UTILIZATION OF WASTE POLYETHENE BAGS AND CRUSHED WASTE GLASS IN HOT MIX ASPHALT

Abstract

Currently transportation infrastructure is playing a vital role in the daily life of human

beings. The sustainability of this important infrastructure needs suitable and cost- effective design technique which depends upon the selection and proportion of binder

and aggregate. Transportation infrastructure plays a vital role in daily life. Transportation agencies are carrying out different research and development programs to strengthen and improve the durability of pavements. Plastic bags are either burnt releasing toxic chemicals or dumped at landfill sites that create various types of pollution. Similarly, glass is one of the widely used materials and is non-biodegradable material due to its inert nature. Safe disposal of these wastes is a big problem nowadays. Sustainable pavement design is the need of time. This research is based on the utilization of waste plastic bags and waste glass in hot mix asphalt (HMA) as a partial replacement of optimum bitumen content (OBC) and 4.75 mm aggregates, respectively. NHA gradation B, Attock Refinery Limited bitumen grade 60/70, LDPE from the dump yards of Islamabad and waste glass from glass cutting sites were used in this study. Penetration, ductility, and temperature testing were carried out on virgin and bitumen with 2%, 4%, 6% contents of LDPE for determination of optimum modifier content. Waste glass was incorporated as 5%, 10% and 15% of the weight of 4.75mm aggregates. Determination of OBC, volumetric properties, flow and stability and optimum glass content was done via Marshall testing. Using OBC and incorporating different waste contents, performance evaluation including moisture susceptibility and resilient modulus test of virgin and modified HMA mixes were evaluated and compared. It was observed that 4% of LDPE as a replacement of OBC and 10% of waste glass as a replacement of 4.75 mm aggregates in HMA mix can be used as optimum modifier contents and yielded 78% improved resilient modulus, tensile strength ratio for moisture susceptibility evaluation was also above specified limit of 80%. Cost comparison was also carried out which showed 4% reduction in material cost by utilizing 4% LDPE and 10% glass as replacement of virgin materials.