This study is part of the development of sands and gravels in the locality of Attiékoi (south-east of Côte d'Ivoire) in public works technique. The objective is to determine the lithological and geotechnical characteristics of the formations in order to assess the depth, extent and quality of the gravel deposit to be exploited. After the lithological characterization and according to AFNOR standards, geotechnical tests were carried out on the samples. These are the sieve size analysis, the Atterberg limits, the modified Proctor, CBR and VBS tests, the sand equivalent, the specific gravity, the apparent density, the Los Angeles, the Micro-Delval and chemical analyzes. (Magnesium, Calcium, Salinity). The results revealed six lithological units, including coarse-grained sands, mottled clays, conglomerate formations, gravelly sand, lateritic clay and bar earth. The geotechnical characterization testifies to three preponderant classes of aggregates (fillers, sands and gravel). These tests show that these materials do not meet the minimum specifications and cannot be suitable for public works.
Two ternary diagrams were constructed according to the distribution of granulometric sizes in the mixed terrigenous clastic sediments and sedimentary rocks starting from some classifications and sedimentological definitions. These diagrams are: ternary diagram SSC and ternary diagram GSM. The poles of diagram SSC are occupied by the sediments "Sand", "Silt" and "Clay" and those of diagram GSM by the sediments "Gravel", "Sand" and "Mud". These diagrams make it possible to differentiate three terrigenous clastic sediments and sedimentary rocks types: proper sediments and rocks, mixed sediments and rocks with two elements and mixed sediments and rocks with three elements.