# Engineering Performance, Environmental and Economic Assessment of Pavement Reconstruction Using Cold In-Place Recycling with Foamed Bitumen: A Municipal Road Case Study

## TL;DR

Cold in-place recycling with foamed bitumen improves road durability, reduces waste and emissions, and lowers costs for municipal road projects.

## Contribution

A comprehensive assessment of CIR-FB for municipal roads in Central and Eastern Europe, integrating fatigue analysis, LCA, and LCCA.

## Key findings

- CIR-FB increased fatigue life by 3–21 times compared to conventional methods at equal thickness.
- The approach reduced CO2 emissions by 15.9% and construction costs by 19%.
- Approximately 92% of pavement material was reused in situ, reducing virgin material demand by 27%.

## Abstract

What are the main findings?
CIR-FB design increased fatigue life by approximately three to twenty times at equal thickness.About 92% of pavement was reclaimed and reused in situ, and virgin material demand fell by approximately 27%.Demolition waste decreased by approximately 39% and transport demand was reduced by a factor of five to six.The carbon footprint was approximately 16% lower, and the construction-stage cost was reduced by approximately 19%.Higher FB/C stabilizer content increased stiffness and fatigue resistance, but also increased embodied emissions, confirming the need for balanced stabilizer dosage.

CIR-FB design increased fatigue life by approximately three to twenty times at equal thickness.

About 92% of pavement was reclaimed and reused in situ, and virgin material demand fell by approximately 27%.

Demolition waste decreased by approximately 39% and transport demand was reduced by a factor of five to six.

The carbon footprint was approximately 16% lower, and the construction-stage cost was reduced by approximately 19%.

Higher FB/C stabilizer content increased stiffness and fatigue resistance, but also increased embodied emissions, confirming the need for balanced stabilizer dosage.

What is the implication of the main finding?
CIR-FB supports the implementation of circular economy principles in municipal road networks.The method enables material conservation and reduces environmental impact.The approach decreases fuel consumption, transport intensity and binder consumption.The framework is scalable for low- and medium-traffic municipal applications.The findings support policy goals related to GHG emission reduction and resource efficiency objectives.

CIR-FB supports the implementation of circular economy principles in municipal road networks.

The method enables material conservation and reduces environmental impact.

The approach decreases fuel consumption, transport intensity and binder consumption.

The framework is scalable for low- and medium-traffic municipal applications.

The findings support policy goals related to GHG emission reduction and resource efficiency objectives.

Modernizing municipal roads requires rehabilitation strategies that ensure adequate structural performance while reducing environmental and economic burdens. Although cold in-place recycling with foamed bitumen (CIR-FB) has been widely investigated, integrated assessments combining mechanistic–empirical modeling with LCA and LCCA remain limited—particularly for municipal roads in Central and Eastern Europe, where reclaimed asphalt pavement (RAP) quality, climatic conditions and budget constraints differ from commonly studied regions. This study compares two reconstruction variants for a 1 km road section: a conventional design using virgin materials (V1-N) and a recycling-based alternative (V2-Rc) incorporating RAP from the existing wearing and binder layers and reclaimed aggregate (RA) from the existing base. CIR-FB mixture testing (stiffness ≈ 5.25 GPa; foamed bitumen = 2.5%, cement = 2.0%) was integrated into mechanistic–empirical fatigue analysis, material-flow quantification, LCA and LCCA. The V2-Rc variant achieved a 3–21-fold increase in fatigue life compared to V1-N at equal thickness. Material demand decreased by approximately 27%, demolition waste by approximately 39%, and approximately 92% of the existing pavement was reused in situ. Transport work was reduced five-fold (veh-km) and more than six-fold (t-km). LCA showed a 15.9% reduction in CO2-eq emissions, while LCCA indicated approximately 19% lower construction cost, with advantages remaining robust under ±20% sensitivity. The results demonstrate that CIR-FB, when supported by proper RAP/RA characterization, can substantially improve structural, environmental and economic performance in municipal road rehabilitation.