## 1 Introduction  
In the last thirty years, there has been a development of a new type of concrete material called self-compacting concrete (SCC). The emergence of self-compacting concrete has been linked to Japan and research conducted by [PERSON] and [PERSON] et al. [1,2]. The prototype of SCC was made in 1988 from materials that were on the market at the time, and it proved to be extremely good in terms of its properties, in both fresh and hardened states. Since the advent of self-compacting concrete, the potential of using it in the construction of buildings has been investigated in many countries, such as Japan, Canada, China, the United States and many European countries [3]. The term SCC refers to a type of high-performance concrete that does not require additional vibration in the placing process but is placed only under its own weight. The key characteristics of fresh self-compacting concrete are: workability and viscosity, i.e., the ability of fresh concrete mass to pass freely between densely arranged reinforcement bars, as well as the resistance to segregation. The first research related to the emergence of SCC focused on the design of an adequate concrete mix as well as on the methods of placing and testing of placed concrete [4, 5, 6, 7]. SCC as a relatively new material represents a still insufficiently researched area, both in terms of its properties in the fresh and its characteristics in the hardened state. Numerous studies related to SCC referred to its properties in the fresh state [8; 9], while it was believed that its characteristics in the hardened state are similar to vibrated concrete [10; 11; 12; 13]. Tests of SCC in fresh and hardened states resulted in the emergence of the first recommendations for proper designing of SCC, which were published by the European Federation of National Associations Representing for Concrete (EFNARC) in 2002 [14]. The European design commission, composed of five European associations, defined the European Guidelines for self-compacting concrete in 2005 [15]. In the period from 2008 to 2020, most of the experimental tests were based on the comparison of test results of the beams made of SCC and conventional vibrated concrete (VC), as well as on comparisons with recommendations defined by regulations for structures made of VC [16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31]. Experimental examination of the ultimate bearing capacity and ultimate serviceability of beams of different cross sections made of SCC exposed to bending and shear has been presented in a large number of scientific publications [16; 17; 18; 19; 22; 24; 27; 28; 29; 30; 31]. Almost identical characteristics of the beams made of vibrated and SCC exposed to short-term static load were observed, and the SCC beams showed equal or lower ultimate shear and flexural strength than VC test members. Based on the experimental results of long-term loaded beams made of SCC and conventional VC, it was determined that under the same environmental conditions, the shrinkage-time curve of self-compacting concrete is very similar to that of conventional vibrated concrete [16]. Regarding the limit value of the bending moment, the moment-curve relationship, the use of SCC for the production of prestressed beams meets the criteria defined by the Eurocode (EC) 2 [21], as well as by the American Concrete Institute (ACI) regulations when high strength self-compacting (HSSC) concrete is used for the manufacture of prestressed beams [31]. Based on the experimental examination of beams exposed to cyclic loading, a faster development of deformations and cracks was observed in beams made of SCC compared to conventional VC [24]. Research [21; 25] dealing with structural performance of SCC used in reinforced concrete beams, as well as the comparison between the experimental results and theoretical calculations based on the code provisions, has shown that the criteria defined in EC 2 and ACI 318M-11 are met.