Effect of strain ageing on the mechanical properties of steel and concrete materials under extreme loading

The behaviour of structural materials under extreme loading conditions is a key element in retrofitting of partially-damaged structures. Mechanical properties of construction materials can substantially change by time effects, which is the main focus of this research work. The strain ageing effect on partially damaged structures has not been incorporated in civil engineering design guidelines. The strain ageing effect is comprehensively investigated in this thesis for steel and concrete materials partially-damaged by single or combined actions of quasi-static, cyclic or high strain rate loading and thermal loading. The original experimental results reported in this research work can be used to develop constitutive material models incorporating strain ageing effect for the prescriptive codes of practice and finite element method based software packages where rational structural analysis and design are required.