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Title: Comparative Study of the Effects of Microsilica and Nanosilica in Concrete
Accession Number: 01157595
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: It is well recognized that the use of mineral admixtures such as silica fume enhances the strength and durability of concrete. This research compares the effects of adding silica fume and nanosilica to concrete and provides a better understanding of the changes in the concrete nanostructure. Nanoindentation with scanning probe microscopy imaging was used to measure the local mechanical properties of cement pastes with 0% and 15% replacement of cement with silica fume. A reduction in the volume fraction of calcium hydroxide in a sample with silica fume provides evidence of pozzolanic reaction. Furthermore, replacing 15% cement by silica fume increased the volume fraction of the high-stiffness calcium silicate hydrate (C-S-H) by a small percentage that was comparable with the decrease in the volume fraction of calcium hydroxide. A parallel study of cement pastes with nanosilica showed that nanosilica significantly improves durability of concrete. This research provides insight into the effects of nanosilica on cement paste nanostructure and explains its effect on durability of concrete. The nanoindentation study showed that the volume fraction of the high-stiffness C-S-H gel increased significantly with addition of nanosilica. Nanoindentation results of cement paste samples with similar percentages of silica fume and nanosilica were compared. Samples with nanosilica had almost twice the amount of high-stiffness C-S-H as the samples with silica fume.
Monograph Title: Monograph Accession #: 01157583
Report/Paper Numbers: NANO10-0050
Language: English
Authors: Mondal, ParamitaShah, Surendra PMarks, Laurence DGaitero, Juan JPagination: pp 6-9
Publication Date: 2010
ISBN: 9780309142762
Media Type: Print
Features: Figures
(5)
; Photos
(1)
; References
(12)
; Tables
(2)
TRT Terms: Uncontrolled Terms: Subject Areas: Materials; I32: Concrete
Files: TRIS, TRB, ATRI
Created Date: May 24 2010 3:25PM
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