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Title:Re-Use of Mine Waste Materials Amended with Fly Ash in Transportation Earthworks Projects
Authors:Mohammad H. Gorakhki, Sultan A. Alhomair, and Christopher A. Bareither
University:Colorado State University
Publication Date:Oct 2017
Report #:MPC-17-332
Project #:MPC-411
TRID #:01653309
Keywords:cement, compressive strength, fly ash, mechanical properties, mines and mineral products, permeability, road construction, waste products
Type:Research Report – MPC Publications



The objectives of this study were to assess geotechnical properties of mine waste amended with fly ash and evaluate reuse of fly ash amended mine waste as road construction material. Three types of fly ash and one type of cement were used as cementitious binder. Natural and synthetic (i.e., laboratory prepared) mine tailings were used as mine wastes to assess the effects of tailings properties and solids content on hydraulic and mechanical behavior of fly-ash amended materials. The influence of fly ash-amendment on hydraulic conductivity of mine tailings was attributed to (i) molding water content and (ii) plasticity of the mine tailings. Unconfined compressive strength increased with an increase in tailings particle size, solids content, and/or increase in CaO-to-SiO2 ratio of fly ash for amended mine tailings. The compressibility of mine tailings decreased with an increase in fly ash content and an increase in CaO content and CaO-to-SiO2 ratio of fly ash, which resulted in more effective bonding between particles. Fly as-amended mine wastes were shown to have hydraulic and mechanical properties suitable for transportation earthwork applications.

How to Cite

Gorakhki, Mohammad H., Sultan A. Alhomair, and Christopher A. Bareither. Re-Use of Mine Waste Materials Amended with Fly Ash in Transportation Earthworks Projects, MPC-17-332. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2017.

NDSU Dept 2880P.O. Box 6050Fargo, ND 58108-6050