Performance of Geocell-Reinforced Rap Bases Over Weak Subgrade Under Full-Scale Moving Wheel Loads

Recycled asphalt pavement (RAP) has been increasingly used as an energy efficient and environmentally friendly paving material and is currently the most reused and recycled material in the United States. RAP has been used in new hot mix asphalt (HMA) mixtures and in base courses for pavement construction. When RAP is used as a base course material, the presence of asphalt in RAP may cause excessive deformation under traffic loading. Geocell, three-dimensional (3D) polymeric geosynthetic cells, was proposed in this study to minimize the deformation by confining the RAP material. Full-scale accelerated pavement tests were conducted to evaluate the effect of geocell reinforcement on RAP base courses over weak subgrade. Two types of RAP were used and a total of seven geocell-reinforced and unreinforced RAP sections were tested under full-scale traffic loads. The road sections were excavated and examined after each moving wheel test. The benefits of geocell reinforcement were evaluated in rut depths for a specific number of passes of the wheel load and the angle of stress distribution from the surface to the base course-subgrade interface. The test results demonstrated that the novel polymeric alloy geocell reinforcement improved the performance of unpaved RAP sections by widening the stress distribution angle and reducing the rut depth if the base courses were equally compacted in unreinforced and reinforced sections.