Experimental Investigation Of Waste Plastic-Coated Aggregates For Unpaved Road Surface Treatment: A Case Study Around Jigjiga Town.

Abstract

Most roads in Ethiopia are unpaved roads and facing rapid traffic growth as the result of rapid urbanization and industrialization leading to the packing of different industrial products like plastic bottles. Unpaved roads rapidly deteriorated due it being susceptible to various factors as its construction minimized and aggregate surfaced roads became coarser after a few years of construction. These cause dust emission problems as the fines in the surfacing material were kicked up by traffic and blown away by the wind, and fugitive dust has caused more health problems. These problems arise when there is surface material loss, which results in loss of profile and failure of the slope and profile of gravel road segments over time due to increasing traffic loads and other factors. Therefore, it is, necessary to improve the performance of unpaved roads require their pavements to be more efficient with longer life spans and utilize the waste effectively with technical development. This research was initiated to do an Experimental investigation of waste plastic and Binder coated aggregate aggregates in the construction of unpaved roads through a modified wet mix - process to enhance the desired performance of aggregate unpaved road mix and to reduce plastic bottle disposal problems. In the MWM process, bitumen was heated to a temperature of between 160 and 170 °C for 16 hours. The Polyethylene Terephthalate additive was added to the heated bitumen for the MWM process at rates of 2 % (1%B + 1%PET), 4% (2%B +2%PET), 6% (3%B + 3%PET), and 8% (4%B + 4%PET) the coated the aggregate. Polyethylene Terephthalate particles and bitumen were introduced into aggregate separately at a rate of 0%, 2%, 4%, 6%, and 8% Polyethylene Terephthalate total weight of binder (binder coated aggregate) and aggregate (Waste plastic coated aggregate). The introduction of various concentrations of Polyethylene Terephthalate from 0% to 8% of coated aggregate resulted in a decrease in flakiness index; of 22.16%, Los Angeles abrasion of 30.06%, and crushing values of 35.02% + of normal aggregate. This signifies that the strength of all characteristics’ coated aggregate is greater than the strength of normal aggregate. A low Los Angeles abrasion test number is preferable since it implies less material detachment or distortion of the road material and suggests hardness. Aggregates with reduced flakiness indexes and crushing values would provide a longer service life for the road as well as more economical performance and reduce waste plastic from the landfill to minimize environmental pollution. Finally, for this matter, this study recommends different governmental (ERA and ACRA) and non-governmental organizations involved in road construction work, it is better to include such waste material input as an important improving agent in flexible pavements at a certain percentage as new finding technology on flexible pavement especially with high traffic volume.