Using ecological materials such as raw earth represents an ancestral building practice that has been revisited for modern construction, thanks to its availability, low cost, environmental friendliness, and thermal properties, which offer optimal insulation and thermal comfort. This article explores the development of a new composite based on raw earth reinforced with 15% mussel shells, a by-product of the aquaculture industry, combined with two stabilizers: lime or cement (3%, 5% and 8%), in distinct formulations. This study aims to characterize the chemical and mineralogical composition of the soil and mussel shells and the thermal and mechanical properties of the composites. The results indicate that the gradual addition of lime to the soil-mussel shell mixture decreases dry density, which reduces dry mechanical strength due to increased porosity but enhances thermal properties. Conversely, incorporating cement into the soil-mussel shell mixture improves significantly mechanical properties while limiting the thermal performances.
This study investigates the damping behavior of olive trees under trunk shaking by assessing transmitted acceleration and logarithmic decrement in the soil and tree, as well as the actual shaking, damping, and elastic powers within the tree. The trunk shaker was operated at five attachment heights: 0.4, 0.5, 0.6, 0.7, and 0.8 m. Results revealed that the peak elastic power of 8.8 kW occurred at 0.8 m, after which elasticity declined, indicating that the tree reaches its maximum elastic capacity before inertia dominates. The transmission of acceleration to the root-soil system is influenced by attachment height and trunk diameter, with larger diameters and lower attachment points reducing transmitted acceleration. The highest transmitted acceleration of 30.7 ms- 2 was measured at 0.8 m. Along the x-axis, acceleration progressively increases from the base to the branches, while the y-axis is mostly absorbed by the trunk. Additionally, the logarithmic decrement decreases with distance from the shaker, reflecting greater damping in the trunk compared to the branches. These findings suggest that optimizing attachment height during mechanical harvesting can enhance energy efficiency and minimize damage by improving elastic responses and managing acceleration and damping dynamics.