Factors Affecting Development of Roughness in Hot Mix Asphalt Pavements

The objective of this study was to determine the factors that contribute to roughness in Hot Mix Asphalt (HMA) pavements. The progression of actual roughness extracted from raw longitudinal profile data of the HMA pavements employed in LTPP is investigated. Power Spectral Density (PSD) of longitudinal 25mm profiles of the pavements are calculated and the progression of the severity of roughness features at different wavelengths are identified. The effect of several factors such as structural design, mix design and climatic variables on the progression of roughness features at different wavelengths were investigated. Once the development of roughness is understood, measures in construction, mix design or design details can be taken to reduce the adverse influence of these factors.