Autoclaved SIFCON with high volume Class C fly ash binder phase

The effect of incorporating high volume of Class C fly ash (FA) on mechanical properties of autoclaved SIFCON (slurry infiltrated fiber concrete) has been investigated in this study. Cement was replaced with up to 60% FA in SIFCON compositions and three different steel fiber volumes (2%, 6% and 10%) were used. Test results were presented in comparison with the control mix (0% FA and 0% fiber). Mechanical properties were positively affected almost at every FA replacement. Moreover, by increasing the fiber volume, flexural strength and toughness were remarkably increased. This behavior was more pronounced at 10% fiber volume. At this fiber volume ratio, flexural strength of 55 MPa could be achieved with 60% FA replacement.