9.14. Carbonation of Concrete

Try these first

1. 1.

   What is carbonation in concrete?

   Hint

   Think about what happens to concrete when CO₂ is present.

2. 2.

   What indicator is commonly used to test for carbonation?

   Hint

   What turns pink in alkaline conditions?

3. 3.

   What does carbonation in concrete primarily affect?

   • Compressive strength
   • pH level
   • Thermal conductivity

   Hint

   Consider how CO₂ interacts chemically with concrete.

4. 4.

   True or False: Carbonation increases the protective alkalinity around reinforcement.

   • True
   • False

   Hint

   Think about the impact of CO₂.

5. 5.

   Illustrate how carbonation can impact the lifespan of a concrete structure over 50 years and what specific measures should be considered in design to mitigate these effects.

   Hint

   Consider the years of exposure to environmental conditions.

6. 6.

   Analyze a structure where the phenolphthalein test shows significant carbonated areas. Propose an actionable plan for repairs and prevention moving forward.

   Hint

   What repair strategies can extend the life of the structure?