21.2. Fiber Characteristics Influencing Performance

Try these first

1. 1.

   What is the typical range for the aspect ratio of fibers?

   Hint

   Think about how the length compares to the diameter.

2. 2.

   Define volume fraction in the context of FRC.

   Hint

   Consider its impact on the mix.

3. 3.

   What typically increases when using higher aspect ratio fibers?

   • Workability
   • Strength
   • Cost

   Hint

   Consider the role of fibers in reinforcing concrete.

4. 4.

   True or False: A lower volume fraction of fibers can lead to improved workability.

   • True
   • False

   Hint

   Think about how fiber concentration affects mixing.

5. 5.

   If increasing fiber length improves tensile strength, at what point might workability become an issue? Justify your reasoning with examples.

   Hint

   Consider practical construction scenarios.

6. 6.

   Design an optimal FRC mix for a bridge that requires high toughness and resistance to cracking. Discuss the specific fiber characteristics you would choose.

   Hint

   Reflect on the bridge's environmental conditions.