Pseudo-lower bound method for assessing concrete slabs

Abstract

Slabs and plate-shaped concrete structures are extensively used for the construction of floors and bridges. Nowadays, engineers make use of plenty of methods and techniques for assessing the capacity of slabs, but many such methods are either over-conservative, inadequate for daily uses or non-automated. A new pseudo-lower bound method for the assessment of concrete slabs, in which such shortcomings are addressed, is proposed in this paper. The technique is based on a linear-elastic finite-element method considering moment redistributions due to yielding. The solution is achieved through an automated local optimisation procedure with a monotonically increasing load. As outputs, the method provides a lower bounded estimate of the intensity of load causing global failure and a configuration of yielded elements in the slab. Different examples are reviewed and the results were found to estimate load-bearing capacities well.