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Hugo Manuel Ribeiro Dias da Silva

Bio: Hugo Manuel Ribeiro Dias da Silva is an academic researcher from University of Minho. The author has contributed to research in topics: Asphalt & Natural rubber. The author has an hindex of 21, co-authored 102 publications receiving 1346 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the effectiveness of rejuvenator agents in improving the aged binders' properties and the recycled mixture performance and concluded that totally recycled asphalt pavement can be a good alternative for road paving, especially if rejuvenators are used to reduce their production temperature and improve their performance.
Abstract: The recycling of reclaimed asphalt pavement (RAP) helps road authorities to achieve their goal of a sustainable road transport system by reducing waste production and resources consumption. The environmental and economic benefits of using RAP in hot mix asphalt (HMA) applications could be pushed up to the limit, by producing totally recycled HMAs (100% RAP), but the performance of this alternative must be satisfactory. In fact, these mixtures could possibly present problems of workability and durability, higher binder aging and low fatigue cracking resistance. Thus, the objective of this study is to determine if totally recycled HMA mixtures could be a good solution for road paving, by evaluating the merit of some rejuvenator agents (commercial product; used engine oil) in improving the aged binders’ properties and the recycled mixture performance. Several binder samples were prepared with the mentioned rejuvenators and characterized (Pen, R&B and dynamic viscosity), in order to select the best rejuvenator contents. The production temperatures of the corresponding recycled mixtures were evaluated based on their workability. Totally recycled HMAs were produced with the best previously observed combinations, and their performance (water sensitivity, rutting resistance, stiffness, fatigue resistance, binder aging) was assessed. The main conclusion of this study is that totally recycled HMAs can be a good alternative for road paving, especially if rejuvenator agents are used to reduce their production temperature and to improve their performance.

186 citations

Journal ArticleDOI
TL;DR: In this article, the properties of different blends of base bitumens (softer to harder ones) containing a range of synthetic wax contents, as well as the performance of the corresponding warm mix asphalts, were assessed.

148 citations

Journal ArticleDOI
TL;DR: In this article, a surfactant-based additive was used to reduce the mixing temperatures of asphalt rubber and asphalt concrete mixtures without compromising their performance, and this can be seen as a great step forward towards the production of cleaner asphalt rubber mixtures.

148 citations

Journal ArticleDOI
TL;DR: In this article, the importance of the use phase of a road in the LCA of different paving alternatives was analyzed by evaluating energy consumption and gaseous emissions throughout the road pavement's life.
Abstract: In order to assess sustainability of products and processes, different methodologies have been developed and used in the last years. In the road pavement construction area, most methodologies used for Life Cycle Assessment (LCA) are essentially focused in the construction phase. The present paper analyses the importance of the use phase of a road in the LCA of different paving alternatives, namely by evaluating energy consumption and gaseous emissions throughout the road pavement’s life. Therefore, a new LCA methodology for road pavements was developed, and the results of its application to a case study involving the construction of alternative pavement structures are discussed. The study intends to assess the influence of using more sustainable paving construction alternatives (asphalt recycling vs. conventional asphalt mixtures), and/or different surface course materials (which have a higher influence on the rolling resistance and, therefore, affect the performance during the use phase). The LCA results obtained for this case study showed that the reductions in energy consumption and gaseous emissions obtained during the use phase, for pavement alternatives with a lower rolling resistance surface course, are higher than the total amount of energy consumption and gas emissions produced during construction. It is therefore clear that some improvements in the characteristics of the surface course may have an effect over the road use phase that will rapidly balance the initial costs and gas emissions of those interventions. The LCA results obtained also showed that the sustainability of pavement construction may also be improved using recycled asphalt mixtures.

95 citations

Journal ArticleDOI
TL;DR: In this article, the authors evaluate the possible advantages of modifying the bitumen with different plastic wastes, namely polyethylene (high density HDPE and low density LDPE), ethylene-vinyl acetate (EVA), acrylonitrile-butadiene-styrene (ABS), and crumb rubber, in order to improve the properties of the resulting binders for use in high performance asphalt mixtures.
Abstract: With the increase in road traffic more demands are placed on pavements, and thus the structural and functional performance of road pavements needs to be improved. One method that can greatly improve the quality of the flexible pavements is the addition of polymers to the bitumen or to the asphalt mixtures. Although the modification of bitumen with virgin polymers can improve the properties of asphalt mixtures, the use of recycled plastic may also show a similar result with additional environmental advantages. This work aims to evaluate the possible advantages of modifying the bitumen with different plastic wastes, namely polyethylene (high density HDPE and low density LDPE), ethylene-vinyl acetate (EVA), acrylonitrile-butadiene-styrene (ABS) and crumb rubber, in order to improve the properties of the resulting binders for use in high performance asphalt mixtures. The performance of modified binders with recycled polymers was compared with that of the conventional bitumen and the one of a commercial modified binder (Styrelf). The results of the laboratory tests (basic characterization, dynamic viscosity, resilience and storage stability) will be used in the selection of the best plastic waste materials and production conditions that should be used in the modification of bitumen in order to optimize its behaviour, emphasizing that this study aims to promote the reuse of plastic waste in a more environmental and economic way.

65 citations


Cited by
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Journal ArticleDOI
01 Apr 1988-Nature
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

9,929 citations

Journal ArticleDOI
TL;DR: In this paper, an overview of the different technologies used in the manufacturing of WMA is presented, as well as the materials, additives, mix design and performance of the asphalt made by this technology.

551 citations

Journal ArticleDOI
TL;DR: In this article, a state-of-the-art article focuses on various aspects of the WMA technology incorporating Sasobit® which includes the rheological characteristics of asphalt binders.

284 citations

Journal ArticleDOI
TL;DR: A review of the main aspects involved in WMA technology, including constituent materials, mix design and mechanical performance issues, as well as technological specificities, is presented in this paper.

279 citations

Journal ArticleDOI
TL;DR: In this paper, the state-of-the-art approaches for increasing the amount of reclaimed asphalt pavement (RAP) in asphalt mixtures above 40% are summarized and methods to optimise the mix design as well as production technology in order to allow manufacturing of such sustainable mixtures are described.
Abstract: Asphalt is the most recycled material in the USA at a re-use rate of 99%. However, by average only 10–20% reclaimed asphalt pavement (RAP) is used in a given mix design and large part of the RAP is degraded for use in lower value applications. The amount of RAP in asphalt mixtures can be significantly increased with the application of good RAP management practice, readily available modern production technologies and advanced knowledge of mix design. This paper summarises the state-of-the-art approaches for increasing the amount of RAP in asphalt mixtures above 40%. The production challenges and common pavement distresses of very high RAP content mixtures are identified and methods to optimise the mix design as well as production technology in order to allow manufacturing of such sustainable mixtures are described. The best practices for RAP management and economic benefits of high RAP use are also discussed.

249 citations