Enabling Foldable Textile Reinforcement Through Flexibility Modification via Tailored Fibre Placement

Abstract

The use of high-performance textile reinforcement for concrete enables the reduction of overall dimensions and thus the dead weight of structural members. These textiles are typically fabricated as orthogonal grids and impregnated with a polymeric resin. The impregnation of the textile is paramount to guarantee high strength and an effective load transfer from the concrete to the reinforcement. However, such impregnations stiffen the textiles and reduce drapability significantly. Other fabrication methods that are investigated in this work may offer more design flexibility. The production technology called Tailored Fiber Placement (TFP) is already well established in various fields of engineering, like the automotive and aerospace industries. This technology enables customized placement of rovings, wires, and tubes. By changing the orientation of the yarns at specific locations, we aim to tailor the flexural stiffness of the finished textile through this programmed anisotropy for enhanced bendability. This paper describes the manufacturing of internal textile reinforcements for concrete members with TFP and subsequent demonstration of the foldability of such advanced textiles. Therefore, different embroidered layouts were tested under bending tests to show their foldability. The results confirm an enhanced formability of the textiles compared to conventional orthogonal textile grids. The programmed anisotropy of the textile reinforcement led to a localisation of deformation at specific regions where the reinforcement provides minimal resistance, thereby achieving the desired outcome. Some of the designed patterns could achieve a 445% higher lateral displacement, compared to the orthogonal reference grid, before the first damage appeared.