EMPIRICAL POST-MORTEM ANALYSIS AND HEALING APPROACH OF FLEXIBLE AND RIGID PAVEMENT FAILURES IN ANAMBRA STATE

Abstract

The early failure of pavement in some major cities of Anambra state has been of much concern. The paper examined the possible causes of the failure of three (3) roads in three major cities of the state. The cities are Awka, Onitsha and Nnewi. Cored asphalt samples and concrete samples were taken from failed portions of the pavement to examine the asphalt properties and compressive strength of the concrete samples respectively. For the asphalt samples, bitumen extraction tests and binder gradation tests were carried out. Marshall Stability of the asphalt are adequate in each case but the flow are outside of specification limits. The bitumen content by weight of aggregate is beyond specification limits in all the samples. The binder gradation shows the aggregates used falling outside the grading envelope. The compressive strength tests also show the strength of the concrete below specification limits. Four pathological healing processes of healing flexible pavement with flexible pavement, healing rigid pavement with rigid pavement, healing flexible pavement with rigid pavement and healing rigid pavement with flexible pavement were proposed.

KEYWORDS: Flexible pavement, Cracks, Pavement failure, Traffic loads, Structural design, Marshall Stability, Binder, Aggregate, Flow