equivalent to a low C3A (Type V). While high C3A would take care of free Cl-
by
complexing it, critical concentration admixture would lower down the C3A content
equivalent to that present in type V cement. Such cement would be simultaneously
resistant to sulfate attack and chloride induced reinforcement corrosion.
Another approach to address chloride - sulfate problem is to formulate high durability
performance modified cements by blending Type I cement with pozzolanic materials
such as silica fume, flyash and BFS. Results of the studies [Rasheeduzzafar et al.,
1992] conducted at KFUPM on blended OPC or Type I cements showed that silica
fume, flyash and BFS blended cement concretes performed 7 to 5 times better than plain
Type V (C3A : 2%) and 3 to 2 times better than Type I (C3A: 14%) cement concrete in
terms of time of initiation of corrosion. A significant conclusion arrives from this study
is that same blended high C3A cements performed 1.2 to 2 times better in terms of
sulfate resistance than the plain Type V (C3A:2%) cement.