Effect of thermoplastic impregnation on the mechanical behaviour of textile reinforcement for concrete

In recent decades, textile reinforced concrete (TRC) has become increasingly important, both in research and the construction industry. It is a resource-efficient material alternative to conventional, steel reinforced concrete due to the use of non-corroding high-performance textile reinforcements and the resulting material savings. Typically, thermoset polymer materials are used as impregnation for the textile reinforcement to improve the mechanical behaviour. However, due to their chemically crosslinking behaviour, these materials prevent subsequent product-specific shaping of the reinforcement. The use of thermoplastic impregnation materials shows potential to allow shaping by utilizing the thermal forming behaviour, provided that the resulting properties of the reinforcement system in terms of mechanical performance are not inferior to those of the already available impregnations. In this study, four impregnation systems are investigated on AR-glass textiles with regard to their effect on the mechanical behaviour of the reinforcement and classified in comparison to the current benchmark epoxy and styrene butadiene rubber (SBR) by conducting single yarn tensile tests and supporting microscopy analysis. The thermoplastic impregnation increased the tensile strength of the AR glass fibre to values in the range of around 1200 MPa with a low coating content to 1500 MPa with a high coating content. A strong dependence of the impregnation efficiency on the impregnation composition, in this case the solid content of the dispersion, was demonstrated as a result of pore formation. In conclusion, thermoplastic impregnation materials achieve strengths comparable to those of commonly used materials.