Title: Effect of Cement Composition on Fresh State and Heat of Hydration of Portland Cement with Limestone and Slag
Author(s): Agathe Bourchy, Laury Barnes-Davin, Laetitia Bessette, and Jean Michel Torrenti
Publication: Materials Journal
Appears on pages(s): 153-165
Keywords: cement composition; compressive strengths; early age; experimental design; heat; hydration
The exothermy of cement hydration causes a temperature increase, the development of temperature gradients, and a risk of cracking or delayed ettringite formation in large concrete structures. A review of constituents and characteristics of cement has been performed to determine which have the most influence on the thermal activity and heat release. Considering the fast hydration reactions of C3A, which highly increases temperature and mainly forms ettringite during hydration or delayed ettringite if the appropriate conditions are met, two types of clinker (with and without C3A but only C4AF) are selected. The temperature rising in cement is also influenced by the presence of addition. Currently, limestone and slag are mainly used in concrete formulation to improve mechanical and durability properties. Therefore, these two additions have been studied. Three experimental designs are constructed with the variation of three parameters—addition quantity, anhydrite quantity, and medium diameter—on three levels. The results show that the composition of clinker and the addition type impact the hydration heat and the mechanical properties of the cement. The C3A content seems to be the most influential early-age parameter. Finally, when the addition quantity is high, there is a loss of fineness effect on hydration heat produced or mechanical strengths, which can decrease the grinding costs.