Plastic has widely contributed to our lives because of its many advantages as an inexpensive, lightweight, versatile, and durable man-made material. However, the recycling rate of plastics after consumption is still low. Therefore, 12 billion tons of plastic waste is expected to be collected in landfills or the environment by 2050. Governments have called the public and industry for help and support against plastic pollution. Societies have taken some initiatives for the wise use of plastics. Also, some companies have collaborated with research centres to find solutions, such as reusing plastics to manufacture clothes, shoes, carpets, toys, etc. One of the solutions is using plastics in concrete, the second most used material after water in our world. This research aims to insert plastic PET bottles in concrete as reinforcing fibres. Few studies have been conducted in this direction, and there are still two questions regarding the optimal length and volume fraction of the fibres in concrete. Experimental work has been undertaken in this research to answer the prior questions and find the impact of plastic fibres on concrete in terms of its mechanical properties and shrinkage. Concrete mixes have been made and evaluated for this purpose. Besides the optimal use of plastic fibre, it was concluded that plastic fibres can produce ductile concrete with low shrinkage.