Study of using resins to increase the durability of flax and sisal fibres to be used into FRCM

The aim of this project is to study the influence of the durability of the natural fibre coated with a different type of resins (polyester and epoxy resins). Sisal and flax are the natural fibres used in this study coated with polyester and epoxy resins. There are 2 polyester resins which are Cronolita and a mixture of Cronolita and FT Silmar, and another 2 epoxy resins which are MasterBrace and Resoltech. The samples are immersed in the alkaline solution for 24hours, 7days and 14 days as the alkaline solution which is sodium hydroxide with the concentration of 0.1M simulated the alkaline environment in the cementitious matric fabric. As well as taking the uncoated fibres as control samples. After the immersion, the samples are tested for the tensile strength test using an electromechanical MTS press and the data are recorded. From the results obtained from this project, it is observed that the coating of sisal and flax with polyester and epoxy resins increases the tensile strength and tensile modulus of the natural fibres. After the immersion for 7 days, the samples coated with polyester resin (Cronolita+FT Silmar) show a significant loss in tensile strength for flax. The flax coated with both polyester resins and epoxy resins show loss of tensile strength and tensile modulus after the immersion in the alkaline solution. The results show that there are physical and chemical degradation in the sample. While there is a high scatter within the results of the sisal coated with the resins. However, it is observed that the tensile strength is increased for the sisal coated with Cronolita and MasterBrace after the immersion in the alkaline solution. On the other hand, the sisal coated with Cronolita+FT Silmar and Resoltech loss their tensile strength. In addition, the tensile modulus shows a similar pattern as the tensile strength for the sisal coated with polyester and epoxy resins. The sisal coated with Cronolita and MasterBrace increased their tensile modulus after the immersion in the alkaline solution while the sisal coated with Cronolita+FT Silmar and Resoltech loss their tensile strength