What is development length in reinforced concrete?

Development length is the minimum length of reinforcing bar required to develop full tensile strength through bond with surrounding concrete. It ensures the bar doesn't pull out before reaching its yield strength. Development length depends on bar diameter, concrete strength, bar coating, spacing, and cover. Longer development lengths are needed for larger bars, lower concrete strength, and epoxy-coated bars. Insufficient development length leads to bond failure and structural collapse.