Author
Tezer, M. M., Bundur, Zeynep Başaran
Publication Date
2022-03-01
Publication Place
-
ASCE
Subject
Bentonite, Biomineralization, Diatomaceous earth (DE), Self-healing, Sepiolite, Water absorption
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
0899-1561
Record ID
394461db-f829-47a3-a4ab-b73fdd5a6f5d
Library Location
Civil Engineering
Date
2022-03-01
Sample Text
Cracks in cement-based materials are one of the main factors affecting the durability of structure. Recent research in the field of concrete materials showed that self-healing in cement-based systems can be achieved by triggering biogenic calcium carbonate (CaCO3) precipitation. The goal of this study is to establish a comparative evaluation of the use of sepiolite, bentonite, and diatomaceous earth (DE) as an immobilization barrier of Sporosarcina pasteurii (S. pasteurii) cells to trigger self-healing in cement-based systems. For the first time in the literature, this study will provide insight into the use of natural minerals, such as bentonite and sepiolite, as protective carriers for vegetative S. pasteurii cells in cement-based materials and present a comparative evaluation of factors influencing crack healing, such as the microstructure and composition of immobilization barriers. A two-phase self-healing bioadditive was obtained by immobilizing vegetative S. pasteurii cell samples on natural porous minerals with or without the use of required nutrients. Then the samples were cracked by a three-point bending test, and the healing process was screened via stereomicroscope imaging and ultrasonic pulse velocity (UPV) testing after subjecting the cracked samples to 28 days of moist curing. Flexural cracks induced in mortar samples were filled with biogenic precipitate. Relatedly, the water absorption capacity of the samples was decreased in mortar samples containing bacterial cells, the nutrients were added in the curing solution. Fourier transform infrared spectroscopy and scanning electron microscopy analyses showed that calcite was the predominant polymorph of CaCO3 sealant in cracks.
DOI
10.1061/(ASCE)MT.1943-5533.0004098
Cilt
34
