The flexural behavior of reinforced rubberized concrete beams was assessed, and it was demonstrated that they exhibited a constant performance decline with an increase in rubber content. Numerical simulations are critically important in the study and engineering of concrete elements due to several key reasons, as follows: to allow engineers to anticipate the behavior of concrete components under diverse loads; to help elucidate intricate mechanisms such as crack initiation, propagation, and fracture processes; and to explore new materials, geometries, and reinforcement layouts without the need for extensive prototyping. This paper presents both experimental and numerical investigations on the flexural behavior of conventional and rubberized concrete reinforced beams. The parameters of the research included the percentage replacement of natural aggregates by rubber particles and the change in the longitudinal reinforcement ratio. The results showed an increase in the load-carrying capacity and a decrease in the midspan deflection with an increase in reinforcement ratio. Substituting natural aggregates with rubber particles resulted in a slight decrease in the load-carrying capacity but an increase in the midspan deflections. Numerical simulations using ATENA v5 software predicted the load-carrying capacity, failure mode, and cracking patterns of the reinforced concrete beams.

High-rise residential buildings (22 m < buildings’ height < 36 m) represent an architectural-engineering performance model that optimizes the ratio between the percentage of occupied land and the utility of the space built. Designing residential buildings with a structural system composed of reinforced concrete (RC) frames with wide rectangular columns (WRC) is a challenge accepted and met by engineers. This type of structures can allow a prefabrication percentage of the structural elements up to 70% (only the columns and the slabs are cast in place). Another advantage is represented from the architectural point of view by the absence of the inner corners, which cannot be avoided in case of classical columns. Such buildings were designed and erected in Iași, Romania in the 1980s, in accordance with the calculation models and regulations of that period. The paper presents the analysis of an existing high-rise residential building with WRC by response spectrum (RS) and Time-history analysis (THA). A set of artificial accelerograms was generated based on earthquakes recorded at the site. The numerical model was chosen to match the input data used for the initial calculation of the structure. The results show that these types of buildings are stiffer than traditional framed structural systems and that under the action of major earthquakes the possibility of failure is high. The results have been compared with the current requirements of the standards highlighting the performance and weaknesses of these structural systems. The aim of the research is to identify vulnerabilities for rapid and targeted response in the event of a major earthquake.