Masters Dissertations

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Browsing Masters Dissertations by Author "Abdulla, Amin Khalid"

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    Establishment of sources of failure in labour-Based construction projects in Zanzibar
    (University of Dar es Salaam, 2013) Abdulla, Amin Khalid
    This study establishes the sources of failures resulting from the construction of labour-based road construction projects in Pemba. It encompasses six roads namely: Chanjamjawiri- Tundauwa, Chanjaani – Pujini, Mzingani – Wambaa, Kenya-Chambani, Mtambile-Kangani and Mtambile-Kengeja located in southern Pemba. A stratified two – stage sampling method was deployed. Each stratum was represented by each of the 13 shehias affected by the roads. The main instruments used in data collection were interviews, questionnaires and physical observation. Results of the study found the major failures to be: cracking of the road surface and deformations. Medium failures included cracking at the edges, potholes and fatting up of binder while the minor failure was slipperiness of the road surface. Laboratory records showed that the roads’ sub ‘grade was weak. It further pointed at improper upgrading of the in situ-sub-grade and omission of the sub-base layer thus causing road failures. This led to a conclusion that road failures were caused by poor site preparation, insufficient compaction, inadequate use of road construction materials and unavailability of adequate construction equipment. In order to improve the performance of labour-based road construction methods, this study recommends that the project team from the contracting agency should comprises of experts to strictly monitor the works. They should be equipped with the appropriate laboratory equipment and that focus should be placed on good quality and appropriate supervision.