ASTM C977

Quicklime and Hydrated Lime for Soil Stabilization

Applicability: ASTM C977 applies to quicklime (calcium oxide, CaO) and hydrated lime (calcium hydroxide, Ca(OH)₂) manufactured for use in the chemical stabilization and modification of subgrade soils, road bases, and embankment fills. It covers high-calcium and dolomitic hydrated lime products used in highway, airfield, and foundation construction. Products intended for other applications such as flue gas desulfurization, water treatment, or agricultural liming are outside the scope of this specification.

Purpose: ASTM C977 establishes minimum chemical and physical requirements — including available calcium oxide equivalent, residue on specified sieves, and particle fineness — for lime products used to treat fine-grained soils and improve their strength, plasticity, and workability. Compliance with this specification ensures that lime products provide sufficient reactivity with clay minerals to produce pozzolanic cementation, reducing the plasticity index (PI) and increasing the bearing capacity and long-term compressive strength of treated subgrade and base course layers.