Detailed characterization of current North American portland cements and clinkers and the implications for the durability of modern concrete

The current study has been undertaken with a view to rationalize the relation between the cement characteristics and concrete properties with the fresh set of data collected from the North American portland cements. The important chemical and physical characteristics of the cement discussed are (a) chemical analysis, (b) phase calculations, (c) various particle characterizations and (d) rheological properties. The important concrete properties discussed are (a) alkali silica reactivity, (b) sulfate attack, (c) delayed ettringite formation (d) chloride ion permeability and (e) compressive strength. Relationship between the cement characteristics and concrete durability was determined using regression methods.; The heat of hydration was mainly influenced by the variation in C ₃A, SO₃, equivalent Na₂O contents, and fineness of portland cements. When there was no variation in C₃A, SO ₃, and fineness, the hydration kinetics of the cement was mainly controlled by the silicate phase hydration. The 7-day hydration was negatively correlated to C₂S or C₄AF content. As the C₂S or C ₄AF content increased, the 7-day heat of hydration decreased. C ₃S content showed a positive correlation to 1 and 7-day heats of hydration, but significant negative correlation to 14 and 28-day hydration.; Equivalent alkalis showed a strong positive correlation to ASR at 2 weeks. SO₃ content of portland cement also showed a positive correlation to ASR expansion. A strong negative correlation was observed between C₄AF content of portland cement and sulfate attack expansion at 4 and 6 months of exposure. The correlation to sulfate attack was stronger when the ratios of C₃A/C₄AF were taken into account.; C₃A content exhibited a negative correlation to chloride ion permeability. This correlation decreased as the curing period increased. SO ₃ content also exhibited a negative correlation to the chloride ion permeability. Only alkalis showed a strong negative correlation to the compressive strength after 3-day curing period. In the present study, a modified Stark method was used to evaluate the expansion produced by SEF/DEF. Analyses of SEF/DEF mortar data showed that the total length change was negatively correlated to SO₃ and positively correlated to CaO contents of cement. The present study showed that there does not appear to be an SEF/DEF expansion problem if (1) the cement contains low SO₃ (less than 3.5), SO₃/Al₂O₃ ratio less than 0.7, and SO ₃/CaO ratio less than 0.06, and (2) the concrete is air-entrained and the temperature does not exceed 60°C.