Contents of this article
What are the main components of concrete antifreeze?
What are the ingredients of concrete antifreeze?
What is the role of propylene glycol in concrete?
At what temperature is antifreeze usually used on concrete?
What is the effect of calcium nitrate on concrete?
What are the types of concrete antifreeze?
What are the main antifreeze components in concrete antifreeze?
What are the main components of concrete antifreeze?
Concrete antifreeze has different uses and different ingredients. Antifreeze is divided into chlorine-containing salt type, chlorine salt rust-inhibiting type, chlorine-free high-alkali type and chlorine-free low-alkali type.
Antifreeze consists of antifreeze component, early strength component, water reducing component, air entraining component and activation component.
The ingredients of early-strength concrete antifreeze include sodium sulfate, sodium chloride, sodium nitrite, calcium lignosulfonate and naphthalene series high-efficiency water reducing agent.
What are the ingredients of concrete antifreeze?
The main ingredients of concrete antifreeze are: sodium sulfate, sodium chloride, sodium nitrite, calcium lignosulfonate and naphthalene series superplasticizer.
Antifreeze concrete is a substance that hardens at negative temperatures, achieves expected performance under specified curing conditions, and prevents moisture in the material from freezing at low temperatures. Ensure the normal construction of concrete under negative temperature and reduce the freezing point in the concrete mixture. It can be combined with water-reducing agent, air-entraining agent, etc. to achieve better antifreeze effect. Used for various concrete projects and during construction in cold seasons.
Making concrete hydrate normally in a negative temperature environment of 0℃ to -15℃; lowering the freezing point and improving the early strength of concrete. The lower the concrete is used, the better the antifreeze effect of the antifreeze. The more time (including negative temperature zone) there is to increase the strength, the possibility of reaching the critical strength of frost resistance is greatly increased.
The antifreeze component can change the liquid phase concentration of concrete, lower the freezing point, and ensure that the liquid phase exists in the concrete at negative temperatures, so that the cement can continue to hydrate. The water-reducing component can reduce the water consumption for concrete mixing, thereby reducing the amount of ice in the concrete, making the ice crystals finer and evenly dispersed, and reducing the damage stress to the concrete. The air-entraining component introduces a certain amount of tiny closed bubbles to reduce frost heave stress.
What is the role of propylene glycol in concrete?
Propylene glycol is used as a raw material for epoxy resin, tackifier, surfactant, demulsifier and desulfurizer. Propylene glycol can also be used as concrete antifreeze and a heat carrier. Propylene glycol is not the main raw material of saturated polyester, epoxy resin, and polyurethane resin. The usage of these accounts for about 45% of the total consumption of propylene glycol. This type of unsaturated polyester is often used in surface coatings and elastomer materials. .
At what temperature is antifreeze usually used on concrete?
When concrete antifreeze is constructed at 0~ -5℃, 4~6% can be added; when constructed at -5~ -10℃, 5~8% can be added; -10~ - For construction at 15℃, 8~10% can be added. The lower the service temperature of concrete, the better the antifreeze effect of the antifreeze. The concrete has more time (including negative temperature areas) to grow in strength, thereby greatly increasing the possibility of reaching critical anti-freeze strength. The usage standard is the dosage corresponding to the temperature. The temperature is above zero within 24 hours, and then below minus 2°. It has little effect on the concrete, but the concrete surface should be covered with insulation materials.
What is the effect of calcium nitrate on concrete?
Calcium nitrate plays a role in promoting hardness, early strength and antifreeze in concrete. When used as antifreeze, it can be used in combination with calcium nitrite and sodium sulfate. They do not react with each other and all interact with the mineral components in cement. However, these were all used in the early 1970s and 1980s. Now with the emergence of new admixtures such as high-efficiency water reducing agents, they are basically no longer used.
What kinds of concrete antifreeze are there?
Concrete antifreeze can be divided into strong electrolyte inorganic salts (chlorine salts, chlorine salt rust inhibitors, chlorine-free salts), water-soluble organic compounds, and compounds of organic compounds and inorganic salts according to their ingredients. Class and compound antifreeze.
—Chlorine salts: additives using chlorine salts (such as sodium chloride, calcium chloride, etc.) as antifreeze components;—Chlorine rust inhibitors: containing rust inhibitor components and using chlorine salts Admixtures that are antifreeze components: - Chlorine-free salts: admixtures that use inorganic salts such as nitrite and nitrate as antifreeze components; - organic compounds: some alcohols, urea and other organic compounds are used as antifreeze components - Compound antifreeze: an antifreeze component combined with early strength, air entrainment, water reduction and other additives. Concrete antifreeze is combined with winter temperature conditions, which can accelerate the condensation and hardening of concrete under negative temperature conditions. The strength increases significantly and does not affect the later strength development. Chloride-free salt avoids corrosion of steel bars and improves the durability of concrete. 1. Dosage: liquid temperature -5 ~ -20℃, accounting for 2.0-5.0% of the cementitious material; powder temperature -5 ~ -20℃, accounting for 2.0-5.0% of the cementitious material; 2. Function: mainly used for commercial concrete. Suitable for reinforced concrete, prestressed concrete and fly ash-mixed concrete.
What are the main antifreeze components in concrete antifreeze?
Laxatives and antifreeze are usually sodium sub-basin, which is usually added to the admixture. This also lowers the freezing point of the admixture and makes it less likely to be frozen. In addition, it is recommended that the finished concrete can also be insulated. Sodium oxide accounts for about 5% of the admixtures, and the admixture parameters are generally 1%. Overall, sodium oxide accounts for about 5% of the admixtures.The ratio is less, so it is best to take insulation measures.
In addition, the hydration crystallization of concrete needs to overcome a certain energy barrier. If the insulation measures are not done well, the heat will dissipate quickly, which is not conducive to hydration. </p
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