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TECHNICAL PAPER

systems, its performance depends on optimizing particle
stabilization, dissolution kinetics, and interaction with evolving
hydration chemistry [19, 31, 34] .

4. CONCLUSIONS
Future direction lies in combining SCMs with nano-silica
to produce high-performance concretes that are not only
mechanically efficient but also environmentally sustainable.
Such blended systems maximize clinker reduction, enhance
pozzolanic utilization of industrial by-products, and leverage
nano-scale modification to achieve superior durability without
compromising dimensional stability. By integrating advanced
cement chemistry with resource-efficient material design, nano-
Figure 2: Schematic representation of the nucleation effect of nano- enhanced cementitious composites offer a sustainable pathway
silica on UHPC: (a) mechanism of C-S-H seeds generation and towards lowering CO 2 footprint while extending the service life
(b) effect of nano-silica amount on the microstructure development and of the infrastructure.
porosity of UHPC [41]

At this stage, nano-silica also functions as a C-S-H seeding 5. ACKNOWLEDGEMENT
agent, where early nanometric C-S-H clusters precipitate on its I sincerely appreciate Dr Snehal K., an alumnus of Sustainable
surface and promote templated growth, leading to a denser Construction and Building Materials Laboratory and currently
and more continuous gel network at very early ages . This working as Assistant Professor in the Department of Civil
[40]
mechanism is schematically illustrated in Figure 2a, showing Engineering at Motilal Nehru National Institute of Technology
the transition from unhydrated cement grains to nano-silica (MNNIT) Allahabad for her valuable contributions in the initiation
dispersion and subsequent formation of uniformly distributed of research towards the inclusion of nano-silica as a super
C-S-H seeds . Because CH is simultaneously consumed by pozzolanic material in the development of high performance
[41]
superior pozzolanic reaction, the equilibrium is chemically blended cementitious composites here at NITK Surathkal.
shifted, further driving C 3 S dissolution and accelerating early-
age C-S-H precipitation.
REFERENCES
Furthermore, Figure 2b highlights the effect of nano-silica [1] Neville, A. M. (2011). “Properties of concrete“,
dosage on pore structure, where insufficient silica results 5 Edition, Pearson Education, London, UK.
th
in incomplete pore refinement, excessive silica leads to [2] Claverie, J., Wang, Q., Bernard, S. K., and Bernard, F.
agglomeration and micro-defects, and an optimal dosage (2022). “Assessment of the reactivity and hydration of
produces the most refined and homogeneous pore network [41-43].
Portland cement clinker phases from atomistic simulation:
Moreover, nano-silica interacts with dissolved aluminate species, A critical review”, Cement and Concrete Research,
especially in systems containing supplementary cementitious Vol. 154, No. 106711, pp. 1-16.
materials, promoting the formation of modified hydrates such as [3] Taylor, H. F. W. (1997). “Cement chemistry”, 2 Edition,
nd
aluminosilicate-substituted C-A-S-H, Al-incorporated C-S-H, and Thomas Telford, London, UK.
in some cases strätlingite (C 2 ASH 8 ) [39-40] ,
[4] ACI Committee 207 (2005). “1R-05: Guide to mass
concrete”, American Concrete Institute, Farmington Hills,
– – 2+
H 3 SiO 4 + Al(OH) 4 + Ca + H 2 O → C-A-S-H (12)
(aluminosilicate-substituted gel) MI, USA.
[5] Mehta, P. K., and Monteiro, P. J. M. (2014). “Concrete:
This incorporation alters the layer charge and interlayer th
chemistry of hydrates, reducing ion diffusivity and enhancing microstructure, properties, and materials”, 4 Edition,
[39]
chemical binding capacity for chlorides and alkalis . However, McGraw-Hill Education, New York, USA.
the high reactivity of nano-silica leads to rapid internal water [6] Mindess, S., Young, J. F., and Darwin, D. (2003).
nd
consumption (self-desiccation) and a steep early reduction “Concrete”, 2 Edition, Prentice Hall, Upper Saddle River,
in internal relative humidity, which can induce autogenous NJ, USA.
shrinkage if dosage and dispersion are not carefully [7] Kosmatka, S. H., Kerkhoff, B., and Panarese, W. C. (2002).
controlled . Thus, while nano-silica represents the most “Design and control of concrete mixtures”, 14 Edition,
[19]
th
chemically active evolution of SiO 2 -based additives in cement Portland Cement Association, Skokie, IL, USA.

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