阅读说明：本技术 一种抗碳化混凝土增强剂及其制备方法 (Anti-carbonization concrete reinforcing agent and preparation method thereof ) 是由 吴伟 王龙 黄玉美 米尔科·格鲁博 刘昭洋 王龙飞 李茜茜 连彦丽 刘旭飞 于 2021-08-13 设计创作，主要内容包括：一种抗碳化混凝土增强剂及其制备方法,所述抗碳化混凝土增强剂的结构式如下：R：C-(2)-C-(6)。制备方法：在反应釜内加入烷基胺、乙醇溶液低速度室温搅拌溶解,然后升温至40-50℃并滴加O-甲基异脲硫酸盐水溶液,控制在30～35分钟滴加完成,保持温度40-50℃反应3-4小时,反应完成后冷却至室温,然后加入消泡剂搅拌均匀即得。本发明提高了混凝土强度,提高了混凝土的抗碳化性能,增强了混凝土结构的耐久性能,延长了混凝土的使用寿命。(The structural formula of the anti-carbonization concrete reinforcing agent is as follows: R：C 2 ‑C 6 . The preparation method comprises the following steps: adding alkylamine and ethanol solution into a reaction kettle, stirring and dissolving at a low speed at room temperature, heating to 40-50 ℃, dropwise adding O-methylisourea sulfate aqueous solution, controlling the dropwise adding to be completed within 30-35 minutes, keeping the temperature at 40-50 ℃ for reaction for 3-4 hours, cooling to room temperature after the reaction is completed, adding a defoaming agent, and stirring uniformly to obtain the catalyst. The invention improves the strength of concrete, improves the anti-carbonization performance of the concrete, enhances the durability of the concrete structure and prolongs the service life of the concrete.)

1. The anti-carbonization concrete reinforcing agent is characterized by having the following structural formula:

R：C₂-C₆。

2. a method for preparing the anti-carbonization concrete reinforcing agent of claim 1, which is characterized by comprising the following process steps: adding 100-150 parts of alkylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring and dissolving at a low speed and a room temperature, wherein the mass ratio of water to ethanol in the ethanol solution is 1: 2-2.5, heating to 40-50 ℃, dropwise adding 660-665 parts of O-methyl isourea sulfate aqueous solution, controlling the dropwise adding to be completed within 30-35 minutes, the mass percentage concentration of the methyl isourea sulfate aqueous solution is 40-45%, after the dropwise adding is completed, keeping the temperature at 40-50 ℃ for reacting for 3-4 hours, cooling to the room temperature after the reaction is completed, and then adding 3-5 parts of defoaming agent and stirring uniformly to obtain the anti-carbonization concrete reinforcing agent.

3. The method for preparing a concrete reinforcing agent against carbonization according to claim 2, wherein the alkylamine has a primary amine structure with C2-C7.

4. The method for producing a concrete reinforcing agent against carbonization according to claim 2, wherein the alkylamine is ethylamine or heptylamine.

5. The method for producing a concrete reinforcing agent against carbonation according to claim 2, wherein said alkylamine is in a range of excess molar ratio to O-methylisourea sulfate, and the molar ratio of alkylamine to O-methylisourea sulfate is 1.5 to 2.2: 1.

6. The method for preparing the concrete reinforcing agent against carbonization as claimed in claim 2, wherein the defoaming agent is silicone oil type defoaming agent, which is product Evonik Tegopern 7008, or polyoxyethylene/propylene, acetylenic diol ethylene oxide/propane type product.

7. The method for preparing the anti-carbonization concrete reinforcing agent according to claim 2, characterized in that it comprises the following process steps: adding 100 parts of ethylamine and 300 parts of ethanol solution into a reaction kettle equipped with a high-speed stirrer and a reflux condensing device, stirring at a low speed and at room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 40 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes, uniformly dropwise adding, wherein the mass percentage concentration of the methylisourea sulfate aqueous solution is 40%, after dropwise adding, keeping the temperature at 40 ℃ for reaction for 3 hours, cooling to room temperature after reaction, adding 3 parts of defoaming agent, namely defoaming agent silicone oil, and uniformly stirring to obtain the anti-carbonization concrete reinforcing agent.

8. The method for preparing the anti-carbonization concrete reinforcing agent according to claim 2, characterized in that it comprises the following process steps: adding 150 parts of heptylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring at low speed and room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 50 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes until the dropwise adding is completed, keeping the mass percentage concentration of the methylisourea sulfate aqueous solution at 40%, reacting at 50 ℃ for 4 hours, cooling to room temperature after the reaction is completed, adding 5 parts of defoaming agent, namely defoaming agent silicone oil, and stirring uniformly to obtain the anti-carbonization concrete reinforcing agent.

Technical Field

The invention relates to a concrete reinforcing agent, in particular to an anti-carbonization concrete reinforcing agent, belongs to the technical field of building material chemical additives, and relates to an additive for improving the strength and anti-carbonization capacity of high-volume cementitious material system concrete. The invention also relates to a preparation method of the anti-carbonization concrete reinforcing agent.

Background

With the continuous popularization of national policies of energy conservation and emission reduction and carbon neutralization, the environmental protection consciousness of people is gradually improved, and urgent needs are provided for green construction and green building materials. The building material industry is used as a 'head-end-draining soldier' for solid waste accommodation, and green and environment-friendly solid waste resources are gradually developed and applied in large quantities as concrete admixture. However, in practical engineering applications, the following problems exist: 1. when the content of the admixture is more than 30%, although the 90d strength is satisfactory, the 28d strength is low. 2. The concrete has reduced alkalinity and deepened carbonization because the use amount of the admixture cement is reduced, the protective effect of the concrete on the reinforcing steel bars is gradually weakened, and the deterioration of the concrete is accelerated. 3. In order to reduce carbon emission, the development of high dicalcium silicate cement in cement plants also has the problem of slow strength development, which affects the construction progress.

In order to improve the utilization rate of the admixture serving as a solid waste resource in concrete, the problems need to be solved, and a carbonization-resistant concrete reinforcing agent needs to be developed. The slow development speed of the concrete strength is mainly limited by the dissolution speed of mineral phases, sodium hydroxide, potassium hydroxide or water glass and the like are commonly adopted to accelerate dissolution, but the risk of alkali aggregate is brought, and the later strength of the concrete is seriously influenced; also, in the patent literature, diethyl or triethanolamine is used to improve the early strength, the early strengthening effect is good, but the later strength is not increased or even has the phenomenon of reverse shrinkage, and meanwhile, the problem of adaptability to cement exists, and the addition amount is extremely sensitive. Mainly, the prior cement generally adopts the alcohol amine grinding aid, and alcohol amine is over-doped when alcohol amine substances are doped again in the production of concrete, so that the strength is reduced by 30% even when the setting time is abnormal and serious. The currently more effective method for the problem of concrete carbonation is to increase the cement dosage, but this runs counter to the concept of carbon neutralization and solid waste utilization; the addition of the alkyl alcohol amine can effectively inhibit carbonization, but the influence of the mixing amount on the strength is avoided; the addition of 2-4% of alkyl polyethylene glycol amine as a cementing material can effectively inhibit carbonization, but the addition amount of the alkyl polyethylene glycol amine is too high, so that the gas content of the concrete is abnormal and the economical efficiency is too low.

The related patent documents: CN101555111A discloses a high-efficiency activated cement grinding aid reinforcing agent and a preparation process thereof, wherein the high-efficiency activated cement grinding aid reinforcing agent adopts the following main components in percentage by weight: 38-44% of water, 8-12% of high-efficiency polycarboxylic acid water reducing agent, 4-10% of sodium acetate, 1-3.6% of urea, 13-19% of modified lignin, 8-12% of 85% of triethanolamine, 14-20% of syrup, 0.11-0.11% of tween-TO-200.08 and 0.08-0.11% of organic silicon defoamer. CN103102093A discloses a special anti-corrosion anti-cracking reinforcing agent for concrete, which comprises the following components in percentage by weight: 2-5% of a shrinkage reducing component, 4-8% of an early plastic shrinkage resisting component, 60-80% of a chlorine salt erosion resisting component, 10-30% of an anti-carbonization component, 0-0.5% of an air entraining component and 0-2% of a retarding component. The early concrete plastic shrinkage resisting component is described as polypropylene fiber and polyacrylonitrile fiber, the chlorine salt erosion resisting component is an inorganic non-metal compound and comprises a mixture of superfine mineral powder and magnesium oxide, and the carbonization resisting component is an active silicon compound. CN111269025A discloses a lithium-based penetrating fluid modified concrete surface reinforcing agent and preparation and use methods thereof. The lithium-based penetrating fluid modified concrete surface reinforcing agent consists of lithium-based penetrating fluid, sodium sulfate, latex powder, talcum powder, a film forming additive, a defoaming agent and water, and by using the technology, the effective strength repair can be efficiently carried out aiming at the insufficient concrete surface strength caused by honeycomb pitted surface, surface dusting and sanding, segregation and bleeding and the like on the surface of the structural concrete, so that the repairing performance and the cohesiveness are high, the surface strength of the structural concrete can be improved, the impermeability, the carbonization resistance and the corrosion resistance of harmful chemical substances of the repaired concrete are improved, the surface compactness of the concrete is improved, the durability of a structure is enhanced, and the service life of the concrete is prolonged.

The above techniques do not provide specific guidance for how to make the anti-carbonization concrete reinforcing agent have good performance, improve the concrete strength, improve the anti-carbonization performance of the concrete, and enhance the durability of the concrete structure.

Disclosure of Invention

The invention aims to provide a concrete reinforcing agent with good performance, which can improve the strength of concrete, improve the anti-carbonization performance of concrete and enhance the durability of a concrete structure, thereby prolonging the service life of the concrete.

Therefore, another technical problem to be solved by the present invention is to provide a method for preparing the above anti-carbonization concrete reinforcing agent.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the technical scheme is that the structural formula of the anti-carbonization concrete reinforcing agent is as follows:

R：C₂-C₆(2-6 carbon atoms).

The preparation method of the anti-carbonization concrete reinforcing agent is characterized by comprising the following process steps: adding 100-150 parts of alkylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring and dissolving at a low speed and a room temperature, wherein the mass ratio of water to ethanol in the ethanol solution is 1: 2-2.5, heating to 40-50 ℃, dropwise adding 660-665 parts of O-methyl isourea sulfate aqueous solution, controlling the time to be 30-35 minutes, uniformly dropwise adding the methyl isourea sulfate aqueous solution, the mass percentage concentration of the methyl isourea sulfate aqueous solution is 40-45%, after dropwise adding, keeping the temperature to 40-50 ℃, reacting for 3-4 hours, cooling to the room temperature after reaction, adding 3-5 parts of defoaming agent, and uniformly stirring to obtain the anti-carbonization concrete reinforcing agent.

In the above technical solution, a preferable technical solution may be: the alkylamine contains a primary amine structure by adopting C2-C7. As the alkylamine, ethylamine or heptylamine can be used. The alkylamine is in excess of the molar ratio of O-methylisourea sulfate, and the molar ratio of alkylamine to O-methylisourea sulfate is preferably 1.5 to 2.2: 1. The defoaming agent is silicon oil defoaming agent (defoaming agent silicone oil), such as Evonik Tegopern 7008 which is a commercial product, or polyoxyethylene/propylene, acetylenic diol ethylene oxide/propane which is a commercial product.

In the above technical solution, a preferable technical solution may be that: the preparation method of the anti-carbonization concrete reinforcing agent comprises the following process steps: adding 100 parts of ethylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring at a low speed and room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 40 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes, uniformly dropwise adding, wherein the mass percentage concentration of the methylisourea sulfate aqueous solution is 40%, after dropwise adding, keeping the temperature at 40 ℃ for reaction for 3 hours, cooling to room temperature after reaction, adding 3 parts of a defoaming agent (defoaming agent silicone oil, which can be a commercial Tegopern 7008), and uniformly stirring to obtain the anti-carbonization concrete reinforcing agent.

In the above technical solution, a preferable technical solution may be that: the preparation method of the anti-carbonization concrete reinforcing agent comprises the following process steps: adding 150 parts of heptylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring at low speed and room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 50 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes until the dropwise adding is completed, keeping the mass percentage concentration of the methylisourea sulfate aqueous solution at 40%, reacting at 50 ℃ for 4 hours after the dropwise adding is completed, cooling to room temperature after the reaction is completed, adding 5 parts of defoaming agent (defoaming agent silicone oil, which can be a commercial Tegopern 7008), and stirring uniformly to obtain the anti-carbonization concrete reinforcing agent.

The synthesized carbon dioxide switch type surface active alkyl biguanide is used as a reinforcing agent and an anti-carbonization substance, is basically neutral under alkaline conditions, is not adsorbed on a mineral phase like an alcohol amine substance but remains in a pore solution, so that the problem of adaptability is solved, and the promotion effect of the synthesized carbon dioxide switch type surface active alkyl biguanide on the dissolution of silicon, aluminum and calcium phases is better than that of the alcohol amine substance; the invention has the same mass doping amount as that of an alcohol amine system on the aspects of carbon dioxide capture capacity or anti-carbonization performance; in order to improve the residue in the liquid phase, part of alkyl is introduced to cause the gas content of the concrete to be increased by 1-2%, and in order not to reduce the strength increasing effect of the alkyl, the defoaming agent is added in the compound preparation, so that the bubble liquid film is loosened, and the gas content of the concrete is reduced.

The invention is added in the concrete production stirring process, and can accelerate the dissolution rate of silicon, calcium and aluminum phases in the cementing material, thereby improving the concrete strength, particularly the 28d strength. Meanwhile, the invention has good carbon dioxide capture capacity, can absorb carbon dioxide to form salt under the condition of existence of moisture, thereby avoiding the reaction of carbon dioxide and calcium hydroxide, greatly delaying the neutralization speed of concrete and effectively preventing the concrete from deterioration. The invention is particularly suitable for concrete with large-dosage auxiliary cementing materials (fly ash, mineral powder, furnace slag, coal gangue and the like), can effectively solve the problems of large carbonization depth and slow strength development of the concrete, and provides powerful guarantee for increasing utilization of solid waste resources and carbon neutralization and carbon emission reduction.

In conclusion, the invention improves the strength of concrete, improves the anti-carbonization performance of the concrete, enhances the durability of the concrete structure and prolongs the service life of the concrete.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 3: the structural formula of the anti-carbonization concrete reinforcing agent is as follows:

R：C₄。

example 1: the preparation method of the anti-carbonization concrete reinforcing agent comprises the following process steps: adding 100 parts of ethylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring at a low speed and room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 40 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes, uniformly dropwise adding, wherein the mass percentage concentration of the methylisourea sulfate aqueous solution is 40%, after dropwise adding, keeping the temperature at 40 ℃ for reaction for 3 hours, cooling to room temperature after reaction, adding 3 parts of a defoaming agent (defoaming agent silicone oil, which can be a commercial Tegopern 7008), and uniformly stirring to obtain the anti-carbonization concrete reinforcing agent.

Example 2: the preparation method of the anti-carbonization concrete reinforcing agent comprises the following process steps: adding 150 parts of heptylamine and 300 parts of ethanol solution into a reaction kettle provided with a high-speed stirrer and a reflux condensing device, stirring at low speed and room temperature for dissolving, wherein the mass ratio of water to ethanol in the ethanol solution is 1:2, heating to 50 ℃, dropwise adding 660 parts of O-methylisourea sulfate aqueous solution, controlling the time for 30 minutes until the dropwise adding is completed, keeping the mass percentage concentration of the methylisourea sulfate aqueous solution at 40%, reacting at 50 ℃ for 4 hours after the dropwise adding is completed, cooling to room temperature after the reaction is completed, adding 5 parts of defoaming agent (defoaming agent silicone oil, which can be a commercial Tegopern 7008), and stirring uniformly to obtain the anti-carbonization concrete reinforcing agent.

The following are the experimental part of the invention: the concrete mixing proportion and the materials are as follows:

cement: yadong waterMud P.O42.5, density 3.11g/cm³Specific surface area 362m²Per kg, Rafaky P.O42.5R, density 3.08g/cm³Specific surface area 353m²/kg

Fly ash: sichuan Bo Leili I grade fly ash, density 2.3g/cm³The detection data are as follows:

TABLE 1 fly ash physical examination data

Sample (I)	Fineness of fineness	Loss on ignition	Water demand ratio	Index of activity
					Bo Lei (an ancient Chinese character)	8％	2.70％	95％	78％

Mineral powder: double-solid S95 mineral powder with density of 2.9g/cm³Specific surface area 400m²Perkg, 28d activity index 99%.

Sand: the fineness modulus of the medium II sand is 2.8, the fineness modulus of the medium III sand is 2.3, and the apparent density is 2680kg/m³。

Stone: artificial macadam 5-31.5 mm, water absorption 0.3%, needle sheet content 6%, and apparent density 2840kg/m³。

Water reducing agent: a high-performance polycarboxylic acid water reducing agent sold in the market, Shijiazhuang Yongyuancai building materials Co. The mixing amount is 1.6 percent of the weight of the cement. The commercial high-performance polycarboxylate superplasticizer is a polyether polycarboxylate high-performance superplasticizer, and the synthesis process comprises the following steps: polymerization reaction: 220g of acrylic acid are metered in, together with 210g of deionized water, and pumped into the titration flask A for further use (as charge A). 2g of vitamin C and 7.60g of thioglycolic acid are metered and added with 420g of deionized water and pumped into a titration tank B for standby (serving as a material B). Adding 2300g of deionized water and 1800g of allyl alcohol polyoxyethylene ether into a reaction kettle, stirring, heating from room temperature to 55 ℃, adding 12.0g of hydrogen peroxide, simultaneously titrating the material A and the material B, titrating the material A for 2.5 hours, titrating the material B for 3 hours, keeping the temperature for 1.5 hours, and controlling the temperature to be 60 +/-2 ℃ to obtain the polymer. Neutralization reaction: and (3) cooling the polymer to below 50 ℃ (45 ℃), adding a sodium hydroxide aqueous solution (with the mass percentage concentration of 30%) while stirring, adjusting the pH value to 6.5-7, and finishing the reaction to obtain the polyether polycarboxylic acid high-performance water reducing agent with the solid content of about 40%.

Mix ratio 1 was the baseline p.o42.5r, normal C30 production mix ratio. The mixing proportion 2 is the mixing proportion of the high-doped auxiliary cementing material, and the admixture (fly ash and mineral powder) is 38 percent of the total cementing material. The results of the strength tests are shown in Table 3. The results of the anti-carbonation tests are shown in Table 4.

TABLE 2 concrete mix proportions

TABLE 3 Strength test results (the contents are percentages by mass of the gelled materials)

TABLE 4 durability test results (the mixing amounts are the mass percentages of the gelled materials)

In conclusion, the invention improves the strength of concrete, improves the anti-carbonization performance of the concrete, enhances the durability of the concrete structure and prolongs the service life of the concrete.