Axial compression behaviour of retrofitted long timber columns

Abstract

Spliced joints are used widely in retrofitting traditional timber structures, especially in heritage conservation applications where as much original material as possible needs to be retained. However, in practice this method is mainly applied based on experience, and there is a lack of understanding and quantification of the mechanical behaviour of retrofitted timber members. This article presents an experimental study on the axial compression behaviour of splice-jointed timber columns. The splice joints are reinforced by steel jackets, steel jacket with adhesive, ear hoops and carbon fibre–reinforced polymer wrapping, respectively. The performances and effect among these enhancement methods have been compared based on the failure modes and deformation, stiffness and strength measurements. The results show that the load-bearing capacity of the spliced columns reinforced with steel jacket and further enhanced by epoxy adhesive could recover about the full capacity of the reference columns. The load-bearing capacity of the retrofitted columns reinforced by ear hoops could reach 91% of the reference specimens. The weaker rigidity of the carbon fibre–reinforced polymer joints tends to affect negatively the loading capacity of the retrofitted columns.