Thermal coating with rigid recycled polyurethane foam as a partial substitute of limestone aggregate

Abstract

This research presents the results of an experimental study about the effect of the rigid recycled polyurethane foam used as a partial substitute of limestone aggregates in the elaboration of cement-based coating, with the objective of reducing the consumption of natural aggregate by replacing it with a recycled material and reducing the thermal conductivity of the coating. The rigid recycled polyurethane foam was crushed to be used as a partial substitute of the fine limestone aggregate in proportions of 15, 20 and 25% in volume, maintaining a cement:sand ratio of 1:3., and its mechanical, physical and thermal properties were evaluated. The mortar of coating with 20% of substitution of recycled polyurethane foam by limestone aggregate, presented a better physical-mechanical and thermal behavior to a laboratory level; therefore, so it was used in real conditions as an exterior coating in a construction prototype elaborated with a wall of blocks and exposed to environmental conditions for a year. The results demonstrated that the modified coating improved its thermal performance by decreasing the interior temperature of the prototype by around 15% compared to the traditional coating, with a difference of 0 to 1.5 °C low, thus maintaining it for most of the year and with relative humidity without significant changes.