1.3. Duration of Mixing

Try these first

1. 1.

   What is the typical duration for machine mixing of concrete?

   Hint

   Consider what is commonly recommended for other mixing processes.

2. 2.

   What does over-mixing cause?

   Hint

   Think about what happens when components separate.

3. 3.

   What is the optimal mixing duration for machine mixing concrete?

   • 1 minute
   • 1.5 to 2 minutes
   • 3 minutes

   Hint

   Consider what is typically stated in standards for concrete mixing.

4. 4.

   True or False: Over-mixing is beneficial for concrete workability.

   • True
   • False

   Hint

   Reflect on the effects of mixing time discussed earlier.

5. 5.

   During a construction project, the team mixed concrete for 2.5 minutes. Describe the potential quality issues they may face and propose solutions.

   Hint

   Consider what mixing time is prescribed and what happens with improper practice.

6. 6.

   If a survey reveals a pattern of frequent over-mixing in a company's projects, what steps would you recommend to correct this behavior?

   Hint

   Focus on the balance between education and enforcement.