Towards modular Textile Reinforced Concrete (TRC) Shells

: A combined geometrical - structural - prototyping study

Abstract

Curved thin-walled shellstructures are very promising towards the future, as they possess the ability to carry their loads efficiently, resulting in very thin designs and therefore a reduced material consumption. However, the interest in these structures has declined over the last decades. The main influential factors for that are the demand of labour intensive fabrication techniques, the required skills of the workers and the high cost of the formworks. Recent developments of new construction materials and innovative fabrication techniques have led to a resurgence in this research domain. Using Textile Reinforced Concrete (TRC) in the shell designs significantly reduces the required cross-sectional thickness, because the fibres in the concrete cannot corrode and therefore have no need of a thick concrete cover. On top that, the fibres are very flexible, making it possible to easily create nicely curved surfaces. Still, a major issue is the cost of the formworks, as they are in many cases project-specific and therefore not reusable. Fortunately, recent research towards a modular design approach may solve this problem. Several modular parts are already designed, which can be assembled in many different ways to create a wide variety of shell configurations. As a result, only a few amount of formworks need to be made that can serve for a vast amount of shell structures. The main objective of my research is to investigate the structural behaviour these configurations and to evaluate their load bearing efficiency. A second objective is to evaluate the influence of considering different types of connections between the modules on the overall structural behaviour of the shells. The load bearing efficiency of the shells will be evaluated by looking at the section forces and the section moments that arise in them under self-weight. A few shells will undergo a more extensive evaluation in which there will be looked at the deformations, the stresses and their buckling behaviour. Two shell configurations will then be examined under an asymmetrical load, and the same evaluation parameters will be considered as the onesthat are used in the structural evaluation under self-weight. The entire evaluation will be done considering both fully fixed and fully hinged connections between the modules. The results are very promising, as it is observed that some of the considered shell configurations possess a better load bearing behaviour than the form-found structure from which the modules are extracted. The use of hinged connections is also justified, as no loss of structural integrity is detected in any of the shells. The asymmetric loads cases have led to higher maximum internal moments in the shells, compared to the ones induced under self-weight. This however is an expected result, and the magnitude of these maxima remains limited, which keeps it interesting to conduct further research on them.

Date of Award	2021
Original language	English
Supervisor	Tine Tysmans (Promotor) & Lars De Laet (Co-promotor)