Work

Physical and Mechanical Properties of Geopolymer Mortars Produced with Different Bacterial Strains within a Circular Economy Framework

Year: 2026

Type: conference-paper

Abstract: This study investigates the physical and mechanical performance of metakaolin–slag-based geopolymer mortars containing ureolytic bacteria, such as Sporosarcina pasteurii , and cave-derived bacteria, including Bacillus safensis and Micrococcus aloeverae , with a view toward exploring their self-healing potential. The incorporation of microbial healing in geopolymer systems aligns with circular economy principles by valorizing industrial by-products, enhancing material durability, and reducing the need for resource-intensive repairs. While laboratory strains like Sporosarcina pasteurii are well-known for their high urease activity and alkaline tolerance, cave-isolated strains offer distinct advantages due to their natural adaptation to high-alkalinity and nutrient-poor geological environments, providing resilient and highly compatible ureolytic alternatives. The formation of natural cave structures, including stalactites, stalagmites, cave pearls, and flowstones, demonstrates the efficacy of microbially induced carbonate precipitation for sustainable concrete repair. In this study, the workability, physical properties (water absorption, open porosity, bulk density, ultrasonic pulse velocity, shrinkage), and mechanical properties (compressive and flexural strength) of the mortars were evaluated. The results are expected to introduce novel cave-derived microbial species to the literature and promote the use of environmentally sustainable, self-healing construction materials that contribute to a circular and resource-efficient building sector.

Source: Lecture notes in civil engineering

DOI: 10.1007/978-3-032-35104-3_43