Performance Evaluation Of Asphalt Pavement Using Waste Plastic As Filler And Rap As Aggregate Replacement

Abstract

Growing transportation demands and infrastructure development necessitated the construction of better pavements with longer service life. Since conventional materials are scarce to do so, we need to recycle waste materials. Almost every product after using will eventually become waste that needs to be disposed of, and reusing them as raw materials or modifiers is the best way to handle this waste and for good pavement performance. The objective of this research was to use the Marshal Mix Design approach to examine how the properties of hot mix asphalt mixture were affected by the use of RAP aggregate and waste plastic powder filler. To determine the Optimal Bitumen Content, four different percentages of bitumen binder content (4%, 4.5%, 5%, and 5.5% by weight of total mix) were used. Following NAPA (National Asphalt Pavement Association) method the optimum bitumen content was selected. Five varying percentages of RAP aggregate combined with a constant percentage of waste PET plastic powder filler with a rate of 0% (control), 10 % RAP & 10% PET, 20% RAP &10% PET, 30% RAP & 10% PET, 40% RAP & 10% PET, and 50% RAP & 10 % PET were prepared using OBC to obtain the workable combination of replacement percentage. The study evaluated the performance of asphalt mixes using Marshall stability and flow with corresponding volumetric properties, and moisture susceptibility using the Indirect Tensile Strength (ITS) test. In total, 63 samples were used to conduct both Marshall tests and Water Susceptibility tests. From those samples, 12 were for the control mix, 15 were for replacement, and 36 were for the Indirect Tensile Strength test. From the Marshall test, it was found that the OBC was determined as 4.9% according to the NAPA procedure. From the test result, it was found that the HMA mix volumetric properties such as Va, VFA, and VMA were satisfactory with the ERA specification at (20% RAP with 10% PET) additive combination. Whereas, for the volumetric parameter, bulk specific gravity, and Marshall properties such as stability and flow, the Marshall test result has satisfied the ERA specification throughout the proposed percentage proportions. The most consistent additive proportion was therefore found at 20% RAP and 10% PET. For the performance test (moisture susceptibility test), it was found that from (10% up to 20% RAP with 10% PET) percentage proportions, satisfactory results were found, and from (30% up to 50% RAP with 10% PET) the HMA mix was susceptible to moisture. It can be concluded that RAP and waste PET plastic can be used as aggregate and filler materials instead of conventionally used aggregates and crushed stone dust fillers respectively with good performance (10-20% RAP &10% PET).