ABSTRACT

The study is aimed at investigating the causes of major roads in Edo state using Ekehuan road as a case study. It views the the heavy traffic on the Ekehuan road and how it leads to road failure. It also elucidates the general causes of road failures in our roads, it is noted that a high traffic volume affects the durability and strength of the road pavement when it is not properly designed.

This research was carried out by taking two samples from different points along the road for soil tests to determine the strength and resistance of the subgrade material to traffic load being exerted on the road. Furthermore traffic count was performed along the Ekehuan road for two days in the morning, afternoon and towards evening to determine the total Equivalent Single Axle Load (ESAL) being exerted along the pavement which will help in determining the thickness of the components of the pavement to be designed. Considering pavement rehabilitation is currently ongoing along the road, the road may not be operating at full capacity hence it is advisable to create an extra allowance, hence we would be using a slightly higher ESAL.

From the investigation carried out, the soil samples were analyzed, it was found out that the CBR of both samples is between 13% - 20%. It was then concluded that the CBR strength is sufficient for the sub-grade component according to the specifications of the federal ministry of works (1997), therefore the materials of either the sub-base or the base course or both is not suitable. It is recommended that the thickness of the subgrade according to specifications of the federal ministry of works (2013) be 650mm and the subbase and base layer stabilized.