SULFATE RESISTANCE OF MORTARS WITH LIMESTONE POWDER

Abstract

In this investigation, mortar specimens made from two types of ordinary
Portland cements, Type I and Type V, and Type I and Type V cements with
limestone powder and fly ash were exposed to sulfate solutions. Performances
in sulfate environment of mortars using these cementitious binders were
evaluated by measuring expansion and weight loss of the specimens. Test
results indicated that in both sodium sulfate (NS) and magnesium sulfate (MS)
solutions the expansion of mortar bar specimens made from Type I and Type
V cements with limestone powder and fly ash were smaller than those made
from Type I cement. In addition, smaller or closer expansion can be observed
when compared with specimens made from Type V cement. In regard of weight
loss, mortar cube specimens submersed in NS solution at the age of 68 weeks
still had no loss in weight for all type of specimens. On the other hand, in MS
environment weight losses were rather high for mortar cube specimens made
from Type I and Type V cements with fly ash when compared with those made
from Type I and Type V cements. However, it was found that weight loss of
mortar cube specimens with limestone powder gave closely results to those
made from Type I and Type V cements.