Analysis of the Impact of Overloading for Trucks on the Design Life of Flexible Pavement

Abstract Premature deterioration of flexible pavements due to increased truck axle loads poses a significant challenge on Iraqi roadways. This study focuses on managing the properties of the wearing layer to achieve a better balance between the damage ratio and the longest design life at the expense of the binder layer’s properties. The pavement performance and design life assessment, considering fatigue cracking and rutting damage, was conducted using KENLAYER software, which employs Asphalt Institute design models and formulas to compute stresses and strains in the asphaltic pavement. The overload rate was also calculated in the range (from 2 to 40%). This rate regardless of overloading rate, the majority of trucks exceeded their legal limit except for some kinds which are [Type 2(T), Type 2(F), Type 3(T), Type 4(M), Type2-S2 (F), Type2-S3(F), Type2-S3(T) Type 3-S2(F) and Type 3-S3(T)] where were used to transport a specified material such as water, fuel, food and shipping container therefore, the overloading rate should be considered in the design and measured carefully according to truck type cargo. This study emphasizes the importance of considering heavy truck axle loads and their effects on pavement deterioration. The findings contribute to understanding the structural behavior of pavements subjected to overloading, providing insights for optimizing pavement design and improving the longevity of flexible pavements under challenging traffic conditions.