Creep Influence on Reliability and Stability of Concrete Structures

Precast and prestressed concrete slabs and beams have been investigated. For structural and crack predictions, the virtual work principles have been successfully used to estimate specifically for the slabs (a) transient bi-directional strains due to the concrete creep and shrinkage, (b) the resulting time-dependent bi-directional stress redistribution, as well as (c) bi-directional displacement variations in the slabs and finally (d) bi-directional prestressing losses in the prestressed tendons. A series of test experiments with once evaluated strength parameters has been successfully used to provide encouraging support for the numerical evaluations said at above points (a) - (d) in addition to (e) calibrating the parameters likely to enable the estimation of the above said losses, (f) predicting the beams and slabs sections’ stiffness and hence, (g) devising a definition for durability and integrity, with regards to the concrete stress-strain relationship under prolonged service loads.