Enhancing resilience of underground concrete structures using indigenous soil bacteria and supplementary materials

Concrete degradation threatens the durability of underground structures, as cracks allow water and gases to penetrate, compromising steel reinforcement. This research aims to enhance the resilience of underground concrete by leveraging indigenous soil bacteria instead of adding bacteria directly to the mix. High pH levels and reduced pore space in concrete hinder bacterial survival. To address this, supplementary materials were used to reduce pH and promote bacterial activity. This study builds on previous studies at the University of Derby.  It replaces 50% of Ground Granulated Blast Furnace Slag (GGBS) in cracked cement mortar with saturated natural soil, targeting sustainable solutions for concrete degradation. Crack sealing was assessed using microscopy, water absorption tests, and SEM-EDX analysis. Soil sieve analysis and pH measurements were also conducted to evaluate the chemical environment. Findings contribute to innovative, sustainable methods for improving the performance and durability of underground concrete structures.