Ceramics-Silikáty 54, (1) 65 - 71 (2010)

The purpose of this work is to study simultaneous influences of both microsilica and limestone powder, i.e. pozzolanicity and plasticity respectively, on important physicomechanical properties of fresh and hardened Portland cement paste. Different ternary mixes were prepared and studied by determining their relative workability, 7- and 50-day compressive strengths, water absorption, bulk specific gravity, and volume of permeable pore space. The obtained results confirm that the plasticizing effect of limestone powder makes it possible to replace Portland cement by a proportioned mixture of microsilica and limestone powder for improving the strength behavior at a constant W/C-ratio without any dispersing agent. It is also possible to produce ternary composite cements containing relatively high contents of microsilica and limestone powder with no considerable loss in both workability and compressive strength compared to plain Portland cement paste.