Strength and hydraulic conductivity of sedimented ash deposits treated with lime column

Singh, S. P.; Roy, Nagendra; Sangita, S.

doi:10.1080/19386362.2016.1208415

Cited by 8 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is also possibility that high concentration of fly ash could decrease bacterial metabolic activity by reducing the bioavailability of nutrients, which leads to lesser precipitation. Fly ash, further, generates more amounts of hydration products coming from pozzolanic reaction 24 that also increase the strength of expansive soils. In addition, it is known as a self-cementing agent (that property was enhanced in the presence of biocement) to increase the strength and to stabilize soil 22 .…”

Section: Resultsmentioning

confidence: 99%

Fly ash incorporated with biocement to improve strength of expansive soil

Fang

Kawasaki

et al. 2018

Sci Rep

View full text Add to dashboard Cite

Microbially induced calcium carbonate precipitation (MICP) results in the formation of biocement (BC). This process, also known as biocementation, is recently widely used to improve the strength and durability of building materials including soils. In the present study, effectiveness of biocement as admixture with fly ash (FA) was investigated as first few studies to improve geotechnical properties of expansive soils. Biocement precipitated by Bacillus megaterium was blend with four formulations of fly ash at concentrations of 0, 10, 25 and 50%, namely 0% FABC, 10% FABC, 25% FABC, and 50% FABC, respectively. These formulations were separately added to expansive soils. Specimens with 25% FABC resulted in significant improvement in unconfined compressive strength of expansive soil that was more than two-times higher than control. Further, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses characterized microstructures of soil specimens, and depicted the process of MICP in improving strength of expansive soils. This research indicates that incorporation of biocement in fly ash is an effective means of increasing the strength of expansive soils.

show abstract

Section: Resultsmentioning

confidence: 99%