MICROSTRUCTURE CHARACTERISTICS IN THE CEMENT PASTE CONTAINING MICRONIZED SAND FILLER

摘要

In recent decades, the cement industry became aware, more and more, of the economic andenvironmental problems of concrete associated with the use of ordinary Portland cement(OPC). Attempts have been made to partially replace the cement by active or inertcomponents, such as limestone filler, fly ash and finer sands. Whether the blend material isfeasible and guarantees the long term properties in comparison with OPC is still an openresearch area. In this study, cement pastes with and without micronized sand have beeninvestigated by means of mercury intrusion porosimetry (MIP) and electronic scanningelectron microscope (ESEM). The proportion of replacement was 20% by weight. From theresults, paste with micronized sand (CM6) can increase the rate of hydration compared withOPC paste when the water to binder ratio is kept constant (w/b=0.4). When the water tocement ratio is kept constant (w/c=0.4), paste with micronized sand has lower porosity andfiner pore structure compared with OPC paste. Seen from the interfacial transition area, bigpores are mainly located around sand particles. Sand particles can give some contribution tocompensate the increasing of porosity in CM6.