Search results for "Reclaimed asphalt"
showing 10 items of 34 documents
Linear viscoelastic properties of high reclaimed asphalt content mixes with biobinders
2017
The use of high Reclaimed Asphalt (RA) content mixtures together with binders produced from renewable resources (biobinders) is one of the current challenges in pavement engineering research. On the one hand, RA has been used for decades, but there are still some concerns about its performance, especially when high contents are used (>30%). On the other hand, biobinders are relatively new materials, which have to be deeply characterised and studied in order to develop good practices for their use. In this paper, linear viscoelastic properties of biobinders and bio-mixtures manufactured with high RA content and biobinders are analysed and discussed. High-modulus mixtures with 50% RA were…
Fundamental characterisation of reclaimed asphalts: The importance of testing homogeneous specimens
2013
This study highlights the importance of defining appropriate specimen manufacturing procedures when assessing the fundamental properties of reclaimed asphalt (RA) mixes for further modelling purposes. Two gyratory compactor procedures were used: the first leading to specimens with a non-uniform air voids distribution and the second tailored to obtain homogeneous specimens. The study was performed by using three stone mastic asphalts incorporating up to 30% of RA but designed to have identical properties. A detailed characterisation of the loose mixes and binders, an X-ray computer tomography micro-structural study of the manufactured specimens and a further mechanical characterisation showe…
Performance of asphalt mixes with high recycling rates for wearing layers
2016
The corresponding paper presents selected results of a research on the feasibility of going toward 100% recycling of asphalt pavements into surface courses through an increasing percentage of RA within the mixes. The research is carried out within a two-year CEDR Transnational Road Research project, AllBack2Pave, led by the Technische Universitaet Dresden (Germany), together with the University of Nottingham (UK) and the University of Palermo (Italy), and finalised in January 2016. The main objectives of the project are - to establish, through laboratory tests on binders and asphalt mixes, whether the use of high rates of RA is feasible in developing mixes with high level of durability, and…
Recommendation of RILEM TC237-SIB on fragmentation test for recycled asphalt
2019
This recommendation describes how to characterize the reclaimed asphalt through the fragmentation test. The guidelines given hereafter are based on the results of a round robin test organized by the RILEM Technical Committee 237-SIB ‘‘Testing and characterization of sustainable innovative bituminous materials and systems’’ and provide information on the testing procedure, data analysis and indications for the preparation of a test report.
Investigating Tools for Sustainability Assessment of Road Pavements in Europe
2022
Sustainability assessment (SA) is a method to support decision making processes through the evaluation of system effectiveness, environmental integrity, economic valuation, and social implications [1]. SA can be carried out through the application of life-cycle-based techniques for quantitative assessment, or by performing a mainly qualitative approach via sustainability rating systems (SRS). In the field of civil engineering, many SRS have been proposed, all based on assigning point values to actions that are determined to contribute to the overall sustainability of the project. However, only few of these systems can be applied specifically to compare road pavement technologies and/or main…
A life cycle scenario analysis of different pavement technologies for urban roads.
2019
In the past, lowest price was the award criterion, given that structural capacity and safety were assured. In the last years, environmental, energy, and long-term impacts have been introduced (climate change, resource depletion, energy consumption, generated solid waste, discharged water, and emissions). Unfortunately, the introduction of new pavement technologies and materials (i.e., waste plastics) affects maintenance and rehabilitation processes and call for accurate and timeliness studies and criteria. Consequently, this paper presents an energy and environmental assessment of an Italian urban road and considers different material-related scenarios that fully comply with emerging techno…
Integrating Circularity in the Sustainability Assessment of Asphalt Mixtures
2020
Rising concerns about the impacts that the road engineering industry is imposing to the environment have redirected national road authorities to firmly re-consider the sustainability implications of their operations. Lately, though, sustainability has established a forceful correlation with the Circular Economy and its principles. The road engineering industry, therefore, is moving towards more circular approaches. However, this is occurring without the assessment of the potential impacts of such a transition. For this reason, in this study, a composite indicator, namely, Environmental Sustainability and Circularity indicator (ESCi), for investigating the potential effects that increased ci…
From Laboratory Mixes to Full Scale Test: Rutting Evaluation of Bio-recycled Asphalt Mixes
2021
The present paper describes the rutting behavior of innovative mixes incorporating 50% of Reclaimed Asphalt (RA) with bio-materials. They were assessed in the laboratory and in a full-scale accelerated experiment. The innovative mixes studied here contained bio-materials especially designed to help recycling by re-activating the aged binder from RA. Four mixes were evaluated: three of them are manufactured with bio-materials, (two bio-rejuvenators and one bio-binder) and one was a control mix, which was a high modulus asphalt mix (EME2). In this study, the rutting resistance of the four mixes was first evaluated in the laboratory with both European and US methods. The full-scale test was th…
Interpreting Life Cycle Assessment results of bio-asphalt pavements for more informed decision-making
2020
Due to emerging climate challenges, engineers are looking to replace the conventional asphalt pavements by utilizing bio-materials combined with Reclaimed Asphalt (RA). However, there is insufficient record in the literature assessing their environmental performance. This study addresses the analysis of the results obtained from a life cycle assessment exercise of asphalt pavements containing bio-materials and RA within their binder courses, developed within the BioRePavation project. The aim is to analyze the environmental benefits achieved, by means of hotspot mapping and sensitivity analysis of the most impactful factors of their lifecycles. Two alternatives are compared to a conventiona…
Organic Compounds Evaluation from Fumes Generated in Laboratory by Bio-recycled Asphalt Mixtures
2021
Using bio-binder and bio-additives as recycling agents for asphalt mixtures with high-content of reclaimed asphalt (RA) is proving to be feasible. It is still not clear whether this combination might provide new hazardous emissions from airborne binder fumes. The health hazard related to airborne bitumen fume generation is primarily relevant for paving crews while there is little opportunity for exposure related to asphalt plant workers. In this study, measurements of gaseous organic compounds from airborne binder fumes of selected bio-asphalt mixtures have been measured during the laboratory mixing process, by using a thermo-mixer equipped with a chimney at University Gustave Eiffel. Param…