Since the effects of global warming and climate change are becoming serious today, most countries are trying to develop their own green road rating system to put sustainable practices into practice on their roads. This study presents a comprehensive review to identify and determine the material and pavement technology elements most suitable for the development of green road rating systems. The relevant literature has
been examined to help identify the material and pavement technology elements. These elements are tabulated and classified in the existing green road rating systems to show the importance of each element.
Understanding the comparison of these elements in existing green road rating systems would help to identify and overcome element scarcity. The entire road rating system can subsequently be developed as a performance measurement or as a baseline reference for different environments and weather conditions. The result shows that recycled materials and regional materials are the most appropriate elements in material and pavement technology in road development. These elements could optimize sustainable designs, encourage the use of recycled materials and minimize transport that helps reduce pollution and energy consumption.
Transportation is a major contributor to the environmental impacts, particularly harmful emissions of CO2, which would increase global warming. Transportation consumes 22% of the world’s energy, burns about 25% of fossil fuel and releases 30% of air pollution and greenhouse gasses. These factors contribute to the increasing concern about natural and non – renewable resources depletion, global climate change, ecosystem disruption and toxic pollution. Since rising incomes are linked to higher levels of car ownership and use and higher journey rates and distances, transport activity and the resulting CO2 emissions could significantly increase along with economic growth and consumer influence.
Elements of material and pavement technology should be seriously concerned by any party involved in the development of highways. A thorough review of sustainable material and pavement technology elements can improve the understanding of the green road concept among road users.
The recycling of existing paving materials during road rehabilitation and reconstruction offers a more sustainable alternative to conventional methods such as the complete removal and replacement of paving materials. The existing deteriorated asphalt surface can be pulverized and mixed with the underlying materials to form a new recycled base layer (RPM). Recycling road materials on site is environmentally friendly, leading to reduced energy consumption, greenhouse gas emissions and waste disposal. However, the asphalt binder in RPM and fines in the gravel of the road surface can adversely affect the strength, rigidity and plastic deformation of recycled materials used as a base course.
Chemical stabilization with binders such as cement, asphalt emulsion, lime, cement kiln dust or fly ash is a method for improving the performance of these recycled road materials. In addition, the use of industrial waste by products such as fly ash, steel slag, gum, glass, etc. can reduce transport, energy consumption and dangerous gas emissions such as greenhouse gas CO2. It also minimizes the quantity of waste material that is being thrown into the landfill. The performance of the plastic tar road proves conclusively that it is good for heavy traffic because of better binding, increased strength and better surface condition for an extended period of exposure to climate change. In fact, the process would help to easily and efficiently eliminate waste plastics.
Another element of pavement technology is the quiet pavement that can reduce noise from the interconnection between pneumatic and pavement. Noise from the interaction between the tire and the pavement becomes a dominant source when the speed of the vehicle is 35 km / h. These floors include rubberized asphalt, open graded asphalt and mastic asphalt in stone to reduce noise. The noise level is affected by the speed of the vehicle, where the increase in the speed of the vehicle can generate a higher noise level. Therefore, by introducing a quiet pavement on the green road, it controls and reduces the noise level on the road.
Soil bioengineering is a discipline dealing with the stabilization of mountain slopes, river banks and earth embankments, which has gained worldwide popularity in recent decades. In the element of biotechnology, the focus was on slope protection and landscape development. In slope protection, it is suggested that the soil or embankment be protected using green techniques such as turfing, native vegetation planting and hydro seeding. The use of soil biotechnology treatment, which combines the plant materials with the structural elements, can also contribute to the protection of slopes, stabilization and erosion control.
Warm mixed asphalt is one of the technologies used in the paving development project to achieve a sustainable green road. The warm mixed asphalt concept is that substantial energy is used during production and compaction to heat mixed asphalt at temperatures exceeding 150 ° C. Warm mixed asphalt can also make significant energy savings for the asphalt industry by reducing the heat temperature during production by 16 to 55 ° C below the typical heat mixed asphalt. Warm mixed asphalt has the potential to reduce viscosity of the binder and to reduce the short – term aging of the mixture during production. In addition, warm mixed asphalt reduces the air pollution impact of heat mixed asphalt by 24 percent and reduces fossil fuel consumption by about 18 percent. Warm mixed asphalt can also reduce the environmental impacts of heat mixed asphalt by 15 percent.
To conclude, recycled materials and regional materials are the most appropriate and recommended green elements to be used in green road rating systems. The use of elements in green materials and pavement technology can reduce gas emissions and harmful substances with good economic, social and environmental impacts. In addition, the use of environmental protection materials and pavement technology, such as recycling techniques, can reduce pollution to a greater extent. All these elements are therefore worth applying to or implementing in road development projects. Finally, these elements could become a basis for the development of a comprehensive green road rating system in the future and can be implemented for sustainable practices in road construction and design in other surrounding and weather-friendly countries.