Browsing by Author "Ferron, R. D."

Now showing 1 - 4 of 4

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Biomineralized cement-based materials: impact of inoculating vegetative bacterial cells on hydration and strength
(Elsevier, 2015-01) Bundur, Zeynep Başaran; Kirisits, M. J.; Ferron, R. D.; Civil Engineering; BUNDUR, Zeynep Başaran
Biomineralization in cement-based materials has become a point of interest in recent years due to the possibility that such an approach could be used to develop a self-healing cement-based system. The objective of this study was to investigate the impact of vegetative cells of Sporosarcina pasteurii on the hydration kinetics and compressive strength of cement-based materials. The hydration kinetics were greatly influenced when a bacterial solution consisting of urea-yeast extract nutrient medium and vegetative cells was used to prepare bacterial cement pastes; specifically, severe retardation was observed. In addition, an increase in calcium carbonate precipitation, particularly calcite, occurred within the bacterial pastes. Furthermore, after the first day of hydration, the bacterial mortar displayed compressive strength that was similar to or greater than the compressive strength of the neat mortar.
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Evaluation of self-healing of internal cracks in biomimetic mortar using coda wave interferometry
(Elsevier, 2016-05) Liu, S.; Bundur, Zeynep Başaran; Zhu, J.; Ferron, R. D.; Civil Engineering; BUNDUR, Zeynep Başaran
Calcium carbonate biomineralization is a bio-chemical process in which calcium carbonate precipitation is obtained by leveraging the metabolic activity of microorganisms. Studies have shown that biomineralization can be used to repair surface cracks in cement-based materials. One of the challenges in determining whether biomineralization is a feasible option for internal crack repair pertains to how to monitor and quantify self-healing of internal microcracks. In this study, mortar samples with and without microcracks and microorganisms were cured in different environments until 50 days. Coda wave interferometry measurements, a nondestructive method that is very sensitive to small changes in material, were conducted on these samples to evaluate the extent of self-healing during the entire curing period. Compressive strength tests were performed after 7 and 28 days of curing. The results indicated that the cracked mortar samples with microorganisms showed significantly higher strength development and higher relative velocity change than samples without microorganisms.
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Use of biomineralisation in developing smart concrete inspired by nature
(Inderscience, 2015) Zhang, B.; Bundur, Zeynep Başaran; Mondal, P.; Ferron, R. D.; Civil Engineering; BUNDUR, Zeynep Başaran
Recently, interest has focused on leveraging the biological functions of microorganisms to develop smart cement-based materials. This paper provides an overview of the calcium carbonate biomineralisation process in nature and presents a review of the work conducted by various groups around the world on biogenic calcium carbonate formation as it relates to the hydration, microstructure, properties, and performance of cement-based materials. Promises and concerns of applying biomineralisation in cement-based materials are also discussed, and directions for future research are explored.
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Use of pre-wetted lightweight fine expanded shale aggregates as internal nutrient reservoirs for microorganisms in bio-mineralized mortar
(Elsevier, 2017-11) Bundur, Zeynep Başaran; Kirisits, M. J.; Ferron, R. D.; Civil Engineering; BUNDUR, Zeynep Başaran
Interest in developing bio-based self-healing cement-based materials has gained broader attention in the concrete community. One of challenges in developing bio-based self-healing cement-based materials is that cell death or insufficient metabolic activity might occur when the cells are inoculated to the cement paste. This paper investigates the use of internal nutrient reservoirs via pre-wetted lightweight fine expanded shale aggregates to improve cell viability in mortar. Incorporation of internal nutrient reservoirs resulted in an increase in the vegetative cells remaining without any substantial loss in strength. These results pave the way to develop a self-healing and self-curing concrete with an extended service life.