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Volume Title: ICASGE2015

DOI: ICASGE-MAT

E.E. Etman; A.M. Atta; M.H. Taman; A. M. Wahba

In this study, the effect of nano-Cr2O3 and different-phase Al2O3 nanoparticles addition on the fresh and hardened properties of cement mortar has been investigated. Ordinary Portland cement was replaced by nano powder at 0.5%, 1.25% and 2.5%wt percent. Nano Cr2O3 and Al2O3 nanoparticles were prepared via citrate-precursor autocombustion method. The structure of the prepared nanoparticles was characterized using X-ray diffraction (XRD). The results illustrate that the obtained powders have a single phase structure. The morphology and the size of the synthesized nano-particles were analyzed using Transmission Electron Microscope (TEM). Photographs confirmed nanoscale crystallized structure. Properties of fresh density and flow percentage were evaluated in fresh state. The compressive strength along age of the cement paste was the evaluated property in hardened state. Different mixing methods to uniformly disperse the nanoparticles within the cement matrix were explored and a suitable mixing technique was suggested. Scanning electron microscope (SEM) revealed that the microstructure of the composites with -phase Al2O3 nanoparticles were more compact and dense than that of plain composite.

Nano-Cr2O3; Nano-Al2O3; cementitious materials