Angle of internal friction for pond ashes

Thermal power stations use pulverized coal as fuel, producing enormous quan tities of ash as a waste product of combustion. Nearly 800 million metric t ons of ash is produced each year all over the world. In India, presently 97 million metric tons of ash is produced annually by power stations. The pro blem of ash disposal is a difficult one due to the limited availability of vacant space around the power plants. In view of the large quantities of as h, its bulk utilization is essential, which is possible only through geotec hnical applications such as embankments, back-fill material, subbase materi al, and the like. For the above applications, one of the important engineer ing properties is the angle of internal friction, which is determined eithe r by box shear or triaxial shear tests. This paper examines the angle of re pose of pond ashes and its relation with the angle of internal friction, us ing direct shear tests. Determination of the angle of repose is an easy and quick procedure for cohesionless materials. The angles of repose of sand a nd of quarry dust also are examined for comparison purposes. A relationship between angle of internal friction for materials in the loose, dry conditi on and the angle of repose is established. Further, a simpler method of mea surement of the angle of repose is proposed.