Ahmed M. Elsharief

Failure Investigation for Recently Constructed Road in Khartoum State

This paper will visually and experimentally assess the level of deterioration of one of the new constructed ring road pavements in Khartoum State as well as to examine and identify the causes of the failed pavement. A series of field and laboratory exercises were carried out on the materials that were used in the construction of the designated pavement. Huttab, a natural gravelly material, was used in both subbase and base blend of this deteriorated pavement. The experimental tests consisted of two tasks: the first covered the study of the actual causes of pavement distress, whereas the second explored typical base material alternatives that satisfy base course needs. The tests involved basic tests and dynamic tests such as sieve, Atterberg limits, linear shrinkage, compaction, CBR (California bearing capacity), abrasion whereas the dynamic tests included MR (resilient modulus), and PD (permanent deformation). The routine tests showed that an improper base blend was used in the failed road that resulted in excessive rutting whereas in the second tests scenario the results showed that the proper base blend from the named materials gave high strength and stiffness values and low PD compared to the natural one. On the other hand, the pure crushed sample reported high MR values and the lowest PD compared to the base blend alternative.