Akademik Veri Yönetim Sistemi
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, cilt.528, ss.7012-7019, 2011 (SCI-Expanded)
In this article, the single, binary and ternary effects of three nano-sized powders of the main oxides of cement (nano-SiO2, nano-Al2O3 and nano-Fe2O3) on the compressive strength and capillary permeability of cement mortars containing silica fume were investigated. The powder amounts were chosen at proportions corresponding to 0.5%, 1.25% and 2.5% of the binder amount. Compressive strength was determined for early age (3- and 7-day), standard age (28-day), and late age (56- and 180-day) mortars, while capillary permeability was determined for 180-day-old mortars only. It was concluded from the experimental results that the type and amount of nano the powders, and mortar production methods had a significant effect on the fresh and hardened properties of cement mortars. The nano-powders used singly or in combination increased the 28-day compressive strength of silica fume-containing mortars by up to 27%, with the exception of nano-SiO2 powder used at a proportion of 2.5%. However, the compressive strength values fluctuated at early and later ages. The best results for compressive strength and capillary permeability at the end of day 180 were obtained with 1.25% nano-Al2O3 powder in single uses, 0.5% nano-SiO2 + nano-Al2O3 powders in binary combinations, and 0.5% in ternary combination. However, it was determined that the interaction between the powders used in binary and ternary combinations led to negative effects on the physical-mechanical properties of the mortars. For this reason, nano-Al2O3 powder and single use were primarily recommended in cases where an increase in the performance of cement-based composites is desired. The findings of the experiments suggested the conclusion that the improvement in the mechanical and physical properties of mortars was caused by the rise in pozzolanic activity induced by the favorable influence of the powders rather than the filler effect. 2011 Elsevier B.V. All rights reserved.