Impact of different performance prediction models on mechanistic-empirical flexible pavement design / Momen Ragab Mousa Mohamed ; Supervised Ahmed Atef Gadallah , Mostafa Amin Abohashema

Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

Over the last several years, there has been a shift of the flexible pavement design from the Empirical to Mechanistic-Empirical (M-E) procedure. Several prediction models have been developed for the M-E procedure to analyze fatigue and rutting failures. Each model has its own parameters, limitations, and magnitude of failure damage. This research presents an assessment of the performance of commonly used fatigue and rutting models under different conditions of traffic loading and climate for new and rehabilitated pavement structures. The study was performed to calculate Ac thickness required for two existing pavement cross sections located on major road network in Egypt under wide range of ESALs and two different climatic conditions. Six fatigue models and four rutting models were considered in this study together with six fatigue/rutting failure criteria. A total of 880 computer runs were performed for different combinations of fatigue/rutting models, failure criteria, traffic conditions, and climate using OLFLEX software. This software was developed in a previous study at Cairo University based on Egyptian environmental conditions. For each run, the required AC overlay thickness and fatigue/rutting damage ratios were calculated. The analysis of results indicated that the design is mostly controlled by fatigue failure in old asphalt layer. The analysis also indicated that the Asphalt Institute (AI) and Transport and Road Research Laboratory (TRRL) models are the most appropriate ones to be used in the M-E flexible pavement design.

Issued also as CD