Current practices and the way forward in waste rubber utilization for infrastructural and geoenvironmental engineering applications

ABSTRACTRubber manufacturers, and especially the automobile industry, along with urban local bodies, recyclers, and society by large, are facing a major challenge in terms of reuse and/or valorization of the huge quantities of the Waste Rubber, read as WasRub. The WasRub being highly resistant to thermal, biological, chemical, and photochemical degradation, due to its cross-linked (vulcanized) structure, is a major threat to the ecosystem. Thus, the need of the hour is to devise novel strategies and methodologies that would facilitate bulk utilization of the WasRub by fulfilling the requirements associated with the sustainable development goals, SDGs. In this context, efforts made by earlier researchers and technologists to address the efficacy of the schemes by which WasRub can be valorized are worth appreciating. However, being the case- and site- specific, these efforts (i) are limited and hence the findings cannot be generalized, (ii) lack insight into the grain-scale characteristics of WasRub, and (iii) do not present the pros and cons of the pathways adopted for the valorization of WasRub. Keeping this in view, a comprehensive and critical appraisal of the literature dealing with the valorization of WasRub for infrastructural and geoenvironmental applications was conducted, and a synthesis of what the problem is, why it persists, and what is the way forward have been discussed in this paper. Efforts have also been made to highlight the influence of (i) micro-mechanisms and (ii) the parameters, that control utilization of WasRub as a manmade resource for attaining SDGs without any apprehension(s).KEYWORDS: Waste rubbervalorizationmicro-mechanismmanmade resourcesustainable development goals Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Notes on contributorsPrithvendra SinghPrithvendra Singh is research scholar in the Department of Civil Engineering at Indian Institute of Technology Bombay. He obtained Master's in Geotechnical Engineering from the National Institute of Technology Patna and Bachelors in Civil Engineering from the National Institute of Technology Silchar. He is working on utilization of waste rubber for infrastructural and Geoenvironmental applications to achieve sustainable development goals and circular goals. His research areas also includes the characterization of anthropogenic/manmade resources, industrial byproducts, dredged sediments, freezing-thawing mechanisms, thermal and electrical properties, deformation mechanisms of flexible- and rigid- porous media, THMCB coupling, tire micro- & nano- plastics, rubberized concrete and polymer composites.Venkata Siva Naga Sai GoliVenkata Siva Naga Sai Goli is a research scholar at the Department of Civil Engineering, Indian Institute of Technology Bombay, India. He obtained MTech in Environmental Engineering from Warangal, India. Currently, he is working on the utilization of municipal plastic waste, landfill mined resides, and industrial by-products as a part of a broad approach to integrated solid waste management. His research areas also include the characterization of microplastics and polymer waste recycling.Devendra Narain SinghDevendra Narain Singh (FNAE, F.ASCE, FICE(UK)) is a Professor at the Department of Civil Engineering, Indian Institute of Technology Bombay, India. His research and developmental activities are in quite diversified areas of environmental geotechnics (viz., mechanics of unsaturated soils, soil characterization based on mineralogical, thermal and electrical properties, contaminant transport through porous media, utilization and recycling of industrial and municipal waste, etc.). Prof. Singh has founded Environmental Geotechnics, ICE Publishing, London, UK, and has been its Editor-in-chief. He has published numerous technical articles in the refereed journals and collaborated with several international and national agencies and institutes.