An Experimental Investigation on Thermal Conductivity of Lightweight Foamcrete for Thermal Insulation
Keywords:Foamed concrete, thermal conductivity, lightweight concrete, porosity, void size
Presently, the construction industry has shown considerable consciousness in utilizing lightweight foamcrete as a building material. The demand of lightweight foamcrete is becoming higher now where this material has increased many folds in recent years due to its intrinsic economies and advantages over conventional concrete in a range of structural and semi-structural applications. The major specialties of lightweight foamcrete are its excellent thermal conductivity, low self-weight, high impact resistance and good freeze thaw resistance. The aim of this experimental study is to investigate the thermal conductivity property of lightweight foamcrete with various densities. The main parameters that will be considered are density of lightweight foamcrete, the void size and porosity. The lightweight foamcrete samples are made with constant water-cement ratio of 0.5 and cement-sand ratio of 2:1. According to experimental results, lower densities lightweight foamcrete transforms to lower thermal conductivity values. Meanwhile, the density of lightweight foamcrete is controlled by the porosity where lower densities indicate larger porosity values. For this reason, thermal conductivity of lightweight foamcrete changes significantly with the porosity because air is the poorest conductor in comparison to solid and liquid owing its molecular constitution. The measured values of thermal conductivity should provide a useful database for evaluating the thermal performance of lightweight foamcrete structures.
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