Now showing 1 - 3 of 3
  • Publication
    Reliability assessment of braided BFRP reinforcement for concrete structures
    (CRC Press, 2017-05-25) ;
    In recent years the long term durability of reinforced concrete structures has become a major concern. The effect of harsh loading conditions and aggressive environmental factors can lead to corrosion of reinforcing steel in civil engineering applications. This in turn leads to undesired repairs, additional costs and shorter service lives. Advanced composite materials, such as Basalt Fibre Reinforced Polymer (BFRP), have the capacity to significantly address this problem. These materials have enhanced physical properties such as higher mechanical and corrosion resistance, and have the potential to replace traditional steel rebars as tension reinforcement in concrete. There are however limitations that prevent their use on a larger scale, and lack of ductility is the most significant. Braiding techniques could provide the required performance benefits related to the additional ductility and flexibility needed, as well as enhancing the bond between FRP and concrete. If this is achieved, it has the potential to prevent a brittle failure and successfully meet strength, reliability and cost demands. This study focuses on the basics of materials characterization and reliability analysis of internal BFRP reinforcement for concrete structures towards design optimization for structural reliability over their service life. 
    Scopus© Citations 4  338
  • Publication
    Development of Braided Basalt FRP Rebar for Reinforcement of Concrete Structures
    (The Hong Kong Polytechnic University, 2016-12-16) ; ;
    In recent years, the development and use of Fibre Reinforced Polymer composite materials in infrastructure have gained increasing attention worldwide. More specifically, natural mineral fibres such as basalt are currently being developed and are showing promising properties. Within an appropriate polymer matrix, their use as reinforcement in concrete structures offers performance benefits related to their environmentally friendly and non-corrodible nature. In particular, BFRPs have the potential to replace conventional internal steel rebar and thus, to be the next generation material in concrete reinforcement applications. A detailed literature review indicates that a careful selection of the appropriate manufacture technique and design methodology are required in order to prevent brittle failure on a concrete structure reinforced with FRP composite material. This paper reports on how to use the additional helical reinforcement and the braid configuration in order to increase strength, structural ductility and long term durability. Moreover, this study outlines the development of an analytical numerical model to predict the longitudinal elastic modulus of braided composites, as well as its validation by comparison of the results with available data from the literature.
      625
  • Publication
    A comparative study on different BFRP rebar design methodologies
    This study compares the physical properties and tensile behaviour of two different basalt fibre reinforced polymer (BFRP) rebar designs. Both types are developed using basalt fibres and epoxy resin as reinforcement and matrix respectively; composites with a constant cross section of 8 mm diameter are manufactured using a vacuum assisted resin infusion technique. The first configuration consists of eight braided layers at various angles, while the second one combines a unidirectional core with four outer braided layers. The latter hybrid design is introduced to improve the elastic modulus of braided BFRP reinforcement used in concrete structures. Tensile performance of all BFRP rebars produced in UCD laboratory is numerically and experimentally evaluated, and results for both approaches are compared. The effective longitudinal in-plane modulus and the fibre volume fractions (φf) of each sample is calculated using the classical laminate theory and then, tensile tests are performed in accordance to the B2_ACI 440.3R-04 standard to experimentally validate the numerical results. Initial findings indicate that the elastic modulus of BFRP rebar can be enhanced by combining braiding with a unidirectional fibre core while a sufficient tensile strength is obtained, but additional research towards an optimal hybrid design is required.
      415