Topological Exploration of Reinforced Concrete Shells

Author: Caterina Rovati
Language: English

Abstract

The constantly growing demands on infrastructure and the resulting consumption of resources pose a great technical and ecological challenge. This Master's thesis investigated the potential and suitable application areas of thin curved concrete load-bearing structures. For this purpose, an optimised procedure for the design and dimensioning of free-form shells was developed. The efficiency of the shells in terms of their load-bearing capacity and material consumption were evaluated using various criteria. The deformations of the structure under normative loading were compared with the serviceability limits. Using a design approach based on the sandwich model, which considers a central orthogonal reinforcement mesh of two layers, it was possible to determine the required reinforcement at each point of the shell. From the resulting reinforcement as well as the shell thickness, the CO2 footprint of the structures was compared. The aim was to identify the key parameters that lead to the most efficient shells. From the analysis, it was found that continuously supported shells with a concave plan geometry were the most efficient, especially when the edges at the supports were more curved. However, it must be taken into account that the results obtained are only an estimate, as the sandwich model was not applicable in every case. Furthermore, the importance of a flexible optimisation of the concrete thickness was shown, since, as expected, the concrete played the biggest role in determining the carbon footprint. Finally, the discretisation of the FE mesh plays an essential role in the applicability of the sandwich model, which offers great potential for improvements in both the modelling and the achievable design efficiency of the shells.