Citation

Ojeaga K, Archinbong UD, Afokoghene A. NIPES J. Sci. Technol. Res. 2022; 4(1): 179-185.

Copyright

(Copyright © 2022, Nigerian Institution of Professional Engineers and Scientists (NIPES))

DOI

10.37933/nipes/4.1.2022.15

PMID

unavailable

Abstract

The study evaluated the possible causes of pavement failures in Benin Technical School Road, Benin City, Edo State. Disturbed soil samples were collected from three (3) Sampling points in the study area at a depth of 1m each. Soil samples were kept inside a polyethene bag and taken to the laboratory and their geotechnical characteristics was analysed according to ASTM. Sieve analysis, natural moisture content, specific gravity, Atterberg limits, Compaction and California Bearing Ratio (CBR). The results of the test showed that the soil samples were mainly silty /clay with little amount of fine sand. The percentage of soil passing the 75 mm sieve size ranges from 20% - 33.1% for sampling points 1, 2 and 3. The liquid limits was determined to be 31.94%, 23.38% and 21.03%, while the plasticity index ranges from 11.95% - 17.67% for the three sampling points. The specific gravity ranges from 2.48-2.51. The maximum dry density values (MDD) are 1.83g/cm3, 1.84g/3and 1.81g/cm3, while the optimum moisture content values were 12.87%, 12.0% and 11.19% respectively for the three sampling points. The California Bearing Ratio, (CBR) ranged from 3.46% to 21.70% for soaked and 16.10 -37.59 for unsoaked samples in the three sampling points. From the CBR result it can deduced that none of the soil samples met the criteria for road sub-grade as CBR values for all the soil samples were above the required 10%.

FINDINGS indicates that failure along the study area were due to the unsuitability of the soils as sub grade material and effect of ground water intrusion.As a consequence may be responsible for the road instability; ultimately leading to failed portions.The soil was classified as A-2-4 soil based on AASHTO soil classification system. Also, the results of this research will add to existing literatures in the in design and construction of roads that can stand the test time.

Language: en