The aims of this work is to study the influence of the partial substitution of natural aggregates by the nut shells of Ricinodendron heudelotii known as AKPI, on the physical-mechanical properties of concrete. The substitution rates made are 5%, 10% and 15%. Test results indicate that the presence of Akpi nut shells (ANS) causes increased porosity and reduced compressive strength of concrete. Increasing of porosity and decreasing of strength become important when the quantity of shell increases in concrete. However, the kinetics of hardening at a young age of the concrete is improved from 1% to 7%.