Synopsis
Traditionally, anchorage of reinforcement has been achieved through the bond strength between the concrete and the reinforcement, or with an L-shaped bar, or a combination of the two. Headed reinforcement bars are an alternative method for anchoring reinforcement in concrete members. This paper explains where headed bars can be used to improve the design and buildability of the concrete section and how to ensure there is sufficient anchorage strength.
Existing codes of practice provide limited guidance on the use of headed bars, and use simplifying assumptions that can be restrictive. This paper introduces all the failure mechanisms that can occur and explains how to design the headed bars so they have sufficient cover and spacing to ensure that all the potential failure mechanisms are considered. It draws together, in one location, the output of research and the design guidance that has been published in North America and Europe and provides some helpful design aids to simplify the design process.