ABSTRACT
This ongoing theoretical and experimental study relates to pre-stressed concrete portal frames, subjected to long-term loads. For structural and crack predictions, virtual work principles was used to estimate (a) transient strains due to the concrete creep and shrinkage, (b) the resulting time-dependent stress redistribution, as well as (c) the displacement variations in the frames and finally (d) the pre-stressing losses in the high yield tendons. The concrete shear stresses have been evaluated by the principle of Juravskiy. The need to validate the numerical results, required a series of controlled experiments supporting the evaluations at (a) to (d), in addition to (e) calibrating the parameters of the pre-stressing losses, (f) predicting the portal frames sections’ stiffness and strength by determining the flexural and non-linear creep capacity of the frames’ sections and hence, (g) devising a definition for structural durability and integrity, with regards to concrete stress-strain relationship under sustained service loads.
