Construction Joint - Raft

[slickdeals]

All,

I am reviewing a pour sequence for a 2.5 m thick raft based on contractor's pour volume limitations. I am ensuring that these joints are at least 5-6 feet away from a vertical member.

The contractor is using an expandable mesh (hyrib expamet) with mat top and bottom rebar running through the joint (no shear key). In addition, I am providing 2#6 (T20) @ 600 o.c. at mid-thickness. Based on shear friction calculations using the 2#6 rebar and the raft flexural steel in the mat, there is adequate capacity.

Is there anything else I need to worry about?

 

[slickdeals]

A follow-up question:
Assuming the section has been sized for moment and there is adequate flexural reinforcement. In a scenario (odd) where the amount of flexural reinforcement is not sufficient for shear transfer, where does the additional shear reinforcement be added? Closer to the tension face or distributed over the height of the joint?

 

[slickdeals]

Anyone?

 

[hokie66]

slickdeals,
Perhaps you are not getting any response because no one is familiar with using this expanded mesh as reinforcement. I'm not.

As to the shear transfer in a thick mat, I try to locate any construction joints at or near centre span. If there is an irregular spacing of columns, that can be a problem.

So I intend for shear to be minimal, but something you still have to allow for. As I am not much of an advocate of shear friction, I would tend to provide shear keys. In a 2500 thick mat, you could easily provide keys 800 deep at mid-depth.