This thesis comprises eight chapters. Some chapters represent a manuscript or a series of manuscripts at various stages of publication joined by a common theme.
Chapter 1: This chapter provides the aim and objective, and also introduces the rationale for this project.
Chapter 2: In this chapter, current progress in the fields of recycled plastic fibre reinforced concrete is reviewed. In Sect. 2.1, various workable technologies in the mechanical reprocessing of PP waste, which have been successfully developed and widely applied in the recycling industry, are reviewed, and have been published as S. Yin, R. Tuladhar, F. Shi, R.A. Shanks, M. Combe, T. Collister, M. Jacob. Mechanical reprocessing of polyolefin waste: A review. Polymer Engineering and Science. 2015, 55(12):2899-2909. In Sect. 2.2, recent developments in the area of macro plastic fibre reinforced concrete are discussed, as published in S. Yin, R. Tuladhar, F. Shi, M. Combe, T. Collister, N. Sivakugan. Use of macro plastic fibres in concrete: A review. Construction and Building Materials. 2015, 93:180-188. In Sect. 2.3, characterisation methods of toughness and post-cracking behaviour of fibre reinforced concrete are reviewed. Advantages and disadvantages of the current methods are presented. Based on the properties of recycled PP fibres in this research, the most suitable characterisation methods are chosen. The Sect. 2.4 reviewed current progress of life cycle assessment on recycling plastic waste.
Chapter 3: This chapter presents the production of fibre, and discusses about the development of a melt spinning and hot drawing technology, through which recycled PP fibres of high tensile strength and Young’s modulus are successfully produced under the factory conditions. The findings have been published as S. Yin, R. Tuladhar, R. A. Shanks, T. Collister, M. Combe, M. Jacob, M. Tian and N. Sivakugan. Fiber preparation and mechanical properties of recycled polypropylene for reinforcing concrete. Journal of Applied Polymer Science, 2015, 132(16):1-10.
Chapter 4: This chapter explores durability of 100% recycled PP fibre in concrete alkaline environment, studies reinforcement of the 100% recycled PP fibre in different concretes, designed for footpaths and precast panels, and proves the industrial feasibility of using 100% recycled PP fibre to replace virgin PP fibre. The results were submitted in S. Yin, R. Tuladhar, J. Riella, D. Chung, T. Collister,
M. Combe, N. Sivakugan. Comparative evaluation of virgin and recycled polypropylene fibre reinforced concrete. Construction and Building Materials. 2016, 114:134-141.
Chapter 5: In this chapter, ability of various newly developed recycled PP fibres to enhance post-cracking performance of concrete is ascertained. The effects of tensile strength, Young’s modulus and surface indents of the different recycled PP fibres on their reinforcing effects in concrete are studied. The results of this investigation have been published as S. Yin, R. Tuladhar, T. Collister, M. Combe,
N. Sivakugan, Z. Deng. Post-cracking performance of recycled polypropylene fibre in concrete. Construction and Building Materials. 2015, 101(1):1069-1077.
Chapter 6: This chapter assesses the environmental impacts of producing 100% recycled PP fibres from domestic and industrial plastic waste, compared with the production of virgin PP fibre and SRM. This study is based on Australian conditions and quantifies the environmental impacts in terms of material consumption, water use, and emissions to the environment by using life cycle assessment methodology. The outcomes of this study have been published in S. Yin, R. Tuladhar, M. Sheehan, M. Combe, T. Collister. A life cycle assessment of recycled polypropylene fibre in concrete footpaths. Journal of Cleaner Production. 2016, 112(4): 2231-2242.
Chapter 7: This chapter showcases the industrial application of 100% recycled PP fibre. The fibre performance is tested in various real-life applications which include concrete footpaths and precast concrete drainage pits.
Chapter 8: Concluding remarks and a recommendation for future work are presented in this chapter.