According to the standard, the use of RAP for SMA is permissible. The types, quantities, and requirements for RAP to be used in SMA mixes should be specified in an NAD appropriate to the intended use.
RAP should be classified according to EN 13108-8 and should conform to the relevant requirements for a particular application.
The maximum size of a particle in RAP cannot be larger than size D of the SMA mix. The quality of aggregate in RAP cannot deviate from the requirements for a new aggregate to be used in a given SMA.
When the used RAP contains road binder (unmodified) and when the binder added to the mixture is road binder then additionally one of two values should be determined: either the penetration at 25°C or the softening point (R&B) of a mixture created by combining the recovered binder from the RAP with the new binder added during SMA production. The test result (Pen25 or SP) of this binder mixture should meet the requirements for the target (design) road binder selected for a given SMA. Formulae for calculating properties of binder mixes can be found in the standard EN 13108-5, Annex A. The method of recovering binder from recycled asphalt paving mixture should be in accordance with EN 12697-3 (binder recovery—rotary evaporator) or EN 12697-4 (binder recovery—fractionating column). The penetration should be determined according to EN 1426 and the softening point according to EN 1427. Such an additional requirement is used in following cases:
• In a wearing course when more than 10% (m/m) RAP is used
• In a regulating (leveling) and intermediate course when more than 20% (m/m) RAP is used
When used RAP or the new SMA contains a modified binder or a modifier additive, according to Item 5.1 of the standard the amount of RAP cannot exceed the following:
• 10% by mass of the total mixture if the SMA is intended for a wearing course
• 20% by mass of the total mixture if SMA is meant for a regulating* or intermediate course or a base course
Both the client and the producer of the SMA mix may arrange otherwise, provided that other local (national) regulations are not infringed upon.
14.4.4 Additives
Additives should conform to the requirements for constituent materials; namely, they should have the determined suitability—marked by complying with an appropriate EN standard, ETA, or a demonstrable history of satisfactory use.
