Suchergebnisse

The reduction in the use of natural and finite resources and the reuse of waste materials are current concerns of different research areas. Therefore, the main aim of this study is to develop enhanced modified bitumens with waste engine oil and recycled engine oil bottoms combined with polymers (waste polyethylene, crumb rubber and styrene-butadienestyrene), in order to minimize the use of bitumen. After a thermochemical characterization, different compositions were studied with penetration, softening point and viscosity tests. The bitumens modified with waste engine oil products and polymers have similar penetration values, and softening point temperatures higher than those of commercially modified binders. A rheological analysis of the most encouraging solutions showed low thermal susceptibility, high values of high temperature PG and low non-recoverable creep compliance values, which could indicate a promising performance using high amounts of waste materials. ; Portuguese Government and EU/FSE within a FCT PhD grant (SFRH/BD98379/2013), in the scope of POPH/QREN, as well as the funding by ERDF through the Competitiveness Factors Operational Programme (COMPETE) and by national funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of PLASTIROADS Project (PTDC/ECM/119179/2010) ...

The innovative Horizon 2020 program sponsored by the European Union (EU) aims to promote and develop processes of waste integration in construction materials. However, several potential health hazards caused by building materials have been identified and, there-fore, there is an ongoing need to develop new recycling methods for hazardous wastes and effi-cient barriers in order to prevent toxic releases from the new construction solutions with wastes. This paper presents an overview that focus on two main aspects: the identification of the health risks related to radioactivity and heavy metals present in building materials and identification of these toxic substances in new construction solutions that contain recycled wastes. Different waste materials were selected and distinct methodologies of toxicity evaluation are presented to analyse the potential hazardous, the feasibility of using those wastes and the achievement of op-timal construction solutions involving wastes. ...

Every year, millions of tons of plastic waste, with potential to be reused, are wasted in landfills. Based on a literature review and in a local market analysis, cross-linked polyethylene (PEX) waste arose as the material with the greatest potential to be tested for incorporation in asphalt mixtures due to the difficulty in its recycling and the lack of solutions for its reuse. Thus, in the present work, mixtures produced with and without PEX were tested in order to compare their performance, aiming at understanding if this waste could successfully be used as an alternative material for this type of application. Thus, water sensitivity, rutting resistance, stiffness modulus and fatigue cracking resistance tests were carried out on asphalt mixtures with up to 5% PEX. Based on the results obtained, it can be concluded that the incorporation of PEX in asphalt mixtures is a viable solution for paving works, especially when high service temperatures are expected. It also decreases the density of the mixture, which can be attractive to lighten structures. Thus, this technology contributes to give new life to cross-linked polyethylene plastic waste. ; The authors gratefully acknowledge the funding provided by the Portuguese Government (Portuguese Foundation for Science and Technology) and by the Competitiveness Factors Operational Programme (EU/ERDF funds), through the FCT project PLASTIROADS (PTDC/ECM/119179/2010). ...

This study aims to develop an innovative bitumen with large quantities of waste materials to improve asphalt mixtures performance. Different amounts of waste motor oil and waste HDPE were added to a new bitumen. The bitumen modified with 10% of waste motor oil and 5% of HDPE showed promising characteristics (high softening point temperatures and penetration slightly higher than the conventional bitumen). After the selection of the most promising modified bitumen, three asphalt mixtures were produced with different bitumens (namely conventional bitumen, commercial modified bitumen and the selected modified bitumen). Beyond that, this modified bitumen improved some mechanical characteristics of the asphalt mixture where it was used, in comparison to conventional and modified asphalt mixtures. ; Portuguese Government and EU/FSE within a PhD fellowship (SFRH/BD98379/2013) of the FCT, in the scope of POPH/QREN, by FEDER through the Competitiveness Factors Operational Programme (COMPETE) and by national funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of PLASTIROAD Project ...

The environmental concern about waste generation and the gradual decrease of oil reserves has led the way to finding new waste materials that may partially replace the bitumens used in the road paving industry. Used motor oil from vehicles is a waste product that could answer that demand, but it can also drastically reduce the viscosity, increasing the asphalt mixture?s rutting potential. Therefore, polymer modification should be used in order to avoid compromising the required performance of asphalt mixtures when higher amounts of waste motor oil are used. Thus, this study was aimed at assessing the performance of an asphalt binder/mixture obtained by replacing part of a paving grade bitumen (35/50) with 10% waste motor oil and 5% styrene-butadiene-styrene (SBS) as an elastomer modifier. A comparison was also made with the results of a previous study using a blend of bio-oil from fast pyrolysis and ground tire rubber modifier as a partial substitute for usual PG64-22 bitumen. The asphalt binders were tested by means of Fourier infrared spectra and dynamic shear rheology, namely by assessing their continuous high-performance grade. Later, the water sensitivity, fatigue cracking resistance, dynamic modulus and rut resistance performance of the resulting asphalt mixtures was evaluated. It was concluded that the new binder studied in this work improves the asphalt mixture?s performance, making it an excellent solution for paving works. ; The authors gratefully acknowledge the funding provided by the Portuguese Government (Portuguese Foundation for Science and Technology) and by the Competitiveness Factors Operational Programme (EU/ERDF funds), through the FCT project PLASTIROADS (PTDC/ECM/119179/2010) and the PhD grant SFRH/BD98379/2013. Authors also want to acknowledge all companies mentioned in this document for supplying all the materials, which were essential to obtain the final results presented in this paper. ...