In recent years, degradation of reinforced concrete (RC) structures due to corrosion of reinforcing steel has become a major concern worldwide. This affects long-term durability, total service life and structural safety of RC elements. Advanced composite materials, such as Basalt Fibre Reinforced Polymer (BFRP), are currently being developed and are showing promising results as a viable alternative to steel in infrastructure applications. More specifically, these materials can offer significant advantages related to both their non-corrodible nature and their enhanced physical and mechanical properties. However, their brittle nature is considered as the main limitation preventing their use on a larger scale. A detailed investigation of manufacturing technologies and design methodologies for the optimum development of BFRP composites, indicates that braiding methods could provide the required performance benefits through increased ductility and flexibility; it can also enhance the bond between FRP and concrete.
This study focuses on exploring the potential of braided Basalt Fibre Reinforced Polymer reinforcement through design optimisation and evaluation of their structural performance. Braided BFRP preforms with different configurations were produced changing key braiding parameters in order to achieve the desired structural geometry and meet the performance characteristics of existing rebar reinforcement. Following from that, successful epoxy resin impregnation trials in regular and spiral configurations confirmed the possibility of manufacturing braided BFRP composites in complex shapes. Moreover, a theoretical numerical approach based on Classical Laminate Theory (CLT) has been developed to determine the stiffness properties of manufactured braided composites, calculating the effective longitudinal in-plane modulus of each braided sample. The relation between geometrical factors and processing conditions on the physical and mechanical properties of the braided rebars was clearly observed. Future plans include assessment of the manufacturing process for improved rebar design, advanced material analysis and characterization tests combined with experimental validation of the developed numerical approach. In addition, finite element analysis (FEA) models will be developed for braided BFRP composites in order to assess the relation between braiding parameters and rebar performance.