Contents of this article
-
How to use concrete antifreeze correctly?
-
What are the regulations for the use of concrete antifreeze?
-
How much antifreeze should be added to 10 cubic meters of concrete?
-
How many kilograms of antifreeze should be added to a square of concrete?
-
How much antifreeze should be added to C25 concrete?
-
C30 antifreeze concrete ratio?
-
How to add antifreeze to road construction?
-
What are the antifreeze measures for concrete?
How to use concrete antifreeze correctly?
Usage and dosage
1. Dosage: add 2-4% of the cement weight.
2. Before mixing, rinse the mixer with hot water or steam. First add sand, gravel and hot water and stir for about 1 minute, then add cement and antifreeze and stir for 3 minutes. The temperature of the mixing water is determined by ensuring that the temperature of the concrete entering the mold is ≥10°C.
3. Minimize water consumption while ensuring normal construction workability; because as the amount of free water in concrete increases, the frost resistance will significantly decrease. The concrete mixture mixed with antifreeze is dry but not hard. Pay attention to control the slump of the newly poured concrete not to be too large.
4. Sand and stones should be covered with canvas or plastic sheeting to prevent the sand and stones from freezing. The cement must not be heated directly and should be transported to a greenhouse for storage one day before use to keep it at a positive temperature.
5. Before pouring concrete, the ice, snow and dirt on the formwork and steel bars should be removed. However, steam must not be used to melt ice and snow directly to avoid refreezing. Timely remove the concrete residue adhering to the container and remove the ice, snow and frozen blocks in time. The container must be tightly covered after use to keep it warm. The exposed surface of newly poured concrete should be covered with plastic film and insulation materials in time, and cured under negative temperature conditions. The concrete should not be watered. Work continuously in accordance with the principles of pouring, vibrating and covering.
6. For cement, use Portland cement or ordinary Portland cement with a strength grade of 32.5 or above. Sand and stones must be clean and sieved, and must not contain ice, snow and other frozen substances and substances that are easy to freeze and crack.
The mixing of concrete mixed with antifreeze should comply with the following regulations
1. Strictly control the amount of antifreeze;
2. Strictly control the water-cement ratio, by The moisture brought into the aggregate and the water in the antifreeze solution should be deducted from the mixing water;
3. Before mixing, rinse the mixer with hot water or steam, and the mixing time should be extended by 50% compared to normal temperature;
4. The exit temperature of concrete mixture mixed with antifreeze shall not be lower than 15℃ in severe cold areas; and shall not be lower than 10℃ in cold areas. The mold entry temperature shall not be lower than 10°C in severely cold areas and shall not be lower than 5°C in cold areas.
The curing of concrete mixed with antifreeze should comply with the following regulations
1. When curing under negative temperature conditions, watering is not allowed. After concrete is poured, plastic film and insulation materials should be used immediately. Cover, and insulation measures should be strengthened in severe cold areas;
2. The initial curing temperature shall not be lower than the specified temperature;
3. When the concrete temperature drops to the specified temperature, the concrete strength must reach the required temperature. Freezing critical strength; when the lowest temperature is not lower than -10°C, the compressive strength of concrete shall not be less than 3.5Mpa; when the lowest temperature is not lower than -15°C, the compressive strength of concrete shall not be less than 4.0Mpa; when the lowest temperature is not lower than At -20°C, the compressive strength of concrete shall not be less than 5.0Mpa;
4. After the formwork is removed, if the difference between the surface temperature of the concrete and the ambient temperature is greater than 20°C, it should be covered and maintained with insulation materials.
Notes
1. If this product becomes damp and agglomerates, there are two treatment methods: (1) crush it through a 0.315mm square hole sieve before use; (2) Dissolve liquid for use.
2. In addition to the transportation and pouring of antifreeze-added concrete, the requirements for concrete without antifreeze should be met. The surface should be covered with plastic film and insulation materials in a timely manner after pouring. For concrete mixed with antifreeze, the concrete mixer tank should be wrapped with an insulating jacket
What are the regulations for the use of concrete antifreeze?
The usage method is as follows: For construction at 0~ -5℃, 4~6% can be added. For construction at -5~ -10℃, 5~8% can be added at -10~ -15℃ Under construction conditions, 8~10% concrete antifreeze can be added. Early strength antifreeze uses special antifreeze materials, which can effectively reduce the freezing point of concrete and mortar and greatly improve the antifreeze performance of concrete and mortar at negative temperatures.
And it can increase the early strength of concrete and mortar by more than 80% without reducing the later strength, thereby ensuring that the strength is equally developed under positive and negative temperature conditions. The effect is remarkable.
How much antifreeze should be added to 10 cubic meters of concrete?
The correct proportion of C30 concrete and antifreeze is: 5% when the temperature is below 10 degrees Celsius, and 3% of the antifreeze when the temperature is below 5 degrees Celsius. The parameter is 3% – 5% of the cement dosage. Antifreeze concrete is a substance that hardens at negative temperatures and achieves expected performance under prescribed curing conditions and prevents moisture in the material from freezing at low temperatures.
Ensure the normal construction of concrete at negative temperatures 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. Allow the concrete to hydrate normally in a negative temperature environment of 0°C to -15°C; lower the freezing point and improve the early strength of the concrete.
How many kilograms of antifreeze should be added to a square of concrete?
Generally, the amount of antifreeze added is 5% of the concrete volume, which is closely related to the concrete strength and concrete volume. Adding antifreeze to concrete can ensure normal use of concrete at low temperatures. Of course, if you add antifreeze at the same time,��Water reducing agent and air entraining agent, the antifreeze effect will be better.
Generally, the antifreeze and water-reducing agent adulterated in commercial concrete contains a certain early strength component, and the dosage in winter is about 3.0-3.5% of the total cementitious materials, such as C30 total cement. If it is 380KG, the antifreeze should be mixed at 3.5%, which is 380*3.5%. As for the specific early strength component in the antifreeze, the admixture factory will adjust the proportion accordingly based on the test.
Concrete antifreeze is combined with winter application 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. The chloride-free salt avoids the corrosion of steel bars and improves the strength. Durability of concrete.
1. Dosage:
Liquid temperature -5 ~ -20℃, accounting for 2.0-5.0% of the cementitious material
Powder temperature -5 ~ – 20℃ accounts for 2.0-5.0% of cementitious materials
2. Function: Mainly used for commercial concrete, suitable for reinforced concrete, prestressed concrete and fly ash-mixed concrete.
How much antifreeze should be added to one side of C25 concrete?
Add 19 kg of antifreeze to each side of C25 concrete. Since the strength levels of concrete are different, the amount of cement is also different. Antifreeze should be added according to the amount of cement, which cannot be more than 5% of the cement amount. Generally, 3% to 4% of the cement amount is added. An admixture that can harden concrete at negative temperatures and achieve expected performance and sufficient anti-freeze strength under specified curing conditions. It is a substance that can prevent moisture in materials from freezing at low temperatures.
C30 antifreeze concrete ratio?
The correct proportion of C30 concrete and antifreeze is: 5% when the temperature is below 10 degrees Celsius, and 3% of the antifreeze when the temperature is below 5 degrees Celsius. The parameter is 3% – 5% of the cement dosage.
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.
Makes concrete hydrate normally in a negative temperature environment of 0℃ to -15℃; lowers the freezing point and improves the early strength of concrete.
Antifreeze can be divided into strong electrolyte inorganic salts (chlorine salts, chlorine salt rust inhibitors, chlorine-free salts), water-soluble organic compounds, and composites of organic compounds and inorganic salts. , Compound antifreeze.
It is divided into two categories: freezing point lowering type and surfactant type. Those that lower the freezing point include low-carbon alcohols, glycols and amides. Surfactant types can form a hydrophobic absorption film on the surface of materials, such as acidic phosphate ester amine salts, alkyl amines, fatty acid amides, organic acid esters, alkyl succinimides, etc. For example, if it is mixed into concrete for winter construction, it can harden the concrete at negative temperatures and reach sufficient anti-freeze strength within the specified time.
Extended information
Mechanism of action
The antifreeze component can change the liquid phase concentration of concrete, lower the freezing point, and ensure the existence of liquid phase in concrete at negative temperatures. The cement can still 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, reducing the damage stress to the concrete.
The air-entraining component introduces a certain amount of tiny closed bubbles to reduce frost heave stress.
The early strength component can improve the early strength of concrete and enhance its ability to resist freezing damage.
Rust inhibitors such as nitrite can prevent the corrosion of steel bars by chlorine salt to a certain extent, and have both anti-freeze and early strength effects.
How to add antifreeze to road construction?
According to the 4% to 6% dosage of cementitious materials in concrete, the specific dosage should be proportioned according to the requirements in the instruction manual. The adaptability of concrete antifreeze to use at temperatures above minus 10°C can ensure that fresh concrete quickly reaches the critical strength to resist frost damage, preventing concrete from suffering frost damage, and does not affect the later strength and other properties of concrete.
What are the antifreeze measures for concrete?
Anti-freezing can be carried out using the greenhouse method or the thermal storage method. In fact, it is to add some materials to the surface of the pouring block for heat preservation. After the concrete is constructed, it must be covered with insulation materials to prevent it from being exposed to the cold winter.
Antifreeze needs to be operated from two aspects:
Use antifreeze: Antifreeze can greatly reduce the freezing point of mixing water and prevent the freezing and expansion of water inside the concrete in the plastic state and early stage. , frostbitten concrete. </p