Engineering geogrid enabled low carbon and aggregate efficient flexible pavements.

Area of Science:

• Civil Engineering
• Geotechnical Engineering
• Sustainable Infrastructure

Background:

• Flexible pavements consume significant virgin aggregates and contribute to carbon emissions.
• Geosynthetic reinforcement, particularly geogrids, offers a solution for improved structural efficiency and material savings in pavements.
• Sustainable infrastructure development necessitates minimizing environmental impact and material utilization in pavement construction.

Purpose of the Study:

• To evaluate the impact of geogrid reinforcement on the structural and environmental performance of flexible pavements over soft subgrades.
• To determine optimal geogrid placement depths for varying subgrade California Bearing Ratios (CBR).
• To quantify material savings and carbon footprint reductions achieved through geogrid reinforcement.

Main Methods:

• Advanced 3D finite element simulations using PLAXIS 3D were conducted.
• Geogrid axial stiffness was systematically varied (400-1500 kN/m).
• Simulations were validated against field plate load test data for reliability.

Main Results:

• Optimal geogrid placement depths were identified for different subgrade CBR values (2%, 5%, 10%).
• Modulus Improvement Factors (MIF) ranged from 1.3 to 3.0, correlating with geogrid stiffness.
• Pavement layer thickness was reduced by 15-30%, leading to a 6-24% decrease in carbon footprint.

Conclusions:

• Geogrid reinforcement significantly enhances pavement structural performance and sustainability.
• Tailored reinforcement strategies based on subgrade conditions are crucial for optimal results.
• The study provides practical guidance for integrating geosynthetic reinforcement in mechanistic pavement design, supporting low-carbon infrastructure.