Trade Journals for the Concrete Industry

Concrete with metal fibres was already mentioned into the 1960s in connection with initial investigations into the use of metal fibres in concrete pipes. The replacement of reinforcing steel by metal fibres offers structural advantages. In fact, the formation of cracks can be controlled by the addition of such fibres to concrete and the behaviour of the concrete after the formation of cracks (ductility) can be improved. Metal fibre reinforced concrete has developed significantly in the last 5 decades. The most diverse types of concrete have been developed, from the traditional high strength fibre reinforced concrete to concrete with an extremely dense microstructure, which ultimately enabled ultra high strength fibre reinforced concrete to be developed. This concrete enables concrete products to be produced that are particularly innovative with respect to design and mechanical characteristics. However the use of these fibres also gives rise to various problems, e.g. the handling of the small metal fibres, whose diameter lies within the order of microns. A further problem concerns the aesthetics, e.g. the corrosion of the fibres at the concrete surface. In parallel to this, new fibres have appeared on the market, such as polymer fibres, mineral fibres, carbon fibres etc. The research and development centre of the French concrete industry (CERIB, Centre d’Études et de Recherche de l'Industrie du Béton) initiated a study aimed at inves tigating more precisely the use of these non-metallic fibres for precast concrete parts. In this experimental study, the effects of the fibres on different types of concrete (from conventional to ultra-high-performance concrete) were investigated. The study design was selected in such a way that behaviour can be reproduced that resembles that of metal fibre reinforced concrete as closely as possible.