In 2022 and 2023, Virginia tested recycled plastic and old asphalt on six state roads; all six were rated in very good condition at the first follow-up

Virginia transportation officials tested asphalt mixtures that contained recycled plastic and reclaimed road material on six state-maintained road sections in 2022 and 2023. The projects used different combinations of recycled materials, which included reclaimed asphalt pavement and recycled plastics, with some mixtures containing around 40% reclaimed asphalt pavement. The Virginia Transportation Research Council rated all six sections in very good condition at the first follow-up inspection.Researchers monitored the test sections after construction and compared their condition with nearby conventional pavement. The first inspection did not establish how the mixtures would perform over the full life of a road, and the Virginia report described the early results as a first assessment, with continued monitoring required before broader conclusions could be drawn.Six road sections, several recycled mixturesReclaimed asphalt pavement, or RAP, consists of asphalt pavement that had been removed during milling or reconstruction, and instead of sending the material away, transportation agencies can process it and incorporate it into new asphalt mixtures. The recovered material contains both aggregate and aged asphalt binder.Plastic can be incorporated into asphalt in different ways, and depends on the material and mixture design, with the purpose of the field trials being to examine how the resulting mixtures behaved under actual road conditions. Some of the test sections contained relatively high percentages of reclaimed asphalt pavement, and the report documents mixtures that contained up to 40% RAP. The researchers collected information on the pavement's surface condition and structural performance, and also recorded construction details and material properties so that the field results could be compared with laboratory expectations.What the first inspection foundThe Virginia Transportation Research Council reported that all six sections were in very good condition during the initial evaluation, and that assessment covered visible pavement condition. Early performance is useful for identifying obvious cracking, deformation, or surface deterioration, but it cannot determine the pavement’s behavior after years of heavy traffic, temperature changes and repeated freeze-thaw cycles.A mixture can perform well soon after construction while developing problems later in its service life, and conversely, early differences from conventional asphalt do not necessarily mean a recycled mixture will perform worse. The Virginia researchers planned continued monitoring of the demonstration sections to collect additional performance data.Why do transportation agencies use reclaimed asphalt?Recycling old pavement can reduce the amount of virgin aggregate and asphalt binder required for a new road, and also gives transportation agencies another use for material that has been removed during resurfacing and reconstruction. The Federal Highway Administration describes reclaimed asphalt pavement as one of the most commonly recycled materials in the United States, since it can be processed and incorporated into new hot-mix or warm-mix asphalt, subject to the requirements of the mixture and roadway.Higher RAP percentages require closer attention to the aged binder that has already been contained in the material, and the older binder can be stiffer than the new asphalt binder, so engineers have to account for its properties when designing the new mixture. The Virginia trials also incorporated recycled plastic into some pavement mixtures, and the field work gave researchers an opportunity to examine those combinations outside a laboratory.The next question was durabilityAfter continued inspections, it was found that pavement performance changes with traffic volume, weather, maintenance and the characteristics of the underlying road. The six sections provided real-world test sites for that longer assessment, and researchers could compare their condition over time rather than relying only on laboratory measurements.Every one of the six Virginia test sections was rated in very good condition during the first follow-up, but that does not answer how the pavement will perform after 10 or 20 years. It establishes that the mixtures that contained recycled materials did not show obvious early deterioration at the time of the initial inspection. That made the sections useful as continuing field trials for Virginia transportation officials, and further inspections would determine whether the early condition remained consistent as the roads accumulated traffic and exposure.You use AI every day. Now get your AI Quotient. Take the AIQ test.