Research Articles | Challenge Journal of Concrete Research Letters

Effective thermal conductivity of foamcrete of different densities

Md Azree Othuman Mydin
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Abstract


The main purpose of this study is to investigate the thermal conductivity of foamed concrete. Various densities of foamed concrete samples ranging from 650, 700, 800, 900, 1000, 1100 and 1200 kg/m3 with constant cement-sand ratio of 2:1 and water-cement ratio of 0.5 were produced. This study was limited to the effect of density, porosity and pore size on thermal conductivity of foamed concrete. Hot-guarded Plate method was used to obtain the thermal conductivity of foamed concrete at different densities. The porosity value of foamed concrete was determined through the Vacuum Saturation Apparatus. In turn to examine the effect of pore size on thermal conductivity of foamed concrete, pore size measurements were made under a microscope with a magnification of 60x. Lower density foamed concrete translates to lower thermal conductivity. The density of foamed concrete is controlled by the porosity where lower density foamed concrete indicates greater porosity. Therefore, thermal conductivity changes considerably with the porosity of foamed concrete because air is the poorest conductor compared to solid and liquid due to its molecular structure.

Keywords


foamed concrete; thermal conductivity; hot-guarded plate; thermal properties; lightweight concrete; porous material

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