained by mixing calcium nitrite, sodium ethylenediaminetetramethylenephosphonate, and ferrous phosphate in a mass ratio of 1:1:1.

[0014] Furthermore, the water reducer is a powdered water reducer, specifically a powdered naphthalene-based water reducer and / or a powdered polycarboxylic acid water reducer.

[0015] Furthermore, the water is one or more of drinking water, tap water, and clean river water.

[0016] A method for preparing a new-old concrete interface treating agent for concrete structure repair comprises the following steps:

[0017] (1) mixing 2-acrylamide-2-methylpropane sulfonate sodium solution, lactic acid, allyl polyoxyethylene ether solution and defoaming agent to obtain a composite functional mother solution for later use;

[0018] (2) Mix silicate cement, steel bar rust inhibitor and water reducing agent, add water and stir to form cement slurry for later use;

[0019] (3) The composite functional mother liquid obtained in step (1) and the cement paste obtained in step (2) are mixed and stirred evenly to form a mixed paste, which is the final product interface agent.

[0020] The method for using the interface agent of the present invention is as follows: after the interface agent is prepared, a conventional spraying construction process or a manual brushing process can meet the requirements. The construction process is simple, and the spraying thickness can be within the range of 1-3 mm and can be adjusted according to the engineering application requirements.

[0021] The present invention provides a new interface agent, which uses 2-acrylamide-2-methylpropane sodium sulfonate, lactic acid, and allyl polyoxyethylene ether as main functional components, and the three act synergistically to achieve a significant improvement in the performance of the new and old interfaces. Among them, 2-acrylamide-2-methylpropane sodium sulfonate is used as an emulsifying, thickening, and water-retaining thickener in cement-based slurry to increase the degree of cement hydration per unit time, reduce the porosity of the interface between the new and old concrete, and improve the bonding performance of the cement-based slurry at the interface between the new and old concrete. Lactic acid reacts with calcium hydroxide, a cement hydration product, to form calcium lactate, which not only improves the unidirectional distribution of flaky calcium hydroxide, one of the hydration products at the interface between the new and old concrete slurries, but also promotes the chemical equilibrium to move to the right. These calcium lactate can fill the pores and increase the density of the hardened cement slurry, thereby significantly improving the overall strength of the interface concrete. Allyl polyoxyethylene ether has a lubricating and water-retaining effect on cement slurry, so that the cement-based interface agent slurry has good spreadability and softness, and can be sprayed and brushed. The construction properties are greatly improved.

[0022] The present invention also adds a defoaming agent component, and the polyether surfactant can effectively eliminate the foam generated during the stirring and mixing of various organic raw material liquids, so as to break the foam adsorbed on the concrete interface, thereby enhancing the interface density and interface bonding strength of new and old concrete.

[0023] The function of steel bar rust inhibitor is to prevent the possibility of further corrosion of steel bars at the interface between new and old concrete, and improve the durability of the overall reinforced concrete structure. The function of naphthalene or polycarboxylic acid high-efficiency water reducer is to improve the dispersibility of cement particles, reduce the water-cement ratio, and improve the fluidity of slurry, which is conducive to machine spraying construction or manual brushing.

[0024] In summary, the beneficial effects of the technical solution of the present invention are:

[0025] The interface agent of the present invention is mainly composed of sodium 2-acrylamide-2-methylpropane sulfonate, lactic acid, allyl polyoxyethylene ether and high-grade cement paste. The organic and inorganic materials work together to effectively bond the interface between new and old concrete into one, so that the mechanical properties of the bonding surface are better than the mechanical properties of the concrete body, the weak surface of the interface between new and old concrete is eliminated, and the purpose of reinforcement is achieved. The interface agent of the present invention has the advantages of simple construction and good operability. It can be widely used in the bonding and repairing of the interface between new and old concrete in water conservancy and hydropower projects, road projects, houses and bridges, as well as in the fields of steel bar anchoring in concrete, crack repair, and pore color difference repair on the surface of clear water concrete. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0027] Example 1

[0028] A new-old concrete interface treating agent for repairing concrete structures comprises the following raw materials in parts by weight: 4 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 4 parts of lactic acid, 4 parts of allyl polyoxyethylene ether solution, 0.02 parts of defoaming agent, 70 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.8 parts of water reducing agent and 17 parts of water.

[0029] The mass concentration of the sodium 2-acrylamide-2-methylpropane sulfonate solution is 50-53%, and the density is 1.20-1.23 g / cm 3 .

[0030] The allyl polyoxyethylene ether solution is an aqueous solution with a mass concentration of 75%.

[0031] The defoamer is a polyether surfactant with a solid content of 50-52%, a pH of 4-7, and a density of 0.97-1.01 g / cm 3 .

[0032] The silicate cement is 52.5 grade ordinary silicate cement.

[0033] The steel bar rust inhibitor is obtained by mixing calcium nitrite, sodium ethylenediaminetetramethylenephosphonate and ferrous phosphate in a mass ratio of 1:1:1.

[0034] The water reducer is a powder water reducer, specifically a powder naphthalene-based water reducer.

[0035] The water is drinking water.

[0036] A method for preparing a new-old concrete interface treating agent for concrete structure repair comprises the following steps:

[0037] (1) mixing 2-acrylamide-2-methylpropane sulfonate sodium solution, lactic acid, allyl polyoxyethylene ether solution and defoaming agent to obtain a composite functional mother solution for later use;

[0038] (2) Mix silicate cement, steel bar rust inhibitor and water reducing agent, add water and stir to form cement slurry for later use;

[0039] (3) The composite functional mother liquid obtained in step (1) and the cement paste obtained in step (2) are mixed and stirred evenly to form a mixed paste, which is the final product interface agent.

[0040] Example 2

[0041] A new and old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 3 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 3 parts of lactic acid, 3 parts of allyl polyoxyethylene ether solution, 0.03 parts of defoaming agent, 50 parts of silicate cement, 1.2 parts of steel bar rust inhibitor, 0.3 parts of water reducing agent and 40 parts of water.

[0042] The mass concentration of the sodium 2-acrylamide-2-methylpropane sulfonate solution is 50-53%, and the density is 1.20-1.23 g / cm 3 .

[0043] The allyl polyoxyethylene ether solution is an aqueous solution with a mass concentration of 60%.

[0044] The defoamer is a polyether surfactant with a solid content of 50-52%, a pH of 4-7, and a density of 0.97-1.01 g / cm 3 .

[0045] The silicate cement is 52.5 grade ordinary silicate cement.

[0046] The steel bar rust inhibitor is obtained by mixing calcium nitrite, sodium ethylenediaminetetramethylenephosphonate and ferrous phosphate in a mass ratio of 1:1:1.

[0047] The water reducer is a powder water reducer, specifically a powder polycarboxylate water reducer.

[0048] The water is tap water.

[0049] A method for preparing a new-old concrete interface treating agent for concrete structure repair comprises the following steps:

[0050] (1) mixing 2-acrylamide-2-methylpropane sulfonate sodium solution, lactic acid, allyl polyoxyethylene ether solution and defoaming agent to obtain a composite functional mother solution for later use;

[0051] (2) Mix silicate cement, steel bar rust inhibitor and water reducing agent, add water and stir to form cement slurry for later use;

[0052] (3) The composite functional mother liquid obtained in step (1) and the cement paste obtained in step (2) are mixed and stirred evenly to form a mixed paste, which is the final product interface agent.

[0053] Example 3

[0054] A new and old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 2 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 2 parts of lactic acid, 2 parts of allyl polyoxyethylene ether solution, 0.01 parts of defoaming agent, 60 parts of silicate cement, 0.7 parts of steel bar rust inhibitor, 0.6 parts of water reducer and 33 parts of water.

[0055] The mass concentration of the sodium 2-acrylamide-2-methylpropane sulfonate solution is 50-53%, and the density is 1.20-1.23 g / cm 3 .

[0056] The allyl polyoxyethylene ether solution is an aqueous solution with a mass concentration of 50%.

[0057] The defoamer is a polyether surfactant with a solid content of 50-52%, a pH of 4-7, and a density of 0.97-1.01 g / cm 3 .

[0058] The silicate cement is 52.5 grade ordinary silicate cement.

[0059] The steel bar rust inhibitor is obtained by mixing calcium nitrite, sodium ethylenediaminetetramethylenephosphonate and ferrous phosphate in a mass ratio of 1:1:1.

[0060] The water reducer is a powder water reducer, specifically a powder naphthalene-based water reducer.

[0061] The water is clean river water.

[0062] A method for preparing a new-old concrete interface treating agent for concrete structure repair comprises the following steps:

[0063] (1) mixing 2-acrylamide-2-methylpropane sulfonate sodium solution, lactic acid, allyl polyoxyethylene ether solution and defoaming agent to obtain a composite functional mother solution for later use;

[0064] (2) Mix silicate cement, steel bar rust inhibitor and water reducing agent, add water and stir to form cement slurry for later use;

[0065] (3) The composite functional mother liquid obtained in step (1) and the cement paste obtained in step (2) are mixed and stirred evenly to form a mixed paste, which is the final product interface agent.

[0066] Example 4

[0067] A new-old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 1 part of 2-acrylamido-2-methylpropane sulfonate sodium solution, 1 part of lactic acid, 1 part of allyl polyoxyethylene ether solution, 0.01 part of defoaming agent, 50 parts of silicate cement, 0.7 part of steel bar rust inhibitor, 0.3 part of water reducing agent and 45 parts of water.

[0068] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0069] Example 5

[0070] A new-old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 4 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 2 parts of lactic acid, 1 part of allyl polyoxyethylene ether solution, 0.02 parts of defoaming agent, 60 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.5 parts of water reducing agent and 32 parts of water.

[0071] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0072] Example 6

[0073] A new-old concrete interface treating agent for repairing concrete structures comprises the following raw materials in parts by weight: 2 parts of 2-acrylamido-2-methylpropane sulfonate sodium solution, 4 parts of lactic acid, 1 part of allyl polyoxyethylene ether solution, 0.02 parts of defoaming agent, 60 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.5 parts of water reducing agent and 32 parts of water.

[0074] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0075] Example 7

[0076] A new-old concrete interface treating agent for repairing concrete structures comprises the following raw materials in parts by weight: 1 part of 2-acrylamide-2-methylpropane sodium sulfonate solution, 2 parts of lactic acid, 4 parts of allyl polyoxyethylene ether solution, 0.02 parts of defoaming agent, 60 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.5 parts of water reducing agent and 32 parts of water.

[0077] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0078] Example 8

[0079] A new-old concrete interface treating agent for repairing concrete structures comprises the following raw materials in parts by weight: 2 parts of 2-acrylamido-2-methylpropane sodium sulfonate solution, 1 part of lactic acid, 4 parts of allyl polyoxyethylene ether solution, 0.02 parts of defoaming agent, 60 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.5 parts of water reducing agent and 32 parts of water.

[0080] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0081] Example 9

[0082] A new-old concrete interface treating agent for repairing concrete structures comprises the following raw materials in parts by weight: 3 parts of 2-acrylamido-2-methylpropane sulfonate sodium solution, 2 parts of lactic acid, 1 part of allyl polyoxyethylene ether solution, 0.01 parts of defoaming agent, 50 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.3 parts of water reducing agent and 43 parts of water.

[0083] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0084] Example 10

[0085] A new-old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 1 part of 2-acrylamide-2-methylpropane sodium sulfonate solution, 2 parts of lactic acid, 3 parts of allyl polyoxyethylene ether solution, 0.01 parts of defoaming agent, 50 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.3 parts of water reducing agent and 43 parts of water.

[0086] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0087] Embodiment 11

[0088] A new-old concrete interface treating agent for concrete structure repair comprises the following raw materials in parts by weight: 2 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 1 part of lactic acid, 3 parts of allyl polyoxyethylene ether solution, 0.01 parts of defoaming agent, 50 parts of silicate cement, 1 part of steel bar rust inhibitor, 0.3 parts of water reducing agent and 43 parts of water.

[0089] Except that the raw material composition ratio of this embodiment is different from that of embodiment 1, the rest of the preparation method and use treatment method are the same as those of embodiment 1.

[0090] Comparative Example 1

[0091] Common concrete additives were used to replace the sodium 2-acrylamide-2-methylpropane sulfonate solution to prepare an interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0092] 4 parts of aqueous solution of sodium hydroxyethylidene diphosphonate (HEDP, mass concentration 50-53%);

[0093] 4 parts of lactic acid;

[0094] 4 parts of allyl polyoxyethylene ether solution;

[0095] Defoaming agent 0.02 parts;

[0096] 70 parts of Portland cement;

[0097] 1 part of steel bar rust inhibitor;

[0098] 0.8 parts of powder high-efficiency water reducing agent;

[0099] 17 parts water.

[0100] The only difference between this comparative example and Example 1 is that the sodium 2-acrylamido-2-methylpropane sulfonate solution is replaced by the sodium hydroxyethylidene diphosphonate solution, and the other raw materials and preparation method are the same as those in Example 1.

[0101] Comparative Example 2

[0102] Common concrete additives were used to replace the sodium 2-acrylamide-2-methylpropane sulfonate solution to prepare an interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0103] 3 parts of polyvinyl pyrrolidone aqueous solution (mass concentration 50-53%);

[0104] 3 parts of lactic acid;

[0105] 3 parts of allyl polyoxyethylene ether solution;

[0106] Defoaming agent 0.03 parts;

[0107] 50 parts of Portland cement;

[0108] 1.2 parts of steel bar rust inhibitor;

[0109] 0.3 parts of powder high-efficiency water reducing agent;

[0110] 40 parts of water.

[0111] The only difference between this comparative example and Example 2 is that polyvinyl pyrrolidone solution is used to replace the sodium 2-acrylamide-2-methylpropane sulfonate solution, and the remaining raw materials and preparation method are the same as those in Example 2.

[0112] Comparative Example 3

[0113] Common concrete additives were used to replace the sodium 2-acrylamide-2-methylpropane sulfonate solution to prepare an interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0114] 2 parts of diethylenetriamine pentasodium methylenephosphonate aqueous solution (mass concentration 50-53%);

[0115] 2 parts of lactic acid;

[0116] 2 parts of allyl polyoxyethylene ether solution;

[0117] Defoaming agent 0.01 part;

[0118] 60 parts of Portland cement;

[0119] 0.7 parts of steel bar rust inhibitor;

[0120] 0.6 parts of powder high-efficiency water reducing agent;

[0121] 33 parts water.

[0122] The only difference between this comparative example and Example 3 is that diethylenetriamine pentasodium methylenephosphonate solution is used to replace the sodium 2-acrylamido-2-methylpropane sulfonate solution, and the remaining raw materials and preparation method are the same as those in Example 3.

[0123] Comparative Example 4

[0124] Common concrete additives were used to replace the sodium 2-acrylamide-2-methylpropane sulfonate solution to prepare an interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0125] 4 parts of dipropylene glycol methyl ether aqueous solution (mass concentration 50-53%);

[0126] 4 parts of lactic acid;

[0127] 4 parts of allyl polyoxyethylene ether solution;

[0128] Defoaming agent 0.02 parts;

[0129] 70 parts of Portland cement;

[0130] 1 part of steel bar rust inhibitor;

[0131] 0.8 parts of powder high-efficiency water reducing agent;

[0132] 17 parts water.

[0133] The only difference between this comparative example and Example 1 is that dipropylene glycol methyl ether solution is used to replace the sodium 2-acrylamido-2-methylpropane sulfonate solution, and the remaining raw materials and preparation method are the same as those in Example 1.

[0134] Comparative Example 5

[0135] The common concrete additive acetic acid was used to replace lactic acid to prepare the interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0136] 4 parts of sodium 2-acrylamido-2-methylpropane sulfonate solution;

[0137] 4 parts of acetic acid;

[0138] 4 parts of allyl polyoxyethylene ether solution;

[0139] Defoaming agent 0.02 parts;

[0140] 70 parts of Portland cement;

[0141] 1 part of steel bar rust inhibitor;

[0142] 0.8 parts of powder high-efficiency water reducing agent;

[0143] 17 parts water.

[0144] The only difference between this comparative example and Example 1 is that acetic acid is used instead of lactic acid, and the other raw materials and preparation methods are the same as those in Example 1.

[0145] Comparative Example 6

[0146] The commonly used concrete additive isopentenol polyoxyethylene ether solution was used to replace the allyl polyoxyethylene ether solution to prepare an interface agent for comparison. The specific composition of the interface agent in this comparative example is:

[0147] 4 parts of sodium 2-acrylamido-2-methylpropane sulfonate solution;

[0148] 4 parts of lactic acid;

[0149] 4 parts of isopentanol polyoxyethylene ether solution (mass concentration is 75%);

[0150] Defoaming agent 0.02 parts;

[0151] 70 parts of Portland cement;

[0152] 1 part of steel bar rust inhibitor;

[0153] 0.8 parts of powder high-efficiency water reducing agent;

[0154] 17 parts water.

[0155] The only difference between this comparative example and Example 1 is that the isopentanol polyoxyethylene ether solution is used to replace the allyl polyoxyethylene ether solution, and the remaining raw materials and preparation method are the same as those in Example 1.

[0156] Experimental testing

[0157] (1) 11 groups of cubic specimens (three specimens in each group) with a molding strength grade of C30 and a concrete mold size of 150 mm × 150 mm × 150 mm were cured under standard curing conditions until 28 days old, and the splitting tensile strength was tested in accordance with the Standard for Test Methods for Mechanical Properties of Ordinary Concrete (GB / T50081-2019). The loose particles on the splitting surface of the concrete specimen that was split into two halves were brushed off with a wire brush, and then the interface treatment agent prepared according to Example 1-Example 11 and Comparative Example 1-Comparative Example 6 was sprayed on the splitting surface, with a spraying thickness of about 2 mm, and then new C30 concrete with the same ratio was poured to obtain a 150 mm × 150 mm × 150 mm standard specimen again. After 28 days of laboratory standard curing, a splitting test was used to test the tensile strength of the concrete specimens with and without the spraying binder, as shown in Table 1.

[0158] Table 1 Splitting tensile strength of concrete specimens before and after spraying interface treatment agent

[0159]

[0160]

[0161] According to the test data in Table 1, it can be seen that Example 2 has the best bonding performance and the best mechanical properties, and is suitable for the treatment and repair of construction joints of concrete beam-column components; Example 4 has a lower cost and can be used for the interface treatment between the original concrete floor slab and the later poured leveling mortar or fine stone concrete at the floor surface.

[0162] In Comparative Examples 1 to 6, although sodium hydroxyethylene diphosphonate and pentasodium diethylene triamine penta (methylene phosphonate) can react with Ca in the cement hydration process, 2+ Mg 2+ , Fe 3+ etc. act as chelating agents, promote the hydration reaction of cement, and improve the cement interface bonding strength; polyvinyl pyrrolidone can be used as a dispersant, emulsifier, and thickener for cement-based slurry; dipropylene glycol methyl ether can be used as a coupling agent for cement-based slurry. However, the composite functional mother liquor composed of sodium hydroxyethylene diphosphonate, polyvinyl pyrrolidone, pentasodium diethylenetriamine penta (methylene phosphonate) and dipropylene glycol methyl ether, lactic acid, and allyl polyoxyethylene ether respectively, does not exert a good interface strengthening effect. The functional mother liquor composed of sodium 2-acrylamido-2-methylpropane sulfonate, lactic acid, and allyl polyoxyethylene ether of the present invention has mutual synergy among the three, and has a good interface bonding treatment effect when used simultaneously, and none of the three is indispensable.

[0163] To further test the performance, the product was formed, cured and tested for performance according to the JC / T 907-2018 "Concrete Interface Agent" standard. The 24h surface water absorption was sampled, cured and tested according to the relevant requirements of JG / T468-2015 "Interface Treatment Agent for Walls". A blank test was performed for comparison during the 24h surface water absorption test. The surface water absorption without the concrete interface treatment agent was 6mL.

[0164] The test performance is as follows:

[0165] Table 2 Physical and mechanical properties of interface treatment agents

[0166]

[0167]

[0168] The data of comprehensive tests (1) and (2) can be concluded that the new-old concrete interface treatment agent prepared by the present invention has good bonding performance, and has good sealing performance for the concrete base, and can significantly reduce its water absorption. Spraying the interface treatment agent prepared by the present invention at the interface of the new and old concrete can ensure that the concrete interface will not become a weak link that destroys the integrity of the concrete. The new-old concrete interface treatment agent of the present invention can be sprayed or manually applied in actual use, with fast construction speed, simple construction method, and low labor intensity of construction personnel.

[0169] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A new and old concrete interface treating agent for concrete structure repair, characterized in that: The invention comprises the following raw materials in parts by weight: 1-4 parts of 2-acrylamide-2-methylpropane sodium sulfonate solution, 1-4 parts of lactic acid, 1-4 parts of allyl polyoxyethylene ether solution, 0.01-0.03 parts of defoamer, 50-70 parts of Portland cement, 0.7-1.2 parts of steel bar rust inhibitor, 0.3-0.8 parts of water reducer and 17-45 parts of water; the mass concentration of the 2-acrylamide-2-methylpropane sodium sulfonate solution is 50-53%; the mass concentration of the allyl polyoxyethylene ether solution is 50-75%.

2. The new-old concrete interface treating agent for concrete structure repair according to claim 1, characterized in that: The defoamer is a polyether surfactant with a solid content of 50-52% and a pH of 4-7.

3. The new-old concrete interface treating agent for concrete structure repair according to claim 1, characterized in that: The silicate cement is 52.5 grade ordinary silicate cement.

4. The new-old concrete interface treating agent for concrete structure repair according to claim 1, characterized in that: The steel bar rust inhibitor is obtained by mixing calcium nitrite, sodium ethylenediaminetetramethylenephosphonate and ferrous phosphate in a mass ratio of 1:1:

1.

5. The new and old concrete interface treating agent for concrete structure repair according to claim 1, characterized in that: The water reducing agent is a powder water reducing agent.

6. The new-old concrete interface treating agent for concrete structure repair according to claim 5, characterized in that: The water reducer is a powdered naphthalene-based water reducer and / or a powdered polycarboxylic acid water reducer.

7. The new-old concrete interface treating agent for concrete structure repair according to claim 1, characterized in that: The water is one or more of drinking water and clean river water.

8. A method for preparing the new-old concrete interface treating agent for repairing concrete structures according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing 2-acrylamide-2-methylpropane sulfonate sodium solution, lactic acid, allyl polyoxyethylene ether solution and defoaming agent to obtain a composite functional mother solution for later use; (2) Mix silicate cement, steel bar rust inhibitor and water reducing agent, add water and stir to form cement slurry for later use; (3) The composite functional mother liquid obtained in step (1) and the cement paste obtained in step (2) are mixed and stirred evenly to form a mixed paste, which is the final product interface agent.

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