Increasing Axle Load Repetitions (N_f) Causing Fatigue Failure in Highway Flexible Pavements through Rubberization: Light Traffic Study

Enwuso A. Igwe

Department of Civil Engineering Rivers State University of Science and Technology, Nkpolu Oroworukwo P.M.B 5080, 5080, Port Harcourt, Rivers State, Nigeria (Tel: +2348037077751; Email: igwe2002@yahoo)

Accepted 03 June 2014

Abstract

A realistic prediction of the long-term service life of flexible pavements is one of the most challenging tasks for pavement engineers in Highway Engineering especially because of its complex system having multiple layers made up of different materials. This very large infrastructural component during use suffer many drawbacks resulting from different adverse conditions such as irregular traffic loading, and varying environmental conditions like temperature, moisture and oxidation rates. Therefore, this has resulted in the need for modifications that can enhance its durability during use. The present research used rubber latex to modify the material property of asphalt concrete in order to ascertain changes that can increase axle load repetition during use; since it is believed that these axle loads are major contributors to fatigue failure. The results obtained revealed that the rubber latex modified asphalt concrete produced pavements with increased axle load repetitions for all loading frequencies considered for the given traffic category. Overall the addition of rubber latex at 3% maximum produced pavement having increases of 16 times the original axle load repetition at frequency of 1hz, 15 times at frequency of 5hz and approximately 10 times at frequency of 10hz respectively. Furthermore, the results revealed that increase in axle load repetition responsible for fatigue failure was linear from 0-3% for all frequencies considered.

Key words: Axle Load Repetition, Fatigue Failure, Flexible Pavement and Rubberization