Hygrothermal properties of clayey plasters with olive fibers

This research deals with how to use agricultural waste materials in constructions considering that the development of innovative materials has to respond to both environmental and energy issues. The leaves and the small branches derived from the pruning of olive trees were incorporated, after drying, into a clay-sand mixture to obtain a bio-based plaster. Earthen samples, containing different percentages of olive fibers, were prepared and tested to investigate their hygrothermal behaviour. Thermal conductivity and the effects of several parameters on thermal performance were analyzed. The evaluation of the hygric behaviour was based on the measurement of the water vapour diffusion resistance factor and of the isothermal sorption curves. Results showed that the addition of olive fibers in the earth matrix enhances the insulating and hygric performances. The ability of the material to exchange moisture was studied by calculating the ideal Moisture Buffering Value (MBVideal). Results showed that the effects of moisture adsorption/desorption improved with the increase of the fibers content.