Entwicklung thermisch‐mechanisch aktivierter Betonbrechsande als Betonzusatzstoff – Projektvorstellung und erste Ergebnisse.

Development of thermally and mechanically activated concrete fines as supplementary cementitious material – project presentation and first results In the light of resource demands for construction and limited availability, an efficient recirculation of building materials is essential. For concrete production, this means the use of recycled aggregates as partial replacement of gravel and sand, with the latter being severely restricted. Since crushing yields a concentration of porous hydrated cement in the fine particles, the application of crushed concrete fines as aggregates or milled supplementary cementitious material (SCM) results in limited concrete performance. Present results show that hydrated cement can be reactivated through an additional thermal processing, yielding improved mechanical and durability properties like carbonation or chloride penetration when used as SCM in concrete. The promising results initiated a funded research project, which investigates influencing factors of the thermal‐mechanical processing of crushed concrete sands with varying compositions on the performance as SCM. [ABSTRACT FROM AUTHOR]