176 research outputs found
Machine learning algorithms for monitoring pavement performance
ABSTRACT: This work introduces the need to develop competitive, low-cost and applicable technologies to real roads to detect the asphalt condition by means of Machine Learning (ML) algorithms. Specifically, the most recent studies are described according to the data collection methods: images, ground penetrating radar (GPR), laser and optic fiber. The main models that are presented for such state-of-the-art studies are Support Vector Machine, Random Forest, NaĂŻve Bayes, Artificial neural networks or Convolutional Neural Networks. For these analyses, the methodology, type of problem, data source, computational resources, discussion and future research are highlighted. Open data sources, programming frameworks, model comparisons and data collection technologies are illustrated to allow the research community to initiate future investigation. There is indeed research on ML-based pavement evaluation but there is not a widely used applicability by pavement management entities yet, so it is mandatory to work on the refinement of models and data collection methods
Experimental analysis of enhanced cement-sand-based geothermal grouting materials
Nowadays, Ground Source Heat Pumps (GSHP) are achieving significant efficiencies, mostly because of the development of their electromechanical components. However, concepts such as the technical performance of the grouting materials deserve more profound analysis, as becoming essential in areas where good potential thermal performance of the GSHP and serious risks of groundwater contamination exist. In this paper, several fluid mortars with enhanced characteristics have been evaluated. Results show improved mechanical and thermal properties compared to conventional grouting materials. Likewise, mortars exhibited good performance after being subjected to durability treatment. For now, the cost of some mortars may constitute a barrier.This work is based on the project with reference BIA2013-40917-R. This project was financed by the Ministry of Economy and Competitiveness through the State General Budget and the European Regional Development Fund (FEDER)
Asphalt solar collectors: A literature review
Asphalt pavements subject to solar radiation can reach high temperatures causing not only environmental problems such as the heat island effect on cities but also structural damage due to rutting or hardening as a result of thermal cycles. Asphalt solar collectors are doubly effective active systems: as they solve the previously mentioned problems and, moreover, they can harness energy to be used in different applications. The main findings of the existing research on asphalt solar collectors are gathered together in this review paper. Firstly, the main heat transfer mechanisms involved in the solar energy collection process are identified and the most important parameters and variables are presented. After analyzing the theoretical foundations of the heat transfer process, this review focuses on the types of studies carried out so far on asphaltâs thermal behavior, different methodologies employed by other authors to study asphalt solar collectors and influence of the variables involved in thermal energy harvesting
Environmental impact assessment of induction-healed asphalt mixtures
This paper demonstrates the sustainability of induction-healed asphalt mixtures (HEALROAD) by comparing the impacts this technology causes with those generated by asphalt mixtures maintained byconventional practices such as mill and overlay. The functional unit selected is a 1 km lane with ananalysis period of 30 years, and the stages considered are production, construction, maintenance,congestion, leaching and end-of-life. Two case studies have been analysed to evaluate the influence ofdifferent traffic strategies on the environmental impact of each maintenance alternative. Results showthe benefits of using the induction technology at hot points where traffic jams occur.This work was supported by the ERA-NET Plus Infravation 2014 Call under grant agreement no. 31109806.0003 - HEALROAD. Funding partners of the Infravation 2014 Call are: Ministerie van Infrastructuur en Milieu, Rijkswaterstaat, The Netherlands, Bundesministerium fĂŒr Verkehr, Bau und Stadtentwicklung, Germany, Danish Road Directorate, Denmark, Statens Vegvesen Vegdirektoratet, Norway, Trafickverket-TRV, Sweden, Vegagerdin, Iceland, Ministere de lâEcologie du Developpement Durable et de lâ Energie, France, Centro para el Desarrollo TecnolĂłgico Industrial, Spain, Anas S.P.S, Italy, Netivei Israel - National Transport Infrastructure Company LTD, Israel and Federal Highway Administration USDOT, USA. The HEALROAD project has been carried out by the University of Cantabria, University of Nottingham, German Federal Highways Research Institute (BASt), European Union Road Federation (ERF), Heijmans Integrale projecten B.V. and SGS INTRON B.V
Thermal and hydraulic analysis of multilayered asphalt pavements as active solar collectors
The fulfillment of current environmental aims like reducing fossil fuel consumption or greenhouse gas emissions entails the development of new technologies that enable the use of cleaner, cheaper and renewable energies. Furthermore, the need to improve energy efficiency in buildings encourages scientists and engineers to find new ways of harvesting energy for later uses. The use of asphalt pavements as active solar collectors is introduced in this article. Several authors have studied the use of roads as an energy source before. However, a new technology is presented in which a multilayered pavement with a highly porous middle layer is used instead of a solar collector with an embedded pipe network. These collectors are fully integrated within the road infrastructure and may offer low cost solar energy for water heating. The paper includes a brief comment on the state-of-the-art. Then, a broad methodology is presented in which data, materials and procedures needed to run the tests are fully described. Finally, the results of the laboratory tests are stated and discussed. The prototype used in the laboratory provided excellent thermal efficiency. However, these good results contrast with the low flow rate levels registered during the tests. Thus, although this technology seems to be very promising, new experimental tests should be performed before an effective application is possible.This paper is based on the initial literature review for the Fenix Project. The development of the Fenix Project (www.proyectofenix.es) has been possible thanks to the financial contribution of the Center for Technological and Industrial Development (CDTI) within the framework of the Ingenio 2010 programme, through the CENIT Programme. The companies and research centers involved in the project wish to express their gratitude for the contribution
Freezeâthaw durability of cement-based geothermal grouting materials
The authors wish to express their gratitude to the Spanish
Ministry of Economy and Competitiveness which funded this study through the research project BIA2009-
08272. Finally, authors wish to acknowledge the financial support provided by the research projects FICYT
FC-10-EQUIP10-17 and BIA-2008-00058
Mechanical performance of fibers in hot mix asphalt: a review
The use of fibers in hot mix asphalt (HMA) has become a much more attractive alternative for the con-struction of road pavements. Numerous studies have shown that the incorporation of fibers in the mix-ture improves fatigue resistance, permanent deformation and stiffness. The aim of this paper is to presenta review of the mechanical impact of fibers in HMA by analyzing their reinforcement effect in a qualita-tive and quantitative manner. Fiber properties and characterization tests on fiber-modified bitumen arediscussed. Quantities, blending procedures and performance of bituminous mixtures with different typesof fibers are presented. Results of mechanical improvement are displayed. Based on the current researchresults, depending on the properties and the type of mixture in which they are used, each type of fiberseems to improve certain parameters more than others. Coconut fibers and waste fibers are describedas environmentally friendly alternatives
Multi-Response Optimization of Porous Asphalt Mixtures Reinforced with Aramid and Polyolefin Fibers Employing the CRITIC-TOPSIS Based on Taguchi Methodology
For the optimum design of a Porous Asphalt (PA) mixture, different requirements in terms of functionality and durability have to be fulfilled. In this research, the influence of different control factors such as binder type, fiber content, and binder content were statistically investigated in terms of multiple responses such as total air voids, interconnected air voids, particle loss in dry conditions, particle loss in wet conditions, and binder drainage. The experiments were conducted based on a Taguchi L18 orthogonal array. The best parametric combination per each response was analyzed through signal to noise ratio values. Multiple regression models were employed to predict the responses of the experiments. As more than one response is obtained, a multi-objective optimization was performed by employing Criteria Importance through Criteria Inter-Correlation (CRITIC) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methodologies. The weights for the selection of the functional and mechanical performance criteria were derived from the CRITIC approach, whereas the ranking of the different experiments was obtained through the TOPSIS technique. According to the CRITIC-TOPSIS based Taguchi methodology, the optimal multiple-response was obtained for a polymer modified binder (PMB) with fiber and binder contents of 0.15% and 5.0%, respectively. In addition, good results were obtained when using a conventional 50/70 penetration grade binder with a 5.0% binder content and 0.05% fiber content.FORESEE project has received funding from the European Unionâs Horizon 2020 research and innovation programme under grant agreement No. 769373
3D numerical modelling and experimental validation of an asphalt solar collector
Research about renewable technologies for thermal energy collection is crucial when critical problems such as climate change, global warming or environmental pollution are concerned. Transforming solar energy into thermal energy by means of asphalt solar collectors might help to reduce greenhouse gas emissions and fossil fuel consumption. In this paper, a laboratory-scale asphalt solar collector formed by different slabs has been characterized by applying numerical techniques. An experimental test where the thermal performance of the collector was determined for three values of heat exchange fluid flow rate was carried out for the validation of the numerical model. Then, the CFD model was used to analyse the thermal response of the collector according to the following parameters: flow rate, solar irradiance, size and thickness. Results show that increasing values of heat exchange fluid flow rate result in better thermal performances. Likewise, increasing values of irradiance and size of the collector lead to higher values of thermal performance, although other parameters should also be considered for the final design of the system. Finally, under the conditions here considered, the thickness of the collector turned out not to be as significant as expected in relation to its thermal response. The combination of experimental tests and CFD codes can be considered a powerful tool for the characterization of asphalt solar collectors without incurring significant costs related to experimental field tests.This project, with reference BIA2013-40917-R, is financed by the Ministry of Economy, Industry and Competitiveness and funded by the State General Budget and the European Regional Development Fund (FEDER)
Application of Non-Destructive Techniques to the Recording and Modelling of Palaeolithic Rock Art
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