Water-reducing agents are often used in the preparation of concrete and are commonly used admixtures. However, in the process of use, water-reducing agents can easily cause foam problems. Air bubbles easily affect the quality of concrete and the effect after construction. Therefore, it is necessary to add a polycarboxylic acid water reducer defoamer to treat the foam.
lCauses of foaming during the application of water reducing agent
The application of water reducing agent can easily cause bubbles in concrete. There are many reasons for concrete foaming, mainly due to the application of admixtures and mixing technology. Concrete foaming is mainly caused by the following reasons:
1. In the configuration of concrete, water reducer and other admixtures are often added to improve its performance. In the process of adding water-reducing agent, it will often strengthen the performance of concrete together with other chemical additives. Many of these chemical auxiliaries are surfactants, which have air-entraining effects and easily lead to foam generation and stability. Secondly, the reaction occurs during manual stirring and mixing or the operation of the machine, which will cause its chemical instability and fail to reach the chemical equilibrium state in chemistry, which will lead to the production of foam.
2. It is related to the equipment form and time of concrete production mixing and transportation
The mixing time is unreasonable, and the short mixing time will cause uneven mixing and different density of bubbles. However, if the mixing time is too long, more air bubbles will be introduced into the concrete. Due to the long transport distance, excessive air bubbles will also be introduced during the mixing process of the concrete by the concrete truck.
3. Improper selection of release agent
Some construction units continue to use the old release agent, and often use the waste engine oil recovered from the machinery factory. This waste engine oil has a strong adsorption of air bubbles. When air bubbles in the concrete come into contact with it, they will be adsorbed on it. The mold is formed on the surface of the concrete structure, especially when the temperature is low, the use of this release agent is not conducive to the discharge of air bubbles. There are also some release agents, even if they are water-based release agents, they still have the effect of adsorbing the air bubbles generated in the concrete, so that the air bubbles in the concrete cannot rise with the mechanical vibration and gradually rise with the contact surface of the formwork, so that they cannot be discharged from the inside of the concrete. The resulting bubbles. Uneven application of mold release agent during on-site construction will also cause an increase in air bubbles.
(Pic: Water-reducing agents)
The foam produced by concrete will seriously affect the density and quality of concrete, and affect its durability and strength. In some tofu dregs projects, concrete blistering is also one of the reasons. The common solution is to add defoamer.
lNanhui compound defoamer solution
Defoamers are mainly used to eliminate foam by chemical defoaming methods, and are widely used in textile printing and dyeing, water-based coatings, adhesives, paper production and other industries. Many industries are prone to foam during the production process, which is mainly related to the formulation and production process. For example, the textile printing and dyeing industry usually needs to add softeners, bleaches, and dispersants to ensure the good performance of good textile printing and dyeing products. , Thickeners and other additives, many of which are surfactants. In some high-speed mixing processes, it is easy to produce a large amount of foam, and this type of foam is very stable and difficult to eliminate by itself, which not only affects the printing and dyeing products The quality, color, color uniformity and so on. Have a negative impact on the quality of the product.
In the preparation of concrete, in addition to the base material, water-reducing agents and other admixtures are also added to improve its performance, and for other reasons, it is easy to cause air bubbles in the concrete and affect its quality. Harmful bubbles need to be controlled as soon as possible. The problem can be solved by a defoamer for polycarboxylic acid water reducer.
(Pic: Water-reducing agents defoamer)
However, defoamers have certain pertinence. Some defoamers have obvious effects in textile printing and dyeing, but they may not be effective when used in water reducers. At this time, you must choose a targeted defoamer!
Nanhui defoamer manufacturer integrates production, research and development, and provides one-to-one solutions. According to the customer's application field, use environment, and defoamer requirements, research and development tests can be carried out based on samples to develop compound defoamers.
Nanhui compound defoamer has the following advantages:
1. On-demand research and development, targeted at design, with obvious defoaming effect;
2. Concentrated formula, high concentration, small dosage, and high cost performance;
3. Good defoaming stability, acid and alkali resistance, high temperature resistance, and continuous defoaming under harsh conditions.
