connecting / anchoring thick RC slab

mats12 · Jun 21, 2017

Hi guys. Im wondering how do you usually anchor new RC slab to existing when slabs are pretty thick (200 mm or more). I usually do anchoring in the middle of a slab, but since slabs are 200 mm thick I think its better idea to do anchoring in two rows like shown below:

JAE · Jun 21, 2017

Is this a slab-on-grade? Or a structural slab?

If on grade - we usually (always) use dowels in the center. If you get too close to the edge and some vertical shear is introduced, then you risk the top bars spalling out the concrete surface.

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EngineeringEric · Jun 21, 2017

Why are we connecting them at all? if it is just to keep the edges together and no moment than do the middle, drilling and embedding things staggered just seem like we are bound to get close to the edge and spall/crack.

Nor Cal SE · Jun 21, 2017

Presuming you have no need for moment transfer, I agree that centered reinforcing dowels are best. I see single-layer/centered reinforcing commonly for slabs even up to this thickness, at least for slab-on-grade not taking any moment. Only at 10" thick or thicker would I switch to top-&-bottom configuration (sorry for switching from mm to inches!).

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connecting / anchoring thick RC slab

mats12

Geotechnical

JAE

Structural

EngineeringEric

Structural

Nor Cal SE

Structural

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