In the process of concrete production and construction, it is necessary to fully consider the interaction between admixtures and other raw materials, mix ratios, climate and construction conditions to prepare concrete that meets performance requirements. Differences in concrete performance requirements and raw material sources mean that there is no best, only the most suitable admixture. Only by choosing appropriate concrete admixture products with stable performance can the effect of admixtures be fully exerted.
1. The type and dosage of admixtures should be determined through tests based on the cementitious materials used in the project;
2. The impact of admixtures on the shrinkage and other properties of hardened concrete should be provided;
3. For large-volume concrete with high durability requirements or in cold areas, air-entraining agents or air-entraining water-reducing agents should be used.
4. The quality and application technology of the admixtures used should comply with the current national standards “Concrete Admixtures” GB 8076, “Technical Specifications for the Application of Concrete Admixtures” GB 50119 and relevant environmental protection regulations.
5. The quality of mixing water should comply with the relevant provisions of the current national standard “Concrete Water Standard” JGJ 63.
Concrete admixtures are widely used in industry. Admixtures can be used as high-efficiency chelating agents, steel surface cleaners, glass bottle cleaners, and electroplating in industries such as construction, textile printing and dyeing, metal surface treatment, and water treatment. Industrial aluminum oxygen coloring, used as high-efficiency retarder, high-efficiency water-reducing agent, etc. in the concrete industry.
Concrete admixtures are used as cement admixtures:
After adding a certain amount of admixtures to cement, the plasticity and strength of concrete can be increased and have a blocking effect
That is to postpone the initial and final solidification period of concrete. For example, adding 0.15% admixture can extend the initial solidification time of concrete by more than 10 times, that is, the plasticity time of concrete can be extended from hours to days without affecting its fastness. Plasticity and delaying the initial setting time are very important issues in concrete operations. For example, in high-temperature season construction and large-scale engineering operations, delaying the initial setting time is a problem. Admixtures can successfully solve this problem. In addition, it is difficult to glue oil wells at high temperatures. Concrete with added admixtures becomes plastic within a few hours at a high temperature of 170°C, so the above problems can be satisfactorily solved. Therefore, sodium gluconate as a cement admixture has been widely used in important construction projects abroad, such as a large number of bridge projects in the Middle East. However, the application in this area has not yet been promoted in our country. It is said that sodium cellulose sulfonate is extracted from papermaking wastewater, and its effect is not comparable to that of admixtures.
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