Degree of hydration of portland cement pastes with low water/cement ratios as influenced by curing conditions

2007 ◽  
Vol 20 (4) ◽  
pp. 117-120 ◽  
Author(s):  
K. M. Hanna ◽  
S. A. El-Hemaly
Keyword(s):  
Portland Cement ◽  
Cement Pastes ◽  
Curing Conditions ◽  
Degree Of Hydration

Impedance Spectroscopy and the Role of Admixtures in the Hydration of Portland Cement Pastes

1991 ◽  
Vol 245 ◽  
Author(s):  
Bruce J. Christensen ◽  
Thomas O. Mason ◽  
Hamlin M. Jennings
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Portland Cement ◽  
Silica Fume ◽  
Pore Fluid ◽  
Microstructural Development ◽  
Portland Cements ◽  
Cement Pastes ◽  
Degree Of Hydration

ABSTRACTMeasurements of the bulk electrical properties of cement pastes were made using impedance spectroscopy (IS) and are useful for studying hydration. Normalization of these quantities by dividing out changes in the pore fluid reveals information pertinent to the microstructural development of these materials. In this study, observations are made on the influence of accelerators, retarders and silica fume (SF) on pastes of white and ordinary portland cements (OPC). All systems show variations in the normalized electrical properties at the same degree of hydration, as compared to a control. Changes in the microstructure that are implied by these measurements are consistent with the observations of others.

Estimations of degree of hydration of portland cement pastes

1993 ◽  
Vol 23 (2) ◽  
pp. 399-406 ◽  
Author(s):  
J.E. Ash ◽  
M.G. Hall ◽  
J.I. Langford ◽  
M. Mellas
Keyword(s):  
Portland Cement ◽  
Cement Pastes ◽  
Degree Of Hydration

scholarly journals Influence of Ultrasonication of Functionalized Carbon Nanotubes on the Rheology, Hydration, and Compressive Strength of Portland Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5248
Author(s):  
Laura Silvestro ◽  
Artur Ruviaro ◽  
Geannina Lima ◽  
Paulo de Matos ◽  
Afonso R. G. de Azevedo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Portland Cement ◽  
Mechanical Performance ◽  
Isothermal Calorimetry ◽  
Hydration Kinetics ◽  
Cement Pastes ◽  
Degree Of Hydration ◽  
Vis Spectroscopy ◽  
Localized Defects

The functionalization process usually increases the localized defects of carbon nanotubes (CNT). Thus, the ultrasonication parameters used for dispersing non-functionalized CNT should be carefully evaluated to verify if they are adequate in dispersing functionalized CNT. Although ultrasonication is widely used for non-functionalized CNT, the effect of this dispersing process of functionalized CNT has not been thoroughly investigated. Thus, this work investigated the effect of ultrasonication on functionalized CNT + superplasticizer (SP) aqueous dispersions by ultraviolet-visible (UV-Vis) spectroscopy, dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). Furthermore, Portland cement pastes with additions of 0.05% and 0.1% CNT by cement weight and ultrasonication amplitudes of 0%, 50% and 80% were evaluated through rheometry, isothermal calorimetry, compressive strength at 1, 7 and 28 days, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). FTIR results from CNT + SP dispersions indicated that ultrasonication may negatively affect SP molecules and CNT graphene structure. The increase in CNT content and amplitude of ultrasonication gradually increased the static and dynamic yield stress of paste but did not significantly affect its hydration kinetics. Compressive strength results indicated that the optimum CNT content was 0.05% by cement weight, which increased the strength of composite by up to 15.8% compared with the plain paste. CNT ultrasonication neither increases the degree of hydration of cement nor the mechanical performance of composite when compared with mixes containing unsonicated CNT. Overall, ultrasonication of functionalized CNT is not efficient in improving the fresh and hardened performance of cementitious composites.

scholarly journals Surface Characteristics of Portland Cement/Blast Furnace Slag Mixtures

1996 ◽  
Vol 13 (6) ◽  
pp. 461-467 ◽  
Author(s):  
Kh.A. Khalil
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Surface Characteristics ◽  
Hydration Products ◽  
Cement Pastes ◽  
Degree Of Hydration ◽  
Granulated Blast Furnace Slag ◽  
Granulated Slag ◽  
Furnace Slag

The effect of the degree of hydration and amounts of granulated blast furnace slag on the surface properties of Portland cement pastes were studied. The results obtained showed that the specific surface area SBET (m2/g) and pore volume Vp (cm3/g) decreased on increasing the degree of hydration. The addition of different amounts of granulated slag effected a decrease in SBET and Vp to an extent proportional to the amount present. These results were attributed to a replacement of clinker by the amounts of slag added and the formation of hydration products.

Hardened portland cement pastes of low porosity III. Degree of hydration. Expansion of paste. Total porosity

1972 ◽  
Vol 2 (4) ◽  
pp. 463-480 ◽  
Author(s):  
Ivan Odler ◽  
Marvin Yudenfreund ◽  
Jan Skalny ◽  
Stephen Brunauer
Keyword(s):  
Portland Cement ◽  
Total Porosity ◽  
Cement Pastes ◽  
Degree Of Hydration ◽  
Low Porosity
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