Use of recycled aggregates according to new DIN 1045-2

With the future DIN 1045-2 standard, concretes containing recycled aggregates according to DIN EN 12620 will be transferred into the new concept of concrete classes. As before, the general rules will be covered in Section 5.2.3.4, “Recycled Aggregates”, while all others in the reminder will be covered in normative Annex E, “Source Materials”, Section E.2, “Rules for the Use of Aggregates”. Concrete containing recycled aggregates will in future be grouped into the concrete classes BK-N (standard requirements), BK-E (increased requirements) and BK-S (special requirements to be specified) as follows:

- Concrete class BK-N: concrete containing ≤ 25 % by volume of recycled aggregates, replacement of the coarse aggregate (based on total aggregate), and compliance with the general requirements for recycled aggregates according to E.2.3.1

- Concrete class BK-E: concrete containing > 25 % by volume of recycled aggregates, replacement of the coarse aggregate (based on total aggregate) or moisture class WA, and compliance with the general requirements for recycled aggregates according to E.2.3.1 and the special requirements according to E.2.3.2

- Concrete class BK-S: concrete containing recycled aggregates deviating from BK-N and BK-E

It will still be prohibited to use recycled aggregates for prestressed concrete and lightweight concrete. In DIN 1045-2, the terminology has been adapted to DIN EN 12620. The terms “fine” and “coarse” aggregates will in future also be used for recycled aggregates. In this context, some changes have also been implemented regarding the standard requirements for recycled aggregates. The use of fine recycled
aggregate will be allowed when complying with appropriate requirements.
The DAfStb (German Committee for Structural Concrete) guideline “Concrete according to DIN EN 206-1 and DIN 1045-2 containing recycled aggregates according to DIN EN 12620“ (September 2010 edition) currently in force will be withdrawn upon introduction of the new DIN 1045-2 standard by the building authorities.