Ceramics-Silikáty 61, (3) 231 - 243 (2017)

This research focuses on natural quartz and natural quartz-limestone sand mechanoactivation with the high energy milling by collision in disintegrator using different energy rates (8.4 and 25.2 kWh/t) and its application effectiveness as microfiller in Portland cement composites. The obtained microfiller was used to partially replace sand in mortar and to partially replace cement in high performance self-compacting concrete (SCC). The activity factor of disintegrated microfillers in time was investigated to detect the potential changes of sand particle properties during milling and the subsequent storage. XRD, BET, morphological investigation and grading analysis was performed for disintegrated sand. Mechanical, physical and durability properties regarding to chloride penetration and freeze-thaw resistance were determined to prepared cement composites. The results indicate that cement mortar which was prepared with disintegrated microfillers right after their disintegration provides compressive strength increase up to 20% comparing to the reference mixture and the time factor has significant effect on the activity of disintegrated sand. The SCC strength slightly decreased, if cement was replaced by the disintegrated sand up to 15 wt%, while the results of durability test indicate that resistance to freeze-thaw damage and chloride penetration could remain in the level of the reference mixture.