Stabnetze aus Textilbeton : geometrische und konstruktive Studien zur Verwendung von Textilbetonbauteilen bei einlagigen Stabwerkschalen

Schätzke, Christian; Schneider, Hartwig N. (Thesis advisor); Feldmann, Markus (Thesis advisor)

Aachen (2015)
Dissertation / PhD Thesis

Aachen, Techn. Hochsch., Diss., 2015

Abstract

Lattice nets and grid shells are single- or multiply curved bearing structures which consist of bars and nodes. Due to the very convenient ratio of spanned area and material input they have a light and filigree appearance. Steel and timber are the preferred materials for the construction of the supporting structure, while concrete is not suitable here due to its mechanical, constructive and design properties. Textile reinforced concrete (TRC) exists for a few years now and is a new composite material with material characteristics that clearly differ from reinforced concrete and make it useful for light-weight frameworks. In this context, the main issue is how structural shape, production technology and joining methods influence the component design.Due to the two-dimensional textile reinforcement material, using TRC is mainly suitable for flat surfaces like façade elements or monolithic shell structures. However, grid shells consist of a net of load-bearing rod-shaped parts that allow only a very low level of reinforcement. Therefore, when using TRC parts in grid shells, the types of structure systems that induce compression loads and no or low bending loads in the building elements are most suitable. Beyond that, TRC has pronounced prefabrication characteristics which makes joining multiple rods in the manufacturing process useful and results in construction parts with a polygonal or graphene shape. Such types of building element concepts can to some extent already be found in a few historic concrete structures from the 1940s to the 1960s. Compared to systems with bars and nodes, parts with a polygonal or graphene shape show a different relation to the corresponding net of the lattice structure which leads to different local geometrical situations in the nodes of the net and results in different joining principles. By geometric analysis, these aspects are examined in various single- and multiply curved structure shapes and building element concepts. Here, particularly polygonal elements offer options for a radical simplification of the local geometrical situation in the joins.In constructive studies, the effects of local geometry, production technology and joining methods are exemplarily examined and documented with prototypes. As in the geometric analyses, polygonal concepts also show significant advantages in the constructive design. The integration of the textile reinforcement and the joining of the building elements have a strong influence on the shape of the component. The knotless connection of the elements allows the construction of very homogenous lattice nets with aesthetic qualities that have not been connected with concrete in the past.