reveals plenty of pores and needlelike
ettringite structures. At the late age of 28 days,
Figure 4(b) shows more dense structure of
resultant cement which contains less pores
and ettringite needles due to the supplementary
cementing phase of C-S-H. C-S-H gel of the
pozzolanic reaction is a principal coordination
phase to increase compressive strength of
resultant cement