New empirical equations for limiting void ratios as function of particle morphology properties of sand-fly ash binary assemblies

ABSTRACT

The objective of this research is to develop novel empirical equations to predict the extreme void ratios of sand-fly ash mixtures. These equations rely on multiple variables derived from the particle morphology properties of three different types of sandy materials. These sands are mixed with varying fractions of spherical fly ash particles, ranging from 0% to 30% fly ash content. High-quality microscope images of individual particles are used to determine the particle morphology properties. The analysis of the results confirms that combining these particle morphology properties (Acom, Scom, ARcom, Cxcom, and ORcom) provides suitable factors for predicting the extreme void ratios of the examined sand-fly ash mixtures. Furthermore, the study clearly demonstrates the significant influence of particle morphology on the packing density of the materials. The developed multi-variable functions can be systematically employed to predict the limit void ratios of sand-fly ash mixtures commonly encountered in various geotechnical engineering applications.

KEYWORDS:

• Extreme void ratios
• sands
• fly ash
• angularity
• overall regularity
• gradation

Acknowledgments

The authors are grateful to those who effectively contributed to the achievement of this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data, models, and code generated or used during the study appear in the submitted article.

Abbreviation

a, b, c, a’, b’, c’, e, f, m, n, α, β, e’, f’, m’, n’, α’, β’	=	Coefficients of equations;
Ahs	=	Angularity of host sand;
Af	=	Angularity of fly ash;
Acom	=	Combined angularity;
ARhs	=	Aspect ratio of host sand;
ARf	=	Aspect ratio of fly ash;
ARcom	=	Combined aspect ratio;
Cu	=	Coefficient of uniformity;
Cxhs	=	Convexity of host sand;
Cxf	=	Convexity of fly ash;
Cxcom	=	Combined convexity;
D50	=	Mean particle diameter;
emax	=	Maximum global void ratio;
emin	=	Minimum global void ratio;
FA	=	Fly ash content;
Gs	=	Specific gravity;
MAE	=	Mean absolute error;
ORhs	=	Overall regularity of Host sand;
ORf	=	Overall regularity of fly ash;
ORcom	=	Combined Overall regularity;
R2	=	Coefficient of determination;
RSME	=	Root mean square error;
Shs	=	Sphericity of Host sand;
Sf	=	Sphericity of fly ash;
Scom	=	Combined sphericity;
SP	=	Poorly graded sand;
USCS	=	Unified soil classification system.