Mechanical Behavior and Microstructural Study of Biocemented Sand under Various Treatment Methods.
- Resource Type
- Article
- Authors
- Gao, Xuecheng; Han, Shaokang; Yang, Yang; Zhang, Wengang; Zou, Tan; Cheng, Liang
- Source
- Geofluids. 4/5/2022, p1-11. 11p. 2 Black and White Photographs, 1 Diagram, 3 Charts, 6 Graphs.
- Subject
- *SOIL particles
*BACTERIAL cultures
*CALCIUM carbonate
*COMPRESSIVE strength
*UREASE
*SAND
- Language
- ISSN
- 1468-8115
Biocementation mainly relies on the formation of calcium carbonate to bind soil particles. This paper investigates the effectiveness of biocementation in terms of treatment methods. The previously established two-phase methods are compared with newly developed one-phase-low-pH methods on their mechanical behavior and microstructure. The one-phase-low-pH methods present a higher urease fixation rate than two-phase methods, highlighting the cost-effectiveness of this method. A modified one-phase-low-pH using CH3COOH is also compared with HCl-based one-phase-low-pH method. The results show that the morphology and size of precipitated crystals have a great influence on strength development. An optimized treatment method based on the one-phase-low-pH method is also established, which is accomplished via the injection of 5 U/ml of bacterial culture together with 2 M of cementation solution during each treatment. After four times of treatments, a total of 7% cumulative calcium carbonate content can be obtained with an unconfined compressive strength of 2.15 MPa. [ABSTRACT FROM AUTHOR]