Giuseppe Loprencipe

In recent years, the increased use of heavy commercial vehicles with higher axle weights has required the development of innovative technologies to improve the mechanical properties of asphalt concrete conglomerates, such as fatigue resistance and rutting. This study offers a comprehensive comparative analysis of different types of asphalt concrete tested in four trial sections (S1, S2, S3, S4) of the SP3 Ardeatina rural road in Rome, under actual traffic and operational conditions. More precisely, the pavement technologies applied include modified asphalt concrete with graphene and recycled hard plastics for S1, asphalt concrete modified with styrene–butadiene–styrene (SBS) for S2, asphalt concrete with a standard polymeric compound for S3, and traditional asphalt concrete for S4. The evaluation approach involved visual inspections in order to calculate the pavement condition index (PCI) and falling weight deflectometer (FWD) tests. In addition, back-calculation analyses were performed using ELMOD software to assess the mechanical properties. The laboratory tests revealed superior properties of M1 in terms of its resistance to permanent deformations (+13%, +15%, and +19.5% compared to M2, M3, and M4, respectively) and stiffness (10,758 MPa for M1 vs. 9259 MPa, 7643 MPa, and 7289 MPa for M2, M3, and M4, respectively). These findings were further corroborated by the PCI values (PCIS1 = 65; PCIS2 = 17; PCIS3 = 28; PCIS4 = 29) as well as the FWD test results after 5 years of investigation, which suggests greater durability and resistance than the other sections.

As a sustainable substitute for non-renewable mineral resources and solid waste landfilling, municipal solid waste incineration residues (MSWIRs) are useful in road pavements. This study investigates the thermal characteristics and temperature distribution of flexible pavements containing MSWIRs with hollow microsphere structures. First, the volumetric properties of asphalt mixtures containing MSWIR fillers were measured. The effects of MSWIRs on the mixture’s physical characteristics were investigated in terms of thermal conductivity, specific heat capacity, and thermal diffusivity. A three-dimensional finite element model incorporating surface thermal conditions was established and validated to analyze the internal temperature distribution and heat transfer behavior within the asphalt. Finally, the high-temperature conditions of summer were simulated in an indoor irradiation test to evaluate the risk of heat islands in urban areas. The results showed that the mixture containing MSWIRs exhibited a higher specific heat capacity (from 0.8385 to 0.9554 J/(kg·K)) and lower thermal conductivity (from 1.4356 to 1.1362 W/(m·K)) than the reference mixture with limestone filler. Therefore, it contributed to a lower heat flux distribution within the pavement. However, the increase in asphalt surface temperature caused by MSWIRs may exacerbate the urban heat island effect in the summer, which should be considered before using road materials containing MSWIRs.