This European Standard applies to the treatment with lime of natural soils and other materials for roads,airfields and other trafficked areas and specifies the requirements for their constituents, composition and laboratory performance classification.Two types of treatment are covered, improvement and stabilization.This European Standard relates only to lime-treated layers for trafficked areas (as opposed to lime columns or piles for example) but can be used for other civil engineering purposes although additional requirements might be necessary to complement or replace those required by this European Standard.