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Textile-reinforced concrete (TRC) is a high-performance composite material in which technical textiles composed of high-performance reinforcement fibers are embedded in a cementitious matrix. The technical textiles used in TRC are continuous reinforcement composed of a variety of materials such as alkali-resistant glass, carbon, aramid, and polymeric fibers. The continuous textile reinforcement provides enhanced tensile strength, ductility, and other features to the finished TRC composites. The TRC composites tend to be slender, lightweight, and capable of being designed into complex geometrical shapes and configurations. Thin TRC elements are also effective in retrofitting and strengthening existing weak and dilapidated concrete structures. Consequently, the use of TRC continues to grow very rapidly worldwide in a variety of applications. The material science and technology of textile reinforcement and cementitious matrix used for producing TRC composites is advancing rapidly, and is an active area of research and development in both academia and industry. This symposium publication contains papers originally presented in a symposium on TRC sponsored by ACI Committee 549 during the ACI Fall 2005 Convention in Kansas City, Missouri, USA. The symposium explored the current state-of-the-art and recent advances in material science, mechanical behavior, production methods, and practical applications of TRC. Important topics covered in this publication include material science and technology of textile reinforcement and cementitious matrix used in TRC, design methods for TRC, structural behavior of TRC, applications of TRC, production methods of TRC, and numerical modeling of TRC composites. The papers presented in this publication have been peer reviewed by the experts in the field according to the guidelines established by the American Concrete Institute. It should be emphasized that the future of TRC depends largely on its ability to compete cost effectively with the existing and other alternate emerging technologies. Because TRC is an emerging technology in itself, considerable research and development efforts are needed on various fronts to make the art viable and acceptable to end users and the industry. Significant research efforts are required to develop textile reinforcements that are strong, durable, processable, and economical. It is also crucial that research efforts be made to develop cement-based matrixes that have good compatibility and durability characteristics with the textile reinforcements involved. Further research and development efforts are also necessary to develop new processing methods for producing TRC composites efficiently and cost effectively.

Textile-reinforced concrete (TRC) imposes several special requirements on the applicable simulation methods. TRC is highly heterogeneous at several levels of material structures and, therefore, it exhibits a very complex failure process. Examples of interacting effects are the strain localization due to local failure mechanisms in the yarn, bond, and matrix. As a result, except for standard features, the developed models must be able to reproduce discontinuities of the displacement fields, reflect the irregularity of the material structure, special kinematics relations, and the size effect induced either statistically or energetically. This paper reviews the modeling strategies developed and applied in research and development of TRC in the collaborative research centers in Aachen and Dresden.

Textile-reinforced concrete has great potential for use in lightweight, thin-walled structural components. Since such elements participate directly in load transmission in the structural framework, satisfactory fire resistance is often desirable. Experience until now, however, has been limited with respect to the behavior of textile concrete elements subjected to fire. In this investigation, four fire tests have been performed on textile-reinforced concrete sections (I-profiles), in which one side of the sections was exposed to fire. The textiles tested were AR glass, carbon, and carbon coated with styrene butadiene. These experiments demonstrated that the load-bearing behavior of textile-reinforced structural components in fire greatly depends on the textile used, their bond to the concrete, and the behavior of the concrete under high temperatures.

As textile-reinforced concrete structures have small but a wide range of wall thicknesses, appropriate specimen sizes and testing procedures need to be defined. The objective of this paper is to derive the mechanical and fracture mechanical characteristics of the newly developed binder systems in relation to the possible size effects. The influence of specimen size and geometry on the compressive and flexural strength was investigated directly by experimental investigations on specimens of different sizes with a size range of 1:8. Subsequently, the results were analyzed with the size effect law (SEL) of Bazant and by means of FE analysis according to the fictitious crack model (FCM) of Hillerborg. Furthermore, the s-e relation for compression and tension as well as the s-w curve for tension were derived as being required for dimensioning TRC structures.

Textile-reinforced concrete is an interesting and promising material for thin-walled structural elements. Since sufficient fibers can be included when glass fiber reinforcement is introduced in the form of textiles, a distinct strain-hardening behavior can be obtained beyond the introduction of matrix multiple cracking. However, to improve the range of applications in which this material can be used, stress-strain behavior characteristics and crack control should be globally understood, as well as the parameters influencing them. Both properties are discussed as function of fiber volume fraction, matrix-fiber bundle interface, and the influence of complex fiber-matrix interaction. The constitutive material model that is used in this paper is based on the well-known ACK-theory (Aveston-Cooper-Kelly), but includes the fact that matrix cracking occurs progressively with increasing strength and not at one deterministic stress level.