Category: Transient Plane Source
Keywords: building envelope, Building Envelopes, building materials, Bulk Density, concrete, construction, Matrix Density, Mercury Intrusion Porosimetry, Moisture Content, porosity, Scanning Electron Microscopy, Scanning Electron Microscopy (SEM), SEM, Thermal Conductivity, Thermal Constants Analyzer, TPS Technique, Transient Plane Source, Transient plane source (TPS) method, X-ray Diffraction
Abstract: Autoclaved aerated concrete was studied because it has potential to be used in the design of energy-efficient buildings. Three different samples were tested, each with a unique density. Of particular interest to this work was the thermal conductivity of the samples, as this material would be used as a thermally insulating concrete. The thermal conductivities were measured at various percentages of moisture content, and it was found that increasing moisture content resulted in increased thermal conductivity due to the replacement of air (low thermal conductivity) with water (high thermal conductivity relative to air). In addition to this, the relationship between thermal conductivity and porosity was determined and it was found that samples with a lower porosity were more thermally conductive than those with higher porosity. To perform the thermal conductivity measurements, the transient plane source technique was used because it only requires short testing times, which minimizes moisture migration during testing.
Reference: International Journal of Heat and Mass Transfer 92 (2016) 589-602