Which crack type is bending-induced in concrete?

• A. Shear
• B. Flexure
• C. Tension
• D. Compression

Answer: (B)

When a beam or member is bent, it develops a tension zone on the side opposite the applied load and a compression zone on the other. Concrete handles compression much better than tension, so once the tensile stress in the bottom fibers exceeds the concrete’s tensile strength, cracks form there. These bending-induced cracks are called flexural or flexure cracks. They show up on the tension side and are controlled in practice by placing reinforcement to carry the tensile forces. Cracks from shear, direct tension, or pure compression arise from different loading conditions and patterns, so they aren’t the bending-induced type.