## 5 Final Remarks
From the above it can be concluded that the total plastic deformation is reduced to a rotation around the crack of the end section and the first crack from the bottom of the element. The same can be concluded by analyzing the rotation of three characteristic cross-sections. It can be observed that most of the plastic rotation is concentrated in the end section, while in the cross-section of the first crack the amount of plastic rotation is much smaller, and in the cross-section of the second crack (the third cross-section observed) plastification is almost non-existent in most of the specimens tested. From all the above, a conclusion is drawn about the height of the plastic joint for monotonically and cyclically tested specimens, which mainly develops to about the height of the first crack and is 0.7 h, where h is the height of the cross-section in the load direction. For specimens with ribbed reinforcement (monotonically tested), the plastification height extends up to a height of 1.2 h, which corresponds approximately to the values given in [11]. From this it can be concluded that the given expression is calibrated to elements with ribbed reinforcement and its application to elements with smooth reinforcement is questionable. The experiment has shown that for specimens with ribbed reinforcement, the crack widths are evenly distributed over the height of the column, the larger ones at the bottom, and the smaller ones because the distance from the bottom is greater. The same applies to the distribution of rotations along the height. This explains why the plasticizing zone in specimens with ribbed reinforcement is distributed at a higher column height than in specimens with smooth reinforcement. For specimens with ribbed reinforcement, the differences in the results of the cyclic and monotonic tests should be emphasized. The specimen subjected to the cyclic test showed a similar behavior in the area of the plastic joint as the specimen with smooth reinforcement (two cracks dominating at the bottom of the element), in contrast to the monotonically tested specimen where the results are significantly different. Alternating load cycles cause the concrete to be crushed in the vicinity of the reinforcement ribs, resulting in a larger area of the non-anchored part of the reinforcement and therefore greater relative deformation. From all the above it can be concluded that this behavior in the vicinity of the ribbed reinforcement further contributes to the ductility of elements made with highly ductile ribbed reinforcement (B 500 B). The behavior of the elements in the vicinity of the formation of plastic joints under the influence of seismic loads has not yet been sufficiently investigated. This refers primarily to structural elements that were erected before the adoption of regulations and guidelines for the seismic calculation and design of earthquake-resistant elements, to elements that do not have adequate quantities of transverse reinforcement and reinforcement for the concrete core enclosure according to modern design guidelines. Due to the special characteristics of their structural elements, but also the way they react to seismic actions, bridge structures must be included in future guidelines for the assessment of existing structures. These guidelines will certainly become increasingly applicable due to the large number of structures that require a more detailed analysis of the load-bearing elements to determine their actual seismic resistance. The results of this research are applicable to the analysis of the basic indicator (Diagram M/\(\varphi\)) of the seismic resistance of atypical cross-sections. It will allow for the application of an analytical or numerical method with realistic properties of the materials and elements and the derivation of correction factors due to the effect of slippage of the smooth reinforcement from the anchorage area. Conceptualization, M.S. and A.M.I; methodology, M.S. and A.M.I; software, M.S. and A.V. ; validation, A.M.I., A.V., and G.H.K. ; formal analysis, M.S. ; investigation, M.S.