SEM images were used to explore the microstructure of the
corresponding specimens. SEM images of the specimens
with and without SCBA at the age of 56 days were investigated
by means of SEM methods. Figure 6 shows the SEM
photograph of BA0. It can be seen that a lot of hydration
products – like C-S-H gel, Aft crystals, and several pores
were formed on the surface of BA0. Figure 7 shows the
SEM images obtained for the specimen of BA10. Observations
revealed that the rough surface of the mixture of
BA10 showed to contain C-S-H gel, Aft crystals, and also
narrow pores. However, the differences in the microstructural
features between the specimens without and with
bagasse ash are not obvious. With the addition of 10 %
SCBA to the mixture, there takes place the reaction of the
portlandite produced by the hydration of the calcium silicates
in the cement with the silica and alumina reactivates
in the pozzolanic material. This reaction produces C-S-H
gel, which grows into the capillary spaces. Hence, the
paste structure tissue became dense. The observations are
consistent with those of water absorption, initial surface
absorption, compressive strength, and RCPT results.