Hydro-mechanical behavior from small strain to failure of tuffs amended with dune sand – Application to pavements design in Saharan areas

In the context of valorizing local materials at Saharan region for road constructions, a mixture composed 65% tuff and 35% dune sand (named 65T35DS) was previously studied. The 65T35DS shown to have optimum geotechnical mechanical properties. As an extension, this study consists in investigating behavior under coupled hydro-mechanical loadings. Suction-controlled drying-wetting tests were performed on statically compacted modified Proctor (MPO) state. A series small-strain cyclic triaxial constant water content condition then followed. Key findings paper include i) prepared MPO state is able resist severe drought without inducing significant shrinkage. However, it swells during wetting swelling indices are quantified by correlations; ii) elastic modulus small-strains governed suction applied confining stress. effect stress becomes dominant lower level negligible when increases; iii) failure, apparent cohesion drops quickly dry side MPO, wet side, decreases little. friction angle specimens with larger than 5.5%, i.e. wMPO – 5. studied satisfies design standards pavements seems be good compromise valorization materials.