Thermal performance of external wall panel made of cold-bonded fly ash aggregate concrete

The object of research is an external wall panel made of cold-bonded fly ash aggregate concrete. The purpose of this work is to study thermal performance of the external wall panel made of cold-bonded fly ash aggregate based on fly ash from Novosibirskaya GRES Thermal Power Plant. Method. The panel under study consists of three layers: an inner layer of concrete with cold-bonded fly ash aggregate, an intermediate layer of extruded polystyrene, and an outer layer of heavy concrete. For the thermotechnical calculation of the external wall panel, the thermal conductivity coefficient of cold-bonded fly ash aggregate concrete was experimentally determined using the thermal conductivity meter ITS-1 "150". Specimens were made in the form of plates with dimensions of 150x150x30 mm. Demoulding was carried out on the second day after the specimens were made. Subsequently, the samples were stored under normal conditions at a temperature of 20 ± 2 °C and a relative air humidity of at least 60%. After that, the thickness of the insulation was calculated for the panel under study. The thermal performance of the studied external wall panel was compared with a typical three-layer reinforced concrete panel. Results. The thermal conductivity coefficient of cold-bonded fly ash aggregate concrete was experimentally determined, which amounted to 0.94 W/(m·°C). It is shown that in terms of thermal performance, the external wall panel made of cold-bonded fly ash aggregate concrete is not inferior to the well-known three-layer reinforced concrete wall panel. With the same thermal characteristics of the studied external wall panel, a heat-insulating layer of extruded polystyrene of a smaller thickness is required - 90 mm instead of 100 mm for a three-layer reinforced concrete panel.