Fiber-reinforced concrete also improves which of the following?

Fiber-reinforced concrete also improves which of the following?

• A. Impact resistance
• B. Freeze-thaw susceptibility
• C. Water absorption increases
• D. Shrinkage stress increases

Answer: (A)

Fiber-reinforced concrete improves how the material behaves under sudden, dynamic loading. The fibers act as crack bridges, carrying load across cracks and absorbing more energy, which makes the concrete tougher and more resistant to impacts. Freeze-thaw resistance is mainly about air voids and proper curing, not a direct benefit of adding fibers. Water absorption is tied to the porosity of the concrete matrix, not the presence of fibers, so absorption isn’t increased by adding fibers. Shrinkage cracking is mitigated because fibers help restrain crack widths and provide post-crack strength, so shrinkage stresses are not increased and can be reduced. Therefore, the improvement most directly attributed to fiber reinforcement is impact resistance.

Fiber-reinforced concrete improves how the material behaves under sudden, dynamic loading. The fibers act as crack bridges, carrying load across cracks and absorbing more energy, which makes the concrete tougher and more resistant to impacts. Freeze-thaw resistance is mainly about air voids and proper curing, not a direct benefit of adding fibers. Water absorption is tied to the porosity of the concrete matrix, not the presence of fibers, so absorption isn’t increased by adding fibers. Shrinkage cracking is mitigated because fibers help restrain crack widths and provide post-crack strength, so shrinkage stresses are not increased and can be reduced. Therefore, the improvement most directly attributed to fiber reinforcement is impact resistance.