Assessment the Influence of Fe2O3 Micro and Nanoparticles on Properties of Concrete

This work focuses on investigating the behavior of micro and nanoFe2O3 in concrete through the study of microscopy, compressive strength and flexural strength. Seven mixes of concrete are prepared. Three of which include micro Fe2O3 comprising 1%, 3% and 5% as partial substitutions of cement weight and the other three mixes containing 1%, 3% and 5% nanoFe2O3 as a partial substitutions of cement weight, as well as the reference mix. SEM study exhibits that the microstructure of sample produced with micro Fe2O3 show more uniformity and dense compared with reference sample. However, existence of micro cracks in the microstructure in mixes with micro Fe2O3 is clear especially with increasing micro Fe2O3 content to 3% and 5%. In mixes with nanoFe2O3, the new shapes of needle like crystals and flower like crystals can be distinguished. The presence of these types of crystals in thrives amount approve that nanoFe2O3 producing new phases of gel. Hence, the microstructure of samples is condensed, and with the increasing of nanoFe2O3 content the microstructure is completely compacted. The results of compressive strength and flexural strength showed that the mechanical properties are related to microstructure properties. When micro Fe2O3 is used, the mechanical properties drop obviously. While, the mechanical properties are improved in mixes containing nanoparticles in comparison with the control mix.