1,720,969 research outputs found
A SYSTEMATIC LITERATURE REVIEW OF THE HYDROLOGICAL PERFORMANCE OF POROUS PAVEMENTS ON STORM WATER MANAGEMENT AND POLLUTION CONTROL
No full textThe expanding urban landscape has significant hydrological implications. Considerable studies have explored the use of porous pavements to mitigate urban hydrology including how porous pavements impact the permeability of urban surfaces and pollution. The current systematic review synthesizes available literature in the past ten years. The paper reviews findings on the Hydrological Performance of Porous Pavements on Storm Water Management and Pollution Control. The selected studies comprised field experiments, laboratory experiments, and simulations published in the past 10 years. Overall, porous pavements were presented as able to significantly mitigate runoff and offer better storm water management. Further, the review found extensive evidence on the pollution control capability of porous pavements. While the different studies evaluated-based on different settings and unique variables-offered different quantitative results, there was a positive trend in the results. That is, regarding storm water management, Porous pavements were found to increase infiltration, reduce runoff and peak discharges, and have similar hydrological effects. On pollution control, there was considerable evidence especially on non-dissolving pollutants such as suspended solids. The review found that while there was a general positivity in the adoption of permeable pavements, there was considerable fragmentation of knowledge of pervious pavements. Accordingly, more effort is needed to better define adoption and application guidelines across the board. That is; performance mechanism for different soils, loading, pollutant characteristic, and similar hydrological and structural parameters
A Meta-Analysis Of Experiments On Hydraulic Properties Of Porous Pavements
No full textA meta-analysis of studies evaluating the effect of porous pavements on surface hydrology. The analysis investigated experiments on infiltration rate and consequent runoff coefficient of porous pavements. Reviewed literature provided extensive indications on the benefits of porous pavements in mitigating hydrology in the built environment. It was demonstrated that previous pavements improved the hydrological properties of engineered surfaces including mitigating runoff and checking to flood. Accordingly, it was hypothesised that the mean effect among the selected studies is zero. A meta-analysis of selected experiments on porous pavements experiments established that the mean effect among the selected studies was zero. While the study adopted a methodology that included similar studies in terms of method, further study is recommended to control for the various factors that influence hydraulic properties of porous pavers mentioned in the conclusion of this study
POROUS PAVEMENTS IN THE CONTEXT OF SUSTAINABLE URBAN DESIGN CONCERNS
No full textHydrology explores a cycle that entails the transport and storage of water. However, this system of transport and, or storage can be significantly impacted by urbanization. Typically, urban drainage design is intended to create habitable spaces that are typically extensively paved surfaces that have the potential to generate significant run-off. One solution that has been extensively explored is the use of porous pavements to mitigate sustainability concerns posed by urban hydrology. The current paper provides a literature review of sustainable development initiatives, including Sustainable Urban Drainage Systems (SUDS), Low Impact Development (LID), Water Sensitive Urban Design (WSUD). Specifically, the review explores how these approaches have interrogated the use of porous pavements in their strategies. The review found that the three concepts, SUDS, LIDS, and WSUD, have a significant convergence, especially regarding porous pavements. The review noted that SUDS employs strategies to promote groundwater recharge and reduce flooding, LID advocates for mimicking the natural environment by attempting to preserve the pre-development hydrograph. WSUDS encompasses a range of strategies, including LID, and sometimes SUDS, that are intended to restore water balance in urbanized spaces. All these strategies were partly based on the need to reconsider improving the infiltration of urban surfaces. The case meant considering various forms of porous pavements
A Deep Neural Network Approach towards Performance Prediction of Bituminous Mixtures Produced Using Secondary Raw Materials
Full text linkWith the progressive reduction in virgin material availability and the growing global concern for sustainability, civil engineering researchers worldwide are shifting their attention toward exploring alternative and mechanically sound technological solutions. The feasibility of preparing both cold and hot asphalt mixtures (AMs) for road pavement binder layers with construction and demolition wastes (C&DWs) and reclaimed asphalt pavement (RAP) partially replacing virgin materials like limestone aggregates and filler has already been proven. The technical suitability and compliance with technical specifications for road paving materials involved the evaluation of mechanical and volumetric aspects by means of indirect tensile strength tests and saturated surface dry voids, respectively. Thus, the main goal of the present study is to train, validate, and test selected machine learning algorithms based on data obtained from the previous experimental campaign with the aim of predicting the volumetric properties and the mechanical performance of the investigated mixtures. A comparison between the predictions made by ridge and lasso regression techniques and both shallow (SNN) and deep neural network (DNN) models showed that the latter achieved better predictive capabilities, highlighted by fully satisfactory performance metrics. DNN performance can be summarized by R2 values equal to 0.8990 in terms of saturated surface dry void predictions, as well as 0.9954 in terms of indirect tensile strength predictions. Predicted observations can be thus implemented within the traditional mix design software. This would reduce the need to carry out additional expensive and time-consuming experimental campaigns
Surface monitoring of road pavements using mobile crowdsensing technology
Full text linkPavement-surface characteristics should be considered during road maintenance for safe and comfortable driving. A detailed and up-to-date report of road-pavement network conditions is required to optimize a maintenance plan. However, manual road inspection methods, such as periodic visual surveys, are time-consuming and expensive. A common technology used to address this issue is SmartRoadSense, a collaborative system for the automatic detection of road-surface characteristics using Global Positioning System receivers and triaxial accelerometers contained in mobile devices. In this study, the results of the SmartRoadSense surveys conducted on Provincial Road 2 (SP2) in Salerno, Italy, were compared with the Distress Cadastre data for the same province and the pavement condition indices of different sections of the SP2. Although the effectiveness of the crowdsensing-based SmartRoadSense was found to vary with the distress type, the system was confirmed to be very efficient for monitoring the most critical road failures
Additional procedures for characterizing the performance of recycled polymer modified asphalt mixtures
No full textGreat efforts have been made in recent years to improve the mechanical properties of asphalt mixtures by replacing conventional mix components with innovative ones or by adding materials such as polymers. Hence, the innovative-sustainable road materials to be investigated through laboratory tests require articulated procedures, the research here presented aims to provide an experimental-methodological approach to analyse the mechanical performance of untraditional hot asphalt mixtures made up using a polymer compound of recycled plastics. Three Asphalt Concrete 20 (AC20) Hot Asphalt Mixtures (HMA) were analysed by measuring base properties (i.e., indirect tensile strength and moisture damage) and advanced features (i.e., stiffness, fatigue, cracking and rutting resistance). As a result, the addition of polymer compound using dry process might lead firstly to change the laboratory mixing procedure than the traditional hot limestone asphalt solutions. The main benefits derived from the adoption of this innovative technology compared to the conventional ones are as follows: a) an improvement of resistance to moisture damage (at 15 °C); b) a suitable stiffness at 10, 20 and 40 °C; c) an increment of the cracking resistance (at 10 °C) and d) a good rutting resistance in terms of rut depth (at 60 °C)
Multiobjective railway alignment optimization using ballastless track and reduced cross-section in tunnel
Full text linkThe increasing need for railway planning and design to connect growing cities in inland mountainous areas has pushed engineering efforts toward the research of railway tracks that must comply with more restrictive constraints. In this study, a multiobjective alignment optimization (HAO), commonly used for highway projects, was carried out to identify a better solution for constructing a high-speed railway track considering technical and economic feasibilities. Then, two different and innovative scenarios were investigated: an unconventional ballastless superstructure, which is more environment-friendly than a gravel superstructure, and a reduced cross-section in a tunnel, which enables a slower design speed and then, less restrictive geometric constraints and earthmoving. The results showed that the first solution obtained a better performance with a slight increase in cost. Moreover, both scenarios improved the preliminary alignment optimization, reducing the overall cost by 11% for the first scenario and 20% for the second one
Bim parametric modelling of a railway underpass
No full textBuilding Information Models allow designers to achieve greater efficiency among various design alternatives and to derive the optimal solution. Building Information Models contain the data necessary not only for design, but also to support bidding, construction, and subsequently maintenance and management of the operation of the building or infrastructure. This research involved exploring the concept of parametric Building Information Modelling, also known as generative design or algorithmic design, based upon a “reverse engineering” approach applied to a railway underpass in the north-eastern part of Slovenia. Under the BIM approach, international standards are applied wherever possible (e.g., Industry Foundation Classes-IFC, classification system, model naming conventions)
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