Fly ash is a waste product produced by the burning of coal in thermal plants. It is often used as geo material to fill the low areas. The current study is carried out on the fly ash of class F of the Panki nuclear power station, Kanpur. A series of triaxial compression tests and oedometer tests have been performed on fly ash specimens. The test results were used to determine the parameters of the Modified Cam Clay (MCC) model for Panki fly ash. The MCC model is a mathematical framework widely used to make predictions for the tension-deformation behavior of soils. The present study aims to investigate the suitability of modeling tension-strain behavior of fly ash material through the MCC model. Experimental observations have been compared with the predicted response of fly ash under single-element test boundary conditions using the MCC model. This study shows a significant disparity between the experimental response and predicted by MCC model for fly ash. The fly ash particles are hollow spherical and also relatively more flexible than the soils, which can affect the stress strain behavior of the volatile ash in the triaxial tests due to the deformation of the particles. The study suggests that deformation characteristics of fly ash particles may be playing a significant role in the observed mechanical response of fly ash and it may be erroneous to model the behavior of fly ash simply as typical soil behavior.