If you are planning on being so rough with the pex as to rupture it during the pour then you need to plan on making this repair in dirty conditions. This repair will be very difficult to access in the future so do it right. The push to connect devices use an O-ring to seal the outside of the pipe which will be covered in concrete slurry. The standard crimp connections seal to the inside and can be SS rings, copper rings, brass fittings, or plastic fittings. Check with the manufacturer about contact with concrete.
Really, you should plan to do the pour in a way that prevents pex injury. It's pretty tough stuff. You can pump it up to 100 psi and that way if you hurt it, it will be very obvious during the pour and the air will be rushing out so fast that the inside of the pipe should stay clean.