DURABILITY ASSESSMENT OF BASALT FIBER REINFORCED RECYCLED AGGREGATE CONCRETE EXPOSED TO AGGRESSIVE CHEMICAL ENVIRONMENTS

Abstract

The utilization of recycled aggregates in concrete contributes significantly to sustainability; however, durability concerns under aggressive environmental conditions limit their widespread application. This study investigates the durability performance of basalt fiber reinforced recycled aggregate concrete (BFRC) exposed to acidic, sulphate, and chloride environments, focusing exclusively on long-term durability indicators. Concrete mixes were prepared with varying recycled aggregate contents and basalt fiber dosages of 0%, 0.2%, 0.4%, and 0.6%. Durability evaluation was carried out through acid attack using sulphuric acid, sulphate attack using magnesium sulphate solution, and rapid chloride penetration test (RCPT) in accordance with relevant standards for M20 grade concrete. Residual compressive strength was assessed after 28, 56, and 90 days of chemical exposure, while chloride permeability was evaluated at 90 days. The results indicate that recycled aggregate concrete without fiber reinforcement exhibits increased vulnerability to aggressive environments, particularly under acidic exposure. The inclusion of basalt fibers significantly enhances durability performance by improving residual strength retention and reducing chloride ion penetration. Among the fiber dosages investigated, 0.4% basalt fiber consistently demonstrated superior performance across all durability tests, exhibiting the lowest strength degradation under acid and sulphate attack and achieving low chloride permeability classification. The findings highlight the potential of basalt fiber reinforcement to offset durability limitations associated with recycled aggregates, enabling the production of sustainable concrete with enhanced service life and reduced maintenance requirements in aggressive environments.