What term is used when a concrete member is designed to have no tensile stresses under working load?

When a concrete member is described as being designed to have no tensile stresses under working load, it refers to the concept of fully prestressed concrete. In fully prestressed concrete, high-strength steel tendons are tensioned before the concrete is placed, effectively introducing compressive stresses that counteract any tensile forces that may occur during service. This reinforcement approach ensures that the concrete remains in compression throughout its service life, eliminating the risk of tensile cracking under normal loads.

This is particularly advantageous in situations where tensile stresses could lead to structural failure, as conventional reinforced concrete relies on passive tensile reinforcement which may not adequately prevent cracking under certain loads. Therefore, fully prestressed concrete allows for improved performance, durability, and longevity of the structure.