Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars
Cement-based materials are subject to degradation during their service life. Most of the structural failures have been associated with corrosion of the rebar due to chloride ingress, alkali aggregate reaction, and/or sulfate attack. Microbial activities, especially in waste water collection points s...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Journal of Chemistry |
| Online Access: | http://dx.doi.org/10.1155/2020/8212396 |
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| author | Onesmus Mulwa Munyao Joseph Karanja Thiong’o Jackson Muthengia Wachira Daniel Karanja Mutitu Romano Mwirichia |
| author_facet | Onesmus Mulwa Munyao Joseph Karanja Thiong’o Jackson Muthengia Wachira Daniel Karanja Mutitu Romano Mwirichia |
| author_sort | Onesmus Mulwa Munyao |
| collection | DOAJ |
| description | Cement-based materials are subject to degradation during their service life. Most of the structural failures have been associated with corrosion of the rebar due to chloride ingress, alkali aggregate reaction, and/or sulfate attack. Microbial activities, especially in waste water collection points such as sewer lines, may compromise the integrity of concrete structures. This study reports an experimental work carried out to determine the effect of Starkeya novella bacteria species on mechanical and microstructural properties of cement mortars. Mortar prisms were prepared from selected ordinary Portland cement (OPC) and Portland pozzolana cement (PPC) in Kenyan markets. Bacterial solution of 1.0 × 107 cell/mL concentration was used as either mix water, curing media, or both. Distilled water was used to prepare mortar prisms for control samples. Compressive strength was determined after the 7th, 28th, 56th, and 90th day of curing. Scanning electron microscopy (SEM) was tested on both bacterial and control mortar prisms after the 28th day of curing. Both PPC and OPC exhibited significant decrease in compressive strength for bacterial-prepared mortars as compared to controls. SEM analysis showed extreme erosion on the microstructure of the microbial mortars. This was denoted by massive formation of ettringite and gypsum which are injurious to mortar/concrete. |
| format | Article |
| id | doaj-art-a58c007e89cf47dbaf57646488e23807 |
| institution | Kabale University |
| issn | 2090-9063 2090-9071 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Chemistry |
| spelling | doaj-art-a58c007e89cf47dbaf57646488e238072025-02-03T01:26:57ZengWileyJournal of Chemistry2090-90632090-90712020-01-01202010.1155/2020/82123968212396Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement MortarsOnesmus Mulwa Munyao0Joseph Karanja Thiong’o1Jackson Muthengia Wachira2Daniel Karanja Mutitu3Romano Mwirichia4Department of Chemistry, Kenyatta University, Nairobi, KenyaDepartment of Chemistry, Kenyatta University, Nairobi, KenyaDepartment of Physical Sciences, University of Embu, Embu, KenyaDepartment of Physical Sciences, University of Embu, Embu, KenyaDepartment of Biological Sciences, University of Embu, Embu, KenyaCement-based materials are subject to degradation during their service life. Most of the structural failures have been associated with corrosion of the rebar due to chloride ingress, alkali aggregate reaction, and/or sulfate attack. Microbial activities, especially in waste water collection points such as sewer lines, may compromise the integrity of concrete structures. This study reports an experimental work carried out to determine the effect of Starkeya novella bacteria species on mechanical and microstructural properties of cement mortars. Mortar prisms were prepared from selected ordinary Portland cement (OPC) and Portland pozzolana cement (PPC) in Kenyan markets. Bacterial solution of 1.0 × 107 cell/mL concentration was used as either mix water, curing media, or both. Distilled water was used to prepare mortar prisms for control samples. Compressive strength was determined after the 7th, 28th, 56th, and 90th day of curing. Scanning electron microscopy (SEM) was tested on both bacterial and control mortar prisms after the 28th day of curing. Both PPC and OPC exhibited significant decrease in compressive strength for bacterial-prepared mortars as compared to controls. SEM analysis showed extreme erosion on the microstructure of the microbial mortars. This was denoted by massive formation of ettringite and gypsum which are injurious to mortar/concrete.http://dx.doi.org/10.1155/2020/8212396 |
| spellingShingle | Onesmus Mulwa Munyao Joseph Karanja Thiong’o Jackson Muthengia Wachira Daniel Karanja Mutitu Romano Mwirichia Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars Journal of Chemistry |
| title | Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars |
| title_full | Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars |
| title_fullStr | Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars |
| title_full_unstemmed | Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars |
| title_short | Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars |
| title_sort | influence of starkeya novella on mechanical and microstructural properties of cement mortars |
| url | http://dx.doi.org/10.1155/2020/8212396 |
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