Evaluation of Coconut Fiber in Corroded Reinforced Self-Healing Concrete Using NDT Methods

Abstract

The incorporation of natural fibers into concrete has recently emerged as a popular approach in the field of construction materials due to its sustainability and environmental friendliness. In comparison to artificial fibers, natural fibers are more cost-effective and widely available globally. Among the various natural fibers, coconut fiber (CF) stands out for its unique set of advantages. This study aims to investigate the mechanical properties and durability of coconut-fiber-reinforced self-healing concrete (CFR-SHC) in the context of corrosion resistance. Additionally, Bacillus subtilis bacteria (10% by mass) was incorporated into the CFR-SHC. The impact of ±50 mm long CF with varying contents of 0.25%, 0.5%, and 0.75% by mass was examined. Specimens were subjected to corrosion acceleration for 48, 96, and 168 h. Non-destructive testing (NDT) methods of Electrical Resistivity (ER) and Impact Echo (IE) were conducted to test the corrosion resistance. The experimental results demonstrate that CFR-SHC increased the compressive strength by 6% and the flexural strength by 40%. CFR-SHC also exhibits excellent resistance to corrosion, characterized by low inrush current, high ER value, and high IE frequency. The most favorable overall outcomes were observed for the CFR-SHC sample containing 0.5% of the cement mass.