4.11.2. Metro and Tunnel Projects

Try these first

1. 1.

   What is the main purpose of superplasticizers in concrete?

   Hint

   Think about fluidity and strength.

2. 2.

   Name one benefit of waterproofing admixtures.

   Hint

   Consider the environment around tunnels.

3. 3.

   What is the main role of superplasticizers in concrete?

   • To reduce setting time
   • To increase strength
   • To enhance workability and reduce water content

   Hint

   Think about what makes concrete easier to work with.

4. 4.

   True or False: Waterproofing admixtures are unnecessary in tunnel construction.

   • True
   • False

   Hint

   Consider the environmental conditions of tunnels.

5. 5.

   Propose a solution for a construction scenario where the concrete for a metro tunnel has become too stiff to pump. What admixture would you recommend?

   Hint

   Think of what can enhance fluidity.

6. 6.

   If a tunnel's waterproofing admixtures failed and water began leaking, outline the steps you'd take to evaluate the damage and mitigate issues.

   Hint

   Consider how to protect structural integrity and safety first.