A computational approach for direct and a priori estimation of the required pre-stressing in RFC structures

Ever since Eugene Freyssinet, the renowned French engineer first recognised the dramatic improvements in the performance of concrete structures by means of prestressing it has become a well-established method of construction.... [ view full abstract ]

Ever since Eugene Freyssinet, the renowned French engineer first recognised the dramatic improvements in the performance of concrete structures by means of prestressing it has become a well-established method of construction. Concrete naturally has a very high resistance to compressive loads but a much lower one in tension. In order to overcome this poor behaviour in tension, in addition to conventional steel reinforcement the prestressing of concrete structures was introduced to reduce the development of cracks at the extreme tension fibres.

For the design of prestressed members a trial and error approach may be used considering the serviceability and ultimate limit state requirements. This approach, however, can be very time-consuming due to its iterative nature and it is not guaranteed that the optimal prestressing configuration has been found.

In this research, a path-following method [1] has been paired with a Lagrangian formulation of the finite elasticity equations considering non-linear hypoelastic material for the concrete and linear elastic material for the rebars. The approach is implemented in a finite element framework allowing for direct and a priori estimation of the required prestressing in RFC structures. The method is exemplified for an open spandrel arch bridge and the occurring stress levels are subsequently investigated at the transfer and the under service stage, respectively.

[1] S. Skatulla and C. Sansour. On a path-following method for non-linear solid mechanics with applications to structural and cardiac mechanics subject to arbitrary loading scenarios. International Journal of Solids and Structures, 96:181–191, 2016.