In common Iranian site terminology, “ayar” refers to cement content per cubic metre. It is a mass-per-volume value, not a strength class.
Different quantities
Cement content is expressed in kg/m³; compressive strength is expressed in a pressure unit such as MPa. Strength also requires a defined specimen basis, test age and acceptance criteria.
No universal conversion
Identical cement contents do not guarantee identical performance. Materials, water-to-cementitious ratio, air, compaction and curing affect the result.
Ordering information
Provide the approved requirements for each member and pour. Do not substitute an empirical cement-content table for the specified mixture performance and testing.