Technical specifications and the quality of concrete constructions in Tanzania

With the advancement of technology on the global scale, it has been possible to enhance the quality of concrete constructions. As the result, compliance standards for acceptance of concrete products have been raised. In Tanzania, a typical developing country, compliance standards are generally low and as a result the reliability of constructed concrete structures is a problem as evidenced by widespread structural defects and a rather high frequency of structural failures. Attainment of acceptable quality in concrete constructions in Tanzania has long been a problem. In this dissertation an attempt has been made to assess compliance levels of concrete and its constituents vis-a-vis concrete quality enforcing specifications in use in the country. The compliance level surveys were preceded by a survey of technical specifications' awareness amongst clients, consultants and contractors. The results of the surveys indicate that technical specifications are hardly adhered to by members of the construction industry, especially contractors. There exists lack of specifications enforceability on contractors' part as well as on materials manufacturers/suppliers' part, the consequence of which quality concrete constructions are hardly achievable. It was however, also noted that the compliance levels of concrete constituents are much higher than that of concrete itself, suggesting the divergence is caused by lack of effective supervision and poor workmanship on concrete construction sites. Finally, proposals for use of quality assurance schemes in factories, application of auto control and external (audit) tests by manufacturers/suppliers and contractors, and establishment of legal machineries for enforcing contractual specifications, have all been suggested for the local construction industry.