Characterisation and thermal improvement of adobe walls from earth-straw lightweight panels

Soil as a building material has great potential in terms of low embodied energy, although the great diversity of soils means that more research is needed to characterise them with precise values. In addition, their high thermal transmittance is one of the main drawbacks of earths, so the incorporation of agrowastes could imply a reduction of thermal conductivity without any harm to the embodied energy. Three types of agrowastes have been evaluated: long and short wheat straw fibres and a sawdust. These three fibres were mixed with barbotine to reduce the amount of solid material in the mixture. These panels were compared with the performance of a 20-cm-thick adobe wall. The thermal transmittance of the materials was analysed and the results showed that panel 2 with short wheat straw fibres performed well as a thermal insulation board with a thermal conductivity of & lambda; = 0.05 W/mK.