MANUFACTURE AND STUDY OF SELF-HEALING PROPERTIES IN CONCRETE WITH BACILLUS HAYNESSII (RAKAN1508) BACTERIA ISOLATED FROM FARAFRA OASIS, NEW VALLY GOVERNORATE, EGYPT

Abbas, Ahmed S.; Nooman, Mohammed Taha; Ismael, Ashraf F.; Mekky, Alsayed E.

doi:10.21608/auej.2024.254511.1512

MANUFACTURE AND STUDY OF SELF-HEALING PROPERTIES IN CONCRETE WITH BACILLUS HAYNESSII (RAKAN1508) BACTERIA ISOLATED FROM FARAFRA OASIS, NEW VALLY GOVERNORATE, EGYPT

Document Type : Original Article

Authors

¹ Civil Engineering Department, Faculty of Engineering, Al-Azhar University, Cairo, Egypt.

² Mining and petroleum Department, faculty of engineering, Al-Azhar University, Cairo, Egypt.

³ Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Cairo, Egypt.

10.21608/auej.2024.254511.1512

Abstract

Concrete failure can be attributed to various factors, including cracks that allow chemical solutions to seep through this may have a substantial effect on Concrete Structures' Mechanical, Physical, and Durability Aspects. The idea that bones and tissues can repair themselves has been exploited, so we needed to make concrete that can self-heal cracks. The ability of a material to identify and mend internal damage without help from outside sources is known as self-healing. Our goal of this work was to identify, isolate, and create a bacterial consortia that could repair tiny concrete cracks and improve the concrete many qualities. Bacillus bacteria that generate endospores were discovered in four different isolates. Of the four isolates, only one was able to grow at 50°C and produce the urease enzyme; 40°C is the optimal temperature for growth. It also demonstrated growth potential at a pH of 12 with optimal growth at 10. Therefore, this isolate was identified using 16s as Bacillus haynesii RAKAN1508 and is stored in Gen-Bank with accession number OR642761. The progression of the healing ratio and the fracture profile were evaluated using both the scanning electron microscope with variable pressure CT scans using X-rays (also known as X-ray mCT). Additionally, these Studies were conducted to determine how bacteria affected properties concrete qualities. VP-SEM results showed that microbial precipitation fully healed a 0.4 mm crack mouth width, which XRD subsequently confirmed to be calcite and vaterite. Therefore, compared to control specimensthe ,bio-concrete specimens' compressive and tensile strengths increased dramatically by 36.3 and 44% following 28 days of curing. Per the sorpativity test results, which showed that after 28 days of healing, In contrast to the control samples, the bio-concrete specimens showed a substantial 23.1% decrease in permeability. The long-term repair of cracks in the concrete skin may be achieved with bacteria-based concrete self-healing.

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