Fiber reinforcement improves which property primarily?

Fiber reinforcement improves which property primarily?

• A. Crack resistance
• B. Thermal conductivity
• C. Elastic modulus decreases
• D. Porosity increases

Answer: (A)

Fiber reinforcement primarily improves crack resistance. When concrete is stressed, cracks form and can propagate catastrophically in a brittle matrix. Fibers bridge those cracks, transferring load across the crack surfaces and keeping cracks from growing or widening as quickly. This bridging action increases toughness and post-cracking strength, helping the material carry load even after cracks appear. The other properties—thermal conductivity, elastic modulus, and porosity—aren’t the main benefit of adding fibers; they’re governed by other aspects of the material and construction, whereas fibers mainly enhance resistance to crack growth and overall durability.

Fiber reinforcement primarily improves crack resistance. When concrete is stressed, cracks form and can propagate catastrophically in a brittle matrix. Fibers bridge those cracks, transferring load across the crack surfaces and keeping cracks from growing or widening as quickly. This bridging action increases toughness and post-cracking strength, helping the material carry load even after cracks appear. The other properties—thermal conductivity, elastic modulus, and porosity—aren’t the main benefit of adding fibers; they’re governed by other aspects of the material and construction, whereas fibers mainly enhance resistance to crack growth and overall durability.