Tensile strength of sands treated with microbially induced carbonate precipitation
| Autor: | Ashkan Nafisi, Shane Underwood, Douglas Martins Mocelin, Brina M. Montoya |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Precipitation (chemistry) 0211 other engineering and technologies 02 engineering and technology Geotechnical Engineering and Engineering Geology chemistry.chemical_compound chemistry 021105 building & construction Ultimate tensile strength Bending moment Carbonate Geotechnical engineering 021101 geological & geomatics engineering Civil and Structural Engineering |
| Zdroj: | Canadian Geotechnical Journal. 57:1611-1616 |
| ISSN: | 1208-6010 0008-3674 |
| Popis: | During large earthquake events where bending moments within soil cements are induced, the tensile strength of cemented soil may govern the deformational behavior of improved ground. Several studies have been conducted to assess the tensile strength of artificially cemented sands that use Portland cement or gypsum; however, the tensile strength of microbially induced carbonate precipitation (MICP)-treated sands with various particle sizes measured through direct tension tests has not been evaluated. MICP is a biomediated improvement technique that binds soil particles through carbonate precipitation. In this study, the tensile strength of nine specimens were measured by conducting direct tension tests. Three types of sand (coarse, medium, and fine) were cemented to reach a heavy level of cementation (e.g., shear wave velocity of ∼900 m/s or higher). The results show that the tensile strength varies between 210 and 710 kPa depending on sand type and mass of carbonate. Unconfined compressive strength (UCS) tests were performed for each sand type to assess the ratio between tensile strength and UCS in MICP-treated sands. Scanning electron microscopy (SEM) images and surface energy measurements were used to determine the predominant failure mode at particle contacts under tensile loading condition. |
| Databáze: | OpenAIRE |
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