Concrete anti-segregation agent manufacturer, concrete bleeding, how to solve segregation, what is the principle of concrete anti-segregation agent

Contents of this article

• The best formula for concrete anti-segregation agent?

• How to solve concrete bleeding and segregation? What admixtures can be adjusted?

• How to solve the problem of segregation of cement and gravel in concrete? If it is a mixing station, how should the mixing station solve this problem?

• Measures to prevent concrete segregation?

• How to deal with the segregated material?

• What are the reasons for cement segregation in concrete?

• What is the function of sodium polyacrylate?

What is the best formula for concrete anti-segregation agent?

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 the present invention is to provide an anti-segregation agent for concrete and a preparation method thereof to solve the existing concrete anti-segregation problems proposed in the above background technology. The strong flocculation effect of the agent 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 object, the present invention provides the following technical solution: an anti-segregation agent for concrete, the composition of the anti-segregation agent for concrete is as follows:

Fly ash 5- 15 parts, mineral powder 5-15 parts, steel fiber 1-2 parts, polyethylene glycol 1-2 parts, polyhydroxy acid water reducing agent 20-30 parts, tackifier 0.8-1.2 parts, coagulant 0.5- 0.9 parts, 200-300 parts of deionized water, several parts of liquid alkali, 5-10 parts of silicone monomer, 3-5 parts of oxidizing agent, and 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 the PAM is moistened with methanol or ethanol, deionized water is added for stirring, and the mixture is heated to 55 degrees Celsius during stirring to prepare a solution with a concentration of 4%.

Preferably, the oxidizing agent is one or a mixture of hydrogen peroxide, ammonium persulfate, and potassium persulfate.

Preferably, the reducing agent is ammonium persulfate-anhydrous sodium bisulfite or ammonium persulfate-sodium hypophosphite.

Preferably, the alkali solution is sodium hydroxide.

Preferably, the preparation method of the concrete anti-segregation agent includes the following steps:

S1: Mixing: combine silicone monomer, deionized water, polyhydroxyacid water-reducing agent and polyethylene glycol are added into the reaction kettle for mixing;

S2: Oxidation: Stir until the mixture in step S1 is evenly mixed, and add oxidant for oxidation;

S3: Reduction: Add fly ash, mineral powder and steel fiber to the oxidized mixture in step S2, and then add the reducing agent;

S4: Neutralization: Add a tackifier to the reduced mixture in step S3 and coagulant, stir continuously until the mixture is uniform, and then add liquid caustic soda to adjust the pH so that the pH is between 7-9, and then 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 compressive strength of concrete, but also It can also effectively improve the working performance and stratification of concrete, improve the segregation resistance of concrete, and reduce the expansion and slump of concrete. PAM is used as a tackifier because PAM has more -NH2. The tackifier has 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, accelerate hardening, and promote condensation. The invention has wide sources of raw materials, low cost, green and environmental protection, and simple operation.

How to solve concrete bleeding and segregation? What admixtures can be adjusted?

1. Increase the strength of concrete

After using concrete strengthening agent, the strength of concrete can be increased by 8% to 20%; while the strength remains unchanged, the amount of cement can be reduced 10%～20%.

2.

Improve the performance of concrete

Concrete strengthening agent can effectively improve the workability, bleeding resistance, non-segregation and easy pumping of concrete. And the frost resistance and carbonation resistance have been greatly improved.

3.

Strong adaptability

Not only can it be suitable for various types of concrete and has strong compatibility with various types of admixtures, but it can also improve the The adaptability of carboxylic acid water-reducing agent to raw materials (such as low-quality fly ash, sand with a large mud content, and stones with a large stone powder content) reduces the risk of polycarboxylic acid superplasticizers��10%) will make it difficult to control the quality of concrete and prone to concrete segregation. Because the water content in the sand is too large and is in a supersaturated state, when the concrete mixture is mixed in the mixer, the water in the capillary tubes on the surface of the sand cannot be released in time, so it is easy to use too much mixing water during mixing; at the same time During the transportation of concrete, the water in the capillary tubes of the aggregate is continuously released, destroying the bond between the aggregate and the cement slurry, causing segregation and bleeding of the concrete. (4) Excessive mud content in sand and gravel will reduce the bonding force between the cement slurry and the aggregate, and the cement slurry's ability to wrap the aggregate will decrease, leading to the separation of the aggregate and causing concrete segregation. Adding a certain amount of mineral admixtures into concrete can, on the one hand, improve the various properties of the concrete, and on the other hand, it can achieve good economic benefits. Therefore, the use of mineral admixtures is very common in various concrete mixing stations, such as: slag powder, steel slag powder, silica powder, zeolite powder, etc. Various mineral admixtures have different effects on concrete segregation. Silica fume and zeolite powder have strong ability to resist the segregation of concrete and can greatly improve the workability of concrete. Due to its large specific gravity, steel slag powder can increase the density of mortar after being added, which is helpful to improve the workability of concrete. The incorporation of slag powder increases the viscosity of concrete to a certain extent, and concrete is prone to segregation. The degree of influence is closely related to the fineness of slag powder. Generally, the higher the fineness, the better the resistance to concrete segregation

What is the function of sodium polyacrylate?

It is a low molecular weight anionic electrolyte, also known as polymer flocculant. This product can adsorb precipitated substances to form floccules to prevent scaling, and is a good dispersant. In addition to being used as a flocculant for water purification, it can also be used to adjust the viscosity of injected water during oil extraction and to clarify sugar in the sugar industry. liquid, used as a pigment dispersant, a paste for treating synthetic fibers, and as a soil conditioner, latex thickener, paper enhancer, and food additive. It is suitable for inhibiting cement fluidization and aggregates during underwater pouring of concrete. Isolated as anti-dispersing agent.