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The assessment of the durability of twelve cylindrical samples of black cotton soil, a well-known problem soil, stabilized with a combination of 4%lime and 16% sawdust ash were carried out in laboratory using the methods of [1] and that recommended by [2] and [3]. The results showed that the unconfined compressive strength of the samples under varying curing and soaking conditions ranged from 1217kPa to 265kPa while the durability indices were 59.51% and 59% respectively. Thus, the stabilizers have elevated the otherwise non-durable soil into the marginally durable zone.

This study presents the evaluation of flexible pavements in the south-eastern Nigeria in terms of their durability in years, ranking, predominant factors affecting pavement durability and the estimate of durability. In this regard, two separate questionnaires of different contents focusing on the nature of the pavements and their constituent materials, their design and construction process, the disposition of the persons involved in their construction and the interaction of the pavement with the natural environment were designed and distributed across the five south eastern states of Nigeria. These questionnaires were distributed to the general public and to persons possessing the required technical background for road construction. Findings which are in agreement with an experimental case study of one road network which connects four out of the five states under the area of study has shown that the average estimate of pavement durability lies in the range of 1 to 5 years, the ranking of durability which is a function of knowledge of worldwide trends of pavement durability lay between poor durability and average durability while factors like lack of drainage/inadequate drainage, corruption and or deliberate use of poor quality materials, inadequate thickness of pavement surfacing, improper mix design, lack of routine maintenance, and lack of periodic maintenance were among the key factors. Finally Chi-square tests showed that there were significant association between the estimate of durability and factors such as corruption and or deliberate use of poor quality materials and poor workmanship or construction as obtained from the response of the general public, while in the case of respondents with technical background, it is observed that there is a significant interaction between the estimate of durability and the poor design and construction factors and between the estimate of durability and maintenance related factors. The asymptotic significance (2-sided) ranged from 0.001 to 0.044.

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He holds a Master's degree in soil mechanics and foundation engineering from the same university, and specialises in geotechnical engineering. He also runs a financial and engineering consulting firm.