how to dap a concrete beams 1

[bridgeman5858]

i am setting concrete beams and they want the ends dapped my under standing of this they should already come that way they are on a slite angle and pourd that way allready can you shed some lite on this

 

[cooperDBM]

A dapped end is where the bearing area area is significantly higher than the bottom of the beam in the span. This is usually accomplished with a vertical step in the depth of the beam in front of the bearing. A precast beam framing into a ledger beam will often have a dapped end.

This is not the same as casting the bearing area at a slight angle to the bottom of the beam so that the bearing surface is flat after erection under all dead load. This is typical for all large beams such as bridge girders. Since the angle is dependent on the loading the engineer will often specify this angle. If the bridge is on an incline you may get a small notch in front of the bearing to accommodate the bearing angle. This isn't a dapped end and isn't big enough to require special reinforcing.

It sounds like you might be referring to the second situation. Hope that helps.

 

[cooperDBM]

By flat I mean horizontal.