Classification of concrete

-Heavyweight

1. Contain heavy metal atoms such as iron
2. Concrete density 4000 to 8500 kg/M3 ( very high density )
3. Uses to resist force of flowing water , nuclear -radiation -shielding

-Normal /Ordinary weight

1. Natural or artificial
2. Suitable for most purpose
3. concrete density =2300 to 2500 kg/m3

-lightweight

1. Natural or artificial
2. Bulk density =350 to 850 kg/m3 for coarse and 750-1100 kg/m3 for fine aggregates ( low density )
3. High porosity , less strong and specially prepared
4. To reduce weight for the upper parts of a structure
5. To insulate concrete
6. Has tendency to stain concrete surface ( iron compounds washed out by rain )