The paper presents the results of experimental and theoretical studies of polymer binder based on a hot-curing epoxy resin filled with microparticles of micro marble (micro calcite); the binder classified as hybrid organo-mineral. The results of evaluating several epoxy binders' thermal stability filled with micro marble during prolonged exposure in the temperature range from 160 °C to 300 °C are presented. The modulus of elasticity of an unfilled and filled with micro marble epoxy binder was investigated using the three-point bending method at temperatures up to 130 °C; comparing these properties with a theoretical prediction method on FE homogenization using the Design Modeler module of the Ansys package was carried out. A three-point bending method at temperatures up to 180 °C was used to study the elastic modulus of fiberglass on the basis of unfilled and filled with micro marble binder. An assessment of the effectiveness of the use of based on hybrid organo-mineral binder fiberglass in the structures of load-bearing chimneys under thermo-mechanical effects is carried out.