Recycled aggregate concrete (RAC) is an alternative to using natural aggregate (NA) in concrete. Recycled concrete aggregate (RCA) are aggregates obtained by recycling clean concrete waste where content of other building waste must be very low – below few per cent. Based on a Japanese proposed standard on "Recycled Aggregate and Recycled Aggregate Concrete" which was prepared by the Building Contractors Society of Japan in 1977, BCSJ , the following terminology is suggested:

Waste concrete: Concrete debris from demolished structures as well as fresh and hardened concrete which has been rejected by ready-mix or site-mix concrete producers or concrete product manufacturers.

Original concrete: Concrete from reinforced concrete structures, plain concrete structures or precast concrete units which can be used as raw material for production of recycled aggregates (or for other useful purposes). Original concrete is occasionally referred to as old concrete or demolished concrete.

Recycled aggregate concrete: Concrete produced using recycled aggregates or combinations of recycled aggregates and other aggregates. Recycled aggregate concrete is sometimes referred to as new concrete.

Original mortar: Hardened mixture of cement, water, and conventional fine aggregate less than 4-5 mm in original concrete. Some original mortar is always attached to particles of original aggregate in recycled aggregates. Original mortar is occasionally referred to as old mortar.

Original aggregates: Conventional aggregates from which original concrete is produced. Original aggregates are natural or manufactured, coarse or fine aggregates commonly used for production of conventional concrete. When no misunderstanding is possible, original aggregates may also be referred to as virgin aggregates.

Recycled concrete aggregates: Aggregates produced by the crushing of original concrete; such aggregates can be fine or coarse recycled aggregates. Fine recycled aggregate is sometimes referred to as crushed concrete fines. When no misunderstanding is possible, recycled concrete aggregates may be referred to as recycled aggregates. This is the case in the present state-of-the-art report.