Concrete Column Confinement Using CFRP and Expanding Grout

Abstract

During the past earthquakes in Pakistan many existing reinforced concrete (RC) structures were destroyed due to the inadequacy of proper seismic design. It is found that the main failure of columns was due to insufficient shear strength and reduced ductility of structures. Therefore, improvement of seismic performance in such structures with consideration of shear capacity and ductility is vitally required. Low strength concrete is generally in practice in the progressing countries like Pakistan. Different approaches and methods have been used to retrofit and repair the ageing structures using different techniques. Present study focusses on the experimental investigation of concrete columns confined by pre-tensioning. Carbon Fiber Reinforced Polymer (CFRP) with expanding grout. A number of concrete cylinders specimens were prepared using selected quantities of expanding grout which produced various initial pressures. The behavior of pre-tensioned confined concrete with non-pre-tensioned confined concrete and unconfined concrete was compared. It was comprehended that an increase in initial confining pressure resulted in increase in axial stress as well as axial and lateral strains.