Conducted jointly by UL and UAC, this research explores waste valorization in the manufacturing of fired clay bricks in Benin.
Key Takeaway: Conducted jointly by UL and UAC, this research explores waste valorization in the manufacturing of fired clay bricks in Benin.
Gbènondé Sèna Gladys Milohin, researcher at LERMAB (Université de Lorraine).
Thesis defended in 2019 at the doctoral school École doctorale SIMPPé - Sciences et ingénierie des molécules, des produits, des procédés, et de l'énergie (Lorraine).
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
Waste valorization is a major issue in the construction sector in Benin, where clay, although widely available, is often underused. Fired clay bricks, construction materials produced in high volumes, present a significant opportunity to incorporate waste such as glass bottles and wood ash into their manufacturing. This research project is part of a sustainability effort, seeking to reduce the environmental impact associated with waste management while meeting the growing need for local construction materials.
Benin, like many West African countries, faces challenges related to waste management. The volume of waste generated, particularly glass waste and ash from charcoal combustion, calls for innovative solutions for effective valorization. By incorporating these materials into brick manufacturing, it becomes possible to turn a waste problem into a useful resource, thereby contributing to improving the living conditions of local populations.
Methodology
This research was carried out as part of a Franco-African joint supervision (cotutelle) thesis, involving laboratory experiments to determine the optimal formulations for fired clay bricks. The materials studied include clay, wood ash from charcoal combustion, and crushed glass bottles. Dosages of 5% wood ash and 20% crushed glass were tested.
The brick samples were subjected to flexural tensile strength and compressive strength tests, as well as thermal analyses to assess the impact of the added materials on the physical and mechanical properties of the bricks. These tests were carried out on clay blocks from two specific localities, Zogbodomey and Sèmè-Podji, representing clay production areas in Benin.
Key Findings
The experimental results demonstrated that incorporating wood ash and glass bottles into the clay matrix leads to a notable improvement in the flexural tensile strength of the bricks. Specifically, a dosage of 5% wood ash and 20% crushed glass achieved a significant increase in this strength without impairing the compressive strength performance of the bricks.
The thermal properties of the fired blocks were also maintained, indicating that adding these recycled materials does not negatively affect the thermal characteristics of the bricks. These results suggest a possibility of effectively integrating waste into the brick manufacturing process, thereby offering a sustainable alternative for the construction sector in Benin.
Discussion and Outlook
Incorporating wood ash and glass bottles into the manufacturing of fired clay bricks represents a significant advance in waste valorization in Benin. By promoting the use of local resources, this approach could reduce dependence on imported construction materials, which is particularly relevant for a country with limited economic resources.
Beyond the immediate benefits in terms of waste reduction, this research opens the way to a broader reflection on sustainable construction practices. By promoting waste valorization in the construction sector, it is possible to contribute to a circular economy, in which materials are reused and recycled, thereby minimizing the environmental impact associated with the extraction and production of new materials.
The implications of this research also extend to waste management more broadly. By encouraging waste valorization practices, it is conceivable to create local jobs in construction and recycling, thereby stimulating the local economy. Moreover, these initiatives could serve as a model for other West African countries facing similar challenges in waste management and construction.
The path forward includes further studies on the long-term performance evaluation of bricks produced with these recycled materials, as well as exploring other types of waste that could be incorporated into the manufacturing process. Such an approach could broaden the range of possibilities for waste valorization and strengthen the sustainability of the construction sector in Benin.
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Sources and Access
Gbènondé Sèna Gladys Milohin. Valorisation de rebuts de bouteilles en verre et des cendres de bois dans la fabrication de briques en argile cuite. Matériaux. Université de Lorraine; Université d'Abomey-Calavi (Bénin), 2019. Français. ⟨NNT : 2019LORR0126⟩. ⟨tel-02461405⟩