This article focused on quantifying environmental impact of asphalt pavement preservation at construction and use stage using life-cycle assessment (LCA) approach. Preservation treatments considered in the analysis include thin overlay, chip seal, and crack seal that are typically used by highway agencies. At construction stage, there are significant differences in emissions caused by various preservation treatments mainly due to different raw material components and manufacturing processes. At use stage, fuel consumptions vary significantly depending on tire rolling resistance that is affected by pavement surface characteristics. The Carbon Dioxide (CO₂) emissions at the use stage were predicted using the Motor Vehicle Emission Simulator (MOVES) and pavement roughness models obtained from Long-Term Pavement Performance (LTPP) program. The results show that pavement preservation brings significant environmental benefit in reduction of CO₂ emission due to the improved pavement surface condition despite the emission generated at construction stage. Thin overlay produces the highest life-cycle reduction in CO₂ emission due to the large International Roughness Index (IRI) jump after treatment; while crack seal has the lowest reduction of CO₂ emission. The optimum application timing of preservation treatment was determined for chip seal and thin overlay assuming one-time treatment applied before reaching the IRI threshold.

This study investigated the energy harvesting performance of a piezoelectric module in asphalt pavements through laboratory testing and multi-physics based simulation. The energy harvester module was assembled with layers of Bridge transducers and tested in the laboratory. A decoupled approach was used to study the interaction between the energy harvester and the surrounding pavement. The effects of embedment location, vehicle speed, and temperature on energy harvesting performance were investigated. The analysis findings indicate that the embedment location and vehicle speed affects the resulted power output of the piezoelectric energy harvesting system. The embedment depth of the energy module affects both the magnitude and frequency of stress pulse on top of the energy module induced by tire loading. On the other hand, higher vehicle speed causes greater loading frequency and thus greater power output; the effect of pavement temperature is negligible. The analysis of total power output before reaching fatigue failure of the energy module can be used to determine the optimum embedment location in the asphalt layer. The proposed energy harvesting system provides great potential to generate green energy from waste kinetic energy in roadway pavements. Field study is recommended to verify these findings with long-term performance monitoring of pavement with embedded energy harvesters.