# Waste Management in a Sustainable Circular Economy as a Part of Design of Construction
## 2 Theoretical Background
### Construction and Demolition Waste  
In total, up to 36% of waste in Europe is accounted for by the construction industry through construction and demolition work. In the USA, this is up to 60%, and, in China, surveys point to an inlay from 30% to 40% [23; 24; 25; 26]. The generation of construction waste, as well as demolition waste, is related to several construction activities. Among these activities, we can include classic construction work. This includes maintenance and remediation work as well. In generally, an integral part of CDW issues is CDW management which consist of waste generation, waste collection, waste storage, waste processing and waste disposal [27; 28; 29]. Construction and demolition wastes are generated throughout the life cycle of building. We know four basic groups of CDW depending on which phase of the construction life cycle waste is generated: wastes from the operation of construction site facilities; wastes from the construction activities containing also preparatory, ancillary and transport of processes; waste from the use of the construction; wastes from the renovation, modernization and demolition of buildings [30; 31]. The waste management is determined by the waste management hierarchy [32]. CDW disposal is divided into five levels: prevention, reuse, recycling, recovery, disposal. The waste management hierarchy sets out the order of priority of the best environmental choice in the field of waste policy overall. The waste prevention is the most efficient and sustainable strategy for the use of natural resources. Waste reuse is a process that involves separating part of the waste suitable for further direct reuse. This waste may be used for the same activity from which it was generated or in another activity, without changing the properties or form of this waste. Increased attention needs to be paid to this method of waste disposal, especially in construction, given that there is a high potential for applying this principle. An example of this procedure in construction is the reuse of brick products, roofing, etc. The recycling presents a process of reusing previously used materials and products, prevents wastage of resources, reduces consumption of natural materials, reduces the amount of waste stored and reduces energy consumption, thus contributing to the reduction of greenhouse gas emissions against the use of primary materials. The recovery and disposal represent the least appropriate ways of CDW hierarchy from point of the sustainability, e.g. landfilling has a negative impact on environment (water pollution, greenhouse gas emission, global warming etc.) [27; 28; 29; 33]. The waste management also includes the collection, storage and transport of CDW to the site if its processing. The waste processing includes at least pre-sorting, crushing or grinding, magnetic separation of metal elements and sorting. The waste produced consists of many types of materials, such as masonry and concrete. This is the largest component of waste. Asphalt, as well as some metals and plastics, can also be included among these wastes. There are also materials with higher recyclability, such as wood or excavated soil [8]. The problem is that this waste also contains hazardous substances (including asbestos, PCBs, and others) [8]. This poses a high risk to human health and to the environment. This is even truer if this waste is not treated in accordance with safety regulations. CDW has several uses. Its most common use is as a substitute for natural material in road construction. This material is also used for landscing or backfilling [33]. As already mentioned, the most common types of waste are used for various purposes, and these wastes can include mixed concrete waste. In many cases, masonry waste is just as numerous [34]. CDW can also be used to replace materials and raw materials. Some wastes, such as masonry and concrete waste, have a massive potential for recycling.