Lime-sand brick (KS) masonry from demolition belongs to the masonry building materials and consists for the most part of a compound of KS masonry bricks and adhering plaster and mortar, almost always consisting of cement or lime-cement plaster or mortar. At present, due to the composition described above, KS masonry is mostly dumped in mixed masonry stockpiles of processing plants and is not recycled at product level.

Due to the economically significant production and processing of stones and earths, the construction industry is more resource-intensive than all other industries. As a result, the construction industry also represents a very large market for reclaimed building materials and thus also for recycled aggregates. Fine-grained fillers are used in the construction industry for asphalt, concrete and masonry units, among other things, in order to achieve special requirements for the building materials. In the project applied for here, fillers are to be produced from reclaimed KS masonry and tested for their potential use in the manufacture of sand-lime bricks, concrete products and asphalt products.

The research project applied for is intended to create the basis for a future application of KS-RC fillers in concretes according to the principle of equivalent concrete performance. The aim is to determine and define the concrete-technological limits of KS-RC-flour-rich concretes with equivalent concrete performance. In this context, experience is to be gained with concretes with replacement rates with the maximum fines contents permissible according to the standard [DIN 1045-2/DIN EN 206-1].

Hypothetically, it is therefore assumed that the concretes with KS-RC-containing fillers, which essentially consist of CSH phases and ground-up quartzitic aggregate, are also durable and can be produced with a reduced cement content due to the excitation properties of the KS-RC fillers.