The effect of sediment treatment on strength and water absorption capacity of sediment based concrete

摘要

The paper presents the possibility of the Ruzín (Slovakia) reservoír sediments' reuse as a 40% replacement of Portland cement in concrete. Treatment of sediments consists of sediment dry milling, adding of fly ash from local biomass incinerator plant into the dry milling process due to the low CaO sediment content and sediment's mechano-chemical activation using sodium hydroxide in the form of solid and solution as a chemical activator of pozzolanic properties. The results show the possibility of sediment reuse in building materials. However, treatment of sediments with the addition of fly ash doesn't significantly affect the development of compressive strength. Sodium hydroxide is not an effective pozzolanic activator for sediments. The absorptivity of composites increases with the fly ash and sodium hydroxide addition. Also the NaOH application form (as a solid or solution) influences the total absorption water capacity. Pouring the mixture with 5M NaOH increases the absorptivity of the hardened composites.