Reinforced concrete slabs are extensively used for the construction of floors and bridges. Nowadays, engineers dispose of plenty of methods and techniques for analysing structural behaviour of reinforced concrete slabs, but many such methods are either over-conservative, inadequate for daily uses or non-automated. A large part of the technical knowledge associated with slabs collapse today is based on past failures of bridges, floors, flat roofs and balconies. Each collapse mechanism has its unique features which make it difficult to derive a generalised technique that can predict the right mechanism.

A new pseudo-lower bound method for the assessment of concrete slabs and detection of collapse mechanism is proposed in this manuscript.

An estimation of load-bearing capacity of...[ Read more ]

Reinforced concrete slabs are extensively used for the construction of floors and bridges. Nowadays, engineers dispose of plenty of methods and techniques for analysing structural behaviour of reinforced concrete slabs, but many such methods are either over-conservative, inadequate for daily uses or non-automated. A large part of the technical knowledge associated with slabs collapse today is based on past failures of bridges, floors, flat roofs and balconies. Each collapse mechanism has its unique features which make it difficult to derive a generalised technique that can predict the right mechanism.

A new pseudo-lower bound method for the assessment of concrete slabs and detection of collapse mechanism is proposed in this manuscript.

An estimation of load-bearing capacity of slabs is performed through an algorithm 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. Such algorithm provides a lower bounded estimation of the intensity of load causing global failure and a configuration of yielded elements in the slab.

Subsequently, the problem of detection of collapse mechanism is tackled through a junction of combinatorial optimisation algorithms. The proposed approach enables an identification of the domain of existence of yield-lines potentially leading to collapse. The output provides an estimation of a hampered domain of feasible yield-lines through which designers can identify zones of the slab and directions in which yield-lines leading to collapse are more likely to occur.

Numerical applications of the algorithm for assessing load-bearing capacity of reinforced concrete slabs and detecting the most critical collapse mechanism are presented herein. The method is tested on a set of cases of academic and industrial importance including assessment of a railway bridge and a floor slab. In most cases, great accuracy is achieved.

Based on the assumptions at the basis of the method, future research works are recommended to improve the reliability, accuracy and adaptability of the proposed method.