The last decade has witnessed increased attention toward products, services, and works with reduced environmental impacts. In the field of road construction, the use of alternative materials, wastes, or by-products obtained from industries is attracting considerable interest. The Life Cycle Assessment (LCA) is a powerful project-level tool that allows the assessment of the environmental impacts of a road infrastructure, from raw materials production to end of life phase. In this study, the environmental impacts (in terms of global warming potential-GWP) of an embankment construction project are investigated by a cradle-to-gate approach. The analysis focuses on all the processes involved in the construction of an embankment section, from the base to the preparation of the pavement formation level. The results are provided for two different road types and two different stabilization methods, including the use of lignin and lime. All processes that contribute towards global warming are investigated and described in detail. The most important finding of the LCA, in terms of GWP, is that the production of materials is the phase that contributes the significant share of the total environmental impact (more than 90%) for all scenarios. The lowest production-related emissions can be recorded for the scenarios involving lignin treatment for the stabilization of the embankment body. Furthermore, the percentage increase in GWP ranges between 51% and 39% for transportation activities and 10–11% for construction activities, comparing the scenarios including lime stabilization with the scenarios involving lignin treatment.

Recently, the feasibility of using bio-materials to reduce or completely replace the use of bitumen in asphalt mixture has gained increasing attention. Amongst others, an interesting solution is represented by the use of wood co-products with mineral or vegetable oils. This research focuses on the development of bio-binders using vegetable resin (VR) in unmodified form and waste olive oil (WOO) as the main components; in order to optimize the rheological properties of the blends, crumb rubber from end-of-life tyres (CR), Styrene-Butadiene-Styrene (SBS) and polyethylene waxes (PEW) are used as additives. In particular, this investigation focuses on studying different oil/rosin ratios and polymer contents to provide a clear framework on this bio-binder solution; conventional bituminous binders are taken as a reference. The alternative binders are characterized in terms of conventional properties such as penetration depth and softening point, as well as rheological response. Finally, two of the bio-binders studied are selected with the aim of assessing the mechanical properties of the resulting sustainable asphalt mixture using the Marshall Stability test and the Indirect Tensile Strength test, comparing the results with the threshold values set by an Italian road agency. Thus, this research represents a preliminary analysis of the potential application of bio-binder mixtures within the specification limits imposed by road agencies. Although this research represents a first attempt, the results are promising and prove to be worthy of further investigations.

The road surface texture is responsible for controlling several quality/safety road indicators, such as friction, noise, and fuel consumption. Road texture can be classified into different wavelengths, and it is dependent on the material used in the paving solution. With the aim of evaluating and characterizing the surface texture of a microsurfacing road pavement, six microsurfacing samples were made in the laboratory with both traditional materials (basaltic aggregates and bituminous emulsion) and with innovative materials from recycling procedures (crumb rubber (CR) and artificial engineered aggregate (AEA)). The characterization was performed through the use of a conoscopic holography profilometer with high precision and post-processing of the profiles detected through consolidated algorithms (ISO standards). We found that the aggregate type plays a very important role in the pavement texture. The binder agent seems to be highly important, but more studies regarding this are necessary. The use of crumb rubber as an aggregate proved to be feasible, and the texture parameters that were obtained were in accordance with the benchmark ones. In addition, the study shows that the use of artificial engineered aggregates does not impair the surface texture. Finally, the use of the texture parameters defined by the ISO standards, together with a statistical analysis, could be useful for defining the surface texture characteristics of microsurfacing.