Prof. Dr.-Ing. habil. Anette Müller

Progress in the recycling of masonry rubble (Part 2)

»1 Year-2010 incidence of construction waste acc. to [6] and breakdown of building rubble based on [7]

Photo/Foto: Müller

»2 Pure brick rubble

Photo/Foto: Müller

»3 Masonry rubble

Photo/Foto: Müller

»4 Particle-size distributions of recycled masonry rubble

»5 Brick contents of masonry rubble

»6 Material-flow analysis of masonry rubble, differentiated according to particle size and material composition

»7 Locations of unblended major components of masonry and of real masonry rubble in the ternary system SiO₂ - Al₂O₃ - fluxing agent FM

»8 Effects of SiC injection on the apparent specific density of expanded aggregate composed of masonry rubble with 48 mass % brick, fired at 1180 °C (left); and effects of brick content of starting material on apparent specific density of expanded aggregate based on masonry rubble; fabrication conditions: addition of 1 or 3 mass % SiC, fired at 1165-1180°C (right)

»9 Water absorption and particle strength of lightweight aggregate in comparison with expanded clay

»10 Mechanical properties of laboratory concrete made of lightweight mineral aggregates (LG: laboratory-produced lightweight mineral aggregate; HT: lightweight mineral aggregate from small-scale production)

Present practice in the recycling of masonry rubble cannot claim to be contributing to resource efficiency. Building on a 2003 review article on the recycling of masonry rubble [5], this contribution reports on new findings and current developments of relevance. The characteristics of “masonry rubble“ as a material flow category are described, and current research findings and extant technologies explained.

4 Use of brick and masonry rubble as raw material

The term material salvaging, or feedstock recycling, describes the use of recycled material in a transmutating process. In the present context, the chemical composition and reactivity of the material are of key importance, while material properties considered to be important for the aforementioned utilization methods fade into the background. Superfine and fine-grained starting materials can be processed. With sole respect to such construction material production processes as brickmaking or cement production, brick and masonry rubble can be...