Concrete anti-segregation agent-the difference between segregation and bleeding

Table of contents of this article

• What is the difference between segregation and bleeding?

• What is the difference between bleeding and segregation?

• What are segregation and bleeding of concrete mixtures?

• What is the concept of concrete segregation?

• During construction, what is the bleeding of mortar?

• Does the segregated ash affect the strength?

What is the difference between segregation and bleeding?

Different pronunciations, different meanings, and different usages.

Separation: (verb) ①Separate; split: fall apart~. ②Analysis; analysis.

Example: Use the word "xiang" to describe people's misfortunes and blessings. Those who are looking for an image can just write a word at random, that is, in terms of the word and analysis, all of them are extraordinary and famous in the ninth level.

Bleeding: refers to the upward movement of water before the concrete volume has been fixed but before it solidifies.

Example: The mixtures produced by various shell-making and stirring processes have a common feature, that is, the amount of bleeding is greatly reduced.

What is the difference between bleeding and segregation?

Concrete segregation is a phenomenon in which the cohesion between the components of the concrete mixture is insufficient to resist the sinking of the coarse aggregate, and the components of the concrete mixture separate from each other, resulting in uneven internal composition and structure. It usually manifests as the separation of coarse aggregate and mortar from each other, for example, dense particles are deposited at the bottom of the mixture, or the coarse aggregate is separated from the mixture as a whole

Bleeding:

During the transportation, vibration, and pumping of concrete, the phenomenon of sinking of coarse aggregate and rising water is called concrete bleeding. Bleeding is an important aspect of the workability of fresh concrete. Usually, the indicators describing the bleeding characteristics of concrete include bleeding amount (i.e., the average bleeding amount per unit area of ​​the concrete mixture) and bleeding rate (i.e., the ratio of the bleeding amount to the specific moisture content of the concrete mixture).

What are segregation and bleeding of concrete mixtures?

The quality of concrete depends largely on the workability and homogeneity of the mixture. Well-working concrete should not exhibit excessive bleeding or segregation. The phenomenon of concrete segregation is: when the concrete mixture is piled up in a pile, the fluidity of the mixture is very good. After leaving it for a certain period of time, the slurry will secrete from the surface of the mixture and flow out to the edge, with stones exposed on the surface, and the surface of the stones will not form. Account for mortar.

The segregation of the concrete mixture can easily cause the mixture to stratify, that is, the lower layer has more stones and less slurry, and the upper layer of slurry has less or almost no stones. For concrete mixtures with the same mix ratio, the strength of segregated concrete is about 10% lower than that of concrete with good workability.

When the concrete strength is insufficient, the actual bearing capacity of the frame members decreases almost proportionally with the decrease in concrete strength. Therefore, special attention should be paid to the inspection and treatment of insufficient strength of concrete members in actual projects.

Insufficient concrete strength will have different effects on the load-bearing capacity of reinforced concrete components. It will also make the cracks in the component section wider and reduce the durability of the components. Therefore, the construction quality should be checked during the concrete construction process. For existing structures whose concrete strength is less than the design value, corresponding measures should be taken in a timely manner according to the different degrees of impact and the importance of the components to ensure that the building can meet the safety and normal use requirements.

Concrete reinforcement is a polymer solution with active silicate as the core technology. Through full penetration, its active ingredients can quickly react chemically with the free calcium in the concrete to generate crystalline colloids that fill the gaps, increase the density of the structure, and form a solid dense body on the surface of the concrete, greatly improving the strength of the surface layer of the concrete structure. and abrasion resistance, resulting in a permanently sealed, strong, abrasion-resistant, dust-free surface that is resistant to water and most industrial chemicals.

Scope of application of Guwei GWZ820 concrete reinforcing agent:

1. Painting of new and old concrete floors, walls, and columns to enhance strength, hardness, and rebound value can generally increase by 10 -25%. After 7 days of hardening and curing, it can be increased by 40%.

2. Reinforcement and repair of various concrete components or cement components that are dusty, dusty, or sandy.

3. Paint the surfaces of various new concrete components and cement products with insufficient surface strength to increase strength, hardness and extend their service life.

To deal with the problem of insufficient strength of concrete in the later stage, we should first analyze the reasons for the insufficient strength of concrete in the later stage. The water-cement ratio directly affects the later strength of concrete. When the water-cement ratio is too large, excess free water in the concrete evaporates, resulting in excessive pores in the cement slurry surface layer, reducing the compactness and reducing the strength of the concrete surface layer. In addition, if there is too much water on the surface, the polishing time of the concrete surface will be extended, and may even exceed the final setting time of the cement, causing the construction quality to be unable to be guaranteed. In addition to hydration with cement, the water in concrete also plays a role in meeting the requirements of concrete construction. During the construction process, in order to meet the schedule and facilitate construction, the slump of the concrete was amplified as much as possible, and water was even added without authorization to amplify the slump. As a result, a large amount of water bleeds from the surface of the concrete, resulting in insufficient strength of the concrete in the later stage.

For many on-site construction managers, people are often accustomed to religiously reading specifications and standards as Bibles, word for word, and never doubting their rationality. When on-site quality problems arise, more problems arise. Find the reason from your own management area. In fact, as science and technologyWith the continuous progress of �� and the continuous improvement of people's understanding, norms and standards are constantly changing and developing. If the above-mentioned problems cannot be solved reasonably and effectively in time, it will be detrimental to the current progress of concrete technology and scientific development. At the same time, it will have a greater impact on people's life safety.

What is the concept of concrete segregation?

The definition of concrete segregation: The segregation of concrete is that the cohesion between the components of the concrete mixture is insufficient to resist the sinking of the coarse aggregate, and the components of the concrete mixture separate from each other, resulting in the internal composition and structure Uneven phenomenon. It usually manifests as the separation of coarse aggregate and mortar from each other, for example, dense particles are deposited at the bottom of the mixture, or coarse aggregate is separated from the mixture as a whole. Definition of bleeding: The phenomenon in which coarse aggregate sinks and water rises during the transportation, vibrating, and pumping of concrete is called concrete bleeding. Bleeding is an important aspect of the workability of fresh concrete. Usually, the indicators describing the bleeding characteristics of concrete include bleeding amount (i.e., the average bleeding amount per unit area of ​​the concrete mixture) and bleeding rate (i.e., the ratio of the bleeding amount to the specific moisture content of the concrete mixture).

What is mortar bleeding during construction?

Bleeding refers to the upward movement of water after the concrete volume has been fixed but before it solidifies. Bleeding is a special form of concrete segregation.

The greater the water-cement ratio of concrete, the longer it takes for the cement to set and harden, the more free water, the longer the time for water to separate from the cement, and the easier it is for the concrete to bleed; too much additives are added to the concrete , or too much retarding component will cause a large amount of bleeding and precipitation of fresh concrete. A large amount of free water will leak out of the concrete surface, affecting the setting and hardening of the cement. The water retention performance of the concrete will decrease, leading to serious bleeding.

Does the segregated ash affect the strength?

The strength of segregated concrete will definitely be reduced. The extent of the impact depends on the situation of segregation. To ensure the strength of concrete, its workability and wrapping properties must be good, especially C60 concrete.

Generally speaking, the less water in the concrete, the drier and harder the fresh plastic concrete is and the smaller the slump, the smaller the possibility or tendency of segregation, but it does not necessarily mean that segregation will not occur.

Just after mixing, the sand, stones, cement and water in the concrete are relatively evenly distributed. However, during the transportation and pouring of fresh plastic concrete, due to the different proportions of various materials, the proportion of stones Large particles with large particle sizes are easy to sink, and water with the smallest specific gravity is easy to float, which may cause stratification and segregation, that is, high moisture or even bleeding on the top, and high stone content on the bottom. Especially for high-fluidity concrete, delamination and segregation are very prone to occur during the vibration process.