Performance Study on Partial Replacement of Bitumen using Waste Polypropylene Cement Bags for Pavement Construction

Abstract. Flexible pavement is most commonly used in the bituminous material mix. It consists of different binders such as asphalt or bitumen and other minerals are added and compacted and used together in the lower layer of the pavement. Bituminous pavement surface property changes due to varying weather conditions. In hot climatic conditions, the bitumen becomes soft and during cold conditions it becomes too stiff and brittle in nature. In this study, the main concept is to reuse the waste materials and to promote cost-effective solution and reduce environmental pollution. In this project, waste cement bags (polypropylene) are used to replace a portion of bitumen which is used in road construction. Effect of addition of additive materials on the strength of the pavement was evaluated. Previous studies state that polypropylene emits 60ppm less pollution than bitumen while burning. The used cement waste bag when mixed with bitumen improves the behaviour and mechanical properties as per standard specification. In this experimental work, cement bags are shredded into smaller fragments and heated to 90ºC for 30 minutes in a heating mantle till the plastic pieces turned into powder form. On heating, 5 gm of powder was obtained from 20 gm of the used cement bags. This powder was added subsequently to bitumen in 5%, 7%, 9% & 11% for partial replacement of bitumen. Finally, it is inferred that the optimum percentagewas 8.2% without the addition of binders or oxidizing agents, for better efficiency.