Reinforced Concrete Frame Systems Research Articles

Performance of Degrading Reinforced Concrete Frame Systems Under the Tohoku and Christchurch Earthquake Sequences

Field investigations after the recent Tohoku and Christchurch earthquakes reported failure of structural systems due to multiple earthquakes. In most failure cases the reported damage was mainly due to dramatic loss of stiffness and strength of structural elements as a result of material deterioration due to repeated earthquake loading. This study aims to investigate the degrading behavior of reinforced concrete frame systems subjected to Tohoku and Christchurch earthquake sequences. Numerical models of RC frames that incorporate damage features are established and inelastic response history analyses are conducted. The results presented in this study indicate that multiple earthquake effects are significant.

Ethical Considerations for a Better Collaboration Between Architects and Structural Engineers: Design of Buildings with Reinforced Concrete Frame Systems in Earthquake Zones

Architects design building structures, although structural design is the profession of structural engineers. Thus, it is better for architects and structural engineers to collaborate starting from the initial phases of the architectural design. However, this is not very common because of the contradictory design processes and value systems held within the two professions. This article provides a platform upon which architects and structural engineers can resolve the value conflicts between them by analysing phases of the structural design of reinforced concrete frame systems in architecture, the criteria of the structural design for each phase and determining the conflicting values for each criterion. The results shown in the article demonstrate that the architectural design of structures is a complex process, which is based on contradictory values and value systems. Finally, the article suggests to architects and structural engineers to use Value Sensitive Design and to choose an appropriate team leader in order to resolve the unethical conflict between them and to avoid any unreasonable decision making.

Performance-Based Seismic Retrofit of Existing Reinforced Concrete Frame Buildings using Fibre-Reinforced Polymers: Challenges and Solutions

The need for simple and cost-effective seismic retrofit solutions for existing reinforced concrete (RC) buildings, particularly those designed before the 1970s, prior to the introduction of modern seismic code provisions and capacity design principles has been recognized as a critical socio-political priority at the international level. Similar to what was pursued for the design of new structures, a performance-based approach has to be adopted when assessing the vulnerability and defining the retrofit strategy for existing buildings. In this contribution, an overview of recent evidence-based developments in the field of fibre-reinforced polymer strengthening of existing RC frame systems has been presented.Based on experimental tests, and analytical–numerical results as well as experience from on-site applications, particular focus will be given to the discussion on feasibility and efficiency of low-invasive implementation techniques targeting the exterior corner joints of a building in order to guarantee minimum interruption to the functionality of the building.