Proficiency Testing Program for Fly Ash: Ensuring Quality and Consistency Through Standardized Evaluation

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.