The Effect of Biocontamination on Mechanical Strength and Moisture Transfer Performance of Epoxy Basalt Fiber Reinforcement Bar Exposed to Arctic Conditions

This study involved the exposure of epoxy-coated basalt-plastic rebars, with diameters of 6 and 8 mm, to the open climate conditions of Yakutsk and Tiksi, located in the Arctic region of Russia. The exposure duration was 54 months. Basalt-plastic rebars were tested both untreated and after contamination with a set of neutral microorganisms resilient to cold climates, including spore-forming bacteria from the genus <i>Bacillus</i>, and mold fungi from the genera <i>Aspergillus</i>. Results showed that after 12, 24, and 54 months of exposure, the tensile strength and modulus of elasticity of untreated rebars increased by 5-14% due to the post-curing of the epoxy matrix. However, in biologically contaminated rebars, these indicators decreased on average by 11%. Bacterial cells and fungal mycelium, which penetrated surface irregularities of the rebars under open climate conditions, contributed to microcrack development, reducing the mechanical properties of the basalt-plastic rebars and causing additional moisture diffusion in the radial direction of the bars.