Shrinkage and Bond Breaking of Suspended Slab

[mikealpha88]

Hi Friends,

I am designing a suspended concrete slab to fill a void of 6m x 6m and connecting it to existing concrete beams. I am using bondek formwork to span one-way,supported on steel beams at 2000mm crs which will be supported by the concrete beam. I have checked the beams sizes and it all works fine. I am also thinking of connecting the new slab to the existing beam via N12 dowels at 400 crs for additional restraints. Initially I was not going to do that and was going to use a bond breaker around the new slab to allow for shrinkage but the builder is adamant to connect the new slab to the existing beam. I am little worried if the slab shrinks it may try to pull the existing beam however the slab is not too big. Any inputs on using the bond breaker or not will be great.

 

[YuleMsee]

You might be required to drill and anchor rebar to the existing concrete to marry it with the new concrete to prevent a crack forming, it's too much work, a well constructed and sealed joint appears to be a no brainer unless there are other considerations