Multi-variable statistical analysis for scaling resistance of concrete containing GGBFS

This study examines the laboratory de-icing salt scaling performance of concrete containing varying amounts of GGBFS as cement replacement. Using experimental results of concrete tested in accordance with ASTM C 672 and MTO LS-412 reported in the literature, a statistical analysis was carried out to evaluate the significance of several mix design variables, surface finishing, type of de-icing salt and duration of curing. Specifically, two multi-variable statistical models were developed to estimate the salt scaling resistance of the finished surface and the formed surface of concrete containing GGBFS as cement replacement. The models’ results show that (i) w/b ratio and ratio of OPC/binder are statistically significant, (ii) mass loss is not singularly dependant on the amount of OPC, GGBFS and total binder content, however their effect is captured by the ratio of OPC/binder, (iii) entraining air is not a controlling variable for the scaling resistance of the formed surface, (iv) type of de-icing salt affects the surface scaling, (v) both finishing procedure and curing regime are statistically significant for the finished surface, and (vi) resistance of concrete containing GGBFS to salt scaling improves with age. Results also revealed that the previously reported inconsistencies in the scaling resistance of concrete containing GGBFS are due to the differences in the performance of the finished and formed surface and to the uncovered fact that mass loss does not depend on the binder content as typically reported but rather on the ratio of OPC/binder.