Abstract
Several changes to the South African durability indexes test methods have been made over the years; while the latest methods were revised in November 2015 (Nganga, Beushausen & Alexander, 2017). The standardised test methods developed for durability index testing are new, and the results obtained by several laboratories differ significantly. It is important to note that the water sorptivity test has not been formalised as a standard test method, since it is not repeatable (Van Wyk, 2018). The aim of the project is to investigate the repeatability and reproducibility of the water sorptivity indexes test.
The project investigation entailed the testing of the repeatability and reproducibility of the water sorptivity indexes (WSI) test using three different sealing methods. The repeatability of the WSI test was tested at one laboratory, whereas the reproducibility of the test was conducted between five different laboratories. The insulation tape proved to be the sealing method that had the highest percentages with regard to repeatability and reproducibility. The core make-up, the “neatness of sealing the sample,” and the accuracy when coring, were some of the factors that contributed to the changes in results.