Although concrete is seen by many as a single material, it in fact can be produced with many variable characteristics including strength, fluidity, colour and weight.
Non-structural concrete is concrete that has a low strength and will be used when only small compression or temporary loading is involved. For instance it is used in ´blinding layers´ where a surface is covered in non-structural concrete to form a level and possibly more stable surface on which further works can be more readily undertaken.
For a concrete to be used structurally it is designed to have a characteristic strength in excess of 25N/mm2. Concretes’ of lesser strength are termed non-structural.