The aim of this project is to reclaim fly ash from the Bargny coal-fired power plant for use in the production of hydraulic concrete, and also to provide economic and environmental solutions for the storage of industrial waste. To achieve this, the materials used were first characterized, in particular cement, fly ash and aggregates (sand, basalt, flint and limestone), in order to determine their physical and physico-chemical characteristics. Next, a campaign to formulate hydraulic concretes and manufacture 16x32cm cylindrical test bodies was carried out, in which cement was substituted by fly ash at different contents (0%, 5%, 10% and 20%). After conditioning in water, the specimens were progressively crushed at 7, 14 and 28 days of curing. The results showed an increase in compressive strength with increasing curing time for a given substitution rate. However, a decrease in compressive strength was observed for all formulated concretes as the fly ash content increased. On the other hand, the strengths obtained with basalt are higher than the target strength at 28 days (25 MPa), even up to 20% cement substitution.

This article deals with the determination of axial deformations and forces along a pile under axial loading, taking into account the interaction between the pile and the surrounding soil, and more specifically with the parametric study of the behavior of an axially loaded pile using Frank and Zhao’s model and the analytical expression of the conventional limit pressure pl. Frank and Zhao’s (1982) trilinear method of load transfer curves, used in this study, offers an analytical approach for calculating axial strains and forces along the pile. This method, suggested by the French national standard for the application of Eurocode 7 (NF P 94-262) in the calculation of pile settlements, is based on the progressive mobilization of lateral friction and tip pressure, modeled by t-z (lateral friction) and q-z (tip pressure) curves, and enables soil-pile interactions to be simulated. The type of soil chosen for this study is clay (coherent soil), which provides better mobilization of lateral friction around the pile. It emerged from this study that the parameters with the greatest influence on pile behavior are the value of the applied axial load N0, the ratio (D/L) and the pressure modulus EM, in other words, the modulus of deformation E of the soil. In addition to these three essential parameters, we can add the influence of the Young’s modulus Ep of the pile on its behavior. The choice of its value is important, as the compressibility of the pile material is a factor in the calculation of settlement. The results also show that the mechanical characteristics c_u, K_0,γ, α and ν have very little influence on settlement, axial force and deformation curves. All these results confirm the empirical relationships often used to calculate pile settlement, which are based directly on the value of the diameter D or on both the diameter D, the applied load N0, the Young’s modulus of the pile Ep and its length L.