Biopolymers impact on hygrothermal properties of rammed earth: from material to building scale

Three biopolymers were tested as rammed earth (RE) stabilizers, evaluating their impact on the hygrothermal behavior from material to building scale. Hygrothermal characterization included determination of sorption isotherm, water vapor permeability, thermal conductivity at different moisture content, and specific heat capacity. The data used input for simulation whole-building scale considering combined transfer. results evaluated by comparing heating demand, comfort during summer, contribution walls passively controlling indoor humidity. show that hygric properties only slightly affected use while was 33% higher RE stabilized with lignin, consequently increasing demand All effective in reducing temperature oscillations summer. In particular case a canicular event, reduced up 10° compared outdoor value. humidity also benefited passive regulation walls, regardless whether stablizer used.