Thermal Performance of Light Clay Materials: A Volume-based Comparison of Hemp and Straw Fibers

Light-clay materials have gained popularity in the sustainable construction sector for their capacity to use agricultural waste fibres (mainly straw and hempshives) as their main components and clay as a binder. However, despite an increasing number of studies on the thermal properties of light-clay materials based on different fibers, no studies have been made comparing hempshive-based and straw-based light-clay panels bound with the same amount of clay. The results of this study show that the amount of fibres used in the production of the panels has a significant impact on their density, with the usage of hemp shives providing a lower thermal conductivity than straw (respectively 0.05 W/mK and 0.11 W/mK) for a similar composition. Moreover, the low thermal conductivity measured (up to 0.02 kg/m³) for hempshive-based panels indicates that clay-based materials can be utilized efficiently as sustainable insulation.