Need. Whether sprinkling water or covering curing is adopted, the surface of lime-fly ash macadam structure layer should be kept wet within 7 days of curing age, so layered curing is needed. Lime-fly ash macadam, also known as lime-fly ash stabilized macadam, is a semi-rigid structure with strength, which is made of inorganic binder lime, fly ash and graded macadam mixed with a certain amount of water, rolled and maintained.