C : refer to concret 20 : its Resistance of concret cube when we make test on it after 28 days measuring by N/mm2.
with metal and concret
it is a steroid
Water+cement
concret
what rate of trimix concret
Steroid Hormones
The ancient Romans developed concrete.
common noun
non-concret
Concrete is a mixture not a chemical compound.
water+cement=concrete