The minimum diameter Øm (mandrel diameter) to which a bar is bent is called Pin Diameter. It shall be such to avoid bending cracks to the bar and ensure the integrity of concrete inside the bent of the bar where large forces appear. The smaller the mandrel diameter is, the larger these forces are and consequently the concrete may fail thus leading to the disintegration of the cross-section. While reinforcing, each Rebar got End conditions, whether it is straight end or end with bends. To define the bends we have Pin Diameter which gives the information of bends diameter. Sometime one end receive two Pin Dia or one Pin Dia or no dia at all when it is straight.
Hook and User End conditions have 2 pin dia at one end. (See Image below, field 1 and Field 4)
When publishing Bar bending Schedule, it should have specific variable so that these information can be called to Report. To provide solution for this, it is possible that, we can have variables in our lst files like,
1] PinDiaStart12] PinDiaStart23] PinDiaEnd14] PinDiaEnd2
This document will explain with example how these Pin Diameters are distributed at the end and which end indicates which Pin Diameter.
To explain this in more easy way, we have below four example of Rebar with different end conditions which is also showing the different ends of Pin Diameter Start and End.
Hook at One End and straight at other end
Hook at one End and 135° Hook at other End
135° Hook at one End and User End Condition at other End
Hook at one End and User End Condition at other End
Now if we publish the Bar bending Schedule we will see the Pin Diameter and can understand which Pin Diameter signifies to which end.
Bar bending Schedule:
This is the complete explanation of Pin Diameter of different ends.