The bond between the textile reinforcement and the finegrade concrete (cementitious matrix) is essential for the structural behavior of textile reinforced concrete. The analysis of the bond behavior between roving and matrix is important for the development of computational methods analyzing textile reinforced concrete. Therefore, the pullout phenomenon of a roving from a matrix is investigated by analytical methods based on the implementation of various damage models for the interface.

The biocompatibility and osseous integration of a new composite material made of polyurethane and a calcium silicophosphate ceramic was investigated in a loaded implant model in sheep and compared to that of commercially pure titanium. Six months after implantation, interfacial shear strength was higher between the titanium and bone than between the composite and bone. After 2 years, however, the shear strength was significantly higher in the composite group. Histologically, both implants were surrounded by bone and fibrous tissue and there were no signs of inflammation. Direct contact of bone on the composite surface increased significantly with time, whereas there was no time-dependent increase of bone contact on titanium. It can be concluded that the biocompatibility and osseous integration of the composite was very good in the loaded implant model used. It is therefore suggested that the new composite is a promising biomaterial for orthopaedic implants.

Using a high-speed tribometer, coefficients of friction for bobsled runners were measured over a wide range of loads and speeds. Between 2.8 m/s and 28 m/s (equal to 10 km/h and 100 km/h), the measured coefficients of friction showed a linear decrease with increasing speed. e experiments revealed ultra-low friction coefficients of less than 0.01 aer exceeding a sliding speed of about 20 m/s. At maximum speed of 28 m/s, the average coefficient of friction was 0.007. e experiments help to bridge the gap between numerous low-speed friction tests by other groups and tests performed with bobsleds on real tracks. It was shown that the friction data obtained by other groups and our measurements can be approximated by a single master curve. is curve exhibits the largest decrease in friction up to a sliding speed of about 3 m/s. e further increase in speed generates only a small decrease in friction. In addition, friction decreases with increasing load. e decrease stops when ice wear becomes effective. e load point of constant friction depends on the cross-sectional radius of the runner. e larger the radius is, the higher the load is, before the ice shows signs of fracture. It turned out that besides aerodynamic drag (not considered in this work), ice friction is one of the main speed-limiting factors. In terms of runner geometry, a �at contact of runner and ice ensures the lowest friction. e rocker radius of the runner is of greater importance for a low coefficient of friction than the cross-sectional radius.

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Textile reinforced concrete (TRC) is a composite of rovings (multi filament yarns) and fine grained concrete which is used in civil engineering to fabricate new structural elements and to strengthen existing constructions. The proposed multi–scale approach is based on a hierarchical material description on the micro, the meso and the macro scale. The paper deals with structural models of the macro scale, using the detailed information of the micro– and the mesoscopic models to simulate the behavior of typical structural members made of reinforced concrete. Due to the textile reinforcement in TRC the crack opening displacements are very small. This leads to the major influence of the post cracking behavior of concrete on the overall response of the structural member. In the case of a steel and textile reinforced concrete plate the simulated crack width of the meso model is used to capture this effect within the framework of a multi–scale analysis. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)