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Stormwater systems
Published in James C.Y. Guo, Wenliang Wang, Junqi Li, Urban Drainage and Storage Practices, 2023
James C.Y. Guo, Wenliang Wang, Junqi Li
Surface erosion is inevitable when stormwater runs off a pervious surface. In an urban area, stormwater flows are often loaded with trash, debris, solids, chemicals, and petroleum pollutants. It is important to intercept 70–80% of solids before the stormwater enters the drainage system. As a result, a water-quality control basin (WQCB) is often placed upstream of a street inlet for the purpose of pollutant source control. A WQCB is designed to remove the pollutants and solids from stormwater by filtering and sedimentation processes. Examples of WQCBs shown in Fig.1.2 are an infiltration basin, porous pavement, vegetation bed, and wetland. A WQCB is typically small and flat because it was designed to intercept early stormwater from frequent storms such as 3- to 6-month events. Infiltration basins and infiltrating beds are often embedded into the landscaping settings around buildings. Parking lots may be covered with pervious pavements; and wetlands are placed at locations where surface runoff and groundwater are sufficiently available.
Specific Maintenance Procedures and Requirements
Published in Ryan Cruzan, Manager’s Guide to Preventive Building Maintenance, 2020
Water penetrating into asphalt is the biggest cause of parking lot damage. Having repairs made to low areas that tend to pond and making sure to seal cracks can extend the life of a parking lot by several years. Annual seal coating helps to keep water on top of the surface. Parking lots can typically be expected to last 30 to 40 years with one major re-surfacing project at approximately the middle of the parking lot’s useful life.
Evaluation of elastomer–plastomer vulcanised modifiers for using as bitumen binder modifier
Published in International Journal of Pavement Engineering, 2022
Mahmoudreza Favakeh, Saeed Bazgir, Morteza Karbasi, Mohammad Zia Alavi, Ali Abdi
Asphalt mixes are the most widely used construction materials for the paving of roads, runways, and parking lots. More than 96% of the roads in the United States have asphalt mix surface layer, the percentages of asphalt pavements in other countries are about the same or even higher (Roberts et al. 2002). The asphalt pavements face different types of distresses over the service life, including rutting (permanent deformation), fatigue cracking, and thermal cracking caused by traffic loads and environmental actions (Huang 2004). The resistance of asphalt mix to rutting and cracking is governed by its aggregate structure and bitumen properties. Bitumen properties change with temperature and loading time (i.e. vehicle speed), thus can be classified as a viscoelastic substance and fundamentals of rheology can be applied to understand and assess its critical properties.
Towards natural water cycle in urban areas: Modelling stormwater management designs
Published in Urban Water Journal, 2020
Ambika Khadka, Teemu Kokkonen, Tero J. Niemi, Elisa Lähde, Nora Sillanpää, Harri Koivusalo
Design B is an upgrade of design A, where additional LID techniques are introduced to increase on-site storage and infiltration of stormwater, without compromising other urban functions such as emergency services access, playgrounds, and walkways (Figure 2(c)). The LID techniques in design B are placed in series with interception-based techniques at the upstream, storage-based techniques in the middle and conveyance-based techniques at the downstream. The additional LID techniques are primarily storage-based (ca. 10% of the total area), such as bioretention cells and permeable pavements, and interception-based techniques (4%), such as green roofs and rain gardens. The yards are still asphalt to allow easy access for emergency services, but bioretention cells are constructed at corners of yards for stormwater treatment. The bioretention cells have a storage layer to enhance continuous infiltration and underdrain connected to the existing pipe network to prevent ponding of stormwater. Paved parking lots are replaced with permeable pavement. Similar to bioretention cells, permeable pavements have both storage layer and underdrain system. As per the current convention in the City of Turku, roofs of only one-storey buildings are replaced with green roofs (ca. 3% of the total area). Thus, in design B ca. 24% of the total area is covered with stormwater management techniques.
Daytime thermal performance of different urban surfaces: a case study in educational institution precinct of Melbourne
Published in Architectural Science Review, 2018
Salman Shooshtarian, Priyadarsini Rajagopalan
Despite the existence of several impervious materials in RUCC open spaces, this study only considered four dominant materials which covered 51.3% of total area. Site 3 with more than 70% of its surface covered by painted asphalt had the largest extent of impervious materials followed by that in Site 2 with a proportion of 52%. The following section provides an overview of the impervious materials’ thermal performance. Asphalt otherwise known as bitumen is a major construction material for urban surfaces such as sidewalks, parking lots, sport courts, streets and roads. Due to the large-scale usage in urban structures, this impervious material with low emissivity, evaporation and high albedo and heat absorbance (heat resistance) largely accounts for urban heat budget imbalance (Berg 1985; Yilmaz, Toy, and Yilmaz 2007). This material is made of fossil fuel; it maintains heat and is pervious, and stormwater can wash all the dirt, chemicals, pesticides, engine oil and pet excrement into the storm sewers and waterways (Mascaró 2012). Painted asphalt or cool asphalt is proved to be an emerging technique to increase solar reflectance of asphalts. Studies have shown that cool asphalt provides thermal benefits compared to conventional asphalt (Carnielo and Zinzi 2013). In RUCC, the regular and the coloured asphalt concrete was applied in the sidewalk in Site 1 and basketball courts in Site 3. The coloured asphalts proved to maintain lower Ts and possess small surface transfer coefficients (Berg 1985; Kinouchi et al. 2003).