Fundamental principles that govern retrofitting of reinforced concrete columns by steel and FRP jacketing

Extensive investigations on seismic retrofitting of reinforced concrete columns have been undertaken in recent years and many retrofitting methods have been developed and reported in the literature. However contradictory results and conclusions are not rare especially for jacketing of rectilinear columns, and there is not a clear picture on the current state-of-the-art in the literature. This work is based on the review and assessment of more than 120 papers, and collection and analysis of more than 700 column tests. In combination with the authors' original theoretical studies and experimental testing, this work identifies the key factors that affect the effectiveness and deficiencies of different retrofitting techniques and provides engineers with a clearer picture on the capabilities of different retrofitting techniques, in particular how to improve the effectiveness of a jacketing system. From the theoretical studies, this work also provides researchers with fundamental insight and principles that govern the retrofitting of RC columns, which shed light on the development of new models and identification of further research subjects.