Potential of soil-based boards to replace conventional gypsum plasterboards

Gypsum plasterboards are a cornerstone of the western construction practices, appreciated as much for its availability and cheap price than for its properties and workability. However, its low reuse after demolition results in a large volume of construction, renovation, and demolition (CRD) waste and the production of hydrogen sulfide (H2S) at landfill sites. In this study, a new type of soil-based board was developed, combining soil and wood fibers, to achieve the same properties as gypsum plasterboards while improving end-of-life performance. These boards showed far greater hydric properties, having a water storage capacity increased by 303–746 % in comparison to gypsum over the regular RH range observable in buildings and 2.84–3.36 times its moisture buffering value. They also displayed improved acoustic properties, with a STC increased by 10 and a slightly improved sound absorption. The mechanical and thermal properties of these new boards were very similar to those of gypsum, although their higher modulus of rupture (MOR) would make them more difficult to work with on-site. The combustibility of the developed boards, as tested with a cone calorimeter, was also higher, with total heat release values ranging from 2.16 to 2.56 times higher. This concern could, however, be damped by the addition of fireproofing clays like perlite and vermiculite. • Plasterboards were prepared by casting soil and wood fibers between lining papers. • The plasterboards showed similar mechanical properties to those of made of gypsum. • Their acoustic insulation was 8–10 dB higher than gypsum plasterboards. • The thermal inertia and moisture absorption of these plasterboards were very high.