Civil Engineering Reference
In-Depth Information
advanced sensing materials that could be used effectively as construction
materials and at the same time, act as sensors to monitor the health of
the structures. However, despite these exciting developments the study
of nanotechnology for green concrete and the envisioned benefits are still
young science:
∑ We still need to advance methods of dispersion. to achieve good
reinforcement in a composite, it is critical to have uniform dispersion
of the nanoscale fibers within the matrix. So far the major challenge
associated with the incorporation of CNTs and CNFs in cement-based
materials is dispersion.
∑ The effect of nanoscale fibers on the electrical conductivity of CNTs/
CNFs nanocomposites with cement paste and mortar matrix so as to
specify the optimum types of nanoscale fibers, and the study of the
piezoresistive response of the nanocomposites and the capability of
CNTs/CNFs to be used as sensors in concrete are currently considered
key research topics for the application of cementitious nanocomposites
in the construction industry.
∑
Sio
2
nanoparticles can definitely improve the environmental and
mechanical performance of concrete. However, further research is
needed to bridge the gap between potential benefits, reducing pore size
distribution and increasing shrinkage. Recent studies suggest that the
use of nano-Sio
2
increased the 7-day shrinkage by 80% compared with
an equivalent mix with micro-silica (Senff et al., 2010).
20.8 Acknowledgements
the author would like to acknowledge the support of the national Strategic
Reference Framework (NSRF) - Research Funding Program: 'Thales -
democritus university of thrace - Center for Multifunctional nanocomposite
Construction Materials' (MIS 379496) funded by the European union
(European Social Fund - ESF) and Greek national funds through the
operational Program 'Education and Lifelong Learning'.
20.9 References
Belytschko, T; Xiao, S.P; Schatz, G.C.; Ruoff, R. (2002), 'Atomistic simulations of
nanotube fracture',
Physical Review B
65
(23), 235430-235437.
Bjornstrom, J.; Martinelli, A.; Matic, A.; Borjesson, L.; Panas, I. (2004), 'Accelerating
effects of colloidal nano-silica for beneficial calcium-silicate-hydrate formation in
cement',
Chemical Physics Letters
392
(1-3), 242-248.
Chang, T.-P.; Shih, J.-Y.; Yang, K.-M.; Hsiao, T.-C. (2007), 'Material properties of
Portland cement paste with nano-montmorillonite',
Journal of Materials Science
42
(17), 7478-7487.
