Lecture 9 Detailing Concrete Centre
EC2 Webinar – Autumn 2017 Lecture 9/3 Minimum mandrel size, φφφφm • To avoid failure of the concrete inside the bend of the bar: φφφφ m,min ≥ Fbt ((1/ ab)+1/(2 φφφφ)) / fcd Fbt ultimate force in a bar at the start of a bend ab for a given bar is half the centretocentre distance between bars. For a bar adjacent to the face of the member, ab should be taken as