## 1 Introduction  
Environmental regulations and policies increasingly address the issue of conscious waste management. At the same time, consumers are encouraged to be environmentally responsible by means of promotional programmes, guidelines (segregation of municipal waste into coloured containers), or legal requirements. Almost all materials from which raw materials, such as glass, metals, plastics and minerals, paper, textiles, and others can be recovered, can be reused (recycled). Recycling is also becoming an increasingly common concept in the construction sector. According to the definition contained in PN-EN 12620 [1] standard, recycled aggregate is the aggregate coming from the processing of inorganic material previously used in the construction industry. Such materials include, for example, building rubble, road and street demolition debris, or earth and rock masses. The Polish Aggregate Producers Association estimates that the recycling process produces approx. 4.5 million tons of aggregate annually. This amount translates only into approx 2.5% of all building materials used in Poland. Considering the situation in other countries, a thesis can be made that this value will have an upward trend [2]. The problem of environmental pollution with construction waste and depletion of natural resources is not only a Polish problem, but also a global problem [3]. In European countries, 320-380 million tons of this type of waste is generated every year [4] and in China alone this is about 640 million tons annually [5, 6]. A lot of research has been conducted all over the world on recycled aggregates and their application in the production of structural concrete [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26]. Nevertheless, new possibilities of using various types of waste for the production of aggregates used in structural concrete are constantly being sought. The authors of the work [27] showed that the use of recycled glass as a substitute for coarse aggregate in architecturally oriented concrete is possible from a mechanical point of view. They received the compressive strength in the range 19.89-25.26 MPa. The strength is comparable to C25 concrete. [PERSON] et al. [28] studied the properties of concrete made on the basis of aggregate prepared from ceramic tiles. The results of the research show that the samples made of natural aggregate showed better strength parameters. The compressive strength of a concrete with natural aggregates is equal about 49 MPa, and with artificial aggregates it is about 33 MPa. [PERSON] and [PERSON] [29; 30; 31] focused on the use of sanitary ceramics in the production of aggregate. Their tests showed better strength parameters of the samples made on the basis of recycled aggregate. They received higher compressive strength (about 10%) and tensile strength (about 3%) of a concrete with ceramic aggregates (the compressive strength is equal 42.8 MPa and the tensile strength under bending is 6.35 MPa) in the comparison to concrete with natural aggregates (the compressive strength is equal to 46.95 MPa and the tensile strength under bending is 6.52 MPa). The scrub resistance of concrete with ceramic aggregates is about 20% higher than with natural aggregates. The work of [PERSON] et al. [32] concluded that the use of sanitary ceramic cullet as aggregate is the most advantageous in the production of concrete that is resistant to aggressive environments and is recommended for the production of concrete sewage pipes. The influence of an aggressive chemical environment reduces the compressive strength of concrete with ceramic aggregates by about 13.4% and with basaltic aggregates by about 27.8%. In this context, it is very important to recognize the properties and possibilities of using such ecological aggregates in building structures.