In the US, concrete compressive strength is measured in psi. 20 MPa is roughly equivalent to 3,000 psi.
3/8” rebar spaced at 18” seems to be common in my area, which has highly expansive soil. There are regional differences. In some areas it is normal to not have any rebar.
3/8” rebar spaced at 18” seems to be common in my area, which has highly expansive soil. There are regional differences. In some areas it is normal to not have any rebar.