One-third of the global land area suffers from wind erosion, and its prevention is a critical issue in arid regions of the world. During a wind erosion event, the impacts of saltating grains on the surface cause abrasion of crusted soil surfaces. The topic of this study is to examine the efficiency of sand biocementation to diminish the wind erodibility of an aeolian sand. The erosion rate, number of emitted particles, and flux of the eroded mass from surface (as erodibility indicators) of the biocemented crust, formed by Bacillus megaterium, were measured in a wind tunnel at three different wind velocities; moreover, one extra condition with the presence of impacting particles at the lowest wind velocity was tested. According to the results of the tests, the biocemented crust could provide considerable protection for erodible aeolian sand against wind erosion (without impacting particles), diminishing the sand erodibility indicators by two to four orders of magnitude. However, with the impact of saltating particles, the formed crust could reduce erodibility indicators only by one order of magnitude.
28 February 2020 in Land Degradation & Development
This study investigates the mechanical and microstructural properties of loose sandy soil stabilized with alkali-activated Ground Granulated Blast Furnace Slag (GGBFS). To examine the effects of varying GGBFS contents, curing times, and confining pressures on mechanical behavior, undrained triaxial and unconfined compressive strength (UCS) tests were conducted. Microstructural analyses using FE-SEM, EDX, and FTIR were performed to elucidate the nature and development of cementation. The results of mechanical behavior demonstrate that even with limited GGBFS content (1–6%), the treated samples exhibited significant improvements in strength, stiffness, and energy absorption, underscoring the efficiency of alkali-activated GGBFS as a soil stabilizer. Moreover, mechanical parameters from triaxial tests revealed a nearly constant internal friction angle with increasing GGBFS content and curing duration, while cohesion showed remarkable enhancement. A strong linear correlation between UCS and cohesion was also identified, enabling cost-effective estimation of shear strength parameters. These findings highlight the potential of alkali-activated GGBFS for improving granular soils, offering practical implications for sustainable geotechnical applications, particularly in road construction.
6 July 2021 in Earth Surface Processes and Landforms