The management and sustainability of engineering structures represent a critical challenge for road networks in West Africa, where early degradation of these structures generates considerable maintenance costs and safety risks. This study statistically analyzes a database of 1,055 engineering structures inspected across all 14 regions of Senegal, using the French IQOA (Image Qualité des Ouvrages d’Art) assessment framework. The aim is to establish the relationship between construction deficiencies (insufficient cover, concrete surface defects, incomplete drainage systems, honeycombing) and accelerated structural degradation. Results show that 33% of structures are in satisfactory condition (class 1), 46% exhibit minor disorders (class 2), 9% require specialized maintenance (class 2E), and 11% are in structurally concerning condition (classes 3 and 3U). The analysis reveals that construction-related deficiencies — particularly insufficient reinforcement cover and waterproofing defects — are significantly associated with the most severe degradation classes, especially in coastal saline environments. These findings provide unprecedented empirical evidence for improving construction practices and maintenance strategies in West Africa.

In this work, we present a study of heat transfer through the different layers of a frequency modulated pavement structure. Solving the heat equation for the different layers obtained the temperature and the heat flux density of each layer (from the wearing course to the base layer) of the structure. The expression of the equivalent thermal impedance of the wearing course in crushed plastic bag waste and sugar cane residue, found by thermal electrical analogy, allowed to study the diagrams of Bode, its phase and his portrayal of Nyquist. These studies are carried out in the illumination zone and in the shaded zone.