Life Cycle Assessment of low temperature asphalt mixtures for road pavement surfaces: a comparative analysis. Resources, Conservation and Recycling, Elsevier, 2018, pp.

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Medical inpatients often suffer from comorbid psychiatric illness, which has been shown in previous studies to be associated with longer hospital stays. The present analysis used a large representative dataset to examine the impact of patient demographic and clinical characteristics on the relationship between psychiatric comorbidity and hospital length of stay. Analyses showed the existence of a psychiatric comorbidity predicted longer hospital stays for medical inpatients. However, in comparison to previous research, this effect was attenuated in this sample. Patients with mental disorders who were elderly, on Medicare, and those with schizophrenia or mood disorders were especially at risk for slightly longer lengths of stay.

On the Degree of binder Activity of reclaimed asphalt and Degree of Blending with recycling agents It's common practice to assume full blending of the aged binder of reclaimed asphalt (RA) within the design of new asphalt mixtures. Although being practical, this assumption has often led designers to asphalt mixtures lacking binder. Hence, going towards recycled asphalt mixtures (RAM) there is a need to have a better understanding of the blending phenomena, to have a general agreement on terminology and finally adapting RA classification and mix design procedures accordingly. This manuscript aims at being both a reference and stimulus for the scientific community to work in this direction and on this basis provides a nomenclature and a theoretical framework of the blending phenomena. The study is built upon a literature review on definitions, methods and influencing factors related with the blending phenomena and as a result an intrinsic property of RA, the degree of binder activity (DoA), is introduced for the sake of improving RA classification. Furthermore, the two well-known concepts of degree of Blending (DoB) and degree of Availability (DoAv) are redefined, within the proposed framework, together with practical suggestions to introduce them in mix design procedures. Keywords: degree of activity; degree of blending; degree of availability; recycled asphalt; recycling agent, blending phenomena Black Aggregate White Aggregate Softer RA binder: The layer of aged binder that does not move from the RA particles, but becomes softer and acts as a glue. Total RA binder: amount of binder potentially available as binding agent and composed of the RA binder and, when present, recycling agents. Unavailable RA binder: the amount of aged binder that cannot be considered available in a new formulation: This quantity is made of two components: Black Rock RA binder and Absorbed RA binder. 7. References AASTHO M323-12: Standard Specification for Superpave Volumetric Mix Design.

Tire rubber recycling for civil engineering applications and products is developing faster, achieving increasingly higher levels of maturation. The improvements in the material circle, where crumb rubber, generated as a by-product of the tire rubber making process, becomes the resource used for the construction of road asphalt pavement, is absolutely necessary for increasing the sustainability of the entire supply chain. The paper reports the results of an accurate data analysis derived from an extensive literature review of existing processes, technologies, and materials within construction of infrastructure. The current position, the direction, and rate of progress of the scientific efforts towards the reuse and recycling of tire rubber worldwide have been shown. Furthermore, an in-depth analysis of a set of important properties of Crumb Rubber Modified Asphalt has been carried out—fabrication parameters, standard properties, high and low-temperature performance, and rheological properties. Statistics over a sample of selected publications have been presented to understand the main processes adopted, rubber particle size, temperatures, and possible further modifications of crumb rubber modified binder.

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Bituminous sub-ballast in railway track-bed can mitigate the variation of the moisture content in the subgrade and reduce vertical stiffness variations of the track leading to a more durable infrastructure. Nevertheless, durability is only one of the aspects that affects the sustainability of an infrastructure. Other relevant aspects are related to the environmental and economic issues. This research work joins the worldwide effort towards a paradigm shift in civil engineering devoted to assess the sustainability of infrastructures at the design stage. With this in mind, in this study different alternative bituminous sub-ballast mixtures containing recycled materials, namely crumb rubber (CR) and reclaimed asphalt pavements (RAP) were compared by means of the results of a Life-Cycle Assessment (LCA). In comparison with a traditional bituminous sub-ballast the Crumb Rubber Modified (CRM) mixtures showed higher impacts due to the treatment of the rubber as well as the higher amount of bitumen employed in the mixture. In turn, when RAP is used, the LCA results report an improvement of all the indicators considered. The reduction of the impacts is even higher when full blending between the aged and the virgin binder is assumed because it allows reducing the amount of virgin bitumen employed. The results are intended to be used by engineering experts and practitioners to make more assertive judgments on the advantages and disadvantages associated with the use of emerging and commonly called sustainable strategies and practices for railway track-bed.