The purpose of this study is the experimental determination and modelling of the small strain characteristic properties of granular materials. Many researches, Hardin and Blandford (1989), Di Benedetto (1997), Tatsuoka et al. (1997), Tatsuoka and Shibuya (1991) among others, confirmed the existence of a “quasi” elastic domain for small strain amplitude lower than some 10−5 m/m (“very small” strain domain). The investigations presented in the first part of this paper are performed in this small strain domain using an accurate triaxial device (triaxial StaDy) coupling quasi cyclic static loadings and wave propagation tests. The tested material is dry Toyoura sand. This paper focuses on experimental campaign, which took part within an international round robin test on the measurement of shear modulus, Gmax using bender elements. This “Round Robin Test” was organised by the Technical Committee 29 (TC29) of the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE) (Yamashita et al. (2007)). Two types of loading paths have been performed at ENTPE laboratory: isotropic compression test (K = σ3/σ1 = 1) and anisotropic compression test (K = 0.5).