6.15. Guidelines for Mix Design with Mineral Admixtures

Try these first

1. 1.

   What is the typical replacement level for Fly Ash in concrete?

   Hint

   Think about the function of Fly Ash in terms of its benefits.

2. 2.

   What does w/cm stand for in concrete mix design?

   Hint

   Consider how water relates to cement content.

3. 3.

   What is the typical replacement level for Silica Fume in concrete?

   • 5–10%
   • 15–20%
   • 20–25%

   Hint

   Consider why we use it at such a low level.

4. 4.

   True or False: Longer curing duration limits the effectiveness of the pozzolanic reactions when using mineral admixtures.

   • True
   • False

   Hint

   Remember the role of curing in concrete strength.

5. 5.

   Given a concrete mix with 1000 kg of cement, calculate how much Fly Ash would be needed if it replaces 30%. Additionally, explain the benefits of this replacement.

   Hint

   What is 30% of 1000 kg?

6. 6.

   If a project specifies a concrete with a low w/cm ratio of 0.30 but you add GGBS, what adjustments might you need to consider throughout the mixing process?

   Hint

   Think about how low water affects the mix.