Effect of Excess Axle Loads and High Tire Pressures on Flexible Pavement Performance

Abstract

The main objective of this paper is to evaluate the performance of the flexible pavement under different conditions of axle loads and tire pressure of different vehicles (trucks) in Egypt.. Strains of different pavement sections were calculated using computer program based on linear elastictheory. Moreover, theoretical analysis was achieved by using BISAR computer program to obtain regression equations to simplify determination of load equivalency factor (LEF) as a function of axle loads and tire pressure for single and tandem axle loads. A comparison between the values of calculated LEF and these that adopted by the AASHTO specifications was achieved . From theresults analysis, it could be obtained that , at low to intermediate axle loads, high tire pressure could cause marked increase in LEF. At high axle loads, variation of equivalency factor with tire pressure could be neglected. Moreover, increased subgrade elastic modulus had insignificant influence on LEF