Biomineralisation to Increase Earth Infrastructure Resilience

Area of Science:

• Materials Science and Engineering
• Civil Engineering
• Biotechnology

Background:

• Global infrastructure faces significant risks from flooding and rain due to limited adaptive capacity.
• Enhancing infrastructure resilience through bio-resources and improved engineering performance is critical.
• Earth-based and cement-based mortars are common construction materials with varying vulnerabilities.

Purpose of the Study:

• To analyze the engineering performance of earth-based mortars stabilized with microbial mineral precipitation (biostabiliser).
• To compare the performance of biostabilized earth-based mortars with conventional cement-based mortars.
• To investigate the impact of biostabilisation on water absorption, moisture buffering, mechanical strength, and microstructure.

Main Methods:

• Preparation of earth-based and cement-based mortars using S. oneidensis as a biostabiliser (6% binder ratio).
• Microstructure analysis using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS).
• Evaluation of water absorption, moisture buffering capacity, mechanical strength (compressive and flexural), and porosity.

Main Results:

• Biostabilisation significantly reduced water absorption in both mortar types due to calcium carbonate precipitation.
• Cement-based mortars showed a 60% reduction in water migration, while earth-based mortars had up to a 10% reduction.
• Earth-based mortars with biostabiliser showed a 10% increase in compressive and flexural strength; cement-based mortars nearly doubled in strength.

Conclusions:

• Microbial mineral precipitation effectively enhances the resilience of both earth-based and cement-based mortars.
• The biostabiliser's effectiveness in reducing water migration varies between earth and cement matrices.
• Biostabilisation offers a promising approach to improve the durability and mechanical properties of construction materials.