Foam concrete is a kind of concrete with lightweight and has ideal strength. Because of the hollow structure in foam concrete, it has the function of absorbing heat and isolating sound.
The density of foamed concrete is 300-1200 kg/m3, and the thermal conductivity is between 0.08-0.3W/ (m ·K).
Foam concrete is widely used in CLC blocks, lightweight partition panels, roof insulation, floor cushion construction, floor heating backfilling, and other occasions.
At the same time, foam concrete is also a good sound absorption material, which can be used in highway sound insulation boards, sound absorption boards, and other fields.
Generally speaking, foam concrete is a kind of building material with multi-function, environmental protection, and economy, which has a wide application prospect.
What is a water-based defoamer?
Water-based defoamer is mainly used for foam treatment in water-based systems such as water-based coatings and water-based inks. Easy to operate, with excellent defoaming and anti-foaming performance.
Waterborne defoamer an emulsion made of dimethyl silicone oil, silica, emulsifier, etc. It has efficient defoaming performance and remarkable anti-foaming effect. For foam treatment, it is not only to quickly and thoroughly eliminate foam, but also to inhibit foam production for a long time in the foaming system, water-based defoamer can achieve these two requirements. In addition to the excellent performance of defoaming and antifoaming, the defoamer also has the advantages of being used in high temperature environment, rapid dispersion in foaming system, good compatibility with foaming system, low cost, wide range of scenes and so on.
Different types of waterborne defoamers
Silicone defoamer: strong defoaming performance, relatively heat-resistant, but also antioxidant, but the foam inhibition time is not very long, if necessary, can be used with other ingredients of defoamer. Because of its easy access to raw materials and low price, it is widely used in the paper industry.
Defoamer of polyether composition: this kind of defoamer is also very suitable for high temperature environment, excellent anti-foaming performance, strong dispersion in water and widely used.
Mineral oil composition of defoamer: here a kind of defoamer is mainly can not use silicone defoamer industry use more, will not produce silicon spot, defoaming and anti-foaming ability are also quite outstanding, but the addition amount is slightly more.
The more waterborne defoamers are added, the better the effect will be?
As a kind of emulsion, the defoaming performance of waterborne defoamer is not related to its concentration, but may not be good if it is added too much. For most industries, thinner defoamers will have better defoaming effect, because dilution defoamers are easier to disperse in water, dissolve faster and defoamer faster.
Concrete Additives Supplier
TRUNNANO is a reliable concrete additives manufacturer with over 12-year experience in nano-building energy conservation and nanotechnology development.
If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)
We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
Powder defoamer is a solid powder defoamer. Powder defoamer is often used in the building materials industry, which can more quickly eliminate the foam problems caused by technological problems in the construction industry. It is a kind of industrial production additive with good defoaming and anti-foaming effect.
According to its main composition, different type of powder defoamer has different functions:
1. The powder defoamer, which is mainly composed of polymer and organosilane, is often used for defoaming in spray coating process.
2. The high efficiency powder organosilicon defoamer formed by silicone polyether graft copolymerization can be used for foam produced in the process of oil field drilling, delayed coking and oil-water separation.
3. The powder defoamer, which is mainly composed of liquid hydrocarbons, polyethylene glycol and non-crystalline silicon dioxide, is mainly used in the defoaming of grouting material, water reducer, putty powder and so on.
4. The powder polyether defoamer is mainly composed of special modified polyether. It is mainly used for defoaming of all kinds of mortars (such as building mortar, dry powder mortar, dry mixing mortar, gypsum mortar, oil field cementing mortar, etc.), coating, papermaking, water reducer, putty powder, desulphurization and so on. It is also the most widely used and most commonly used powder defoamer.
How to use powder defoamer?
The powder defoamer was dissolved in water and then added to the foaming system several times. Or put the powder defoamer into a cloth filter bag, divide it into several pieces and put it into the foaming system. It is necessary to control the dilution of powder defoamer dissolved in water.
Concrete Additives Supplier
TRUNNANO is a reliable concrete additives manufacturer with over 12-year experience in nano-building energy conservation and nanotechnology development.
If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)
We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
1. Adopt a suitable mixing method
In the process of concrete mixing, the mixing method of admixture has a great influence on the effect of admixture. For example, the mixing method of superplasticizer is generally divided into first mixing method (adding before mixing water), same mixing method (adding at the same time with mixed water), stagnant method (adding superplasticizer lagging behind water 1~2min in the mixing process), and later mixing method (after mixing, it is added to the concrete mixture with a certain content for a certain time after a certain period of time, and then mixed for 2 or more times). Different mixing methods will bring different effects, and different varieties of superplasticizers have different mixing methods because of their different action mechanisms. For example, for naphthalene series superplasticizer, in order to avoid the selective adsorption of C3A and C4AF mineral composition of cement, the later mixing method is better, such as wood calcium superplasticizer, because its action mechanism is macromolecular protection, so the effect of different mixing methods is not significant. The main factors affecting the mixing method of superplasticizer are the variety of cement, the type of superplasticizer, the amount of superplasticizer, the time of adding and other compound admixtures, etc. Which method should be determined by the specific conditions of trial mixing and engineering.
2. Adjust the mix proportion of concrete
Generally speaking, the admixture has no special requirements on the mix ratio of concrete and can be designed according to the common method. However, in the case of reducing water or saving cement, the sand ratio, cement dosage and water-cement ratio should be properly adjusted.
Sand ratio
Sand ratio have great influence on the workability of concrete. Due to the great improvement of the properties after adding superplasticizer, the sand ratio can be reduced appropriately. The reduction is about 1% 4%. For example, the lower limit of wood calcium is 1% 2%, and the upper limit of air-entraining superplasticizer is 3% 4%. If the sand ratio is on the high side, the reduction range can be increased, and the excessive sand ratio not only affects the strength of concrete. it also brings some difficulties to the molding operation.
The amount of cement
The superplasticizers used in concrete have the effect of saving cement in varying degrees. The use of common superplasticizer can save 5%-10%, and efficient water-reducing can save 10%-15%. Using high-grade cement to prepare concrete, adding superplasticizer can save more cement.
Water-cement ratio
The water-cement ratio of concrete mixed with superplasticizer should be determined according to the water-reducing rate of the variety. It turns out that the water reduction rate of those with large water-cement ratio is also higher than that of those with low water-cement ratio. In order to keep the slump the same after saving cement, the water-cement ratio should be the same as that without saving cement or increase by about 0.0.1 to 0.03.
3. Pay attention to the construction
For example, in the process of stirring, the amount of superplasticizer and water should be strictly controlled, and the appropriate mixing method and mixing time should be selected to ensure that the superplasticizer works fully. There should be different points for attention for different mixing methods, such as the water reducer used in dry mixing should have enough fineness, the powder is too thick and the dissolution is uneven, the effect is not good; after mixing or dry mixing, the mixing time must be extended above 1min.
The slump loss of concrete mixed with superplasticizer is generally faster, so the transportation and parking time should be shortened, otherwise the slump protection measures should be increased.
In the process of transportation, attention should be paid to maintaining the homogeneity of concrete and avoiding delamination, and attention should be paid to the delay of initial setting time when adding retarding superplasticizer. For example, if the Chinese and foreign admixtures of steam-cured concrete are not used properly, there will be quality problems such as bulging, cracking and loosening on the surface of steam-cured concrete, and the strength will also decrease significantly, so we should pay attention to the following problems in steam-cured concrete: select suitable admixtures, such as air-entraining admixtures, not suitable for use, control the amount of admixtures, have a certain pre-curing period and rising temperature period, and determine the constant temperature and time through experiments.
4. The construction performance and hardening performance of concrete with strengthening curing and adding admixtures are very different from those of concrete without admixtures, some prolong the setting of concrete, and some increase rapidly in early strength. most admixtures increase the shrinkage of concrete, while expansive agents expand the volume of concrete. Therefore, concrete mixed with admixtures should pay more attention to curing. Keeping concrete curing in wet conditions is the key condition for concrete to meet the design requirements and an important step to avoid concrete cracking.
Concrete Additives Supplier
TRUNNANO is a reliable concrete additives manufacturer with over 12-year experience in nano-building energy conservation and nanotechnology development.
If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)
We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
1. Choose suitable admixture according to engineering characteristics
Admixtures can be used for almost all kinds of concrete, but suitable admixtures must be selected according to engineering needs, construction conditions and construction technology. For example, ordinary superplasticizer is mainly used for general concrete, superplasticizer is used for early strength and high strength concrete, water reducer with high air entraining property is mixed with water reducer when air temperature is low, single retarding superplasticizer is generally not used, compound early strength superplasticizer is often used, in order to improve the water resistance of concrete, waterproofing agent is used, pumping agent should be used when pumping concrete is used in high-rise buildings, in order to give full play to the characteristics of various admixtures. Should not be substituted for each other. At the same time, the admixture has the problem of adaptability to different cement, which must be tested and controlled in use.
2. The quality of admixtures
Admixtures must be tested according to the standard before use, and only the admixtures that meet the requirements of the standard can be used to prepare concrete.
3. The types of cement
Among the raw materials, cement has the greatest influence on the admixture, and the water-reducing and strengthening effects of superplasticizers are different with different types of cement, especially on the water-reducing effect. Superplasticizer is more selective to cement, and the water reducing rate of different cement varies greatly. Cement mineral composition, admixture, pour point regulator, alkali content, fineness and so on will affect the effect of superplasticizer. For example, the cement mixed with anhydrite will produce quick hardening for some concrete mixed with superplasticizer or greatly shorten the initial setting time of concrete, in which naphthalene superplasticizer has little effect, molasses will cause quick hardening, and wood calcium will prolong the initial setting time. Therefore, the effect of the same kind of superplasticizer is obviously different because of different cement under the same dosage. In some cement, some superplasticizer will cause abnormal setting phenomenon. For this reason, when cement is available, the cement that is more suitable for superplasticizer should be selected to improve the effect of superplasticizer. When the superplasticizer is available, the more suitable superplasticizer for construction cement should be selected. in order to make the superplasticizer play a better effect, cement selection test should be carried out in combination with the project before use.
4. Carry out the test before use
In order to ensure the engineering quality, according to the existing standards, for example, the homogeneity test should be carried out before the superplasticizer is used, and the water reducing rate and solid content (moisture content) should be determined, and then the concrete should be tested, such as testing the performance of the superplasticizer concrete, slump, water reducing rate, air content and compressive strength should be measured.
5. Pay attention to the content
Each admixture has a suitable amount, even if the same admixture, different uses have different appropriate amount. If the mixing amount is too large, it is not only economically unreasonable, but also may cause quality accidents. For the superplasticizer with air entrainment and retarding effect, special attention should be paid not to over-dosage. If the amount of wood calcium is more than 0.5% of the weight of cement, excessive air will be introduced to slow the initial setting and reduce the strength of concrete. If the dosage of superplasticizer is too small, it will lose its high efficiency, while if the dosage is too large, the quality will be affected by water secretion. The limitation of chloride salt is well known, and excess will cause steel bar corrosion. The amount of antifreeze is related to temperature, and it is stipulated according to the effect of strength. in short, there are many factors that affect the amount of admixture, such as the method of adding water reducer, the variety of cement, the initial popularity of the mixture and the curing system, etc.
Concrete Additives Supplier
TRUNNANO is a reliable concrete additives manufacturer with over 12-year experience in nano-building energy conservation and nanotechnology development.
If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)
We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
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