Improvements of mechanical and physical features of cement mortar by nano Al2O3and CaCO3 as additives

Abstract

The impact of Nanoparticles of (〖AL〗_2 O_3and 〖CaCO〗_3) particles on the features of cement mortar was explored in current research with a mean diameter of ~50nm, and 100nm in three various amounts of 1, 3, and 5% substitution by cement’s weight as binary blending materials with fixed water/cement proportion 0.46. Cement mortar's mechanical and physical features (compressive strength, density) were tested after 7 and 28 days. The findings illustrated that utilizing nanoparticles of 〖AL〗_2 O_3 improved the mortar compressive strength at early ages at 7 curing days better than 28 curing days, and 3% of substitution was the optimal proportion. Also, utilizing nano-〖CaCO〗_3 as a binary blending mixture with substitution proportion (1, 3, 5%) by cement's weight improved mortar compressive strength at early ages at 7 curing days better than 28 curing days. However, there were no apparent effects when nanoparticles of (〖AL〗_2 O_3 and 〖CaCO〗_3) were replaced on the density and ultrasonic pulse velocity of cement mortar at 7 and 28 days. The interaction impact of substitution 1 and 3 percent of nanoparticles of (〖AL〗_2 O_3 and 〖CaCO〗_3) particles to cement mortar increased the CS by (28 and 74%) at 7 curing days and (30 and 42%) at 28 curing days, respectively.