Chimneys and gas-escape channels elements mostly made of such polymer composite (PC) as glass-fiber plastic, persistently work at the output air temperatures below dew point as opposed to other materials, but can be affected by high temperatures during their use. On this reason it was needed to develop and modify new thermosetting bindings for PC matrix – thermal resistant and heatproof. Thermal resistance characteristic of PC is important for protective coverings, whereas heatproof characteristic is applicable for tensed elements. For a construction made of the new more heatproof PC bearing capacity estimation it is necessary to take normative resistance change and new temperature-time factors demonstration into account in their design resistance. The minimal durability value according to the PC product normative document or technical specification can be considered as normative resistance. For the temperature-time durability coefficients appointment of the new and more heatproof PC the common (base) PC coefficients values can be considered but amending their temperature scale proportionally to heatproof change relative to the base PC.
Keywords: polymer composites, glass-fibers, thermal resistance, heatproof, design resistance, chimneys