Experimental Analysis of Natural Gravel Covering as Cool Roofing and Cool Pavement

Sustainability

Anna Laura Pisello¹  Gloria Pignatta²  Veronica Lucia Castaldo² 

[1] CIRIAF (Interuniversity Research Center on Pollution and Environment “Mauro Felli”), University of Perugia, Via G. Duranti 63, Perugia 06125, Italy;

关键词: cool roof;    cool paving;    highly reflective gravel;    in-field albedo;    energy efficiency in buildings;    cool pavements;    urban heat island;    reduction of cooling demand;   

DOI  :  10.3390/su6084706

来源: mdpi

【 摘 要 】

Passive solutions for building energy efficiency represent an interesting research focus nowadays. In particular, natural materials are widely investigated for their potential intrinsic high thermal energy and environmental performance. In this view, natural stones represent a promising solution as building envelope covering and urban pavement. This paper concerns the experimental characterization of several low-cost and local gravel coverings for roofs and urban paving, properly selected for their natural high albedo characteristics. To this aim, the in-field albedo of gravel samples is measured with varying grain size. These in-field measurements are compared to in-lab measurements of solar reflectance and thermal emissivity. The analysis shows a significant variation of the albedo with varying grain size. Both in-lab and in-field measurements agree that the stones with the finest grain size, i.e., fine sand, have the best optic-thermal performance in terms of solar reflectance (62%). This feature results in the reduction of the surface temperature when exposed to solar radiation. Moreover, a natural mixed stone is compared to the high reflectance stone, demonstrating that the chosen stone presents an intrinsic “cool” behavior. Therefore, this natural, low-cost, durable and sustainable material could be successfully considered as a natural cool roof or cool paving solution.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.