How many kg of 16mm rebar per m3 of concrete?

Volume of reinforcement in concrete varies from project to project and structural element to element and accuracy depends on design of reinforcement & bar bending schedule.

Normally Rough estimate can be done by considering following

1) % of steel volume in fiundation concrete = 1 to 3 %

2) % of steel volume in column concrete = 2 to 5 %

3) % of steel volume in Beam concrete = 1.25 to 3 %

4) % of steel volume in Slab concrete = 0.7 to 1.25 % in single mesh

5) % of steel volume in Slab concrete = 1.4 to 2.5% in double mesh

Lets consider you have column and 3% of steel in column concrete

Desnity of steel rebar=  7850 Kg/m3

Volume of concrete of column = 1m3

Volume of steel rebar in concrete = 3%=3/100*1 =.03 m3

Weight of steel rebar = 0.03*7850 =235.5 kg

Result

235.5 Kg of steel rebar is required for any size of rebar (10mm, 12mm, 16mm, 20mm, 25mm etc.) in column concrete