Analytical Study and Amelioration of Plastic Pavement Material Quality

Abstract

Solid waste increases continue to pose heavy challenges to the population living in most urban communities. The effect of these solid waste challenges is high in most urban areas of low- and middle-income countries. One type of this solid waste, which is a global concern, is plastic waste. To curb the pollution imposed by these plastics, most countries are recycling them to form usable construction materials such as pavement materials. This paper seeks to analyze and ameliorate plastic pavement qualities in order to redefine the qualities of the existing plastic pavement in Cameroon. In this research project, polyethylene terephthalate (PET) and polypropylene (PP) were used as binding materials for the production of plastic pavement. During this research, the effect of combining the two plastics mentioned above for the production of a single pavement was studied to determine the impact of their combined binding characteristics as well. The formulation of the pavement samples for evaluating the binding characteristics of polypropylene (PP) in each pavement was defined as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%, and that of polyethylene terephthalate (PET) was defined as 10%, 15%, 20%, 25%, 30%, and 35% by weight of the total sample. The other percentage is that of sand. In the third phase, the effect of combining the two types of plastics as binding materials in a single pavement production was evaluated, and in this case, the formulations were: 10% PP plus 20% PET, 15% PP plus 15% PET, and 20% PP plus 10% PET, against 70% sand. Physical and mechanical tests carried out on both samples gave interesting results. The results showed that this quality could withstand a stress equivalent to 27.6 MPa, which is equivalent to 49 KN and can be used in less-traffic areas according to the standard (EN196/01-ASTMC). 30% PP as a binding material produced a 22.1 MPa strength that can withstand a load of 40 KN, and 25% PET produced a compressive strength of 14.1 MPa that can withstand a load of 22.4KN. The effect of the flexural strength test demonstrated that the flexural strength increases with an increase in plastic quantity in any pavement. The physical properties like density, porosity, and water absorption gave interesting values (1.953 g/cm3, 14.66%, and 3.1%, respectively) for the formulation of 25% PET, making this formulation to be considered among the best that can be adopted for pavements in water-locked areas. From the results obtained, it can be concluded that, using only 25% polyethylene terephthalate for the production of a plastic pavement, the pavements could be used in monument premises and water-locked areas. Using 30% PP, the pavement could be used in streets and yards, while using 20% PP plus 10% PET, the pavement would be used in less-traffic areas.