Search results for " Recycling"

Characterization of friction stir consolidated recycled billet by uniaxial compression tests with miniaturized cylindrical specimen

2023

Abstract. Friction stir consolidation (FSC) is a solid-state recycling method that directly converts machining scraps into semifinished billets. This process has been proven to be a more energy efficient and environmentally friendly technique compared to remelting based conventional recycling methods. During FSC, machining chips are transformed into a solid billet by the stirring action and friction heat of the rotating tool. Due to process mechanics, especially temperature gradient and strain rate, billets have shown different hardness values and grain size distribution across their sections. Therefore, in this research, miniaturized upsetting samples are extracted from the FSC billet. The…

Fabrication of Billet from Aluminum Alloys AA 2011-T3/7075 Chips through Friction Stir Consolidation

2022

Recently evolving Solid-State Recycling (SSR) techniques have shown promising features to recycle metals scraps more efficiently compared to remelting-based approaches. Among these SSR methods, Friction Stir Consolidation (FSC) has been successfully tested to transform metals chips directly into semi or final solid products. Therefore, researchers explored FSC critical process parameters and their subsequent effects on quality in terms of the mechanical and metallurgical properties of the billet. All the previous studies of FSC were limited to developing billet of mono materials. Therefore, in this research, an attempt was made to go beyond the idea of recycling; in fact, a billet of two di…

Cold recycling of reclaimed asphalt pavements

2018

Pavement engineers have in front of them multiple challenges linked to addressing issues related to social development and society’s expanding needs. One of the most substantial of these issues is perhaps how to effectively rehabilitate and/ or maintain the existing road network while preserving and sustaining limited natural resources. The re-usage of existing pavement materials to reconstruct/ rehabilitate our future pavements is the solution that is now more and more selected by the different road administrations around the world. However, upon closer inspection, one can find many areas and details, not negligible issues, that are simply extensions of HMA technology (i.e. mix design proc…

Bitumen stabilized ballast: a potential solution for railway track-bed

2016

Railway ballast degradation under dynamic loads progressively leads to loss of mechanical performance and geometry of the track, so that maintenance interventions are frequently needed. In order to system- atically avoid this issue, recently solutions have been proposed to reinforce track-bed by using polyur- ethane and/or resins as well as asphalt layers among others. Nonetheless, their main limitations are related to the high initial cost and low productivity. To cope with these limitations, in this study, bitumen stabilized ballast (BSB) is proposed as a new solu- tion for ballast stabilization. This method aims at improving durability and reducing settlement by mod- ifying both stiffnes…

Management of demolition phases and related waste, in a building renovation project near Salerno, Italy

2020

Compliance with recent environmental regulations, the demolition phase, within the building replacement process, plays a decisive role, in terms of execution and management methods. The contribution addresses the problems related to the management of the site, in compliance with regulatory requirements for selective demolition and disposal of waste materials. Possible organisational and procedural solutions were investigated with particular reference to the phases of selective demolition (in compliance with Minimum Environmental Criteria), excavation, handling, treatment, recycling, and disposal of waste materials.

Cadmium Recovery from Spent Ni-Cd Batteries: A Brief Review

2021

The significant increase in the demand for efficient electric energy storage during the past decade has promoted an increase in the production and use of Cd-containing batteries. On the one hand, the amount of toxic Cd-containing used batteries is growing, while on the other hand, Cd is on a list of critical raw materials (for Europe). Both of these factors call for the development of effective technology for Cd recovery from spent batteries. The present paper is aimed at providing a short review of the recent progress in Cd recovery from spent batteries. Statistical data from the past decade on the source of Cd, its global production, and Ni-Cd battery recycling are given in the introducti…

2014

In vertebrate nervous systems myelination of neuronal axons has evolved to increase conduction velocity of electrical impulses with minimal space and energy requirements. Myelin is formed by specialised glial cells which ensheath axons with a lipid-rich insulating membrane. Myelination is a multi-step process initiated by axon-glia recognition triggering glial polarisation followed by targeted myelin membrane expansion and compaction. Thereby, a myelin sheath of complex subdomain structure is established. Continuous communication between neurons and glial cells is essential for myelin maintenance and axonal integrity. A diverse group of diseases, from multiple sclerosis to schizophrenia, ha…

Experimental Investigation on Water Loss and Stiffness of CBTM Using Different RA Sources

2021

Cold recycling of reclaimed asphalt (RA) is a promising technique to build or to maintain roads, combining performance and environmental advantages. Although this technique has been extensively used worldwide, there is no unique and internationally-shared method to characterize cold recycled mixtures. The previous work of the RILEM TC 237-SIB TG6 successfully attempted to characterize different RA sources with both traditional parameters (gradation, bitumen content and geometrical properties) and non-conventional properties (fragmentation and strength testing). The current RILEM TC 264-RAP TG1 mainly focuses on the influence of different RA sources on physical and mechanical characteristics…

STATE OF PRACTICE IN THE C&DW SECTOR WHILE PURSUING CIRCULAR ECONOMY: THE ITALIAN RECYCLED MATERIALS MARKET IN ROAD ENGINEERING

2022

Construction and demolition waste (C&DW) is mainly produced during the construction, demolition, or renovation activities of engineering structures and it accounts for a remarkable amount of the total C&DW generated, as it is estimated to be around 30%. This proportion differs across countries belonging to different types of economies and tends to be greater in countries with developing economies reaching 74% of total annual production. There is a plethora of applications that C&DW can be used for under a circular economic model and in this research study a focus is being given in the utilization of C&DW within the pavement engineering sector, and more specifically, in the u…

Understanding the current state of practice in the construction and demolition waste sector through the lenses of circular economy: The Italian recyc…

Construction and demolition waste (CeDw) is mainly produced during the construction, demolition, or renovation activities of civil engineering structures and it accounts for a remarkable amount of the total C&Dw generated, as it is estimated to be around 30%. This proportion differs between countries belonging to different types of economies and tends to be greater in countries with developing economies reaching 74% of total annual production. There is a plethora of applications that C&Dw can be used for under a circular economic model and in this research a focus is being given in the exploitation of C&Dw within the pavement engineering sector, and more specifically, in the uti…