Coarse recycled materials for the drainage and substrate layers of green roof system in dry condition: Parametric study and thermal heat transfer

Water permeability, water retention capacity, and thermal resistance of green roof layers made with recycled and artificial aggregates

“…This study considered some criteria for selecting materials for the green roof layers: lightweight, high porosity, availability in the market, recycling, and artificial production, as presented in Table 1. Concerning this, the Zinco substrate, including recycled tiles, bricks, and organic matter, was considered for the substrate layer in dry and wet states (SP_Dry and SP_Wet), similarly to what was used by Kazemi et al [12,22,60]. This lightweight substrate, including coarse recycled materials, was commercially available for extensive green roof systems in Northwestern Europe.…”

“…LECA's characteristics were measured in this study. The corresponding attributes for other materials were determined by Kazemi et al [12,22,60]. Specific heat capacity, water vapor diffusion resistance factor, and water absorption coefficient of materials were measured according to standards ASTM D4611-16 [65], EN 1015 [66], and EN 1925 [67], respectively, as explained in detail by Kazemi et al [22,60].…”

“…The findings showed that the increment of the substrate and drainage layers' thickness improved the roofing system's thermal efficiency, despite the effects of thicker layers being the same. In 2021 and 2022, Kazemi et al [22,60] assessed how the green roof with a 15 cm-substrate of coarse recycled materials and a 5-cm drainage layer of recycled coarse aggregates was able to resist the heat-flow in which the R-value as a heat resistance indicator was measured for green roof layers in accordance to ISO 9869-1 standard [61]. As per the results, the Rc-value of green roof layers with and without coarse recycled materials was near to each other.…”

“…Therefore, in this research, a comparative study on thermal resistance of different granular materials as the green roof drainage layer was performed in which the Rc-value of green roof with a dry and wet substrate including coarse recycled materials and the drainage layer of LECA was measured in accordance to ISO 9869-1 standard [61]. Then, the results were compared with those given by Kazemi et al [12,22,60] for the green roof system with the same substrate but with drainage layers made up of other granular coarse aggregates. The water drainage and water holding capacity of commercial substrate and drainage materials including coarse recycled and artificial aggregates were also measured.…”

Mechanical Properties of Recycled Aggregate Concretes Containing Silica Fume and Steel Fibres

“…Concrete is considered the most widely used construction material in the world [1][2][3][4][5][6][7][8][9][10][11][12][13]. Rapid urbanisation due to population growth results in the redevelopment of housing sectors and infrastructures in many cities around the world [14][15][16][17][18].…”