Encouraging Sustainable Use of RAP Materials for Pavement Construction in Oman: A Review

Abstract

The Sultanate of Oman has experienced rapid development over the last thirty years and has constructed environmentally friendly and sustainable infrastructure while it continues to find economical alternative resources to achieve the goals of the Oman 2040 vision. The primary concerns are preserving natural resources and reducing the impact of carbon dioxide (CO₂) emissions on the environment. This review aims to encourage the sustainable use of reclaimed asphalt pavement (RAP) materials in pavement construction and focuses primarily on employing RAP materials in new pavement projects. Currently, new construction projects utilise a significant percentage of demolished asphalt pavement to save costs and natural resources. The key issue that arises when mixing RAP into new asphalt mixtures is the effects on the mixtures’ resistance to permanent disfigurements, such as fatigue cracks, that influence asphalt mixture performance. Numerous studies have assessed the impact of using RAP in asphalt mixtures and found that RAP increases the stiffness of asphalt mixtures, and thus improves rutting resistance at high temperatures. Nevertheless, the findings for thermal and fatigue cracking were found to be contradictory. This review will address the primary concerns regarding the use of RAP in asphalt pavements, and aims to encourage highway agencies and academic researchers in the Gulf countries to develop frameworks for the practical usage of RAP in the construction of sustainable pavement systems.

Pavement sustainability: a tripartite analysis of natural stone pavements in Hanoi, Vietnam

“…The concerns about the necessity of using natural stone and the application of it to all pavements in Hanoi have been raised. Out of many materials that are locally produced and have previously been used, including brick and compact concrete, and other environmentally friendly materials that are globally well-researched, experimented with, and produced, including pervious or permeable concrete, recycled materials, composite materials, and hybrid materials [19][20][21][22][23], the question of why only natural stone is consistently endorsed by the government has not been answered. The hypothesis is that the government has not been informed about the impacts of natural stone on the environment.…”

The Concrete Versus Asphalt Roadways: Case Studies

“…In spite of the fact that RAP increase the stiffness and may have a beneficial effect of the rutting resistance at high temperature, the thermal and fatigue cracking behaviour remains partially unclear. In some cases, the addition to a maximum of 20 % by weight may ease the mix design (Al Dughaishi et al, 2022). Sometimes the use of roadways reclaimed asphalt is not allowed for the top layer of highways, while for the lower courses an addition up to 50 % is permitted.…”

Effects of Rejuvenator Dosage, Temperature, RAP Content and Rejuvenation Process on the Road Performance of Recycled Asphalt Mixture

“…Especially, a large amount of waste asphalt pavement materials, if not timely recycled, not only take up a lot of land and is a waste of resources, but also pollute the environment [1][2][3]. Studies have shown that the reuse of RAP was significant in saving resources, protecting the environment and achieving sustainable development of the construction industry [4][5][6][7][8].…”