6.12.1. Pozzolanic Reaction Mechanism

Try these first

1. 1.

   What is a pozzolanic reaction?

   Hint

   Think about how admixtures improve concrete.

2. 2.

   Name one benefit of C-S-H in concrete.

   Hint

   Consider the strength-giving compound.

3. 3.

   What do pozzolanic materials react with to enhance concrete?

   • Water
   • Calcium Hydroxide
   • Cement

   Hint

   Recall the main reaction in pozzolanic processes.

4. 4.

   True or False: The main benefit of the pozzolanic reaction is the reduction of permeability.

   • True
   • False

   Hint

   Think about how the microstructure changes.

5. 5.

   A concrete mixture uses 500 kg of cement. If 30% of this is replaced with GGBS, calculate how much GGBS is used. Discuss the implications of this replacement on hydration heat.

   Hint

   Apply percentage calculations.

6. 6.

   Predict how the permeability of concrete could change when 20% of the cement is replaced with a highly reactive pozzolan compared to normal cement hydration.

   Hint

   Consider the properties of C-S-H versus Ca(OH)₂.