Reinforcement anchored in tension by heads. Review of capacity formulation and applicability limits

•Head bars for reinforcement anchor.•Failure modes of head bars.•Code formulation and experimental campaigns of head bars.•Review of formulation and applicability limits. Longitudinal reinforcement anchored using heads is becoming more common because it avoids congestion of bars and improves the durability of the anchorage. This paper tries to facilitate its use showing that the specification of the applicability limits is not needed. This work studies the application domains of the different failure modes of the anchorage of headed bars under tension. Each one of the failure modes has its own formulation to calculate the capacity of the headed bar, that it is valid only in a specified domain. This work proposes that the limits of the domain associated with each failure mode can be considered to be implicit in the formulation itself because the domains can be associated to the intersection of the formulations of the failures modes. Due to this assumption no additional information is needed in regard to the definition of the domains which facilitates the calculation of the headed bars anchorage. Furthermore, this work shows that this hypothesis is in accordance with the available experimental campaigns. Some examples are presented.