The purpose of this standard is to establish the classifications and additional technical specifications for natural, crushed aggregates for use in the construction of railway tracks. This standard complements Standard UNE-EN 13450. The need to test all the specified properties, both in this standard and in the UNE-EN 13450 Standard, will be conditioned and will depend on the application of the ballast on the railway track. This standard affects all ballast supplies, whatever their application, in the different high speed, or conventional network railway lines and whether it is contracted as a work unit or in actions supported by the railway administrations budget.