fib-Task Group “Structural Design with flowable concrete

Flowable concrete is evolving from a special type to a widely applied building material. Design guidelines have to consider recent developments on the field of innovative, performance-based materials and production technology. The new fib-Task Group 8.8 (Structural design with flowable concrete) started in 2009 to facilitate the use of innovative flowable materials for the design of concrete structures. Taking into account research findings and practical experience, the main objective of fib TG 8.8 is to write recommendations on the structural design with flowable concrete. Main aspects of the structural design process are to achieve strength, durability and, in case, aesthetical appearance. In order to pursue this goal when using flowable concrete, a 'holistic approach' is needed which has to combine the following three aspects: material properties, casting (production and manufacturing) techniques and the shape of the structure. Due to the flowable nature of such types of concrete, rebars can become an obstacle, components may float or segregate and the casting technique determines the fibre orientation. This paper describes the scope of fib-Task Group 8.8, discusses existing design rules for high performance concretes and indicates the potential of flowable concrete. An international commission works on establishing a basis for the future implementation of flowable concrete in design guidelines