Effect of Modifying Additives on Mechanical Properties of Refractory Concrete

This experimental study presents the results of the combined effect of micro fibre and micro silica content on physical and mechanical properties of refractory concrete after exposure to high temperatures. A complex binder together with firestone aggregates was used for production of refractory concrete, which was reinforced simultaneously with micro fibre (1 wt % and 3 wt %) and micro silica (1.5 wt %, 3.5 wt% and 5 wt%). Unmodified concrete was produced as well. The results show that simultaneous modification with micro silica and micro fibre improves the flexural strength of the refractory concrete at all the temperatures investigated: 100 degrees C, 600 degrees C, 800 degrees C and 1000 degrees C. Contrary, the advantage of reinforcing agents on cold crushing strength of concrete was observed above 800 degrees C. It was determined that the mechanical strength of the refractory concrete increases with the increasing content of micro silica and reduces with the increasing content of micro fibre.