Characteristics of Limestone 15% Mixed Cement Mortar according to Cement Fineness and Clinker Types

Abstract

If the amount of limestone used as a mixing material is increased instead of the amount of clinker used, it may affect the cement mechanical performance, and there is a lack of research on applying limestone mixed cement to mortar. Therefore, in this study, the characteristics of limestone 15% mixed cement mortar were analyzed according to cement fineness and clinker types. As a result of measuring the flow and setting time of limestone mixed cement mortar, as the cement fineness and C₃S content increased, the flow decreased and the setting time was shortened. As a result of measuring the heat of microhydration, the secondary peak value tended to increase as the cement fineness and C₃S content increased. The compressive strength of the test specimen using cement powder level of 4500 ± 100 cm²/g and clinker with high C₃S content on days 1, 3, 7, and 28 was 140%, 124.2%, 115.3%, and 101.6%, respectively, compared to plain. The compressive strength was high at 1, 3, and 7 days, and a similar tendency was observed at the 28-day compressive strength. Therefore, it is believed that increasing the fineness and C₃S content of cement is effective in improving compressive strength.