Modeling the thermal response of hydrating cemented gangue backfill with admixture of fly ash

Cemented gangue backfill (CGB), which is a composite material mixed by coal gangue, binder and water, is used for coal mine backfill to control strata movement and thus, reduce ground surface subsidence. Whether a CGB structure can successfully play the role of supporting the overlying roof or not is dependent on its mechanical strength, which is significantly affected by the temperature development in it. The temperature of CGB is influenced by the heat generated by binder hydration and the heat transfer between the CGB and its surroundings. In this paper, a numerical model is proposed to predict the temperature development and distribution within the hydrating CGB structure. Results from an experimental study are employed to validate the developed model. This validation outcome indicates that the model simulation is in a good agreement with the experiment investigation. The validated model is then used to analyze the effects of various factors on the temperature development within the CGB structure versus curing time.