An admixture for solving the phenomenon of blackening of concrete slurry and a preparation method thereof

Abstract

The application discloses an admixture for solving the blackening of concrete slurry and a preparation method thereof. The admixture is prepared from the following raw materials: iso-pentenyl alcohol polyoxyethylene ether, deionized water, sodium methallyl sulfonate, acrylic acid, maleic anhydride, ammonium persulfate, a fatty alcohol and ethylene oxide condensate, polyethylene glycol monooctyl phenyl ether and 740 defoaming agent. The preparation method comprises the following steps: adding iso-pentenyl alcohol polyoxyethylene ether, deionized water and sodium methallyl sulfonate into a reaction kettle, adjusting the rotating speed, heating the reaction kettle, dropping A liquid and B liquid, making the A liquid drop for 3 hours, making the B liquid drop for 3.5 hours, constant temperature stirring, cooling to normal temperature, then adding the remaining fatty alcohol and ethylene oxide condensate and other raw materials into the reaction kettle, and stirring to obtain the admixture. The admixture can be mixed in the concrete, can quickly solve the blackening problem of the slurry, and is widely applied in the fields of civil engineering, water conservancy engineering, underground engineering, road engineering, bridge engineering and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a concrete admixture, belonging to the technical field of building admixtures, in particular to an admixture for solving the blackening phenomenon of concrete paste. The present application also relates to a preparation method of the admixture for solving the blackening phenomenon of concrete paste. BACKGROUND

[0002] Concrete blackening is generally caused by part of cement clinker mixed in cement and fly ash mixed in concrete. Some cement clinker is calcined from raw material slurry by coal powder in a rotary kiln, and the organic matter in coal accounts for more than 95%, mainly composed of large aromatic rings with fatty side chains and condensed rings. They will produce small black oily powder after incomplete combustion. Fly ash is fine ash collected from flue gas after coal combustion. In modern coal combustion process, in order to improve the efficiency of coal combustion or meet the special operation requirements of power plants, diesel oil or other oily substances are added as combustion improvers during the combustion of coal. These combustion improvers cannot be completely combusted and will retain oil in the cement clinker and fly ash. When the above cement clinker and fly ash are used to mix concrete, the oil floats up and appears as floating black oily substance in the concrete. We call this phenomenon as concrete blackening. Severe blackening will produce a black oil layer and a foam slurry layer on the surface of the concrete structure, and after hardening, it will also produce many bubbles with different sizes and spacings in the structure, which seriously affects the appearance quality and durability of the structure.

[0003] Regarding the solution to the blackening phenomenon of concrete paste, the related patent document CN110885205A discloses a method for solving the blackening of concrete paste, preferably 10 million molecular weight methylhydroxypropyl cellulose, the mass percentage of cellulose in cementitious materials is in the range of 0.008% to 0.015%; the pressure drainage instrument is set to a stable holding pressure of 2.0 MPa and a stable holding time of 180 S; when the concrete mixture slump spread is adjusted to 520-600 mm, and the concrete pressure drainage rate is not greater than 2.6% detected by the concrete pressure drainage instrument, the thickening agent can solve the blackening problem of concrete paste. This technology solves the blackening of concrete paste, ensuring the stability of the mixture performance and the appearance quality of the structure. Since this technology has limitations on the slump spread and pressure drainage rate of the concrete mixture when solving the blackening problem, and adding 10 million molecular weight methylhydroxypropyl cellulose into the concrete will cause a large amount of air entrainment, strength reduction and influence on the performance of water reducing agent, which will accelerate the loss of concrete.

[0004] Therefore, it is currently a research focus in the field to develop an admixture that can well solve the blackening phenomenon of concrete paste without negative effects on concrete. SUMMARY

[0005] The present application aims at the deficiency of the prior art, and provides an additive for solving the blackening phenomenon of concrete slurry, which has good use effect, strong adaptability, can well solve the blackening phenomenon of concrete slurry and has no negative effect on concrete, and has simple preparation method and low price.

[0006] Therefore, another object of the present application is to provide a preparation method of the additive for solving the blackening phenomenon of concrete slurry.

[0007] To solve the above technical problems, the present application adopts the technical scheme as follows:

[0008] The additive for solving the blackening phenomenon of concrete slurry is prepared from the following raw materials in mass fraction: 3.0-3.5 parts of iso-pentenyl alcohol polyoxyethylene ether, 50-110 parts of deionized water, 0.03-0.04 parts of sodium methallyl sulfonate, 0.25-0.3 parts of acrylic acid, 0.25-0.3 parts of maleic anhydride, 0.02-0.03 parts of ammonium persulfate, 10-70 parts of fatty alcohol and ethylene oxide condensate, 30-90 parts of polyethylene glycol monooctyl phenyl ether, and 0.01-0.05 parts of 740 defoaming agent (Swiss Clariant C-740 defoaming agent, commercially available product).

[0009] The preparation method of the additive for solving the blackening phenomenon of concrete slurry includes the following process steps: 3.0-3.5 parts of iso-pentenyl alcohol polyoxyethylene ether (TPEG), 3.0-3.5 parts of deionized water and 0.03-0.04 parts of sodium methallyl sulfonate are added into a reaction kettle, the stirring speed of the reaction kettle is adjusted to 200-220 r / min by opening the stirring device, the heating device of the reaction kettle is turned on to warm up the reaction kettle, when the temperature of the materials in the reaction kettle reaches 60-65℃, A liquid and B liquid are added dropwise at the same time, the A liquid is prepared by mixing 0.25-0.3 parts of acrylic acid, 0.25-0.3 parts of maleic anhydride, 0.4-0.5 parts of deionized water and 2-8 parts of fatty alcohol and ethylene oxide condensate, the B liquid is prepared by mixing 0.02-0.03 parts of ammonium persulfate, 0.8-1.2 parts of deionized water and 1-4 parts of polyethylene glycol monooctyl phenyl ether, the dropping speed is adjusted so that the A liquid is just added dropwise for 3 hours and the B liquid is just added dropwise for 3.5 hours, after the addition is completed, the constant temperature stirring is carried out for 1-1.5 hours, the cooling water is passed to cool the materials in the reaction kettle to room temperature (25℃), then the remaining fatty alcohol and ethylene oxide condensate, the remaining polyethylene glycol monooctyl phenyl ether, 0.01-0.05 parts of 740 defoaming agent and the remaining deionized water are added into the reaction kettle, and the stirring is carried out for 30-60 min to obtain the additive for solving the blackening phenomenon of concrete slurry.

[0010] The preferable technical scheme in the above technical scheme can be: the fatty alcohol and ethylene oxide condensate is made from the following raw materials by weight: octadecanol 80-100 parts, sulfuric acid 0.1-0.5 parts, ethylene oxide 80-245 parts, deionized water 17.5-38.5 parts, potassium hydroxide, the amount of potassium hydroxide should meet the requirements of the pH value of the solution (feed liquid) after adjustment (0.05-0.3 parts can be prepared), the preparation method of the fatty alcohol and ethylene oxide condensate includes the following process steps: clean the empty reaction kettle, turn on the electric heating device to heat the reaction kettle to 70-100℃ and keep constant temperature, open the vacuum device to vacuum for 60-120min, completely remove the residual moisture in the reaction kettle; add the measured octadecanol into the reaction kettle, start the reaction kettle stirring and then add sulfuric acid into the reaction kettle; seal the reaction kettle, turn on the electric heating device to make the temperature in the reaction kettle rise to 40-50℃, replace the air in the reaction kettle with nitrogen for 5-10 times; charge nitrogen to make the pressure in the kettle 0.15-0.6MPa, keep for 30-60min, detect the sealing property of the reaction kettle with detergent water (the detergent water is a detergent water solution, the mass percentage concentration of the detergent water solution is 1%-2%); ensure the sealing property of the reaction kettle is good, then raise the temperature in the reaction kettle to 130-180℃, add ethylene oxide (by adjusting its flow and maintaining a certain ethylene oxide pressure, record the ethylene oxide consumption, temperature and pressure value; when the addition amount of ethylene oxide reaches the predetermined average addition number, stop the ethylene oxide feeding), constant temperature stirring for 60-120min; add 17.5-38.5 parts of deionized water into the reaction kettle, continue stirring for 30-60min; neutralize with potassium hydroxide to pH=5-7, pass cooling water to cool the material in the reaction kettle to 40℃ or below 40℃, depressurize, discharge, get the fatty alcohol and ethylene oxide condensate (target product).

[0011] In the above technical solution, the preferable technical solution can also be that the polyethylene glycol monooctyl phenyl ether is prepared from the following raw materials by weight: octyl phenol 40-42 parts, potassium hydroxide 1-4 parts, ethylene oxide 86-90 parts, glacial acetic acid, hydrogen peroxide 6-8 parts, and the amount of glacial acetic acid should meet the requirement of pH value of the solution after adjustment (6.5-21 parts can be prepared). The preparation method of the polyethylene glycol monooctyl phenyl ether comprises the following process steps: the octyl phenol is added into a reaction kettle, the stirring of the reaction kettle is started, and 1-4 parts of potassium hydroxide is added; the electric heating device is turned on to heat the reaction kettle to 80-100 DEG C (the reaction kettle is heated to 80-100 DEG C), the vacuum pump is turned on to dehydrate for 1-2 hours, and then the vacuum valve is closed; the nitrogen gas is filled to make the pressure in the kettle 0.1-0.2 MPa, and then the vacuum is extracted (the operation can be repeated for 3 times); the ethylene oxide is pressed into the reaction kettle by nitrogen gas, the dropping speed is controlled to make the pressure in the reaction kettle keep at 0.15-3.0 MPa, and the pressure is always lower than that in the ethylene oxide storage tank (otherwise the material will be sucked back); the rotation speed of the reaction kettle is controlled to be 90-120 r / min, and when the pressure in the reaction kettle decreases and the temperature rises, it indicates that the reaction starts; the temperature in the reaction kettle is kept at 150-180 DEG C by adjusting the cooling water, and the process is continued until the pressure in the reactor no longer decreases; the cooling water is turned on to reduce the temperature in the reaction kettle to 90-100 DEG C, and the glacial acetic acid is neutralized to pH = 5-7; the cooling is continued until the temperature in the reaction kettle is 70-80 DEG C, and then the hydrogen peroxide is slowly added dropwise, and the temperature is kept for 15-45 min; the cooling is continued to room temperature, the material is discharged, and the polyethylene glycol monooctyl phenyl ether (the high-viscosity liquid finished product with theoretical yield) is prepared.

[0012] In the above technical solution, the preferable technical solution can also be the embodiment 1, the embodiment 2 and the embodiment 3 of the present application.

[0013] The present application has the following advantages: (1) the present application provides an additive for solving the blackening phenomenon of concrete slurry, and the mixing amount is only 170-240 g per cubic meter of concrete, which has little influence on the cost of concrete; (2) the pore structure of concrete can be significantly improved, the number of air bubbles in the concrete is minimized, and the air bubbles are well distributed; (3) the preparation method is simple, the raw materials are cheap and easy to obtain, and the present application has significant economic and social benefits and good market application prospect; and (4) the present application has no negative influence on the strength of concrete, and can significantly improve the compactness and durability of concrete.

[0014] In summary, the present application has good use effect, strong adaptability, can well solve the blackening phenomenon of concrete slurry (i.e. can well eliminate the blackening phenomenon of concrete slurry), has no negative influence on concrete, and has simple preparation method and low price. DETAILED DESCRIPTION

[0015] For the purposes of the present application, the following terms have the following meanings: "comprising" means "including, but not limited to"; "comprise", "comprises", "comprised" and "comprising" mean "including but not limited to"; "comprised of" means "including, but not limited to"; "consisting of" means "including only"; "consisting essentially of" means "including only, but also including equivalents".

[0016] Example 1: The admixture for solving the problem of blackening of concrete slurry according to the present application is prepared from the following raw materials in the following mass fractions: isoamylene polyoxyethylene ether (TPEG-2400) 3.2 parts, deionized water 104.62 parts, sodium methallyl sulfonate 0.037 parts, acrylic acid 0.29 parts, maleic anhydride 0.29 parts, ammonium persulfate 0.023 parts, fatty alcohol and ethylene oxide condensate 10 parts, polyethylene glycol monooctyl phenyl ether 90 parts, 740 defoamer (Swiss Clariant C-740 defoamer, commercially available product) 0.01 part. The fatty alcohol and ethylene oxide condensate is prepared from the following raw materials in the following weight fractions: octadecanol 85 parts, sulfuric acid 0.2 parts, ethylene oxide 150 parts, deionized water 30.5 parts, potassium hydroxide. The amount of potassium hydroxide should meet the requirements of the pH value of the adjusted solution (feed solution) (0.1 parts can be prepared). The preparation method of the fatty alcohol and ethylene oxide condensate comprises the following process steps: clean the empty reaction kettle, turn on the electric heating device to heat the reaction kettle to 90℃ and keep constant temperature, open the vacuum device to vacuum for 100 min, completely remove the residual moisture in the reaction kettle; add the metered octadecanol into the reaction kettle, start the stirring of the reaction kettle and then add sulfuric acid into the reaction kettle; seal the reaction kettle, turn on the electric heating device to raise the temperature in the reaction kettle to 40℃, replace the air in the reaction kettle with nitrogen for 5 times; charge nitrogen to 0.2 MPa pressure in the kettle, keep for 40 min, test the sealing property of the reaction kettle with detergent water; under the condition of ensuring the sealing property of the reaction kettle, raise the temperature in the reaction kettle to 150℃, add ethylene oxide, constant temperature stirring for 80 min; add deionized water into the reaction kettle, continue stirring for 40 min; neutralize with potassium hydroxide to pH = 5.5, cool the material in the reaction kettle to 40℃ with cooling water, release pressure, discharge, and obtain the fatty alcohol and ethylene oxide condensate. The polyethylene glycol monooctyl phenyl ether is prepared from the following raw materials in the following weight fractions: octyl phenol 40 parts, potassium hydroxide 2 parts, ethylene oxide 90 parts, glacial acetic acid, hydrogen peroxide 6 parts. The amount of glacial acetic acid should meet the requirements of the pH value of the adjusted solution (feed solution) (10 parts can be prepared).The preparation method of the polyethylene glycol monooctyl phenyl ether comprises the following process steps: octyl phenol is added into a reaction kettle, the reaction kettle is started to stir, and 2 parts of potassium hydroxide are added; the electric heating device of the reaction kettle is started to heat to 90 DEG C, the vacuum pump is started to dehydrate for 1.5 hours, and then the vacuum valve is closed; nitrogen is filled to make the pressure in the kettle 0.15 MPa, and then vacuum is applied (the operation can be repeated for 3 times); then, the reaction kettle is filled with ethylene oxide by using nitrogen, the dropping speed is controlled to keep the pressure in the reaction kettle at 0.2 MPa, and the pressure is always lower than that in the ethylene oxide storage tank (otherwise, the material will be sucked back); the rotating speed of the reaction kettle is controlled to be 100 r / min, and when the pressure in the reaction kettle decreases and the temperature rises, it indicates that the reaction starts; the temperature in the reaction kettle is kept at 160 DEG C by adjusting the cooling water, and the process is continued until the pressure in the reactor does not decrease any more; the temperature in the reaction kettle is lowered to 90 DEG C by using cooling water, and the pH value is neutralized to 6 by using glacial acetic acid; when the temperature in the reaction kettle is lowered to 70 DEG C, hydrogen peroxide is slowly added dropwise, and the temperature is kept for 20 minutes; the temperature is cooled to room temperature, and the product, the polyethylene glycol monooctyl phenyl ether, is obtained.

[0017] The preparation method of the above-mentioned external additive for solving the blackening phenomenon of concrete slurry comprises the following process steps: 3.2 parts of isoamylene alcohol polyoxyethylene ether, 3.2 parts of deionized water and 0.037 parts of sodium methallyl sulfonate are added into a reaction kettle, the reaction kettle is started to stir and the rotating speed is adjusted to 200 r / min, the heating device of the reaction kettle is started to heat, and when the temperature of the material in the reaction kettle reaches 60 DEG C, A liquid and B liquid are added dropwise at the same time, the A liquid is prepared by mixing 0.29 parts of acrylic acid, 0.29 parts of maleic anhydride, 0.42 parts of deionized water and 2 parts of a fatty alcohol and ethylene oxide condensate, the B liquid is prepared by mixing 0.023 parts of ammonium persulfate, 1.0 parts of deionized water and 2 parts of polyethylene glycol monooctyl phenyl ether, the dropping speed is adjusted to make the A liquid just be added dropwise for 3 hours and the B liquid just be added dropwise for 3.5 hours, after the addition is completed, the constant temperature stirring is continued for 1 hour, then the material in the reaction kettle is cooled to room temperature by using cooling water, and then the remaining 8 parts of the fatty alcohol and ethylene oxide condensate, the remaining 88 parts of polyethylene glycol monooctyl phenyl ether, 0.01 parts of 740 defoaming agent and the remaining 100 parts of deionized water are added into the reaction kettle, and the stirring is continued for 60 minutes to obtain the external additive for solving the blackening phenomenon of concrete slurry.

[0018] The concrete mixing ratio is: 280 Haibo cement + 80 national standard secondary fly ash + 865 machine-made sand + 1072 stone + 170 water + 0.1 carbon black, unit: kg. The external additive for solving the blackening phenomenon of concrete slurry is added into 1 m 3 The mixing amount in the concrete is 240 g.

[0019] The experiment is carried out according to the above-mentioned ratio, and the bubble number, bubble distribution, bubble area and compressive strength of the concrete test block mixed with the external additive, the color difference of the concrete slurry and the test block are measured, and the results are shown in Table 1.

[0020] Table 1 Test results for the concrete test blocks of Example 1

[0021]

[0022] Example 2: The admixture for solving the problem of blackening of concrete slurry according to the present application is prepared from the following raw materials in the following mass fractions: isopentenyl alcohol polyoxyethylene ether (TPEG-2400) 3.2 parts, deionized water 104.62 parts, sodium methallyl sulfonate 0.037 parts, acrylic acid 0.29 parts, maleic anhydride 0.29 parts, ammonium persulfate 0.023 parts, fatty alcohol and ethylene oxide condensate 20 parts, polyethylene glycol monooctyl phenyl ether 80 parts, 740 defoamer (Swiss Clariant C-740 defoamer, commercially available product) 0.02 parts. The fatty alcohol and ethylene oxide condensate is prepared from the following raw materials in the following weight fractions: octadecanol 95 parts, sulfuric acid 0.5 parts, ethylene oxide 200 parts, deionized water 35 parts, potassium hydroxide, the amount of potassium hydroxide should meet the requirements of the pH value of the solution after adjustment (0.25 parts can be prepared), and the preparation method of the fatty alcohol and ethylene oxide condensate comprises the following process steps: clean the empty reaction kettle, turn on the electric heating device to heat the reaction kettle to 95℃ and keep constant temperature, open the vacuum device to vacuum for 120 min to completely remove the residual moisture in the reaction kettle; add the metered octadecanol into the reaction kettle, start the stirring of the reaction kettle, and then add sulfuric acid into the reaction kettle; seal the reaction kettle, turn on the electric heating device to raise the temperature in the reaction kettle to 50℃, replace the air in the reaction kettle with nitrogen for 8 times; charge nitrogen to 0.5 MPa pressure in the kettle, keep for 60 min, and detect the sealing property of the reaction kettle with detergent water; under the condition of ensuring the sealing property of the reaction kettle, raise the temperature in the reaction kettle to 170℃, add ethylene oxide, and keep constant temperature and stirring for 120 min; add deionized water into the reaction kettle, continue to stir for 60 min; neutralize with potassium hydroxide to pH=7, pass cooling water to reduce the temperature of the material in the reaction kettle to 40℃, release the pressure, discharge the material, and obtain the fatty alcohol and ethylene oxide condensate.The polyethylene glycol monooctyl phenyl ether is made from the following raw materials by weight: octyl phenol 42 parts, potassium hydroxide 3 parts, ethylene oxide 90 parts, glacial acetic acid, hydrogen peroxide 8 parts, and the amount of glacial acetic acid should meet the requirements of the pH value of the solution (15 parts can be prepared) after adjustment. The preparation method of the polyethylene glycol monooctyl phenyl ether comprises the following process steps: octyl phenol is added to the reaction kettle, the stirring of the reaction kettle is started, and 3 parts of potassium hydroxide is added; the electric heating device is turned on to heat the reaction kettle to 100℃, the vacuum pump is turned on to dehydrate for 2h, and then the vacuum valve is closed; nitrogen is filled to 0.2MPa in the kettle, and then vacuum is extracted (the operation can be repeated 3 times); then the ethylene oxide is pressed into the reaction kettle with nitrogen, the dropping speed is controlled to keep the pressure in the reaction kettle at 3.0MPa, and the pressure is always lower than that in the ethylene oxide storage tank (otherwise the material will be sucked back); the rotation speed of the reaction kettle is controlled at 120r / min, and when the pressure in the reaction kettle decreases and the temperature rises, it indicates that the reaction starts; the temperature in the reaction kettle is kept at 170℃ by adjusting the cooling water, and the process continues until the pressure in the reactor no longer decreases; the temperature in the reaction kettle is lowered to 100℃ by opening the cooling water, and neutralized to pH=7 with glacial acetic acid; continue to cool down to 80℃, slowly add hydrogen peroxide, and keep warm for 40min; cool to room temperature, discharge, and prepare polyethylene glycol monooctyl phenyl ether.

[0023] The preparation method of the above-mentioned external additive for solving the blackening phenomenon of concrete slurry comprises the following process steps: 3.2 parts of isoamyl alcohol polyoxyethylene ether, 3.2 parts of deionized water and 0.037 parts of sodium methallyl sulfonate are added to the reaction kettle, the stirring of the reaction kettle is started, and the rotation speed is adjusted to 200r / min, the heating device of the reaction kettle is turned on to heat, and when the temperature of the material in the reaction kettle reaches 60℃, A liquid and B liquid are added at the same time, A liquid is mixed by 0.29 parts of acrylic acid, 0.29 parts of maleic anhydride, 0.42 parts of deionized water and 2 parts of fatty alcohol and ethylene oxide condensate, B liquid is mixed by 0.023 parts of ammonium persulfate, 1 part of deionized water, 2 parts of polyethylene glycol monooctyl phenyl ether, the dropping speed is adjusted so that A liquid is just completed in 3 hours and B liquid is just completed in 3.5 hours, after the dropping is completed, constant temperature stirring is carried out for 1h, then the material in the reaction kettle is cooled to room temperature by cooling water, and then the remaining 18 parts of fatty alcohol and ethylene oxide condensate, the remaining 78 parts of polyethylene glycol monooctyl phenyl ether, 0.02 parts of 740 antifoaming agent, and the remaining 100 parts of deionized water are added to the reaction kettle, and stirring is carried out for 60min to obtain the external additive for solving the blackening phenomenon of concrete slurry.

[0024] The concrete mixing ratio is: 280 Haibo cement + 80 national standard grade 2 fly ash + 865 machine-made sand + 1072 stone + 170 water + 0.1 carbon black, unit: kg. The external additive for solving the blackening phenomenon of concrete slurry is 1m 3 The amount of mixing in concrete is 220g.

[0025] The experiment was carried out according to the above-mentioned proportion, and the bubble number, bubble distribution, bubble area and compressive strength of the concrete test block doped with the additive were determined, and the color difference of the concrete slurry and the test block was determined, and the results are shown in Table 2.

[0026] Table 2 Test results of concrete test blocks of Example 2

[0027]

[0028] Example 3: The admixture for solving the problem of blackening of concrete slurry according to the present application is prepared from the following raw materials in the following mass fractions: isopentenyl alcohol polyoxyethylene ether (TPEG-2400) 3.2 parts, deionized water 104.62 parts, sodium methallyl sulfonate 0.037 parts, acrylic acid 0.29 parts, maleic anhydride 0.29 parts, ammonium persulfate 0.023 parts, fatty alcohol and ethylene oxide condensate 30 parts, polyethylene glycol monooctyl phenyl ether 70 parts, 740 defoamer (Swiss Clariant C-740 defoamer, commercially available product) 0.02 parts. The above-mentioned fatty alcohol and ethylene oxide condensate is prepared from the following raw materials in the following weight fractions: octadecanol 95 parts, sulfuric acid 0.35 parts, ethylene oxide 205 parts, deionized water 25 parts, potassium hydroxide, the amount of potassium hydroxide should meet the requirements of adjusting the pH value of the solution (feed liquid) after adjustment (0.25 parts can be prepared), and the preparation method of the fatty alcohol and ethylene oxide condensate comprises the following process steps: clean the empty reaction kettle, turn on the electric heating device to heat the reaction kettle to 80℃ and keep constant temperature, open the vacuum device to vacuum for 70 min to completely remove the residual moisture in the reaction kettle; add the metered octadecanol into the reaction kettle, start the stirring of the reaction kettle, and then add sulfuric acid into the reaction kettle; seal the reaction kettle, turn on the electric heating device to make the temperature in the reaction kettle rise to 50℃, replace the air in the reaction kettle with nitrogen for 10 times; charge nitrogen to make the pressure in the kettle be 0.55 MPa, keep for 60 min, and detect the sealing property of the reaction kettle with detergent water; under the condition of ensuring the sealing property of the reaction kettle, raise the temperature in the reaction kettle to 135℃, add ethylene oxide, keep constant temperature and stirring for 100 min; add 25 parts of deionized water into the reaction kettle, continue to stir for 40 min; neutralize with potassium hydroxide to pH=7, pass cooling water to reduce the temperature of the material in the reaction kettle to 40℃, release the pressure, discharge the material, and obtain the fatty alcohol and ethylene oxide condensate.The polyethylene glycol monooctyl phenyl ether is prepared from the following raw materials by weight: 41 parts of octyl phenol, 2 parts of potassium hydroxide, 90 parts of ethylene oxide, 6 parts of glacial acetic acid and hydrogen peroxide, and the amount of glacial acetic acid should meet the requirement of adjusting the pH value of the solution (12 parts can be prepared). The preparation method of the polyethylene glycol monooctyl phenyl ether comprises the following process steps: the octyl phenol is added into the reaction kettle, the stirring of the reaction kettle is started, and 2 parts of potassium hydroxide is added; the electric heating device is turned on to heat the reaction kettle to 90℃, the vacuum pump is turned on to dehydrate for 1h, and then the vacuum valve is closed; the nitrogen gas is filled to make the pressure in the kettle 0.2MPa, and then the vacuum is pumped (the operation can be repeated for 3 times); the ethylene oxide is pressurized into the reaction kettle with nitrogen gas, the dropping speed is controlled to keep the pressure in the reaction kettle at 1.0MPa, and the pressure is always lower than that in the ethylene oxide storage tank (otherwise the material will be sucked back); the rotation speed of the reaction kettle is controlled at 120r / min, and when the pressure in the reaction kettle decreases and the temperature rises, it indicates that the reaction starts; the temperature in the reaction kettle is kept at 165℃ by adjusting the cooling water, and the process continues until the pressure in the reactor no longer decreases; the cooling water is turned on to reduce the temperature in the reaction kettle to 90℃, and the neutralization is performed with glacial acetic acid until the pH value is 6; the temperature is continuously reduced to 75℃, and then the hydrogen peroxide is slowly added dropwise, and the temperature is kept for 40min; the temperature is cooled to room temperature, and the product is discharged to obtain the polyethylene glycol monooctyl phenyl ether.

[0029] The preparation method of the additive for solving the blackening phenomenon of concrete slurry comprises the following process steps: 3.2 parts of isoamyl polyoxyethylene ether, 3.2 parts of deionized water and 0.037 parts of sodium methallyl sulfonate are added into a reaction kettle, the stirring of the reaction kettle is started, the rotation speed is adjusted to 200r / min, the heating device is turned on to heat the reaction kettle, when the temperature of the material in the reaction kettle reaches 60℃, the A solution and the B solution are added dropwise at the same time, the A solution is prepared by mixing 0.29 parts of acrylic acid, 0.29 parts of maleic anhydride, 0.42 parts of deionized water and 2 parts of a fatty alcohol and ethylene oxide condensate, the B solution is prepared by mixing 0.023 parts of ammonium persulfate, 1.0 parts of deionized water and 2 parts of polyethylene glycol monooctyl phenyl ether, the dropping speed is adjusted so that the A solution is just added dropwise for 3 hours and the B solution is just added dropwise for 3.5 hours, after the addition is completed, the constant temperature stirring is performed for 1h, then the cooling water is used to reduce the temperature of the material in the reaction kettle to room temperature, and then the remaining 28 parts of the fatty alcohol and ethylene oxide condensate, the remaining 68 parts of polyethylene glycol monooctyl phenyl ether, 0.02 parts of 740 defoaming agent and the remaining 100 parts of deionized water are added into the reaction kettle, and the stirring is performed for 60min to obtain the additive for solving the blackening phenomenon of concrete slurry.

[0030] The concrete mixing ratio is: 280 Haibo cement + 80 national standard grade 2 fly ash + 865 machine-made sand + 1072 stone + 170 water + 0.1 carbon black, unit: kg. The additive for solving the blackening phenomenon of concrete slurry is added in 1m 3 The amount of admixture in the concrete is 200g.

[0031] The experiment was carried out according to the above-mentioned proportion, and the bubble number, bubble distribution, bubble area and compressive strength of the concrete test block doped with the additive were measured, and the color difference of the concrete slurry and the test block was measured, and the results are shown in Table 3.

[0032] Table 3 Test results of the concrete test block of Example 3

[0033]

[0034] From the above examples, it can be seen that the bubble number, bubble distribution, bubble area, color difference of the concrete slurry and the test block of the concrete test block made of the additive (of the present application) for solving the blackening phenomenon of the concrete slurry are far superior to the reference concrete, and the compressive strength has no significant difference with the reference concrete.

[0035] In summary, the present application can be doped in concrete, which can quickly solve the problem of slurry blackening, and is beneficial to the bubble distribution in concrete and has no negative effect on the compressive strength of concrete, so it can be widely used in civil engineering, water conservancy engineering, underground engineering and engineering fields such as road, bridge and the like.

Claims

1. An admixture for solving the problem of blackening in concrete paste, characterized in that, It is made from the following raw materials in parts by weight: 3.0-3.5 parts isopentenyl alcohol polyoxyethylene ether, 50-110 parts deionized water, 0.03-0.04 parts sodium methacrylate sulfonate, 0.25-0.3 parts acrylic acid, 0.25-0.3 parts maleic anhydride, 0.02-0.03 parts ammonium persulfate, 10-70 parts fatty alcohol and ethylene oxide condensate, 30-90 parts polyethylene glycol monooctylphenyl ether, and 0.01-0.05 parts 740 defoamer; The above-mentioned fatty alcohol and ethylene oxide condensate is made from the following raw materials in parts by weight: 80-100 parts octadecyl alcohol, 0.1-0.5 parts sulfuric acid, 80-245 parts ethylene oxide, 17.5-38.5 parts deionized water, and potassium hydroxide. The amount of potassium hydroxide should meet the requirements of the pH value of the adjusted solution. The fatty alcohol and ethylene oxide condensate is prepared by the following steps: clean the empty reaction vessel, turn on the electric heating device to heat the reaction vessel to 70-100 ℃ and maintain the temperature, turn on the vacuum device to evacuate for 60-120 min to completely remove the residual water in the reaction vessel; add the measured octadecyl alcohol to the reaction vessel, turn on the stirring of the reaction vessel, and then add sulfuric acid to the reaction vessel. Seal the reactor and turn on the electric heating device to raise the temperature inside the reactor to 40-50℃. Replace the air inside the reactor with nitrogen 5-10 times. Purge the reactor with nitrogen until the pressure inside is 0.15-0.6MPa, and maintain this pressure for 30-60 minutes. Test the reactor's seal with detergent water. If the reactor is sealed well, raise the temperature inside the reactor to 130-180℃, add ethylene oxide, and stir at a constant temperature for 60-120 minutes. Add 17.5-38.5 parts of deionized water to the reactor and continue stirring for 30-60 minutes. Neutralize with potassium hydroxide to pH 5-7, and cool the material inside the reactor to 40℃ or below by purging with cooling water. Depressurize, discharge, and obtain the fatty alcohol-ethylene oxide condensate. The aforementioned polyethylene glycol monooctylphenyl ether is made from the following raw materials in parts by weight: 40-42 parts octylphenol, 1-4 parts potassium hydroxide, 86-90 parts ethylene oxide, 6-8 parts hydrogen peroxide, and glacial acetic acid. The amount of glacial acetic acid should meet the requirements of the adjusted pH value of the solution. The polyethylene glycol monooctylphenyl ether is prepared by the following steps: Octylphenol is added to a reaction vessel, stirring is started, and 1-4 parts of potassium hydroxide are added; the electric heating device is turned on to heat the reaction vessel to 80-100℃; the vacuum pump is turned on for vacuum dehydration for 1-2 hours, and then the vacuum valve is closed; nitrogen is purged until the pressure inside the vessel is 0.1-0.2 MPa, and then a vacuum is drawn; ethylene oxide is then forced into the reaction vessel using nitrogen. In the reactor, the dropping rate is controlled to maintain the pressure inside the reactor at 0.15-3.0 MPa, and this pressure must always be lower than the pressure inside the ethylene oxide storage tank. The reactor rotation speed is controlled at 90-120 r / min. When the pressure inside the reactor decreases and the temperature increases, it indicates that the reaction has started. The temperature inside the reactor is maintained at 150-180℃ by adjusting the cooling water, and this continues until the reactor pressure no longer decreases. The cooling water is turned on to lower the temperature inside the reactor to 90-100℃, and the mixture is neutralized with glacial acetic acid to pH 5-7. The temperature is further lowered until the temperature inside the reactor reaches 70-80℃, at which point hydrogen peroxide is slowly added dropwise, and the temperature is maintained for 15-45 minutes. The mixture is then cooled to room temperature, discharged, and polyethylene glycol monooctylphenyl ether is obtained.

2. The admixture for solving the blackening phenomenon of concrete paste according to claim 1, characterized in that, It is made from the following raw materials in parts by weight: 3.2 parts isopentenyl alcohol polyoxyethylene ether, 104.62 parts deionized water, 0.037 parts sodium methacrylate, 0.29 parts acrylic acid, 0.29 parts maleic anhydride, 0.023 parts ammonium persulfate, 10 parts fatty alcohol and ethylene oxide condensate, 90 parts polyethylene glycol monooctylphenyl ether, and 0.01 parts 740 defoamer; The above-mentioned fatty alcohol and ethylene oxide condensate is made from the following raw materials in parts by weight: 85 parts octadecyl alcohol, 0.2 parts sulfuric acid, 150 parts ethylene oxide, 30.5 parts deionized water, and potassium hydroxide. The amount of potassium hydroxide should meet the requirements of the pH value of the adjusted solution. The fatty alcohol and ethylene oxide condensate is prepared by the following steps: clean the empty reaction vessel, turn on the electric heating device to heat the reaction vessel to 90°C and keep the temperature constant, turn on the vacuum device to evacuate for 100 minutes to completely remove the residual water in the reaction vessel; Add the measured amount of octadecyl alcohol to the reactor, turn on the reactor stirring, and then add sulfuric acid to the reactor. Seal the reactor, turn on the electric heating device to raise the temperature inside the reactor to 40°C, and replace the air inside the reactor with nitrogen five times. Nitrogen gas was introduced into the reactor until the internal pressure reached 0.2 MPa, and maintained for 40 minutes. The reactor's sealing performance was tested using detergent water. With the reactor's sealing performance confirmed, the internal temperature was raised to 150°C, ethylene oxide was added, and the mixture was stirred at a constant temperature for 80 minutes. Deionized water was added to the reactor, and stirring continued for 40 minutes. The mixture was neutralized with potassium hydroxide to pH 5.5, and cooling water was used to lower the temperature of the material in the reactor to 40°C. The pressure was released, and the material was discharged to obtain a fatty alcohol-ethylene oxide condensate. The aforementioned polyethylene glycol monooctylphenyl ether is made from the following raw materials in parts by weight: 40 parts octylphenol, 2 parts potassium hydroxide, 90 parts ethylene oxide, 6 parts hydrogen peroxide, and glacial acetic acid. The amount of glacial acetic acid should meet the requirements of the pH value of the adjusted solution. The polyethylene glycol monooctylphenyl ether is prepared by the following steps: Octylphenol is added to a reaction vessel, the reaction vessel is stirred, and 2 parts of potassium hydroxide are added; the electric heating device is turned on to heat the reaction vessel to 90°C, the vacuum pump is turned on for vacuum dehydration for 1.5 hours, and then the vacuum valve is closed; nitrogen is purged until the pressure inside the vessel is 0.15 MPa, and then a vacuum is drawn; ethylene oxide is then forced into the reaction vessel using nitrogen, and the dropping rate is controlled to maintain the pressure inside the reaction vessel at 0.2 MPa, and this pressure must always be lower than the pressure inside the ethylene oxide storage tank; the rotation speed of the reaction vessel is controlled at 100 r / min, and when the pressure inside the reaction vessel decreases while the temperature increases, it indicates that the reaction has started; the temperature inside the reaction vessel is maintained at 160°C by adjusting the cooling water until the pressure in the reactor no longer decreases; Turn on the cooling water to lower the temperature inside the reactor to 90°C, and neutralize it with glacial acetic acid to pH=6; continue to cool down until the temperature inside the reactor is 70°C, then slowly add hydrogen peroxide and keep it at that temperature for 20 minutes; cool to room temperature, discharge the material, and obtain polyethylene glycol monooctylphenyl ether.

3. The admixture for solving the blackening phenomenon of concrete paste according to claim 1, characterized in that, It is made from the following raw materials in parts by weight: 3.2 parts isopentenyl alcohol polyoxyethylene ether, 104.62 parts deionized water, 0.037 parts sodium methacrylate, 0.29 parts acrylic acid, 0.29 parts maleic anhydride, 0.023 parts ammonium persulfate, 20 parts fatty alcohol and ethylene oxide condensate, 80 parts polyethylene glycol monooctylphenyl ether, and 0.02 parts 740 defoamer; The above-mentioned fatty alcohol and ethylene oxide condensate is made from the following raw materials in parts by weight: 95 parts octadecyl alcohol, 0.5 parts sulfuric acid, 200 parts ethylene oxide, 35 parts deionized water, and potassium hydroxide. The amount of potassium hydroxide should meet the requirements of the pH value of the adjusted solution. The fatty alcohol and ethylene oxide condensate is prepared by the following steps: clean the empty reaction vessel, turn on the electric heating device to heat the reaction vessel to 95°C and keep the temperature constant, turn on the vacuum device to evacuate for 120 minutes to completely remove the residual water in the reaction vessel; Add the measured amount of octadecyl alcohol to the reactor, turn on the reactor stirring, and then add sulfuric acid to the reactor. Seal the reactor, turn on the electric heating device to raise the temperature inside the reactor to 50°C, and replace the air inside the reactor with nitrogen 8 times; purge the reactor with nitrogen until the pressure inside the reactor is 0.5 MPa, maintain this pressure for 60 minutes, and test the reactor's sealing performance with detergent water; ensuring good sealing performance, raise the temperature inside the reactor to 170°C, add ethylene oxide, and stir at a constant temperature for 120 minutes; add deionized water to the reactor and continue stirring for 60 minutes; neutralize with potassium hydroxide to pH=7, circulate cooling water to cool the material inside the reactor to 40°C, depressurize, and discharge the material to obtain a fatty alcohol-ethylene oxide condensate; The aforementioned polyethylene glycol monooctylphenyl ether is made from the following raw materials in parts by weight: 42 parts octylphenol, 3 parts potassium hydroxide, 90 parts ethylene oxide, 8 parts hydrogen peroxide, and glacial acetic acid. The amount of glacial acetic acid should meet the requirements of the pH value of the adjusted solution. The polyethylene glycol monooctylphenyl ether is prepared by the following steps: Octylphenol is added to a reaction vessel, stirring is started, and 3 parts potassium hydroxide are added; the electric heating device is turned on to heat the reaction vessel to 100°C; the vacuum pump is turned on for vacuum dehydration for 2 hours, and then the vacuum valve is closed; nitrogen is purged until the pressure inside the vessel is 0.2 MPa, and then a vacuum is drawn; then nitrogen is used to force ethylene oxide into the reaction vessel. In the reactor, the dropping rate is controlled to maintain the pressure inside the reactor at 3.0 MPa, and this pressure must always be lower than the pressure inside the ethylene oxide storage tank. The reactor rotation speed is controlled at 120 r / min. When the pressure inside the reactor decreases and the temperature increases, it indicates that the reaction has started. The temperature inside the reactor is maintained at 170℃ by adjusting the cooling water until the reactor pressure no longer decreases. The cooling water is turned on to lower the temperature inside the reactor to 100℃, and the mixture is neutralized with glacial acetic acid to pH=7. The temperature is further lowered until the temperature inside the reactor reaches 80℃, at which point hydrogen peroxide is slowly added dropwise, and the mixture is kept at this temperature for 40 min. After cooling to room temperature, the product is discharged to obtain polyethylene glycol monooctylphenyl ether.

4. A method for preparing the admixture for solving the blackening phenomenon of concrete paste as described in claim 1, characterized in that, The process includes the following steps: Add 3.0-3.5 parts of isopentenyl alcohol polyoxyethylene ether, 3.0-3.5 parts of deionized water, and 0.03-0.04 parts of sodium methacrylate sulfonate to a reactor. Turn on the reactor and stir, adjusting the speed to 200-220 r / min. Turn on the heating device to raise the temperature of the reactor. When the temperature of the material inside the reactor reaches 60-65℃, simultaneously add solution A and solution B. Solution A is composed of 0.25-0.3 parts of acrylic acid, 0.25-0.3 parts of maleic anhydride, 0.4-0.5 parts of deionized water, and 2-8 parts of a fatty alcohol and ethylene oxide condensate. Solution B is composed of 0.02- The mixture consists of 0.03 parts ammonium persulfate, 0.8-1.2 parts deionized water, and 1-4 parts polyethylene glycol monooctylphenyl ether. The dropping rate is adjusted so that solution A is added in exactly 3 hours and solution B in exactly 3.5 hours. After the addition is complete, the mixture is stirred at a constant temperature for 1-1.5 hours. Cooling water is then circulated to cool the materials in the reactor to room temperature. Then, the remaining fatty alcohol and ethylene oxide condensate, the remaining polyethylene glycol monooctylphenyl ether, 0.01-0.05 parts 740 defoamer, and the remaining deionized water are added to the reactor. The mixture is stirred for 30-60 minutes to obtain the admixture for solving the blackening phenomenon of concrete paste.

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