What next with the concrete I have poured for a floor?

Question

I have made a concrete floor slab. 2 parts gravel, 2 parts sand and 1 part cement. I have poured and later the same day patted the concrete to rise up a little liquid on the surface which I then smoothed out creating a more polished effect. The surface looks good and flat and reasonably smooth.....a couple of questions.

When can I walk on it and when can I drill holes to anchor bolts/plugs etc?

The surface (24hrs after pouring) has a two colour effect. Light to dark grey, showing the circular motion which I used to smooth out the surface. This lighter colour surface seemed to come away when I polished it with my finger. Is this normal, and what should I do (and when) to even the colour of the concrete, brush it?

Thanks in advance

Answer 1

The 2 tone color effect is natural when finishing concrete. The lighter color is the concrete that has dried faster than the other.  Once the slab is completely cured, it should even out. As long as your mix stayed consistant, I should say.

Wait at least a week before drilling into the slab or you may experience some chipping at the surface.

You can walk on concrete after it's hard enough not to leave any imprints. This is typically within 10 hrs of pouring.....depending on temperature of course.

Answer 2

Sounds like you didn't mix the stuff good enough Thats why the 2-tone finish.Which also calls into question the strength of the slab.The color is not going to change.You can drill it and walk on it now too.

Answer 3

Depending on ambient condition and how thick the slab it could take a week to dry, anchor holes a bit longer as this stresses the crete. slower drying will get you a stronger concrete. So not let dry too fast, spray a little water for first 2-3 days to dampen up. Uneven drying will cause some color differences, but should even up with age.