Article (Scientific journals)
Water permeability, water retention capacity, and thermal resistance of green roof layers made with recycled and artificial aggregates
Kazemi, Mostafa; Courard, Luc; Attia, Shady
2023In Building and Environment, p. 109776
Peer Reviewed verified by ORBi


Full Text
Author postprint (2.39 MB)

All documents in ORBi are protected by a user license.

Send to


Keywords :
Heat flow measurement; Water permeability; Water retention capacity; Recycled and artificial aggregates; Green roof
Abstract :
[en] Substituting natural aggregates in the green roof substrate and drainage layers with lightweight artificial and recycled coarse materials is an eco-friendly alternative for applying lower load to the rooftops and preserving natural resources. However, a lack of precise understanding of the thermal resistance, water passing ability, and water holding capacity of green roof materials, including recycled and artificial materials, has raised a demand for measuring their Rc-value, water permeability, and water retention capacity as three main indicators for green roof systems. This study comparatively evaluated the thermal resistance, water permeability, and water retention capacity of green roofs with substrate and drainage layers, including coarse recycled and artificial materials. Different kinds of coarse granular aggregates were separately used for the drainage layer, including Natural Coarse Aggregate (NCA), Recycled Coarse Aggregate (RCA), Incinerated Municipal Solid Waste Aggregate (IMSWA), and Lightweight Expanded Clay Aggregate (LECA). The substrate layers were made with coarse recycled materials (SC) and without coarse recycled materials (SP) in wet and dry states. The outcomes revealed the highest thermal resistance and the lowest weight were obtained for 20-cm green roofs with a 15-cm substrate layer and 5-cm drainage layer of LECA. The water permeability of NCA was obtained 1.5 times more than that of LECA, whereas there was no significant difference between the result of the former, RCA, and IMSWA. The water retention capacity of the LECA was two times higher than that of the NCA. SC and SP satisfied the water passing and retention criteria given for green roofs.
Disciplines :
Civil engineering
Author, co-author :
Kazemi, Mostafa  ;  Université de Liège - ULiège > Urban and Environmental Engineering
Courard, Luc  ;  Université de Liège - ULiège > Département ArGEnCo > Matériaux de construction non métalliques du génie civil
Attia, Shady  ;  Université de Liège - ULiège > Département ArGEnCo > Techniques de construction des bâtiments
Language :
Title :
Water permeability, water retention capacity, and thermal resistance of green roof layers made with recycled and artificial aggregates
Publication date :
06 January 2023
Journal title :
Building and Environment
Publisher :
Elsevier BV
Pages :
Peer reviewed :
Peer Reviewed verified by ORBi
Name of the research project :
City Roof
Funding text :
This research was funded through the University of Liège (ULg) and ARC grant for Concerted Research Actions, financed by the French Community of Belgium, Wallonia-Brussels Federation (CityRoof project: Analogous green roofs for urban ecosystem services (2020-2023)).
Available on ORBi :
since 07 November 2022


Number of views
153 (36 by ULiège)
Number of downloads
175 (8 by ULiège)

Scopus citations®
Scopus citations®
without self-citations


Similar publications

Contact ORBi