Structural stay-in-place formwork in textile reinforced cement composites for very slender concrete columns

The increasing interest in the architectural design of columns demands for new formwork and reinforcement techniques. This paper studies the use of textile reinforced cement (TRC) composites as a material for structural stay-in-place formwork of concrete columns. In wet phase, this composite shows similar advantages to fabric formwork for manufacturing freely shaped columns. Hardening at ambient temperatures, the TRC composite formwork allows for facilitated manufacturing of a priori fixed shapes. The TRC composite stay-in-place formwork can moreover replace the steel reinforcement of concrete columns. Eliminating the steel reinforcement, no concrete corrosion cover is required and very slender columns can be designed. This paper evaluates the structural as well as architectural potential of stay-in-place TRC formwork for the design of very slender concrete columns. The influence of the structural formwork on the loadbearing behaviour of circular concrete columns is studied. A design exercise, using these columns in a building structure, illustrates the new architectural design possibilities this stay-in-place formwork technique brings.