Railway sleepers are a very important component of the transport infrastructure, they are dynamically loaded and subject to many stresses that can cause degradation, shorten their service life and also reduce the safety of rail transport. The subject of the study was damaged-highly cracked prestressed concrete railway sleepers, 10 years old, sampled on the railway line route. The results of the investigations carried out to determine the characteristics of the concrete are presented. In order to determine the cause of the damage, low-frequency fatigue tests were also carried out in the laboratory to measure vibrations and to check for cracks. By checking the microstructure of the concrete with SEM-SEI and EDS electron microscopy, we found that the cracks were caused by chemical reactions in the hydrated concrete. The results of the analyses carried out can improve the criteria for the inspection and assessment of the serviceability of degraded railway sleepers during their service life.