Different adding methods will have different effects:

① Adding method of high-efficiency water reducer:
a. The water reducer is dissolved in water and added to the mixing water at the same time;
b. The water reducer is dissolved in water and added when the concrete is basically mixed evenly (added after mechanical mixing for 1 minute);
c. The water reducer powder is added after the concrete is basically mixed evenly.
② The post-addition method of adding high-efficiency water reducer requires extending the mixing time by 0.5 to 1.0 minutes.

The influence of concrete components on water reducers and high-efficiency water reducers:
1. Cement composition: Most high-efficiency water reducers have better water-reducing and plasticizing effects in slag cement than ordinary cement.
2. Cement fineness: Under other conditions that are the same, the fluidity of cement slurry decreases with the increase of cement fineness.
3. Aggregate fineness modulus and particle shape: The water reduction rate of crushed stone concrete with water reducer is greater than that of pebble concrete.
4. Temperature: When the temperature is below +5℃, it is difficult to achieve the purpose of increasing strength by adding high-efficiency water-reducing agent alone, and it will not bring economic and technical effects. A review early strength agent should be added.
5. Ordinary concrete with a small amount of cement: high-efficiency water-reducing agent should be used in a small amount of 0.3% to 0.5%, and high-strength concrete should be used in a large amount of 0.7% to 1.0%. When fly ash is added to concrete, the amount of water-reducing agent and high-efficiency water-reducing agent should be appropriately increased. The amount of calcium lignin sulfonate can be increased from 0.25% to 0.30%. When segregation and water seepage occur after adding high-efficiency water-reducing agent, the sand ratio can be appropriately increased to restore the viscosity of the concrete and improve workability.