Conducted jointly by UL and UAC, this research explores the optimization of earthen grain silos for grain storage in Benin.
Key Takeaway: Conducted jointly by UL and UAC, this research explores the optimization of earthen grain silos for grain storage in Benin.
Clément Labintan, researcher at LERMAB (Université de Lorraine).
Thesis defended in 2018 at the doctoral school RP2E - Ecole Doctorale Sciences et Ingénierie des Ressources, Procédés, Produits, Environnement.
This research was conducted as part of a Franco-Beninese joint supervision (cotutelle), ensuring it is simultaneously grounded in local field conditions and international academic standards.
Context and Problem Statement
Grain storage in northern Benin is mainly carried out in earthen silos known as "greniers." These traditional structures often have limited capacity, which poses a challenge for effectively preserving harvests. Previous efforts to introduce modern storage systems have not achieved the expected success, due to a strong preference among local populations for traditional methods. This thesis by Clément Labintan aims to explore solutions for increasing the storage volume of Yom-type silos without altering their architectural form or the traditional composite material, a mixture of clay, straw, and néré (locust bean) decoction.
Food insecurity in rural areas is a major issue, and optimizing grain storage is a potential way to address it. The study therefore focuses on improving the mechanical characteristics of the construction material, "banco" (mud brick), in order to design larger silos capable of meeting the needs of local communities.
Methodology
The research was structured around several methodological strands. The first step consisted of an experimental characterization of banco, in order to determine the optimal dosage of straw and néré decoction. This approach made it possible to study the influence of these two components on the mechanical properties of raw earth. The proportions of straw and néré decoction were systematically adjusted to identify the mixture offering the best mechanical performance.
Simulations were carried out to analyze the deformations induced by the weight of the grain during the filling and emptying of the silos. These simulations also incorporated modeling of heat transfer within the silo walls, thereby assessing the effect of successive heating cycles on the structure. Temperature profiles were modeled across various oriented cross-sections of the silo, making it possible to assess the wall's capacity to dampen heat flow.
Key Findings
The results of this research indicate that the optimal dosage of straw and néré decoction can be determined to maximize the mechanical characteristics of banco. The analysis revealed that adjustments to the proportions of these materials lead to a significant increase in the material's strength, making it possible to design larger silos while preserving their structural integrity.
Deformation simulations showed that larger silos can be built without compromising structural safety. Grain preservation conditions in these silos are favorable, thanks to the walls' ability to dampen temperature variations. The results of the heat transfer modeling demonstrated that heat flow damping is effective, ensuring ambient conditions conducive to preserving harvests.
Parametric optimization of silo dimensions made it possible to conclude that it is feasible to build community silos or grain banks, accessible to village cooperatives. These structures could play a key role in managing grain stocks and help mitigate food insecurity within rural communities.
Discussion and Outlook
The implications of this research are significant for grain storage management in northern Benin. Increasing the capacity of earthen silos could address the growing food security needs of rural communities. These innovations need to be implemented on a wider scale, taking into account the cultural specificities and traditional practices of local populations.
The interaction between the materials used in silo construction and environmental conditions must also be taken into account in future research. An in-depth study of the economic and social impacts of building larger-capacity silos could inform decision-makers about the long-term benefits of such initiatives.
The results of this thesis open up interesting prospects for sustainable development in the agricultural sector, particularly with regard to food resource conservation. By integrating technical improvements while respecting traditional methods, it is possible to propose viable solutions tailored to the realities of rural communities.
Accéder à l'étude complète
Sources and Access
Clément Labintan. Modélisation thermomécanique de la paroi des greniers de stockage de céréales en banco. Science des matériaux [cond-mat.mtrl-sci]. Université de Lorraine; Université d'Abomey-Calavi (Bénin), 2018. Français. ⟨NNT : 2018LORR0060⟩. ⟨tel-01920643⟩