Which property is typically enhanced by adding fibers to concrete?

Adding fibers to concrete primarily enhances its tensile strength. By incorporating fibers such as steel, glass, or synthetic materials, the concrete gains improved resistance to cracking and separation under tensile loads. This enhancement occurs because the fibers help to bridge cracks that may form as the concrete cures and experiences stress from environmental factors or loads applied.

Fibers improve the ductility of concrete, allowing it to deform more before failure, which is critical in preventing sudden breakage. As a result, fiber-reinforced concrete can withstand tensile forces much more effectively than conventional concrete, thus improving overall structural integrity and durability. The other choices—color stability, thermal conductivity, and water permeability—are not significantly affected by the addition of fibers in the same manner, making tensile strength the clear advantage.