The effect of limestone fineness on ternary cement fresh-state and early-age properties

During cement production, a significant amount of CO₂ is released into the atmosphere, it is estimated that the production of each ton of clinker free about a ton of second carbon oxide. The use of additions as constituents of cement reduces the amount of clinker, where CO₂ emissions are reduced. The combination of two or three additions with Portland cement can develop new types of binders (ternary or quaternary cement) with improved physical and mechanical properties compared to Portland cement alone. The objective of this work involves the study of the effects of the fineness of limestone on the physical and mechanical properties of ternary cements containing pozzolan and limestone with specific area of 3500, 5500 and 11000 cm²/g, respectively. The amount of clinker is fixed at 65% , that of limestone is varied from 10 to 35% by weight of cement, the remain is constituted of pozzolanic addition. The results showed that increasing the surface area of limestone could be with a favorable effect on the physical properties in particular the setting time and the shrinkage; further to good strength, mainly at early ages. The higher dosages of pozzolan reaching 25 % gave better mechanical performances among all other mixtures. It can be concluded that the use of combined mineral additions, limestone and pozzolan could be beneficial to formulate ternary cements with improved physical and mechanical properties for mortars based on such binders.