Collection, detailed explanation of 6 concrete admixtures

Concrete admixtures have long become an indispensable component of concrete. Concrete admixtures play an important role in improving the characteristics of fresh concrete and hard-primed concrete. However, concrete admixtures need to be used rationally otherwise they may cause safety accidents. Anhui Yulong New Material Technology Co., Ltd. lists several commonly used admixtures for you:

Water reducing agent

Water reducing agent plays the role of adsorption, dispersion, lubrication and moisture cooling in concrete. Generally, water reducing agents should be used in concrete with a daily minimum temperature of around 5°C. High-efficiency water-reducing admixtures can be used for foundation cushions, reinforced concrete, and prestressed concrete, and can be used to produce high-toughness concrete. Standard high-efficiency water-reducing admixtures are suitable for use in concrete with a daily minimum temperature of 0°C, and are also suitable for construction. Can be used to steam cure concrete. Polycarboxylate-based characteristic water reducing agent is suitable for use in high-toughness concrete, concrete pumping, fair-faced concrete, concrete engineering and seamless pipe concrete, concrete with high performance indicators or high workability requirements.

Setting regulating agent

Setting regulating agent mainly produces the desired effect of concrete by changing the setting time of concrete. Retarder is suitable for concrete that slows down the setting time, concrete that requires a certain ability to maintain slump, has a long static time or is transported over long distances, self-compacting concrete, and can be used for large volumes of concrete; it is not suitable for use with premature slump. Concrete with strong requirements; and retarder such as sodium citrate (sodium) and tartaric acid (potassium sodium) should not be used alone in poor concrete. When the retarder containing multiple components of glycogen is used in combination with the water-reducing agent, it is necessary to Compatibility test can only be used after passing the test.

Air-entraining agent

Air-entraining agent is an admixture that introduces gas into the concrete mix during the mixing process to form many tiny, closed and stable bubbles. The ingredients of most air-entraining agents are rosin and various sulfonates, such as sodium alkyl sulfonate and sodium alkyl benzene sulfonate, which play an important role in foaming in concrete. It is mainly suitable for use in concrete that requires resistance to freeze-thaw cycles, concrete pumping, and concrete that is prone to bleeding; it is not suitable for steam-cured concrete and prestressed concrete.

Rust inhibitors

Rust inhibitors can be divided into two categories: analytical chemistry and inorganic compounds according to their important components. For concrete mixes, most inorganic compound rust inhibitors greatly improve the cohesion, and the damage to the concrete setting process is similar to that of early strength agents; chemical rust inhibitors have the effect of mitigating the chemical reaction of concrete mixes. For hard-primed concrete, if Ca(NO2)2 rust inhibitor is added, the tensile strength of the concrete in the early and late stages will be significantly improved; it is suitable for use in reinforced concrete and prefabricated concrete in corrosive geographical environments that easily lead to corrosion of building steel. Stressed concrete and steel fiber concrete, prestressed grouting, as well as new concrete work and rehabilitation building projects.

Antifreeze

Concrete antifreeze can ensure sufficient high-efficiency liquid phase in the concrete mix at negative temperatures to facilitate the resumption of the coagulation performance of the concrete. Admixtures that can improve the strength of concrete after warming; its antifreeze components are divided into organic compounds (certain hydrocarbons, automotive urea) and inorganic salts (sodium nitrite, polyphosphate, carbonates, chlorides). At present, most concrete antifreezes are composite types, such as concrete antifreezes that are composed of antifreeze multi-components and early strength, air entrainment and water reduction multi-components. Mainly used for concrete in winter construction measures building construction.

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