Portland cement, type 5

This type of cement has good strength against sulfate attacks; it is suitable for places where soil and underground water is high in sulfate. It is a chemical reaction between the hydration products of C3A and sulfate ions that enter the concrete from the outside environment. The products generated by this reaction have a larger volume than the reactants, and this creates stresses which force the concrete to expand and crack. So the designations for Type V cement focus on keeping the C3A content low. The C3A content of Kerman type 5 cement is lower than %3. Also alkali content of type 5 cement is low (in terms of sodium oxide equivalent is approximately %0.8); it is preferred in environments with the risk of damaging reaction of silica and alkali.