This paper presents a study of the shear strength of sand reinforced with randomly-oriented and vertically-aligned polypropylene mesh elements. A biaxial apparatus was designed to load specimens under plane strain conditions, and photogrammetry was used to measure the strain field within the specimens during loading. The biaxial test results obtained for sand specimens reinforced with randomly-oriented mesh elements illustrate the effect of reinforcement content on specimen strength. Strain localization was observed for both reinforced and unreinforced sand specimens; however, for the reinforced sand specimens, the strain localization phenomenon was not accompanied by a drop in strength. Further testing was performed using a large shear box to impose a fixed shear plane in the reinforced specimens. Sand specimens with randomly-oriented mesh elements, as well as sand reinforced with vertically-aligned mesh elements were tested in the large shear box.