How is mixed construction waste produced?

Focus on demolition work Mixed construction waste is produced during the demolition, renovation and new construction of buildings as well as road and bridge construction. The majority of mixed construction waste comes from the demolition of buildings.

What is mixed construction waste?

Mixed construction waste consists of a variety of materials. When a house is demolished, for example: Building rubble Concrete, cement, clinker bricks, sand-lime bricks, bricks, ceramics, plaster, tiles and asphalt Wood Timber, formwork, doors, window frames, etc. Metals Ferrous and non-ferrous metals such as rebar, steel beams, fittings, pipes, screws, nails, aluminum profiles, cable residues, etc. Insulation materials Synthetic and natural insulating materials such as mineral wool, glass wool, rock wool, polystyrene, perlite, etc. Plastics Plastic and films of all kinds, PVC pipes, packaging, covers made of rigid plastics Other materials Other mixed waste such as cardboard, paper, glass, carpet materials, construction site waste, dust, contaminants and other disposed materials

How is construction waste recycled?

The aim of recycling mixed construction waste and recycling building rubble is to recycle and reuse the individual components and secondary raw materials in an environmentally friendly way. The material is first collected and taken to specialized recycling plants. At the start of the recycling process, a pre-screen can be used here for coarse separation and to reduce the load on the downstream shredder. The shredder then shreds the remaining material that was screened off by the pre-screen. This process step helps to protect the shredding technology, as components that are too large or cannot be mechanically shredded with the existing shredder are kept away from the shredder. Examples of this are parts of steel girders, long formwork timbers or large, heavy concrete parts. Magnetic technology is also used, for example, to recover reinforcement bars, angles and sheet metal as well as screws and nails from iron. Typical magnet technology are overflowing and/or lifting magnets (see also metal recycling ). Non-ferrous metals are separated from non-metallic components (e.g. wood, plastic, glass) using non-ferrous separators, also known as eddy current or eddy current separators. The shredder shreds the material that has not been sorted out by the prescreen and any manual sorters. The so-called hand pickers sort the materials running over a conveyor belt with their hands in a sorting cabin. For example, they can "fish out" valuable metals or sort out unwanted parts (e.g. due to their size or material) for further processing. The construction waste is then sorted by size using screening machines. SPALECK 3D COMBI screening machines have proven to be very effective for this purpose, as they can classify up to five sizes and also reliably screen out the fine fraction. This is important so that the subsequent sorting technology such as eddy current separators, air classifiers and sensor-based sorting devices can function optimally and sort the individual components according to material. So-called combination sorters use 3D object recognition, color sorting, induction sorting and, for example, NIR sorting technology or XRF or XRT sorting technology to separate materials. For example, a red brick can be reliably identified as a red brick due to its three-dimensional characteristics and color. Recycling helps to reduce landfill costs and increase the recycling rates of secondary raw materials.