The pozzolanic reactivity of monodispersed nanosilica hydrosols and their influence on the hydration characteristics of Portland cement

Abstract This study reveals that the nanosilica hydrosols with higher specific surface areas had faster pozzolanic reactivity, especially at early ages; moreover, the results are indicative of the accelerating influence of nanosilicas and silica fume on the hydration of cement. Faster initial and final setting times observed for cement pastes containing nanosilicas are consequence of these mechanisms. However, less hydration degree of cement compared to the plain paste was observed at age of 7 days and after. This can be attributed to the entrapment of some of mix water in the aggregates of nanosilicas formed in cement paste environment, making less water available for the progress of cement hydration. The same mechanism is believed to be responsible for the reduction of flowability of cement pastes.

[1]  T. Kowald,et al.  Hydration Behaviour, Structure and Morphology of Hydration Phases in Advanced Cement-based Systems Containing Micro and Nanoscale Pozzolanic Additives , 2008 .

[2]  R. Iler.  Coagulation of Colloidal Silica by Calcium Ions, Mechanism, and Effect of Particle Size , 1975 .

[3]  E. Matijević,et al.  Stability of colloidal silica: I. Effect of simple electrolytes , 1969 .

[4]  Ali R. Pouladkhan,et al.  Mechanical, rheological, durability and microstructural properties of high performance self-compacting concrete containing SiO2 micro and nanoparticles , 2012 .

[5]  Ivan Odler,et al.  6 – Hydration, Setting and Hardening of Portland Cement , 1998 .

[6]  Mohamad Amran Mohd Salleh,et al.  Experimental investigation of the size effects of SiO2 nano-particles on the mechanical properties of binary blended concrete , 2010 .

[7]  A. Khelidj,et al.  Experimental study of the effect of addition of nano-silica on the behaviour of cement mortars Mounir , 2011 .

[8]  W. Roberts.  12 Manufacturing and Applications of Water-Borne Colloidal Silica , 2006 .

[9]  Vagelis G. Papadakis,et al.  Experimental investigation and theoretical modeling of silica fume activity in concrete , 1999 .

[10]  L. T. Zhuravlev.  The surface chemistry of amorphous silica. Zhuravlev model , 2000 .

[11]  A. Foissy,et al.  Study of Ca2+-induced silica coagulation by small angle scattering , 1990 .

[12]  Ta-Peng Chang,et al.  Effect of nanosilica on characterization of Portland cement composite , 2006 .

[13]  Barbara Lothenbach,et al.  Hydration of a low-alkali CEM III/B–SiO2 cement (LAC) , 2012 .

[14]  J. Thieme,et al.  Pozzolanic reactivity of nanoscale pyrogene oxides and their strength contribution in cement-based systems , 2008 .

[15]  M. Rahaman.  Ceramic Processing and Sintering , 1995 .

[16]  Jong-Bin Park,et al.  Characteristics of cement mortar with nano-SiO2 particles , 2007 .

[17]  Aleksandar Matic,et al.  Accelerating effects of colloidal nano-silica for beneficial calcium–silicate–hydrate formation in cement , 2004 .

[18]  Amitava Roy,et al.  A preliminary assessment of the use of an amorphous silica residual as a supplementary cementing material , 2000 .

[19]  H. N. Stein,et al.  Influence of silica on the hydration of 3 CaO,SiO2 , 2007 .

[20]  Hjh Jos Brouwers,et al.  Water demand of amorphous nano silica and its impact on the workability of cement paste , 2012 .

[21]  J. Depasse.  Coagulation of Colloidal Silica by Alkaline Cations: Surface Dehydration or Interparticle Bridging? , 1997 .

[22]  J. F. Young,et al.  The hydration of tricalcium silicate in the presence of colloidal silica , 1984 .

[23]  J. Labrincha,et al.  Effect of nano-SiO2 and nano-TiO2 addition on the rheological behavior and the hardened properties of cement mortars , 2012 .

[24]  N. Neithalath,et al.  Hydration in high-performance cementitious systems containing vitreous calcium aluminosilicate or silica fume , 2009 .

[25]  Juan J. Gaitero,et al.  Reduction of the Calcium Leaching Rate of Cement Paste by Addition of Silica Nanoparticles , 2008 .

[26]  Surendra P. Shah,et al.  Comparative Study of the Effects of Microsilica and Nanosilica in Concrete , 2010 .

[27]  I. Marinos,et al.  Investigations about the influence of fine additives on the viscosity of cement paste for self-compacting concrete , 2010 .

[28]  J. Young,et al.  Additions of colloidal silicas and silicates to portland cement pastes , 1977 .

[29]  R. Madandoust,et al.  An investigation on the fresh properties of self-compacted lightweight concrete containing expanded polystyrene , 2011 .

[30]  T. Parhizkar,et al.  The influence of different preparation methods on the aggregation status of pyrogenic nanosilicas used in concrete , 2012, Materials and Structures.

[31]  G. Øye,et al.  Effect of pH and Salt on Rheological Properties of Aerosil Suspensions , 2007 .

[32]  A. Chatterji,et al.  Hydration of Portland Cement , 1965, Nature.

[33]  A. Ayuela,et al.  EFFECTS OF NANOSILICA ADDITIONS ON CEMENT PASTES , 2005 .

[34]  Hui Li,et al.  Pore structure and chloride permeability of concrete containing nano-particles for pavement , 2011 .

[35]  Kae‐Long Lin,et al.  Effects of nano-SiO(2) and different ash particle sizes on sludge ash-cement mortar. , 2008, Journal of environmental management.

[36]  A. Amiri,et al.  Influence of pH, high salinity and particle concentration on stability and rheological properties of aqueous suspensions of fumed silica , 2009 .

[37]  Depasse.  Simple Experiments to Emphasize the Main Characteristics of the Coagulation of Silica Hydrosols by Alkaline Cations: Application to the Analysis of the Model of Colic et al. , 1999, Journal of colloid and interface science.

[38]  Tao Ji,et al.  Preliminary study on the water permeability and microstructure of concrete incorporating nano-SiO2 , 2005 .