Thermo-physical characteristics of acrylic-based building external isolation panels produced from different geological materials

Here we describe a new type of environmentally sensitive insulation panels which can be used on exteri-or wall surfaces to minimize all the negative aspects of existing coating materials by taking advantage of natural rock properties. We investigate the decorative characteristics and insulation performance of this new product, obtained by applying materials from different lithologies to Expanded Polystyrene Surfaces (EPS). First, a mortar with 25% acrylic and 75% sand was applied to the EPS by a stripping method using sand size materials from various lithologies (granite, micaschist, basalt, quartzite, and pumice). To determine the optimum thickness, insulation panels containing plaster of 2, 4, 6, and 8 mm thickness were prepared for each lithology. Their thermal conductivity coefficient, bending and compressive strength were tested. Predictably, thermal conductivity coefficient yielded lowest values in 2 mm panels and highest in 8 mm panels for all lithologies. The bending strength also increased proportionaly with thickness. In the compressive strength tests, the highest values were measured for the 2 mm panels while relatively low values were obtained for the 4, 6 and 8 mm panels, except for the micaschist and basalt-based panels. As a result, basalt and pumice offer superior features in the three measured parameters, so, it is expected that different combinations of these two lithologies would offer positive features. In this context, considering its high fire resistance and low thermal conductivity coefficient perpendicular to the planar surface of muscovites, micaschist is the third lithology that can be utilized with the two materials mentioned above. Compared with previous materials, the products investigated in this study are cost effective because they reduce paint costs, application time and total building load. The geomaterials also have aesthetic appeal.