Interfacial properties and structural performance of resin-coated natural fibre rebars within cementitious matrices

This paper investigates the interface and behaviour of continuous natural fibre rebar reinforced cementitious composites. Various resins were used to coat sisal fibres which were then used as reinforcement within the composites. Non-destructive tests (SEM, OM, FTIR) were employed to evaluate the interfacial bonding and interaction between the sisal, resin and cementitious matrix. The results showed that the uncoated fibre could not develop a compact interface due to the moisture absorption/desorption of the fibre, which caused low mechanical properties of the composite. The coating was able to improve the strength of the rebars and reduce the OH- concentration, which improved the interfacial bonding and integrity. The flexural stress-strain relation of the composites exhibited three regions with two clear dips, reflecting the progressive stress transfer and failure of the composite constituents and their interactions. The comparable mechanical properties to those of steel rebar reinforcement demonstrate the potential of the resin-coated sisal fibre rebar for structural applications. (C) 2017 Published by Elsevier Ltd.