Abstract: This case study evaluates a Proficiency Testing Program (PTP) for fly ash testing, focusing on the homogeneity, stability, and performance of participating laboratories. The study aims to identify areas for improvement in testing methodologies to enhance the reliability of fly ash analysis. The PTP adheres to international standards, including ISO 13528:2015 and ISO/IEC 17043:2010, for sample preparation, testing, and data analysis. The PTP ensures the homogeneity of test samples through meticulous division, testing, and data-driven analysis. The stability of samples is monitored through regular tests at predetermined intervals, with results compared to initial homogeneity tests. The methodology of evaluation involves calculating Z' (z-prime) scores to assess the performance of participant laboratories, with scores within ±2.0 considered satisfactory and scores beyond ±3.0 considered outliers. The results of the proficiency testing reveal variations in the performance of participant laboratories across specific gravity, fineness, compressive strength at 7 days, and soundness by autoclave parameters. While most laboratories demonstrate adherence to expected values, some deviations raise concerns and highlight the need for continuous improvement. Laboratories with deviations are encouraged to evaluate their testing methodologies and address factors contributing to the observed deviations. Overall, the study underscores the importance of proficiency testing in ensuring the quality and consistency of fly ash testing. Continued development and refinement of proficiency testing programs are essential for the sustainable utilization of fly ash in various applications.
Abstract: This case study evaluates a Proficiency Testing Program (PTP) for fly ash testing, focusing on the homogeneity, stability, and performance of participating laboratories. The study aims to identify areas for improvement in testing methodologies to enhance the reliability of fly ash analysis. The PTP adheres to international standards, including ISO ...Show More
Abstract: Formwork is among the most determinant factors affecting the cost and completion time of construction projects. In this study, the erection practices, challenges, types, quality and cost of formwork on active building construction projects in Bahir Dar were assessed. The study uses, Questionnaires, site observations and oral interviews with project managers, office and site Engineers, construction managers and carpenters were used to organize and analyse data. From assessment, most of the contractors have given less attention to formwork erection and safety issues. Since the principal criteria for formwork selection are cost and traditional formwork erection, it impacts construction safety and reduces the concrete finishing and quality. Formwork erection is left as the task of carpenters and labourers. There is no proper supervision of the quality of formworks that guarantees construction workers' safety so it is vulnerable to physical injuries and affects employee’s health. From the study, timber formwork is the most dominant type of formwork used for the construction of slabs, beams, columns and stairs due to its availability and low cost. Burnt oil is used as a releasing agent in all construction projects that causes undesirable outputs in concrete surfaces.
Abstract: Formwork is among the most determinant factors affecting the cost and completion time of construction projects. In this study, the erection practices, challenges, types, quality and cost of formwork on active building construction projects in Bahir Dar were assessed. The study uses, Questionnaires, site observations and oral interviews with project...Show More