Engineering Performance, Environmental and Economic Assessment of Pavement Reconstruction Using Cold In-Place...

Area of Science:

• Civil Engineering
• Sustainable Pavement Design
• Materials Science

Background:

• Municipal road modernization requires cost-effective and environmentally sound strategies.
• Cold in-place recycling with foamed bitumen (CIR-FB) is a promising technique, but its integrated assessment for Central and Eastern European conditions is limited.
• Reclaimed asphalt pavement (RAP) quality and regional constraints necessitate region-specific evaluations.

Purpose of the Study:

• To compare a conventional road reconstruction with a CIR-FB alternative for a municipal road section.
• To integrate mechanistic-empirical modeling, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) for a comprehensive evaluation.
• To assess the structural, environmental, and economic performance of CIR-FB using local reclaimed materials.

Main Methods:

• Characterization of reclaimed asphalt pavement (RAP) and reclaimed aggregate (RA).
• CIR-FB mixture design and testing (stiffness, binder/cement content).
• Mechanistic-empirical fatigue analysis, material flow quantification, LCA, and LCCA for two reconstruction variants (conventional virgin materials vs. CIR-FB).

Main Results:

• The CIR-FB variant (V2-Rc) demonstrated a 3-21 fold increase in fatigue life compared to the conventional design (V1-N).
• Significant reductions were observed for V2-Rc: ~27% less material demand, ~39% less demolition waste, and ~92% in-situ reuse of existing pavement.
• Transport work decreased five-fold (veh-km) and over six-fold (t-km).
• LCA indicated a 15.9% reduction in CO2-eq emissions, and LCCA showed ~19% lower construction costs.

Conclusions:

• CIR-FB, when supported by proper RAP/RA characterization, offers substantial improvements in structural performance for municipal roads.
• The recycling-based approach significantly reduces environmental burdens, including CO2 emissions and waste generation.
• CIR-FB presents a robust and economically advantageous alternative for municipal road rehabilitation, even under sensitivity analyses.