The BET method can be used as a tool to assess the potential pozzolanic activity of highly porous materials such as residual RHA (Cordeiro et al., 2011). The results of surface area and average pore diameter of the pozzolanic materials from rice rusk, throughout BET method (Table 3), as SEM results confirmed that BI6727 WRHA showed higher surface area and average pore diameter than the RHA and consequently, may have higher pozzolanic activity.
BET results of RHA and WRHA.Pozzolanic materialsAverage pore diameterSpecific surface area(Å)(m2/g)RHA45.322160WRHA44.042174Full-size tableTable optionsView in workspaceDownload as CSV
As the literature (Nair et al., 2008) has shown, to produce a highly reactive rice husk ash it has to contain the maximum amount of amorphous silica with a high specific surface area and the presence of many silanol groups are essential. Thus, the characterization step of the pozzolanic materials utilized in this paper showed that RHA and WRHA are suitable to be used as a good pozzolanic material.