Evaluating the Performance of Alternative Supplementary Cementing Material in Concrete
The Center for Transportation Research at the University of Texas at Austin has released a report that characterizes and evaluates the performance of eight natural pozzolans to assess their potential as Class F fly ash replacements in concrete.
Uncertainty in the supply of Class F fly ash due to impending environmental restrictions has made it imperative to find and test alternate sources of supplementary cementitious materials (SCMs) that can provide similar strength and durability benefits to concrete as Class F fly ash. This project summarizes the key findings of research that was conducted to characterize and evaluate the performance of eight natural pozzolans, commercially available in Texas, to assess their potential as Class F fly ash replacements in concrete. Of the eight pozzolans tested, six were found to be viable alternatives for Class F fly ash. Methods to further enhance the performance of these SCMs were explored and guidelines are provided on the optimum SCM replacement levels for different applications. Finally, recommendations are presented on how to improve current testing practices for SCMs.
Authors: Saamiya Seraj, Rachel Cano, Shukui Liu, David Whitney, David Fowler, Raissa Ferron, Jinying Zhu, Maria Juenger