What question did this study set out to answer?

This study aims to evaluate the performance of concrete modified with rice husk ash and bacterial agents for enhanced sustainability.

April 27, 2026Open Access

Strength and microstructural characteristics of conventional concrete incorporating rice husk ash and bacteria (Bacillus pasteurii and Bacillus subtilis)

OOOluwafunminiyi John OgundiranUniversity of Lagos OOOmanudhowho Isreal OrevaUniversity of Lagos OOOladipupo Oluwasegun OshoUniversity of Lagos

Key Points

This study aims to evaluate the performance of concrete modified with rice husk ash and bacterial agents for enhanced sustainability.
Incorporated rice husk ash at 0%, 4%, 8%, and 12% by mass alongside Bacillus pasteurii and Bacillus subtilis at dosages of 0–30 mL.
Assessed compressive strength, microstructural characteristics via XRD and SEM analysis.
Evaluated optimal mixes for mechanical properties.
RHA08BS30 mix (8% RHA + 30 mL B. subtilis) achieved peak compressive strength of 36.42 MPa.
RHA12BP20 (12% RHA + 20 mL B. pasteurii) reached compressive strength of 35.86 MPa.
XRD and SEM analyses indicated enhanced pore densification and biomineralization in bacterial mixes.

Abstract

To address the dual challenges of high cement costs and carbon emissions in the Nigerian construction industry, this study evaluates a sustainable high-performance concrete developed by combining agricultural waste (Rice Husk Ash, RHA) and bio-based self-healing agents. This synergistic approach uses the pozzolanic activity of RHA to densify the cement matrix while bacteria provide an autonomous mechanism to seal micro-cracks. The study investigated RHA replacements at 0%, 4%, 8%, and 12% by mass, combined with Bacillus pasteurii and Bacillus subtilis at dosages of 0–30 mL. Results indicated distinct optimal performances: the RHA08BS30 mix (8% RHA + 30 mL B. subtilis) achieved a peak compressive strength of 36.42 MPa, while RHA12BP20 (12% RHA + 20 mL B. pasteurii) reached 35.86 MPa. XRD revealed higher peak intensities for calcite in bacterial mixes, confirming biomineralization, while SEM showed improved pore densification. These findings demonstrate that optimizing bacterial species with specific RHA dosages significantly enhances mechanical properties and microstructural integrity, offering a scalable, sustainable pathway to reduce cement dependency.

Demander à l'IA

Bookmark

View Full Paper