The influence of foaming agent bubble size and exudation rate on foam concrete quality

Synthetic blowing agent overview

The synthetic foaming agent used for concrete is a highly concentrated and efficient liquid used to produce lightweight foamed concrete. Foamed concrete is also called foamed lightweight concrete (CLC).

CLC concrete has great potential in the construction of honeycomb lightweight applications, and the use of the correct type of foaming agent will make a huge difference in product properties (such as the mechanical properties of concrete and its resistance, etc.). Synthetic foaming agents are chemical substances that reduce the surface tension of liquids and are widely used in the manufacture of blocks, bricks, CLC concrete, etc. worldwide. Compared with other foaming agents, when high density is required, it can be formed with less energy. It is strongly recommended for use in the construction industry, as the demand for lightweight concrete continues to increase over time.

Foam concrete foaming agent has an extremely important influence on the quality of foam concrete. High-quality foaming agents can be made into high-quality foamed concrete. The performance of the foaming agent for foamed concrete is not only related to the stabilization time and uniformity of the foam, but also related to the size and exudation rate of the bubbles.

The foam diameter of the foaming agent for foamed concrete should not be too large, it should be about 1mm

The hole has the same requirements for the diameter of the hole, and the diameter of the bubble should also be the same. Many manufacturers require the pore size of the foam to be as small as 0.1 mm. In fact, this is because if the physical foam has a large foam diameter, the stability of the foam is poor and foam concrete cannot be prepared. With the same raw materials and formula, the same equipment and technology, as long as the bubble diameter is changed, the compressive strength of foamed concrete with a bubble diameter of 1mm is at least 20% higher than that of foamed concrete with a bubble diameter of 0.1mm. Therefore, it is wrong to pursue a large bubble diameter of 0.1 mm or more. This is a misunderstanding in the production of foamed concrete and should be corrected.

The foam leakage rate of the foaming agent for foam concrete should be as low as possible, and the use of milky white foam should be avoided

According to the size of the water content, the foam is divided into milky foam with less water added and sponge foam with less water added. Among them, milky white foam is unqualified, and inferior foam cannot be used.

After the foam of the foaming agent for foamed concrete is produced, it will gradually seep water. Bleeding consists of two parts:

(1) Foam liquid film bleeding. This part of water is secreted from the liquid film, which is the water secreted by the liquid film under the combined action of gravity drainage, surface tension drainage and liquid film destruction drainage. The thicker the liquid film of the foam, the greater the exudation; the faster and more the foam bursts, the greater the exudation.

(2) There is water between the bubbles. This part is water, and no bubble liquid film is formed. The poorer the foaming performance of the foaming agent and foaming machine used for foamed concrete, the more water between the bubbles and the inability to form a foamed liquid film. They are actually water that cannot become bubbles.

When the exudation rate of the foam is high, it will be as thin as floating juice, turbulent, cannot accumulate, and the amount of water in the foam is very large. When this foam is added to the cement slurry, the cement slurry becomes very thin, but the foam is very small, the volume of the slurry is small, and the foamed concrete produced has a high density, which does not meet the technical requirements. Claim.

Therefore, milky white foam cannot be used. The appearance of the foam that meets the technical requirements should be sponge-like, small bubbles, pile up like white clouds, like bouncing cotton, and will not flow randomly. The water content of this foam is very small. This shows that the foam liquid film has almost no exudation, the foam is not easy to burst, there is almost no water between the bubbles, and the amount of bubbles is large, and most of them are bubbles. What needs to be emphasized here is that the sponge foam must be small bubbles with a bubble diameter of less than 1mm, not large bubbles with a few millimeters or even tens of millimeters. Large bubbles are easy to accumulate and look like white clouds, but because the diameter of the bubbles is too large, they are unqualified.

Low foam exudation is required to ensure the number of bubbles in the foam and the porosity of the foam concrete, which is to ensure the density of the foam concrete.

The foam of the foam concrete foaming agent has no side effects on the cementitious material

Cementitious materials are the main source of foam concrete strength. Adding the foaming agent used for foamed concrete will not affect its gelation effect, that is, it will not produce negative gelation effect. This cannot be achieved through various bubbles.

In long-term tests, we found that many foams hinder the gelation of cement, magnesite and gypsum, thereby reducing the strength of foamed concrete, and sometimes even hardened concrete basically loses its strength. The stability of these foams is very good. It lasts for several hours. It looks like a sponge, has less bleeding, and has a uniform density. It meets all technical requirements, but is not compatible with cementitious materials, so it cannot be used in production. This shows that foam that is qualified in other aspects (such as impact strength) is ultimately not a technical requirement.

Application of synthetic blowing agent

1. Foaming agent is used to make lightweight (clc) blocks and panels;

2. Blowing agent is used to fill the gap;

Foamed concrete is also very useful for filling voids. Because of its high mobility, it can even be poured into the most inaccessible places. It can be used for planned work, and can quickly provide stability and support in emergency situations;

3. Foaming A gentleman is used for roof insulation;

4. Foaming agent is used to mark CLC blocks, cast-in-place walls, bridge reinforcement wall structures, floor structures, lightweight prefabricated blocks, fire protection, sound insulation, etc.

Synthetic blowing agent price

The price of synthetic blowing agent will vary randomly with the production cost of synthetic blowing agent, transportation cost, international situation, exchange rate and market supply and demand. Tanki New Materials Co., Ltd. aims to help all industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full set of customized services. If you are looking for synthetic blowing agent, please feel free to send an email to get the latest synthetic blowing agent prices.

Synthetic blowing agent suppliers

As a global synthetic blowing agent supplier, Tanki New Materials Co. Ltd has extensive experience in the performance, application and cost-effective manufacturing of advanced and engineered materials. The company has successfully developed a series of foam concrete additives (including lightweight concrete, CLC blocks provide concrete foaming agents, superplasticizers, foam concrete strength enhancers, etc.), oxides, nitrides, high-purity targets, functions Ceramics and structural devices, and provide OEM services.