Concrete, as the largest building material, has developed rapidly. In recent years, high-strength and high-performance concrete has been widely used in engineering. The fluidity of concrete has developed from the previous 70~90mm to the current slump of 180~230mm. Some projects also use self-compacting concrete, and the pumping height is getting higher and higher. However, the fluidity and cohesion of concrete are often incompatible, that is, it is difficult for concrete to maintain high cohesion properties under large flow conditions. In this way, concrete that pursues high fluidity is prone to bleeding and segregation. Moreover, with the gradual depletion of river sand resources and mineral resources in my country, the gradation and fineness of river sand fluctuate greatly, ordinary manufactured sand with poor particle size is used on a large scale, the water retention of cement fluctuates, and high water reduction but The more sensitive polycarboxylic acid-type water-reducing admixtures are constantly being promoted, and the quality control of ready-mixed concrete is facing increasingly severe challenges. The existing concrete anti-segregation agents have a strong flocculation effect, which will cause the concrete to settle quickly and the concrete to lose its flow properties instantly, which is detrimental to the workability of concrete. For this reason, we propose an anti-segregation agent for concrete and its preparation method.
Technical implementation elements:
The purpose of this technology is to provide an anti-segregation agent for concrete and its preparation method to solve the above problems in the background technology The proposed existing concrete anti-segregation agent has a strong flocculation effect, which will cause the concrete to settle quickly, causing the concrete to lose its flow properties instantly, which is detrimental to the workability of the concrete.
In order to achieve the above purpose, the present invention provides the following technical solution: an anti-segregation agent for concrete, which is made of anti-segregation agent for concrete. The composition of the segregating agent is as follows:
5-15 parts of fly ash, 5-15 parts of mineral powder, 1-2 parts of steel fiber, 1-2 parts of polyethylene glycol, 20-30 parts of polyhydroxyacid water-reducing agent, and 0.8-1.2 parts of adhesive, 0.5-0.9 parts of coagulant, 200-300 parts of deionized water, several parts of liquid alkali, 5-10 parts of silicone monomer, 3-5 parts of oxidizing agent, 1-3 parts of reducing agent .
Preferably, the organosilicon monomer is propyltrichlorosilane or vinyltrichlorosilane or fluorosilicone monomer or a mixture of the three.
Preferably, the coagulant is powdered sodium sulfate.
Preferably, the tackifier is PAM, and PAM is moistened with methanol or ethanol, and deionized water is added Stir and heat to 55 degrees Celsius while stirring to prepare a solution with a concentration of 4%.
Preferably, the oxidizing agent is one or more mixtures of hydrogen peroxide, ammonium persulfate, and potassium persulfate. .
Preferably, the reducing agent is ammonium persulfate-anhydrous sodium bisulfite or ammonium persulfate-secondary Sodium phosphate.
Preferably, the alkali solution is sodium hydroxide.
Preferably, the preparation method of the concrete anti-segregation agent includes the following steps:
S1: Mixing: Add silicone monomer, deionized water, polyhydroxyacid superplasticizer and polyethylene glycol into the reactor and mix;
S2: Oxidation: Stir to make the mixture in step S1 evenly mixed, add oxidant for oxidation;
S3: Reduction: Add fly ash, mineral powder and steel fiber to the oxidation mixture in step S2, and then add the reducing agent;
S4: Neutralization: Add tackifier and coagulant to the reduced mixture in step S3, stir continuously, Stir until uniform, then add liquid caustic soda to adjust the pH until the pH is between 7-9, and then you can obtain the anti-segregation agent for concrete.
Compared with the prior art, the beneficial effects of the present invention are: the invention adds powder to the anti-segregation agent Coal ash, mineral powder and steel fiber can not only improve the compression resistance of concrete, but also effectively improve the working performance and layering degree of concrete, improve the resistance to segregation of concrete, and also reduce the expansion and collapse of concrete. Drop degree, PAM is used as the tackifier, because PAM has more -NH2, which makes the tackifier very hydrophilic, making the concrete hydrophilic, water-retaining, thickening, resistance-reducing and viscosity-increasing. Adding calcium sulfate as a coagulant can promote concrete water splashing, accelerate hardening, and promote coagulation. The invention has wide sources of raw materials, low cost, green environmental protection, and simple operation.
ant-caps: normal; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial"/>S4: Neutralization: Add tackifier and coagulation accelerator to the reduced mixture in step S3 agent, stir continuously until the mixture is uniform, then add liquid caustic soda to adjust the pH, so that the pH is between 7-9, and the anti-segregation agent for concrete can be obtained.
Compared with the existing technology, the beneficial effects of the present invention are: the invention adds fly ash, mineral powder and steel fiber to the anti-segregation agent, which can not only improve the resistance of concrete The pressure is light, and it can also effectively improve the working performance and stratification degree of concrete, improve the segregation resistance of concrete, and also reduce the expansion and slump of concrete. PAM is used as the tackifier because PAM has more -NH2 makes the tackifier have good hydrophilicity, making the concrete hydrophilic, water-retaining, thickening, resistance-reducing and viscosity-increasing. Adding calcium sulfate as a setting accelerator can promote concrete water splashing and accelerate hardening. Promoting condensation, the invention has wide sources of raw materials, low cost, green environmental protection and simple operation.
<img src="/upfile/202304/2023041334528065.jpg"/
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