A Review of Approaches for Utilizing Reclaimed Asphalt Pavement in Concrete Pavement Construction

Evaluating the recyclability of materials within the construction industry has emerged as an accelerating research focus over the past decade. This growing interest is rooted in pivotal environmental benefits, such as the preservation of pristine natural resources and the reduction of waste volume disposed of in landfills. Within this context, Reclaimed Asphalt Pavement (RAP), a byproduct generated from the milling and demolition of flexible pavements, has recently garnered significant attention. This material has been extensively evaluated as a potential alternative to natural aggregates (both fine and coarse) in the production of concrete pavements, with its strength and durability performance indicators benchmarked against conventional concrete. However, a fundamental question remains: Does RAP truly constitute a promising and flawless alternative to virgin aggregates? Addressing this critical inquiry, this review paper aims to comprehensively elucidate the feasibility, potential, and limitations of incorporating RAP into concrete pavements. To this end, a thorough investigation of available literature—including conference proceedings, journal articles, technical reports, codal guidelines, and reference books—was conducted to establish a strategic and integrated understanding of RAP-inclusive concrete performance to guide future research. This literature review maps out the evolutionary trajectory and developmental stages that RAP materials have undergone within the civil engineering industry. Furthermore, the evidence indicates that efforts directed toward optimizing and enhancing the strength of RAP-incorporated concrete have been limited thus far; consequently, there is an urgent need to develop novel strategies to upgrade and enrich the functional potential of these materials in rigid pavements.