Improving the Environmental Sustainability of Low Noise Pavements: Comparative Life Cycle Assessment of Reclaimed Asphalt and Crumb Rubber Based Warm Mix Technologies

Abstract

Increasing environmental awareness is pushing towards sustainable approaches to the design and management of transport infrastructures. A life cycle assessment of low noise pavements is carried out here, with the aim to evaluate and compare the use of warm mix asphalts containing crumb rubber (CR) from end-of-life tires (ELTs) and reclaimed asphalt pavement (RAP). Different scenarios have been considered, taking into account production, construction, maintenance activities, and end-of-life of the pavement, according to a cradle to grave approach. Hot mix asphalt (HMA) was used as a reference wearing course. Results show that the simultaneous implementation of warm asphalt technologies and recycled materials can lead to a 50% reduction of the environmental burdens, compared to the standard scenario. The difference is mainly ascribed to the material depletion, the energy consumption, and the emissions associated with the frequency of maintenance of the wearing course. The use of asphalt rubber is environmentally advantageous, if compared to polymer modified binders (PMB); moreover, rubberized open-graded mixtures require the lowest bitumen content and maintenance. The findings of this research support the use of recycled materials and warm technologies as a way to improve the environmental sustainability of low noise pavements.

Life-Cycle Assessment in the Polymeric Sector: A Comprehensive Review of Application Experiences on the Italian Scale

“…Puccini et al approaching to a sustainable design and management of transport infrastructures applied the LCA tool to study different solutions of low noise pavements. Their idea was based on replacing, in the bituminous mixtures, the classic virgin non-renewable materials with secondary materials to lower landfill pressure, maintaining adequate functional properties [ 78 ]. Thus, the classic hot mix asphalt (HMA) was compared with crumb rubber (CR) from EoL tires and reclaimed asphalt pavement (RAP).…”

“… Contribution of the pavement layers to selected impact categories, scenario S. Reprinted from [ 78 ]. …”

“…Contribution of the pavement layers to selected impact categories, scenario S. Reprinted from [78]. Some of the observed reduction (material depletion and energy consumption) was attributed to the different level of maintenance requested.…”

Energy Consumption and Environment Performance Analysis of Induction-Healed Asphalt Pavement by Life Cycle Assessment (LCA)

“…The assessment includes the entire life cycle of a product, process, or activity, including the extraction and processing of raw materials; manufacturing, transportation and distribution; use; reuse and maintenance; recycling and final disposal [ 10 ]. This methodology has previously been used to determine the environmental performance of pavements, principally comparing rigid and flexible layers [ 11 , 12 ], but has also investigated more innovative solutions, such as warm mixed asphalt or recycled materials [ 13 , 14 , 15 ]. However, there is little documentation of its use in the evaluation of induction-healing technology.…”

Analysis of Design and Technological Processes of Hot Recycling Asphalt Mixture at Batch Asphalt Mixing Plants

“…RAP is an additional component which reduces production costs of AM mostly on virgin materials and binder costs. Indeed, the use of reclaimed materials is associated with a reduced demand for virgin non-renewable materials such as bitumen and mineral aggregates (Puccini et al, 2019). Optimization of the producing AM process mixing RAP and virgin materials is necessary in order to ensure correct homogeneity (Vislavičius & Sivilevičius, 2013).…”