TY - THES
T1 - Investigation of the Effect of High Temperature on the Performance of Flexible Pavement: Case Study of Iraqi Roads
AU - Alasadi, Fadhel Jaafer Aziz
AU - Jaafer, Fadhel
PY - 2024/3/11
Y1 - 2024/3/11
N2 - This project aims to investigate the structural design performance of flexible pavements under high temperature and traffic loading in terms of deflection and cracking to develop the most effective design and maintenance techniques for such pavement using Iraqi roads as a case study. The main objectives are to understand the structural design (layers, thicknesses, materials, engineering properties, foundation, etc.) and performance of existing highway flexible pavements for more suitable structural design and maintenance of principal Iraqi roads and to prepare for the effect of climate change in terms of temperature changes. The other objectives are to search for more effective and durable flexible pavement structural design configurations and maintenance in terms of the overlay based on deflection to extend the life of the flexible pavements. The methodology used for this research project combines literature review, site visits to representative Iraqi roads, field measurements, collection and analysis of data concerning the main Iraqi roads and collaboration with various Iraqi highway authorities and highway engineers. Empirical and analytical methods are used in this project to analyse the behaviour and performance of the pavements of the selected Iraqi roads for better new design and more effective maintenance of the existing roads. Specialised software packages, namely, KENPAVE (KENLAYERS, KENSLAB) and SP12, to estimate and analyse the maximum damage ratio and resultant deformation concerning the effect of the rising air temperature in Iraq. The main findings are that subgrade deflection and fatigue cracking (at the bottom of the base layer), which are associated with the failure of flexible pavements as combined with the high temperature loading and traffic loading, will be delayed or avoided by selecting suitable layers configurations, layer thicknesses and most essential materials properties (e.g., asphalt mixes of high modulus and stiffness including EME2). The reported research also established suitable overlay designs for the studied existing Iraqi roads, which is very important to decide the required overlay that extends the pavement life under such temperatures and traffic loading. The softwareobtained deflections correlate well with the site-measured deflection, including closely matching the deflection results. Based on the resultant validated deflections, suitable overlay layer thicknesses for Iraqi roads are developed. The key conclusions are that suitable design of flexible pavements and maintenance will strengthen such pavements against the effect of the rising temperature in hot climates like Iraq. The life of the existing Iraqi roads will be extended with the reported overlay design based on the correlated simulated and measured deflections of these roads.
AB - This project aims to investigate the structural design performance of flexible pavements under high temperature and traffic loading in terms of deflection and cracking to develop the most effective design and maintenance techniques for such pavement using Iraqi roads as a case study. The main objectives are to understand the structural design (layers, thicknesses, materials, engineering properties, foundation, etc.) and performance of existing highway flexible pavements for more suitable structural design and maintenance of principal Iraqi roads and to prepare for the effect of climate change in terms of temperature changes. The other objectives are to search for more effective and durable flexible pavement structural design configurations and maintenance in terms of the overlay based on deflection to extend the life of the flexible pavements. The methodology used for this research project combines literature review, site visits to representative Iraqi roads, field measurements, collection and analysis of data concerning the main Iraqi roads and collaboration with various Iraqi highway authorities and highway engineers. Empirical and analytical methods are used in this project to analyse the behaviour and performance of the pavements of the selected Iraqi roads for better new design and more effective maintenance of the existing roads. Specialised software packages, namely, KENPAVE (KENLAYERS, KENSLAB) and SP12, to estimate and analyse the maximum damage ratio and resultant deformation concerning the effect of the rising air temperature in Iraq. The main findings are that subgrade deflection and fatigue cracking (at the bottom of the base layer), which are associated with the failure of flexible pavements as combined with the high temperature loading and traffic loading, will be delayed or avoided by selecting suitable layers configurations, layer thicknesses and most essential materials properties (e.g., asphalt mixes of high modulus and stiffness including EME2). The reported research also established suitable overlay designs for the studied existing Iraqi roads, which is very important to decide the required overlay that extends the pavement life under such temperatures and traffic loading. The softwareobtained deflections correlate well with the site-measured deflection, including closely matching the deflection results. Based on the resultant validated deflections, suitable overlay layer thicknesses for Iraqi roads are developed. The key conclusions are that suitable design of flexible pavements and maintenance will strengthen such pavements against the effect of the rising temperature in hot climates like Iraq. The life of the existing Iraqi roads will be extended with the reported overlay design based on the correlated simulated and measured deflections of these roads.
M3 - PhD
ER -
