50 million tonnes of automotive waste is generated each year around the globe. Due to development of technology and increase of automobiles, dumping and management of end of life vehicles have become significant environmental and health issues. The use of lightweight plastics and glasses in automotive industry is increasing rapidly due to consumer demand for fuel efficient vehicles. 12-15% of plastics are used in vehicles, and plastic percentage will increase significantly in near future. Average weight of car is around 1500 kg and contains 180-225 kg of plastic materials. Recycling automotive waste is very tedious and difficult due to its heterogeneous composition and nature. Hence, automotive waste is disposed in landfills and has become a major threat to environment. This work investigates the utilization of automotive shredded residue (ASR) and automotive waste glasses as resources to produce lightweight clay based materials for different applications. For this study, clay was supplied by Brickworks Limited, Sydney and waste materials such as ASR and automotive glasses were collected from OneSteel Recycling, Newcastle, Australia. The obtained materials were characterized by carbon and sulphur analyzer, X-ray fluorescence (XRF) spectroscopy, Inductive coupled plasma (ICP) spectroscopy techniques to determine the elemental compositions. The plastics in ASR were analysed by using FT-IR method. Thermal stability of materials was also studied by using thermal analyzer. The results signify that ASR contains majorly polymers, and minor quantities of wood and metals. TGA result of ASR indicates that major weight loss occurs around 380-430℃ with 4-5% solid residue. From the results, it is clearly understood that ASR produces various gases during thermal decomposition and hence can be utilized in manufacturing lightweight clay based materials. The lightweight clay materials were produced by using (a) 1 wt.% ASR and (b) 2 wt.% ASR with clay. The ratios of mixtures were prepared by using water to form pellets. The ASR/clay pellets were dried in hot air oven to remove water content. Sintering process was performed at industrial working temperature 1200℃ for 20 minutes in horizontal tubular furnace. The sintered pellets were subjected for characterization of basic physical properties such as density and porosity which were conducted according to ASTM standards (Archimedes method). Analytical techniques such as SEM-EDS, XRD and compression tests were also used to analyze sintered pellets. The results suggest that the addition of ASR to clay material increases both volume and porosity, and decreases density compared to 100% clay respectively. The compression test results indicate the slight decrease in the mechanical strength of sintered pellets. Hence, waste glass and alumina were used as additives along with ASR in clay to study the effect on mechanical properties. The addition of glass to ASR/clay mixture did not show any significant changes in mechanical properties, whereas alumina addition to ASR/clay mixture showed increase in mechanical property. Alumina acts as a reinforcing material in ASR/clay composites, which helps to attain the mechanical strength as similar to 100% clay. Recycling of ASR by using alumina in manufacturing lightweight clay materials shows promising results in terms of volume increase, porosity increase and also decrease in density without much change in mechanical properties. The obtained superior lightweight and porous clay products by using only ASR can be used in thermal insulation materials and also as substrates in soilless cultivation. The lightweight and high mechanical strength clay aggregates obtained by using ASR and alumina can be used in concrete slab mixes and as pellet pavements. This innovative approach offers a novel solution for increasing recycling rate of automotive waste and also could be a new opportunity for manufacturing industries to incorporate waste materials as resources.
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