An XRD analysis used to study the pozzolanic behavior of the SCBA used in this research and to
identify the hydration products formed during the hydration of OPC. Fig.2. shows the XRD
pattern of OPC and 10% SCBA admixtured cement at 7 days and 28 days. It can be seen that
diffraction peaks of ettringite, Ca(OH)2 and C-S-H phases appeared in all samples obtained
during hydration. The main obvious change in SCBA samples is the peaks of Ca(OH)2
diminished, whereas those of C-S-H increased [10]. This indicates the pozzolanic reaction
between Ca(OH)2 and amorphous silica present in SCBA. This additional C-S-H improves the
strength. Low intensity peaks for AFt formation are observed, this may be due to the conversion
of AFt into AFm phase after 1 day of hydration [8].