# A Review of Sustainable pavement Aggregates
## 8 Conclusions  
The objective of this review was to describe the alternatives currently available for sustainable aggregates for the construction of pavements. This review has revealed materials with environmental benefits, good mechanical responses to traction, appropriate fatigue strength, and qualities that cause low deformation to rolling surfaces. PET presents various reuse opportunities that not only reduce its environmental impact by reducing its discharge to the ground but also improve the properties and durability of asphalt mixtures used on roads. From its use as a binder additive to its incorporation as a substitute for aggregates and sands, PET proves to be a viable and sustainable option for the construction of road infrastructures, offering benefits such as the reduction of traffic noise, greater resistance to deformation, and improvement in the thermal and mechanical stability of asphalt mixtures. These innovations not only contribute to mitigating plastic pollution but also promote efficiency and sustainability in the road construction sector. The use of rubber improves the properties of asphalt mixtures. From reduction of putting to resistance to crack formation, modified comminuted rubber offers significant benefits in terms of durability and track performance. The amount and particle size of rubber have a crucial impact on the rheological properties of the mixtures, and methods such as X-ray reflection spectrometry ensure their long-term quality and performance. Despite the challenges, such as the possible decrease in fatigue strength, the integration of high percentages of modified crushed rubber in asphalt mixtures shows great potential to improve the sustainability and efficiency of road infrastructures. By partially or totally replacing sand in rigid pavements, Waste Glass (WG) not only reduces the demand for natural resources but also improves the plastic properties and strength of concrete. In addition, its use as a fine aggregate in asphalt mixtures contributes to the reduction of thermal sensitivity and improves the response to road fatigue. The combination of glass scrap as an aggregate with condensed milk can fibers even significantly increasing the compressive strength of hydraulic concrete, without compromising its density or slump. These applications demonstrate the potential of glass scrap as a valuable resource in sustainable construction, offering both environmental and structural benefits for the infrastructures of the future. The RAP, which contains residual asphalt binder, can be reprocessed and reused in hot or warm asphalt mixtures, thus reducing the demand for natural resources and improving road stability. Although the optimal RAP content varies depending on the type of mixture between 30% and up to 50%, its incorporation can generate significant savings in manufacturing costs and improve the compressive strength of hydraulic concrete. The addition of rejuvenating additives and the optimization of the RAP ratio can further improve the mechanical properties of the mixtures, increasing their stability and durability. RCA improves the mechanical properties of hydraulic concrete and asphalt mixtures, allowing the manufacture of more durable and resistant pavements. Despite some challenges, such as increased asphalt content in warm asphalt mixes and the need for adjustments in asphalt binder proportions, the use of RCA presents tangible benefits in terms of performance and sustainability. In addition, the partial or total replacement of conventional aggregates by RCA offers a viable alternative to reduce the environmental footprint of construction, while preserving the quality and integrity of structures. The use of treated mining waste reduces the operating costs of the mining industry, in addition to improving the properties of concrete and asphalt mixtures, increasing their strength and stability.