Partially loaded areas in reinforced concrete: Mechanical modelling

The introduction of high compressive forces on concrete members over limited contact areas is a common problem in engineering practice. Despite extensive research, a knowledge gap persists in the mechanical un-derstanding of this seemingly simple problem. This paper first summarises the state of the art regarding the bearing capacity problem in structural concrete and then introduces two new stress field solutions for plane and axisymmetric cases of partial area loading. Contrary to most existing design approaches, which are purely empirical, the models proposed build on consistent mechanical bases that ensure safe design. The stress fields consider consistently the beneficial effect of reinforcement and the multiaxial compressive strength of concrete. Moreover, they enable the flow of forces to be followed through the structure, resulting in consistent dimen-sioning and detailing of the reinforcement. The comparison with existing design approaches shows that the stress fields predict significantly higher bearing capacities, enabling the design of more efficient and sustainable structures. In a companion paper, the stress fields are validated with published experimental data and an extensive test campaign conducted by the authors.