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This paper describes two models used in the modeling strategy for textile reinforced concrete. The modeling of multi-filament yarns and of the bond between yarn and matrix is focused on micromechanical aspects of the material behavior. The calibration procedure of the model is explained on an example of a detailed experimental and numerical study of pull-out specimen. We demonstrate the use of the model for numerical homogenization to derive effective parameters at the meso level. In parametric studies we analyze the influence of local imperfections in the microstructure arising in the production process on the meso- and macromechanical properties of the material.

Although the bond of a multi-filament yarn in a cementitious matrix is controlled by the bond properties between filaments and matrix, more detailed information is needed to evaluate the failure mechanisms of such a complex system under a pull-out load and hence allow an analytical and numerical simulation of this composite. In this study innovative test methods are presented and used to identify the debonding process of a yarn as a result of the pull-out process, and ascertain the contact faces between the individual filaments and the matrix. Additionally, numerical procedures are proposed based on these findings and allow to establish a direct relationship between the load history of a pull-out test, and the failure process of an AR-glass yarn, by means of a mathematical function, defined as the active filaments versus displacement relation NF(O). Together with the load versus displacement relationship P(O) derived also during the pull-out test an analytical characterization and simulation of the bond between an AR-glass multi-filament yarn and a cement based matrix will be possible.

This paper presents the research activities in the field of textile reinforced concrete carried out by the Institute of Textile and Clothing Technology (ITB) of the Technische Universitaet Dresden, Germany. Extensive research has been conducted with the aim to fully use the tensile strength of the applied high-performance fiber material in the reinforcing textile. To achieve this, the textile machinery was adjusted and improved and new testing methods were developed. This research has resulted so far in several innova-tive applications for the repair of buildings as well as the production of precast concrete members. This paper was originally presented in 2005 Spring ACI Convention, New York under the title "State of the art and perspectives of textile reinforcements of con-crete components."

Cement-based materials are brittle in nature, with high compressive strength and low tensile strength and toughness. Therefore, the use of these materials in practice involves their combination with reinforcement. This article demonstrates possible reinforcing strategies by using textile structures with high strength behavior. Different textile structures are shown as they are used in practical applications more and more. A special focus will be put to the production and design possibilities of 3D-textiles. Although there are two definitions for 3D-textiles, the 3D-structures as well as the 3D-geometries here mainly the 3D-structured spacer fabric are described. A double needle bar raschel machine is the most common machine type for this type of 3D-textile production. Those 3D-textiles allow a defined positioning of the reinforcement as well as a providing of reinforcement in the third dimension. Finally a survey of possible applications for 3D-textile reinforced concrete elements are given.

Textile Reinforced Concrete (TRC) is a composite material taking advantage of the non-corrosiveness of fiber materials such as alkali-resistant glass (AR-glass), carbon or aramid in order to design slender and filigree structural elements. Compared to short cut fibers, a textile reinforcement features a higher effectiveness, because the fiber bundles are arranged in the direction of the main tensile stresses. These properties make TRC a promising construction material opening up new fields of application for concrete. In this paper, the results of experimental investigations and numerical simulations on TRC-components are presented. The load bearing behavior and important properties of TRC are described and the differences between the reinforcement materials AR-glass and carbon are elaborated. These differences are not only due to the different mechanical properties of the two materials but particularly the result of their different bond performance. Design models for the tensile strength and the bending capacity of TRC-components are given which have been derived on basis of the investigations.