In short, water-reducing agent has the effect of reducing water consumption and can increase the strength of concrete. It is also a building material admixture that saves cement consumption. However, because it is a surfactant, it is easy to produce foam during the mixing process. Foam will affect the strength and firmness of concrete components, so it is necessary to add water reducing agent defoamer to defoam the foam.
(Picture: Application of defoamer in water reducer)
Cause analysis of foaming of water reducing agent
Water reducer is one of the commonly used admixtures in the building materials industry. Adding an appropriate amount of admixture to concrete can improve concrete quality, improve concrete performance, reduce concrete water consumption, save cement, reduce costs, and speed up construction progress.
With the advancement of technology, admixtures have become the fifth necessary material besides cement, coarse and fine aggregates, admixtures and water. Admixtures are an important measure to optimize the design of concrete mix ratio and improve concrete durability. . Therefore, the newly revised "Hydraulic Concrete Construction Specification" (DL/T5144-2001) emphasizes that the hydraulic concrete must be mixed with appropriate additives.
Although admixtures can enhance or improve the performance of concrete, they can easily cause foam problems. The main reasons for concrete foaming are as follows:
1. It is related to the characteristics of additives such as water reducer
Common water-reducing agents on the market have a certain air-entraining effect, and different types and dosages will affect the number and size of bubbles, and the larger the dosage, the more obvious the effect. For example, polycarboxylic acid water-reducing agent, its water-reducing component itself has a certain air-entraining effect, the content and quality of bubbles introduced into concrete are unstable, mainly-some large harmful bubbles will affect concrete performance. Only the concrete air content test cannot prove the number and size of the bubbles introduced. When the air content meets the requirements, harmful bubbles may also be introduced, which is not good for the strength and durability of concrete.
2. The aggregate gradation of concrete is unreasonable
Unreasonable material grading, too much coarse aggregate, improper size, crushing According to the principle of granular gradation and compaction, during the construction process, the content of flake particles in the stone group is too much, and the actual use of sand ratio in the production process is higher than the laboratory The provided sand rate is too small, so that the fine stone forest drinking period, the space, the derivative granules are not dense, forming a free air barrier, which provides conditions for the generation of gas.
3. The slump is too small or too large
The slump of the concrete mixture should be as low as possible when the slump is less than 12cm. Generally, it is not easy to exhaust when the slump is 120~10. At the same time, when the vibrating process is easy, it is easy to form phase aggregate segregation, and it is not easy to vibrate. Dense, the lake falls more than 2m layered.
The hazard of foaming of water-reducing agent admixture: Excessive foam in concrete will affect the density of concrete components, resulting in a decrease in the performance of water-reducing agent, and affecting the quality of concrete products and construction effects.
(Picture: Cause analysis of foaming in concrete system)
Water reducing agent defoaming formula
Hazardous foam needs to be controlled and treated in time to avoid negative harm to the quality of concrete components. A common treatment measure is to add a defoamer, which is an auxiliary agent used in industry to eliminate harmful foam. For example, defoamer is used in the paper industry to eliminate pulp foam in time and prevent foam from affecting the formation of paper. , To prevent bubbles from causing paper holes, etc.; in the coating industry, defoamers can eliminate bubbles in the coating system in time, thereby preventing large amounts of foaming in the coating film, causing shrinkage after construction, fish eyes and other defects.
Defoamers can eliminate large and small bubbles, as well as foams caused by internal and external reasons. Antifoams are not only effective in papermaking and coatings, but are also used in the building materials industry, such as: cement, gypsum, asbestos tiles, concrete, mortar , Cement mortar, etc. The defoamer can eliminate foam in concrete and other systems and make concrete components more dense.
Here is a special reminder to all manufacturers, if you encounter foam problems such as water reducers, you can find professional manufacturers to design targeted defoamers to solve the foam problem for you.
Nanhui defoamer is a professional manufacturer of defoamers, with a wide range of formulas, with thousands of defoaming formulas, and more than 30 industry defoaming application experiences. Corresponding defoaming formulas can be designed according to customer needs. Strong pertinence and good application effect.
(Picture: Comparison of water reducing agent and defoamer before and after defoaming)
The water-reducing agent defoamer designed by Nanhui defoamer engineers has the advantages of stable defoaming, high temperature resistance and acid-base environment, and can easily eliminate foam in concrete, water-reducing agent, mortar and other systems. In addition, we provide customized services on demand. The designed defoamer is ideal for defoaming and has good application effects.
Nanhui is a manufacturer with years of application experience. It has far more defoaming technology than other antifoaming agents in the market. From the above cases, we prove the strength of our Nanhui defoamer. We have a group of excellent defoaming engineers, and an independent laboratory that facilitates defoaming experiments with foams that are difficult for customers to solve. If you want to know more about defoamer products, you can call our hotline: +86 13428601010.
This article is from the manufacturer of Nanhui defoamer (http://www.nhdefoamer.com/), please indicate the source if you need to reprint.
