Evaluation of Pavement Structural Integrity Using FWD on High-Traffic Urban Roads in the Gulf Region

This research examines the structural integrity of asphalt pavements in urban areas of Gulf Cooperation Council (GCC) cities—Riyadh, Dammam, and Dubai—through Falling Weight Deflectometer (FWD) testing. The study shows a general under-design of base layers with average back-calculated moduli ranging from 200–300 MPa, which is lower than the design standard of 400 MPa. A strong reverse correlation is found between Equivalent Single Axle Loads (ESALs) and asphalt modulus; with every increase of 1 million ESALs, there is a decrease of 10% in modulus. Moreover, ambient temperatures above 45 °C are responsible for a 15% reduction in asphalt stiffness, adding to fatigue and rutting hazards. For solution of these requirements, the paper suggests modified FWD thresholds within the climatic conditions of the Gulf: central deflection (D₀) below 120 µm and Surface Curvature Index (SCI) higher than 0.7. The approach covers a quantitative, non-destructive experimental framework by utilizing FWD surveys in shortlisted urban road corridors with a high volume of traffic. Data analysis entails back-calculation of layer moduli and statistical modeling to determine the effect of traffic loading and temperature fluctuations. The results highlight the need for region-specific pavement design and maintenance practices, incorporating FWD data into Pavement Management Systems (PMS) to improve infrastructure resilience and performance in the GCC region.