Flächige Tragstrukturen aus textilbewehrtem Beton : Experimentelle und numerische Charakterisierung des Tragverhaltens, Bemessung und Herstellungsmethodik

摘要

Textile reinforced concrete (TRC) is an innovative composite material consisting of a fine grained concrete and a non-corroding textile reinforcement made of high strength carbon or alkali-resistant glass fibers. Due to the non-corroding textile fabrics thin-walled, light-weight structures can be constructed with TRC. In Germany in two collaborative research centers, one at RWTH Aachen University and the other at the Technical University Dresden, the new composite material was systematically investigated in recent years. Based on interdisciplinary research results experimental and numerical methods have been developed for material characterization giving a deeper insight in the complex material behavior of the new composite material.The high application potential of TRC in the construction industry has been demonstrated by various application examples ranging from large-sized facade elements, self-supporting sandwich panels to pedestrian bridges. Furthermore, the innovative composite has a high application potential in the field of strengthening of existing steel reinforced concrete structures. The material characteristics of TRC are also particularly attractive for filigree concrete shell structures as the flexible textile fabrics can be easily adapted to complex curved geometries. Due to their low weight TRC structures can be efficiently fabricated as precast elements and mounted on site. Compared to conventional steel reinforced shell structures using labor-intensive formworks the technical challenges arising in the context of TRC constructions shift to lifting, adjusting and coupling of the individual precast elements.As the dimensioning approaches developed within the collaborative research center mainly focus on linear structural elements such as truss and beam elements they had to be adopted to spatial structures and general loading conditions. Therefore a dimensioning approach for TRC shell structures with combined normal and bending loading has been developed. The underlying n-m interaction diagram is based on the cross-sectional strength characteristic of the composite. The nonlinear load-bearing behavior of TRC shell structures including stress redistribution has been investigated with a formulated anisotropic damage model. Starting point of the developed calibration procedure for the material model is the characteristic strain-hardening response of the composite material measured in the tensile tests. In order to provide a reproducible material characterization suitable test setups for TRC are needed. The developed experimental and numerical concepts are described in detail and exemplified for two TRC shell structures recently constructed at RWTH Aachen University. Furthermore, the fabrication technique applied for TRC shell structures is described differing strongly from the approaches used for conventional steel reinforced concrete. Especially the high positional accuracy within the cross-section of the filigree TRC shells requires innovative solutions.