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Oklahoma City, OK, United States

Drake J.,University of Toronto | Bradford A.,University of Guelph | Van Seters T.,Vaughan Foods
Journal of Hydrologic Engineering

The hydrologic performance of three partial-infiltration permeable pavement (PP) systems was evaluated at the Kortright Centre for Conservation in Vaughan, Ontario, Canada over 22 months. Partial-infiltration systems allow some stormwater to infiltrate into native soils and drain excess water by way of underdrains. The native soils at Kortright are composed of clayey silt and silty clay till, with clay content ranging from 7 to 30%. Flow restrictors on the underdrains were adjusted to the smallest orifice possible to assess the potential for stormwater outflow volume reductions. The hydraulic behavior of the PP systems was compared with runoff from an asphalt parking lot control. Peak outflow rates from PP were 91% smaller than peak flowrates of asphalt runoff on average, and attenuation of stormwater was observed during all seasons. Stormwater was found to infiltrate at the surface of the PP systems throughout two winters. Although increases in outflow were observed during periods of seasonal thawing due to the delayed release of infiltrating stormwater, the PP systems (with restricted flows from the underdrains) reduced overall stormwater outflow volume by 43% and completely captured (i.e., infiltrated and evaporated) most rainfall events that were less than 7 mm in depth. The study demonstrated that in cold climates and over low permeability soils, partial-infiltration permeable pavements reduce the volume, peak flow, and frequency of storm flows. These changes to the hydrology of stormwater are important for achieving water quality benefits as well as sustaining a more natural water balance and flow regime. © 2014 American Society of Civil Engineers. Source

Drake J.,University of Toronto | Bradford A.,University of Guelph | Van Seters T.,Vaughan Foods
Journal of Environmental Management

This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave® and Eco-Optiloc®) and a Hydromedia® Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4++NH3), nitrite (NO2-) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3-). The PP systems had mixed performances for the treatment of phosphate (PO43-). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. © 2014 Elsevier Ltd. Source

Ballan S.,Vaughan Foods | Ballan S.,University of Toronto | El-Diraby T.E.,University of Toronto
Electronic Journal of Information Technology in Construction

The use of ICT in construction has progressed over the last two decades. This paper summarizes the results of a survey that aimed at testing the usability of major communication tools and future mobile communication systems in the construction industry. In addition to documenting industry utility regarding the communication tools, the survey also tried to address the main issues that could hinder the use of communication systems in the industry. Three fundamental issues limit the usability of more advanced ICT tools. First, Software: the fundamental problem facing more use of ICT is not the devices themselves. Rather, it is the in-suitability of software systems. This is mainly due to the lack of interoperability between software systems and the low relevance to industry needs. Second, weak process structures: communication takes place in an ad hoc nature in many cases. The weak formalization of work processes is the main reason for this problem. For it to be coherent and relevant, communication has to be blended in a consistent stream conducive for information flow that matches the progress of work process. Finally, culture: construction personnel tend to favor oral and face-to-face communication. However, new entrants to the industry are more perceptive to ICT tools. Three values-generating components are key to overcoming such barriers. First, content: making the content being communicated more meaningful to industry. Second, access: assuring ability to access such information at different contexts. Finally, usability: ease of use and interoperability. Source

Malekpour A.,Vaughan Foods | Karney B.W.,University of Toronto
Journal of Hydraulic Engineering

This paper investigates the source of the spurious numerical oscillations often observed in simulations using the well-known Preissmann slot method and proposes a nonoscillatory numerical fix that can efficiently suppress the numerical oscillations. The root of these oscillations is identified by comparing the orbits calculated by a first-order Godunov type model with an ideal numerical orbit in the phase plane. It is found that in the very thin layer in the vicinity of the conduit roof the numerical model has insufficient numerical viscosity to avoid the often-observed oscillations. In order to remove these spurious oscillations, an approximate Riemann solution is proposed that automatically enhances the numerical viscosity whenever the water level is in the vicinity of the conduit roof and the pressurization of the conduit is proximate. A comparison of results from the proposed model with both experimental data and analytical solutions show that it can provide nonoscillatory solutions over a wide range of the wave velocities ranging from 10 to 1,000 m=s. Furthermore, the proposed model effectively controls data smearing. © 2015 American Society of Civil Engineers. Source

Malekpour A.,Vaughan Foods | Karney B.W.,University of Toronto | Nault J.,University of Toronto
Journal of Hydraulic Engineering

A global energy-auditing approach is used to describe the complex transient flow associated with sudden pressurization of a confined pipe system containing entrapped air pockets. The key concept is that the greatest pressures following pressurization are directly related to the amount of energy absorbed by the air pockets. The energy approach leads to an insightful understanding of the transient pressurization event, one that clarifies the underlying physics and that better explains several previously published observations. Moreover, the energy formulation leads to analytical algebraic expressions that can be numerically confirmed. © 2015 American Society of Civil Engineers. Source

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