CFRP-reinforced concrete-filled steel tubes with timber core under axial loading

This paper experimentally investigates the effect of Carbon Fibre Reinforced Polymer (CFRP) on the axial capacity of concrete-filled steel tubes with different timber cores. The stub columns were designed having the size of the infill and the CFRP as the main two variables. The structural response including failure, ductility, stiffness and structural efficiency were evaluated and discussed. It was found that the effect of timber core is significant in lightening the weight of the composite, although the total capacity of the composite depends upon the material properties of the core versus the grade of concrete and steel employed in the composite columns. For the structural applications, where the weight reduction and ductility are crucial, the development of this innovative composite is highly recommended. To quantify this, the ratio of ductility index to weight is introduced including these two crucial parameters in the seismic design. An equation is also developed to estimate the axial capacity of timber-concrete-filled steel tubes. Furthermore, the environmental and sustainability assessment are touched on briefly to pave a path for the future work aiming at possibly reducing the contribution of the concrete in the construction.