Print Email Facebook Twitter Assessment of the functionality of bacteria-based repair system for concrete through ESEM analysis Title Assessment of the functionality of bacteria-based repair system for concrete through ESEM analysis Author Wiktor, V. Jonkers, H.M. Faculty Civil Engineering and Geosciences Department Structural Engineering Date 2015-06-17 Abstract Biodeposition, a method by which calcium carbonate (CaCO3) precipitation is induced by bacteria, has been proposed as an interesting approach to protect building materials. The liquid-based system presented in this paper aims at the sealing of cracks and decrease of the porosity due to the production of a calcium-based biomineral. In this system, a silicate-based compound, which has a composition similar to concrete, is associated with Microbial Induced Precipitation (MIP), without involving urea hydrolysis pathway. Instead, the metabolic conversion of organic salts through bacterial respiration is used for MIP. The novelty of such system is to combine advantages of both, traditional repair system for concrete (fast reacting, and short term efficiency), and bio-based methods (more sustainable, slow process, and long-term efficiency). This paper presents how environmental scanning electron microscope (ESEM) has been used in the development of the bacteria-based repair system. It is a good evaluation technique to assess the functionality of the bacteria-based repair system and to evidence the involvement of bacteria in the mineral production. The functionality of the bacteria-based repair system has first been assessed in the repair system alone, and then after injection into porous concrete. These results bring more insight regarding the formation of the biomineral. Though the bacteria are active after 1 day, it requires longer time to indeed observe mineral formation. Several days are needed to bacteria to actively convert the feed and produce substantial amount of CO2, leading to favorable chemical environment for calcium carbonate precipitation. The results also showed how FTIR and ESEM analysis are complementary. Vaterite and calcite have been identified thank to FTIR while ESEM observation highlighted the unique features of the biomineral in size, shape and texture. Subject bacteria-based systemrepairconcretebiomineralbacteria imprints To reference this document use: http://resolver.tudelft.nl/uuid:56daf2b5-05c9-46f9-9d83-d97333142385 Publisher Delft University of Technology ISBN 978-94-6186-480-2 Source EMABM 2015: Proceedings of the 15th Euroseminar on Microscopy Applied to Building Materials, Delft, The Netherlands, 17-19 June 2015 Part of collection Institutional Repository Document type conference paper Rights (c) 2015 Creative Commons BY NC ND Files PDF Jonkers_2015.pdf 224.9 KB Close viewer /islandora/object/uuid:56daf2b5-05c9-46f9-9d83-d97333142385/datastream/OBJ/view