Horizontal construction joint in a wall at a vertical lap splice.

[YSINC]

I want to provide a horizontal construction joint in a wall. There is a lap splice of the reinforcement at the same height. I think that the continuity of the steel will be established whether or not the wall is placed in lifts or monolithically.

Will the transfer of force between bars by bond stress be affected if I locate a horizontal construction joint in a wall where the reinforcing steel is lap spliced? Is this permitted by ACI? Has anyone done this before?

 

[haynewp]

You need to have the reinforcing fully developed on both sides of the joint.

If this is a special shearwall, you may want to read thru ACI 21.5.4 for add'l development requirements.

 

[YSINC]

It is in a hydraulic structure. Similar to an open rectangular box. Ext. wall height varies from 24' to 50'.

So, it is assumed that the reinforcement that is not fully developed above and below the construction joint cannot contribute to the strength of the wall. Even partially...

 

[haynewp]

You have to develop the bar for the tensile force that is required. There is an excess reinforcement factor in ACI you can apply that will bring the length required down if there is excess reinforcing. I probably would go ahead and fully develop the bar.

I've never put a horiz joint in a liquid retaining structure, only vertical. I'm not sure what else you need to be careful about, make sure your shear is taken care of across the joint and also waterstops.

 

[YSINC]

Thank you for your opinion haynewp. I need to reassess the proposed construction proceedure.

 

[PEStructural]

What about putting the splice above the construction joint similar to that at the bottom of the wall?