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Reinforced earth or soil structures are becoming increasingly popular in the present day. For proper design of any reinforced structure, it is important to study the soilreinforcement interface properties. The interaction mechanism can broadly be classified into two types: direct shear mechanism and pullout mechanism. In this study, tests were performed as per ASTM D5321 to study the interface characteristics of two types of reinforcements commonly used in practice (geogrid and metal grid) with Indian standard sand. A large-size direct shear test apparatus of dimensions equal to 300mm x 300mm x 200mm (in length, width and depth) is used in the study. Pluviation method is adopted to prepare uniform sand samples with a relative density of 90%. This paper provides details on sample preparation and interface properties of two types of reinforcements with sand material. Based on the test results, the average interface shear strength coefficients of geogrid-sand and metal grid-sand are found to be equal to 0.88 and 1.02 for the normal stresses considered in the study. These coefficients are in good agreement with the results reported in the literature.

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The infrastructure plays a vital role in stimulating economic growth. Any infra project requires proper planning, design, construction, quality control (QC), and quality assessment (QA). It is important to comply with QC and QA to avoid failure and enhance the long-term pavement performance in order to provide a safe and solid system of transportation. Researchers were replacing laborious and time-consuming density-based methods (sand cone and/or core cutter) with advanced stiffness or modulus-based NDT devices for the QC of compacted geomaterials. The lightweight deflectometer (LWD) is such a highly advanced and sophisticated device that was developed to evaluate the deformation modulus (ELWD) of compacted geomaterials as an alternative of density test. This device is portable, light-weight, user-friendly, and it is ideally suitable for all constructional  geomaterials. This study is intended to provide a state-of-the-art on the LWD device as well as presented the ranges of deformation modulus for various geomaterials from several studies. For instance, in the case of soils, aggregates, and asphalt materials deformation modulus values were found to be in the range of 35–60 MPa, 80–120 MPa, and 120–170 MPa respectively. In addition, several studies have been compiled to completely comprehend the relationship between LWD and various devices.