The Challenges of Using Reclaimed Asphalt Pavement for New Asphalt Mixtures: A Review

Abstract

Reclaimed Asphalt Pavement (RAP) material mainly consists of removed asphalt concretes from existing infrastructures and, to a minor extent, of wasted or rejected mixes during the production processes. Being composed of two valuable non-renewable resources, i.e., aggregates and bituminous binder, its conscious use can ensure the sustainability of asphalt pavement construction. Thanks to the use of RAP material in new asphalt products, the USA saved 4.1 million tons of virgin binder and 78 million tons of virgin aggregates in 2018. Therefore, the use of RAP for the production of new asphalt formulations at the top of the recycling hierarchy is preferable instead of being down-cycled in low-value applications. The RAP material represents one of the most re-used construction products worldwide; in 2018, approximately 88% wt. and 72% wt. of RAP were used in USA and Europe, respectively, as aggregates for Hot, Warm and Cold Asphalt Mixtures and for unbound layers. Several studies have revealed positive responses of the recycled asphalt mixtures with high or very high content of RAP. However, the common practices of many countries still limit the RAP content to a 15–20% wt., on average, in the recycled asphalt mixes. The amount of RAP in asphalt concretes can be significantly increased by applying good management practices of the RAP, either processed or not, as well as novel production technologies and advanced mix design approaches. This manuscript aims to summarize the state-of-the-art of use of RAP aggregates in new asphalt mixtures. The economic and environmental benefits are also discussed.

Current Applications of Recycled Aggregates from Construction and Demolition: A Review

“…Another important method of CDW reutilization is to use reclaimed asphalt pavement (RAP) in new roads and or pavements. RAP has become a reality in many countries such as the United States, China, Egypt, Japan, and Australia, among others [ 86 , 87 ]. This practice is becoming popular due to both environmental and economical attractiveness.…”

Fatigue Resistance of Bituminous Mixtures and Mortars Containing High Reclaimed Asphalt Content

“…Concerning the effect of RA on the performance of asphalt mixtures, one of the main engineering problems associated with the inclusion of RA in base layer asphalt mixtures is fatigue cracking [ 3 , 4 , 5 , 6 ]. One of the most critical distress types for asphalt pavements is cracking.…”

The Correlation between the Number of Asphalt Mixing Plants and the Production of Asphalt Mixtures in European Countries and the Baltic States

“…The recycled HMA mixtures containing 20% RAP are easier to compact with RAP heated to 120 • C than the same mixtures with RAP heated to 140 • C. Sivilevičius and Vislavičius [44] proposed algorithms that were developed by using mathematical programming methods, which helped to minimise the bitumen content and, as a result, reduced the final product price. Extensive efforts have been made to use old pavement for new asphalt production in plants [45]. A control system is needed to meet the quality requirements [46].…”