GREEN ROOFS WITH CONSTRUCTION AND DEMOLITION (CD) WASTE IN URBAN STORMWATER RETENTION

摘要

Green roofs are built with different layers and variablernthicknesses depending on the roof type and/or weatherrnconditions. Basic layers, from bottom to top, of greenrnroof systems usually consists of a root barrier, drainage,rnfilter, growing medium, and vegetation layer.rnEnvironmental and operational benefits of green roofs arernmany. Vegetative roofs must be installed on existingrnstructures to maximize their potential environmentalrnbenefits; however, their main disadvantages are cost andrnweight. New technology enabled the use of lightrnmaterials such as: low density polyethylene andrnpolypropylene (polymers) to promote their installation.rnNevertheless, lifecycle analyses demonstrate that morernsustainable products must replace current green roofrnmaterials. This paper evaluates water retentionrnperformance of green roofs built with construction andrndemolition (C&D) waste. Storm water retention of C&Drnbased green roofs were assessed experimentally byrncomparing the rainwater retained in C&D based greenrnroofs with standard green roofs, under the samernenvironmental conditions. Additionally, basic waterrnquality tests were conducted to compare the runoffrnquality with the rainwater quality. Results show thatrnC&D waste, compared to plastics, reduces the waterrnretention performance. However, the runoff water qualityrnis better in terms of electro-conductivity, pH, andrnturbidity. The benefits of installing vegetative roofs inrnthe regions with high rainfall and flood risk arernpotentially enormous.