Properties of multifunctional lightweight mortars containing zeolite and natural fibers.

The article focuses on the development of innovative and multifunctional mortars with low environmental impact for indoor applications acting as passive systems to moderate extremes of humidity and to lower the concentration of pollutants. Mortars are manufactured by keeping constant the water/binder ratio, using sand as reference aggregate, and by replacing the total volume of sand with zeolite. In some mixes the aggregate, is also at 25vol% by wool natural fibers. Regardless lightness, zeolite thanks to its pozzolanic activity, helps to improve the compressive strength of mortars manufactured with wool fibers. In addition, the combination of zeolite and wool increases the hygro-thermal performance of mortars: water vapor resistance factor (22% lower than the reference), moisture buffering value (100% higher than the reference), and thermal conductivity (66% lower than the reference), respectively. Depolluting properties of zeolite-based mortars, in terms of adsorption capacity, are 65% lower than that of reference mortar. [ABSTRACT FROM AUTHOR]