Novel approach for strengthening of column by external wrapping with Carbon Fiber and Internally Embedded Damper System for resilient infrastructure

Abstract Columns as major structural components, lose strength due to sudden and accidental impacts. Such impacted columns can be restored by retrofitting, which increases their load-carrying capacity and lifespan, rather than reconstructing them. The common method of retrofitting involves externally wrapping the columns with fibre sheets. Numerous research studies have been conducted on enhancing the load-carrying capacity of a column by jacketing it with Fiber Reinforced Polymer (FRP). However, there is a lack of research on retrofitting columns internally to overcome vibrations produced due to impact loading. This paper addresses the retrofitting of a column both internally and externally. The external retrofitting is done by CFRP jacketing, and the internal retrofitting is achieved by developing a damper system to overcome damping forces. The experimental work aims to compare the load-carrying capacity of columns retrofitted internally with dampers and externally with CFRP jackets, with a plain concrete column. Dampers are evaluated based on energy absorption in comparison to plain cement mortar. It was found that energy absorption increased by 50% when the concrete was reinforced with 1mm chopped carbon fibers. Such reinforced concrete behaved as dampers, when placed inside the column to absorb the impact energy leading to a 9% increase in load-carrying capacity. The maximum load-carrying capacity was observed in columns wrapped with CFRP and damped with dampers, showing an increase of 25%. Finite Element Analysis is carried out to compare the experimental results and evaluate the damping property. Retrofitting a new column can enhance its initial load-carrying capacity, this helps in reducing the cross-section and percentage of steel usage in columns, contributing to sustainability. Retrofitting approaches to achieve 9th, 12th, and 13th sustainable goals, this leads to a significant contribution in the construction sector.