Bacillus Subtilis Immobilised Areca Fibre Mortar for Robust Self-healing

Abstract

This study focuses on developing a bacteria-based self-healing mortar by immobilizing bacteria with Areca Nut Husk Fibre (ANHF). ANHF is an agricultural waste that is eco-friendly, lightweight, renewable, and sustainable construction material. The objectives of this study include determining the optimal ANHF percentage, self-healing potential, mechanical properties, and durability performance of developed mortar. The type of carrier material significantly influences the viability of bacteria and their calcite precipitation ability in self-healing concrete. The present study examined the possible application of natural fiber, ANHF and to carry bacterial spores that maximize-healing potential while maintaining structural integrity in concrete. Along with Bacillus subtilis VEB4 bacteria, calcium lactate pentahydrate and, urea are used as organic nutrients. The study examined the effect of adding ANHF at different volumes of mortar (0, 0.25, 0.50, 0.75, and 1%).The mortars showed the maximum mechanical strength at an ANHF content of 0.75%. The fiber-reinforced bacteria-immobilized mortars exhibited 100% healing. A maximum crack width of 0.813 mm was healed after 56 days, while controlled specimens healed partially. SEM, FTIR and, XRD tests on Fibre bacterial mix revealed that calcite is the predominant mineral substance with a few microbial imprints on the crystalline surface. Mechanical property analysis includes compressive and flexural strength evaluations. The research assesses the material’s durability through resistance to alkaline and acid substances. The findings aim to contribute to sustainable construction materials by offering an eco-friendly solution to concrete deterioration. The optimized microbial mortar, with improved self-healing, robust mechanical properties, and durability, holds promise for applications in civil engineering, promoting resilient and long-lasting concrete structures. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.