Hydraulic and physical property characterizations of materials for the design of sustainable urban drainage systems

Abstract

In the context of extreme weather events, i.e., floods, and increased population in urban areas, traditional drainage systems fall short. The need to develop alternative runoff-control in urban environments and promote the circular economy has prompted us to study various draining materials, some of them recycled that might be used in SUDS construction and technosols. These include recycled shatter brick, gravel for draining concrete, recycled rubber from car tires, and substrates with different proportions of organic matter like compost, coconut fiber, peat, and manure. Mechanical parameters like porosity, density, and uniformity coefficients (among others) were calculated to assess hydraulic conductivity in the laboratory under saturated and laminar flow conditions. Alternative methodologies were applied to adapt the materials and samples to current standards procedures (UNE and ISO). The results, based on Darcy's law, show values equivalent to those of natural coarse soils, ranging from 4.4·10−5 to 1.1·10−1 cm·s−1.