Stabilization of Airfield Pavement Subgrade Using Recycled Plastic Pin

Matting systems are used for many applications for the military as temporary surfaces to reduce ground pressure exerted by aircraft, heavy equipment, vehicles, and construction material. The US military uses the AM2 airfield matting systems as rapidly constructed airfields to distribute the load on the subgrade pavement to overcome the deformation effect on the pavement. However, most mats are tested and used for soils with a minimum California Bearing Ratio (CBR) range of 5 to 6. However, using airfield mats on softer soils can be challenging. The subgrade needs to be stabilized to transfer the load properly, which requires substantial preparation for the subgrade pavements. The recycled plastic pin (RPP) is an engineered material manufactured using recycled plastic waste and has been proven effective in stabilizing shallow slope failures. RPPs are lightweight and less susceptible to chemical and biological degradation than alternative reinforcing elements. RPPs can stabilize the soil under the matting system and control deformation. The current study presents the effectiveness of RPP in stabilizing the soft soil under the AM2 matting system. The study investigated the performance of the RPP-supported AM2 system using 2D and 3D finite element analysis (FEA). Different RPP length and spacing has been utilized on soils with a CBR range of 1−5. Based on the FEM analysis results, the RPPs with closer spacing created a group effect and can effectively reduce the vertical displacement and support the foundation system under the AM2 mats.