Classification of concrete water-reducing agents. Concrete admixtures can be divided into four categories according to their main functions:
1. Admixtures to improve the rheological properties of concrete mixtures: including various water reducing agents, air entraining agents, pumping agents, etc.
2. Admixtures that adjust the setting time and hardening performance of concrete: including retarder, early strength agent, accelerating agent, etc.
3. Admixtures to improve the durability of concrete: including air-entraining agents, waterproofing agents, and rust inhibitors.
4. Admixtures to improve other properties of concrete: including air-entraining agents, expansion agents, antifreeze agents, colorants, waterproofing agents and pumping agents, etc.
According to the naming and definition of admixtures (GB8075-87), admixtures can be divided into 16 names, and their respective definitions are as follows:
1. Ordinary water-reducing admixture: an admixture that can reduce mixing water consumption under the condition that the concrete slump is basically the same;
2. Early strength agent: an admixture that accelerates the early strength development of concrete;
3. Retarder: an admixture that prolongs the setting time of concrete;
4. Air-entraining agent: an admixture that can introduce a large number of uniformly distributed, stable and closed micro-bubbles during the concrete mixing process;
5. High-efficiency water-reducing admixture: an admixture that can significantly reduce the water consumption of the mixture under basically the same conditions as concrete collapse;
6. Early-strength water-reducing agent: a water-reducing agent with both early-strength and water-reducing functions;
7. Retarding water-reducing agent: a water-reducing agent with both retarding and water-reducing functions;
8. Air-entraining and water-reducing admixture: an admixture with both air-entraining and water-reducing functions;
9. Waterproofing agent: an admixture that can reduce the water permeability of concrete under hydrostatic pressure;
10. Rust inhibitor: an admixture that can inhibit or reduce the corrosion of steel bars or other embedded metals in concrete;
11. Air-entraining agent: An admixture that releases gas due to chemical reactions during the concrete preparation process and can form a large number of pores in the concrete;
12. Expansion agent: an admixture that can cause a certain expansion in the volume of concrete;
13. Antifreeze: an admixture that can harden concrete at negative temperatures and achieve sufficient antifreeze strength within a specified time;
14. Colorants: Admixtures that can prepare concrete with stable colors;
15. Accelerating admixture: an admixture that can harden concrete quickly;
16. Pumping agent: an admixture that can improve the pumping performance of concrete mixture
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