Effect of nano ZnO_{2 and lime water curing on strength and water absorption of concrete

Assessment of nano ZnO2 and lime water curing effects on compressive strength and water absorption of concrete has been carried out in this paper. Nanopowders of ZnO2 considered as a viable fraction of ordinary Portland cement (OPC) in percent of 1, 2, 3 and 4 wt% were added into the binder of concrete. Specimens cured in two media as ordinary water and saturated lime water for 7, 28 and 90 days were analysed for compressive strengths and water absorptions of concrete specimens, as representative indices for mechanical and transport properties, respectively. The results indicate that ZnO2 powders are able to improve significantly the concrete compressive strength, and also reduce water absorption which could lead to enhanced durability of concrete. Improved strength and water resistance was noted when the specimens cured in saturated limewater related with those cured in water. ZnO2 nanopowders can improve the filler effect, and the high pozzolanic action of fine nanoparticles increases substantially the quantity of strengthening gel leading to enhanced and water resistance of nano ZnO2 blended concrete.