Connection's PT Slabs
Connection's PT Slabs
(OP)
Hey,
I am having an issue with typical temporary movement joint detailing using horizontal dowel's grouted after 56 days in my PT-flat plate slab.
The situation:
I am trying to isolate lift/stair well core walls and a shear wall using horizontal dowel connections. They are located 35 m away from each other however the shear wall runs perpendicular to the core's.
The builder and consultant want to use 170mm slabs with 8.3m spans (however not allowed by current codes but they have a tech gliche in there DA) so P/A is quite high to control deflections etc varying b/w 2-2.5 P/A....
The rest of the perimeter is isolated by a building movement Joint...
The question:
In theory the TMJ detail works, however how do you ensure that onsite workers install the horizontal dowel joint system properly and centre the reinforced bars to the PVC piping provided?
.. i.e. normally they will just sit the PVC piping on the bars and it would not be central (gravity). I wouldn't worry about this normally but because of the high P/A shortening of the slab will be quite significant, 170mm deep flat plate will crack quite easily when restrained.
I'd like to hear your technique / system you use for correct installation..
Regards
Bill Mason





RE: Connection's PT Slabs
RE: Connection's PT Slabs
Sorry maybe I was giving to much info..
Simply,
I am using a horizontal dowel connection to transfer the shear from the slab into the support in this instance the core's.
The dowel connection is for example a N16 bar with a PVC duct placed over the bar to allow for temporary movement and after 56 days we can come back and grout through tubing and lock it in. (this is a typical PT detail & doesn't halt construction of the project, and would only be MAX 20 bars)
What techniques / procedure can I use to maintain that the bar will stay central to the duct...??
.. Punching is looked after what they are saving in concrete they will be blowing out in stud rails however they have height issues with the floor below.
RE: Connection's PT Slabs
For post-tensioning work, I"ve often added a short polyurethane 'pipe insul' sleeve to provide a movement space.
Dik
RE: Connection's PT Slabs
RE: Connection's PT Slabs
Stud rails (or any type of punching shear reinforcement) in a 170mm slab! No way.
L/D of 49 with precast, so limited continuity! No way. Who cares if they creep upwards, they still bounce.
Maybe the carpets and floor coverings will stiffen it all up and suupport it all!
RE: Connection's PT Slabs
RE: Connection's PT Slabs
dik was talking about HC which I assume is hollow core precast!
RE: Connection's PT Slabs
RE: Connection's PT Slabs
Dik