In the present work, silica nanoparticles (30-70nm) were supplemented into cement paste to study their influence on degree of hydration, porosity and formation of different type of calcium-silicate-hydrate (C-S-H) gel. As the hydration time proceeds, the degree of hydration reach to 76% in nano-modified cement paste whereas plain cement achieve up to 63% at 28 days. An influence of degree of hydration on the porosity was also determined. In plain cement paste, the capillary porosity at 1hr is ~48%, whereas in silica nanoparticles added cement is ~35 % only, it revealed that silica nanoparticles refines the pore structure due to accelerated hydration mechanism leading to denser microstructure. Similarly, increasing gel porosity reveals the formation of more C-S-H gel. Furthermore, C-S-H gel of different Ca/Si ratio in hydrated cement paste was quantified using X-ray diffractometer and thermogravimetry. The results show that in presence of silica nanoparticles, ~24% C-S-H (Ca/Si<1.0) forms, leading to the formation of polymerised and compact C-S-H. In case of plain cement this type of C-S-H was completely absent at 28 days. These studies reveal that the hydration mechanism of the cement can be tuned with the incorporation of silica nanoparticles and thus, producing more durable cementitious materials.
. [J]. Frontiers of Structural and Civil Engineering, 2016, 10(2): 162-167.
L. P. SINGH,A. GOEL,S. K. BHATTACHARYYA,G. MISHRA. Quantification of hydration products in cementitious materials incorporating silica nanoparticles. Front. Struct. Civ. Eng., 2016, 10(2): 162-167.
Peterson V K, Neumann D A, Livingston R A. Hydration of cement: The application of quasielastic and inelastic neutron scattering. Physica B, Condensed Matter, 2006, 1: 481–486
2
Powers TC, Brownyard TL. Studies of the Physical Properties of Hardened Cement Paste. Res Lab Portland Cem. Assoc Bull, 1948, 22
3
Taylor H F W. Cement Chemistry. 2nd ed. Thomas Telford: London (UK), 1997
4
Rao G A. Investigation on the performance of silica fume incorporated cement paste and mortars. Cement and Concrete Research, 2003, 33(11): 1765–1770
5
Das B B, Kondraivendhan B. Implication of pore size distribution parameters on compressive strength, permeability and hydraulic diffusivity of concrete. Construction & Building Materials, 2012, 28(1): 382–386
6
Alizadeh R, Beaudoin J J, Raki L. Mechanical properties of calcium silicate hydrates. Materials and Structures, 2011, 44(1): 13–28
7
Elahi A, Basheer P A M, Nanukuttan S V, Khan Q U Z. Mechanical and durability properties of high performance concretes containing supplementary cementitious materials. Construction & Building Materials, 2010, 24(3): 292–299
8
Sanchez F, Sobolev K. Nanotechnology in concrete: A review. Construction & Building Materials, 2010, 24(11): 2060–2071
9
Toutanji H, Delatte N, Aggoun S, Duval R, Danson A. Effect of supplementary cementitious materials on the compressive strength and durability of short-term cured concrete. Cement and Concrete Research, 2004, 34(2): 311–319
10
Korpa A, Kowald T, Trettin R. Hydration behaviour, structure and morphology of hydration phases in advanced cement-based systems containing micro and nanoscale pozzolanic additives. Cement and Concrete Research, 2008, 38(7): 955–962
11
Land G, Stephan D. The influence of nano-silica on the hydration of ordinary Portland cement. Journal of Materials Science, 2012, 47(2): 1011–1017
12
Thomas J J, Jennings H M, Chen J J. Influence of nucleation seeding on the hydration mechanisms of tricalcium silicate and cement. Journal of Physical Chemistry C, 2009, 113(11): 4327–4334
13
Qing Y, Zenan Z, Deyu K, Rongshen C. Influence of nano-SiO2 addition on properties of hardened cement paste as compared with silica fume. Construction & Building Materials, 2007, 21(3): 539–545
14
Gaitero J J, Campillo I, Guerrero A. Reduction of the calcium leaching rate of cement paste by addition of silica nanoparticles. Cement and Concrete Research, 2008, 38(8–9): 1112–1118
15
Bjornström J, Martinelli A, Matic A, Borjesson L, Panas I. Accelerating effects of colloidal nano-silica for beneficial calcium-silicate-hydrate formation in cement. Chemical Physics Letters, 2004, 392(1–3): 242–248
16
Abell A B, Willis K L, Lange D A. Mercury intrusion porosimetry and image analysis of cement-based materials. Journal of Colloid and Interface Science, 1999, 211(1): 39–44
17
Diamond S. Mercury porosimetry, an inappropriate method for the measurement of pore size distributions in cement-based materials. Cement and Concrete Research, 2000, 30(10): 1517–1525
18
Hansen T C. Physical structure of hardened cement paste: A classical approach. Materials and Structures, 1986, 19(6): 423–436
19
Quercia G, Spiesz P, Hüsken G, Brouwers H J H. SCC modification by use of amorphous nano-silica. Cement and Concrete Composites, 2014, 45: 69–81
20
Lam L, Wong Y L, Poon C S. Degree of hydration and gel/space ratio of high volume fly ash/cement systems. Cement and Concrete Research, 2000, 30(5): 747–756
21
Sanchez F, Sobolev K. Nanotechnology in concrete — A review. Construction & Building Materials, 2010, 24(11): 2060–2071
22
Singh LP, Bhattacharyya SK, Ahalawat S, Sharma U, Mishra G. Effect of morphology and dispersibiliity of silica nanoparticles on the mechanical behaviour of cement mortar. Journal of Concrete Structure and Materials, 2015, 9(2): 207–217
23
Fagerlund G. Porosity and specific surface of portland cement paste. In Report TVBM Div of Building Materials LTH, Lund university, 2006, 1–91
24
Ramachandran V S. Thermal Analysis: Handbook of analytical techniques in concrete science and technology. Ramachandran V S, Beaudoin J J, eds. ISBN: 0-8155-1437-9, Noyes Publications, New Jersey, 2001
25
Jain J, Neithalath N. Analysis of calcium leaching behaviour of plain and modified cement pastes in pure water. Cement and Concrete Composites, 2009, 31(3): 176–185
26
Singh L P, Goel A, Bhattacharyya S K, Sharma U, Mishra G. Hydration studies of cementitious materials using silica nanoparticles. Journal of Advanced Concrete Technology, 2015, 13(7): 345–354
27
Singh L P, Karade S R, Bhattacharyya S K, Yousuf M M, Ahalawat S. Beneficial role of nanosilica in cement based materials — A review. Construction & Building Materials, 2013, 47: 1069–1077
