Heat Transfer Measurement within Green Roof with Incinerated Municipal Solid Waste Aggregates

Abstract

A green roof is composed of a substrate and drainage layers which are fixed on insulation material and roof structure. The global heat resistance (Rc) within a green roof is affected by the humidity content of the substrate layer in which the coarse recycled materials can be used. Moreover, the utilization of recycled coarse aggregates such as incinerated municipal solid waste aggregate (IMSWA) for the drainage layer would be a promising solution, increasing the recycling of secondary resources and saving natural resources. Therefore, this paper aims to investigate the heat transfer across green roof systems with a drainage layer of IMSWA and a substrate layer including recycled tiles and bricks in wet and dry states according to ISO-conversion method. Based on the results, water easily flows through the IMSWAs with a size of 7 mm. Meanwhile, the Rc-value of the green roof system with the dry substrate (1.26 m2 K/W) was 1.7 times more than that of the green roof system with the unsaturated substrate (0.735 m2 K/W). This means that the presence of air-spaces in the dry substrate provided more heat resistance, positively contributing to heat transfer decrease, which is also dependent on the drainage effect of IMSWA. In addition, the Rc-value of the dry substrate layer was about twice that of IMSWA as the drainage layer. No significant difference was observed between the Rc-values of the unsaturated substrate layer and the IMSWA layer.

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

“…Sustainable urban drainage systems have been increasingly developed for building envelopes such as rooftops to improve the energy efficiency of houses and reduce the high volume of runoff during stormwater events [1][2][3][4][5][6][7][8][9][10]. As a sustainable ecosystem system, the green roof is known for its ability to provide thermal resistance for rooftops in some cases and buffer the surface stormwater runoff in urban areas [11][12][13][14][15][16][17][18]. The shape and type of materials used in green roof drainage and substrate layers significantly impact energy efficiency and rooftop water evacuation [19][20][21][22].…”

“…As per the results, the Rc-value of green roof layers with and without coarse recycled materials was near to each other. Also, Kazemi et al [12] assessed the thermal resistance of green roofs with a 15 cm-substrate of coarse recycled materials and a 5-cm drainage layer of incinerated municipal solid waste aggregates and compared the results of a dry substrate with a wet substrate. As per the results, the heat transfer decreased through the green roof substrate with air voids in dry state.…”

Properties of Lime-Cement Concrete Containing Various Amounts of Waste Tire Powder under Different Ground Moisture Conditions

“…Concrete is considered the most widely used construction material in the world [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Contrary to structural concretes in which achieving high strength values is of special importance, in the case of lime-cement concrete (LCC), as non-structural concrete, attaining high strengths is not required.…”

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].…”