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The pavement engineering industry, having realized the significance of the impacts that it imposes on the environment through the production, construction and management of its products and assets, has been driven towards a more sustainable and circular way of operating. This has partly been through asphalt recycling, which is an area that many road authorities have prioritized. However, not all the National Road Authorities (NRAs) and/or sector stakeholders seem to be adequately familiar with the Circular Economy (CE) concept. This paper attempts to assist the transition of NRAs to a more circular way of doing business, by analyzing the current situation of CE within national/regional authorities and NRAs. To do so, a questionnaire was sent to different NRAs and an online search was conducted to identify the ways that NRAs communicate their CE practices. Findings indicate that, although the majority of the NRAs are familiar with CE as a concept, not many actions have been taken so far towards its holistic implementation. Finally, there is a significant lack of CE expertise and communication within these bodies.
Konstantinos Mantalovas; Gaetano Di Mino; Ana Jimenez Del Barco Carrion; Elisabeth Keijzer; Björn Kalman; Tony Parry; Davide Lo Presti. European National Road Authorities and Circular Economy: An Insight into Their Approaches. Sustainability 2020, 12, 7160 .
AMA StyleKonstantinos Mantalovas, Gaetano Di Mino, Ana Jimenez Del Barco Carrion, Elisabeth Keijzer, Björn Kalman, Tony Parry, Davide Lo Presti. European National Road Authorities and Circular Economy: An Insight into Their Approaches. Sustainability. 2020; 12 (17):7160.
Chicago/Turabian StyleKonstantinos Mantalovas; Gaetano Di Mino; Ana Jimenez Del Barco Carrion; Elisabeth Keijzer; Björn Kalman; Tony Parry; Davide Lo Presti. 2020. "European National Road Authorities and Circular Economy: An Insight into Their Approaches." Sustainability 12, no. 17: 7160.
The construction and maintenance of road pavements need to be undertaken to ensure proper economic and social growth. Considering the high environmental impact that the production of asphalt mixtures for road pavements entails, in terms of energy consumption and greenhouse gas (GHG) emissions, these operations must follow the global transition towards more sustainable development practices. In response to this, previous research has been focused on the development of manufacturing low temperature asphalt mixtures and the use of recycled modifiers such as tire crumb rubber to improve their durability. However, the use of high dosages of the latter reduces mixture workability, thus requiring high manufacturing temperatures to reduce the viscosity of the binder, and therefore limiting the advancement towards more sustainable mixtures. In this regard, further knowledge is needed on this topic to promote the combination of such techniques to maximise their advantages. This study aims to check the viability of producing asphalt mixtures with high crumb rubber contents at reduced temperatures, testing their workability, stiffness, cohesion, resistance to permanent deformations and resistance to moisture damage. Results show that it is possible to manufacture viable, warm, rubberised asphalt mixtures at 150 °C using a high penetration bitumen and reduce this temperature to 130 °C (45 °C less than conventional rubberised asphalt mixtures) by including warm additives, without compromising their mechanical performance.
Miguel Sol-Sánchez; Ana Jiménez Del Barco Carrión; Ana Hidalgo-Arroyo; Fernando Moreno-Navarro; Leticia Saiz; María Del Carmen Rubio-Gámez. Viability of producing sustainable asphalt mixtures with crumb rubber bitumen at reduced temperatures. Construction and Building Materials 2020, 265, 120154 .
AMA StyleMiguel Sol-Sánchez, Ana Jiménez Del Barco Carrión, Ana Hidalgo-Arroyo, Fernando Moreno-Navarro, Leticia Saiz, María Del Carmen Rubio-Gámez. Viability of producing sustainable asphalt mixtures with crumb rubber bitumen at reduced temperatures. Construction and Building Materials. 2020; 265 ():120154.
Chicago/Turabian StyleMiguel Sol-Sánchez; Ana Jiménez Del Barco Carrión; Ana Hidalgo-Arroyo; Fernando Moreno-Navarro; Leticia Saiz; María Del Carmen Rubio-Gámez. 2020. "Viability of producing sustainable asphalt mixtures with crumb rubber bitumen at reduced temperatures." Construction and Building Materials 265, no. : 120154.
Polymer Modified Bitumens (PMBs) are largely used for pavement and roofing membranes applications with Styrene-Butadiene-Styrene Block copolymer (SBS) playing a major role in both markets despite its constantly increasing price due to the rising demand for quality bitumen modifiers. On the other hand, there is an increasing trend of recycling end of life tyres generating Recycled Tyre Rubber (RTR) at affordable price. This investigation aims at engineering a modified bitumen with a combination of Liquid Rubber (LR), a homogeneous blend of 50–70% RTR pre-processed in combination with heavy oils, and a wax denominated Ethylene Bis Stearamide (EBS). In the first phase, the effect of LR and EBS was independently characterised and compared to PMBs. Next, the Response Surface Methodology (RSM) was used to predict the response of different combinations of LR and EBS in terms of low and high temperature properties and cost, to then be optimised targeting conventional and rheological properties of PMBs currently used in asphalt mixtures and roofing membranes in UK. As a result, an optimum combination of LR and EBS was found leading to a cost-effective modified bitumen comparable to PMBs. The work provided also analytical functions that could be of use in further design exercises.
Ana Jiménez Del Barco Carrión; Ayad Subhy; Maria Angeles Izquierdo Rodriguez; Davide Lo Presti. Optimisation of liquid rubber modified bitumen for road pavements and roofing applications. Construction and Building Materials 2020, 249, 118630 .
AMA StyleAna Jiménez Del Barco Carrión, Ayad Subhy, Maria Angeles Izquierdo Rodriguez, Davide Lo Presti. Optimisation of liquid rubber modified bitumen for road pavements and roofing applications. Construction and Building Materials. 2020; 249 ():118630.
Chicago/Turabian StyleAna Jiménez Del Barco Carrión; Ayad Subhy; Maria Angeles Izquierdo Rodriguez; Davide Lo Presti. 2020. "Optimisation of liquid rubber modified bitumen for road pavements and roofing applications." Construction and Building Materials 249, no. : 118630.
Project Delivery Systems (PDS) for public works projects can be summarized in only a few (depending mainly on the project stages they cover, which may even include the financing), but the different names and singularities that can be found in current literature are considerably diverse, and this is the main motivation behind the work that is being presented. This work is an international review of existing PDS for public works, covering both traditional and innovative models, some of which are still being developed. Specifically, the aim has been to construct a PDS international classification, for what several factors such as names, parties, applicability, advantages, disadvantages and distribution of responsibilities (assuming the act of contracting as the allocation of obligations, rights and risks among all parties) have been analysed. Then, the equivalence between these PDS and those defined by the Spanish Public Contracts Law has been established and an analysis of PDS used in Spain has been conducted.
I. De Sande; A. Jiménez-Del-Barco; G. Martínez; Bernardo Gomez Moreno; Francisco Javier Alegre. An International Analysis of Project Delivery Systems for Public Works Projects. Lecture Notes in Management and Industrial Engineering 2015, 3 -18.
AMA StyleI. De Sande, A. Jiménez-Del-Barco, G. Martínez, Bernardo Gomez Moreno, Francisco Javier Alegre. An International Analysis of Project Delivery Systems for Public Works Projects. Lecture Notes in Management and Industrial Engineering. 2015; ():3-18.
Chicago/Turabian StyleI. De Sande; A. Jiménez-Del-Barco; G. Martínez; Bernardo Gomez Moreno; Francisco Javier Alegre. 2015. "An International Analysis of Project Delivery Systems for Public Works Projects." Lecture Notes in Management and Industrial Engineering , no. : 3-18.