Characterization of microstructural evolution and mechanical properties of refractory composite

The possibility to increase the stability of the heating unites combustion zone refractory structures, made of the aluminate cement composite concrete, using for this aim polypropylene and carbon fiber additives, was investigated in this work. The peculiarities of microstructure evolutions in the fiber and binder contact zone, the channels formation, the changes of porosity and compressive strength of fiber additives having refractory binder under temperature treatment was investigated; the investigation results allowed to predict the hybrid fiber more effective action than using them individually. The influence of fiber additives on porosity, mechanical characteristics and resistance to explosive spalling of the refractory concrete with fiber additives was tested. The concrete testing results showed that, when the hybrid fiber additive is used, the synergetic effect, that appeared in this case, is higher than effect, observed in fiber individual application. In particular, in the case of using the hybrid fiber additive in refractory concrete, a risk of explosive spalling of concrete is eliminated and the drop of its compressive strength is prevented, when refractory concrete is fired approaching the limiting temperature.