Geocells are a growing type of geosynthetic product used in many applications, including the reinforcement of unbound granular materials for the construction of flexible pavements. Despite the burgeoning presence of geocells in the civil engineering industry, their acceptance and implementation by design engineers is limited by the lack of a clear design methodology. Although significant research has been conducted to quantify the performance of geocell-reinforced soil masses, there is no accepted design method for these structures. The Mechanistic-Empirical Pavement Design Guide (MEPDG) is a solid framework on which to base a geocell design method. The resilient modulus is the relevant design parameter that should be modified in the MEPDG for the design of pavement structures using geocells. However, a better understanding of the behavior and mechanisms that contribute to the performance of geocell-reinforced materials is necessary to develop theoretically-sound model. As such, the materials and equipment necessary to conduct a thorough analysis of geocells were conceived and developed as part of this study. This equipment is based on the transparent soil concept – transparent soils are two-part media consisting of solid particles and a saturating fluid with matching refractive indices. The large-scale equipment consists of a steel-framed tank with cast acrylic sides. Preliminary results indicate the equipment is adequate to validate the results of prior geocell experiments and provide novel insights into geocell behaviors and reinforcement mechanisms. Generalized results of this study, primarily the experience with transparent soils, can also be used for research into virtually any type of geosynthetic product.