Reflectance properties analysis of mineral based mortars for renders: Research of their energy performance

• Published in: Energy and buildings 2014-06, Vol.76, p.615-621
• Main Authors: Barbero-Barrera, M.M., Campos-Acosta, J., Neila-González, F.J.
• Format: Article
• Language: English
• Subjects: Aggregates; Applied sciences; Buildings; Buildings. Public works; Concretes. Mortars. Grouts; Energy; Exact sciences and technology; External envelopes; Facades; Façade; Fluxes; General (composition, classification, performance, standards, patents, etc.); Lime; Materials; Mortars; Paints and renderings. Protection products; Radiative; Reflectance; Reflectivity; Render; Strength of materials (elasticity, plasticity, buckling, etc.); Structural analysis. Stresses; Wall. Partition
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2014.03.024

•Optical characterization of traditional and non-traditional aerial lime renders.•Aggregate nature, content and roughness in the reflectance of the lime renders.•Colour influence of the samples in different ranges of the electromagnetic spectrum.•The effect of the renders on 4 types of the most common constructive systems of façades is analyzed.•A reduction up to 134 times of the thermal fluxes in summertime is achieved. Passive performance of buildings is nowadays one of the key points, not only for reducing energy consumption of buildings, but also for decreasing “fuel poverty”. Among the constructive systems in buildings, façades are the ones having higher influence on thermal performance in urban spaces. Lime renders are specialized systems which can improve not only the durability of the support but also the thermal properties. According to previous researches, a modification of their radiative properties can reduce thermal fluxes between 24% and 89%. In this paper, the influences of the aggregate content in lime pastes, as well as the nature of the aggregates, colour and roughness, on the visible near and medium infrared reflectance are analyzed. Ten types of aerial lime mortars were prepared and two methods of reflectance determination were performed. Finally, the effect of the resulted reflectance on the constructive systems of façades was analyzed using pseudotime-dependent software, for which an annulation of the thermal fluxes or significant reduction of them can be observed, when modifying the aggregate nature.