Results 241 to 250 of about 89,639 (290)

Surface magnetic relaxation in cement pastes

Magnetic Resonance Imaging, 1994
Surface magnetic relaxation in porous media is usually attributed to hindered rotation or to paramagnetic impurities on the surface. In cement pastes, however, it seems reasonable to attribute surface relaxation to dipole interactions in water adsorbed as water of hydration on grain surfaces.
K S, Mendelson, W P, Halperin, J Y, Jehng, Y Q, Song   +3 more
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Workability of Cement Pastes

ACI Materials Journal, 2001
This research investigated problems that have occurred when high-range, water-reducing admixtures have been used with various cements. The literature survey showed that prior work indicated that the problems were caused by the specific surface area, sulfate morphology, and aluminate content of the cements. The experimental work involved a comprehensive
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Carbonation-cementation of recycled hardened cement paste powder

Construction and Building Materials, 2018
Abstract Well-hydrated cement paste powder was prepared to imitate recycled hardened cement paste powder. Compacted blocks were formed with the powder, and subjected to carbonation at different CO2 pressures. The effects of water/powder (w/p) ratio and compacting pressure in block preparation, and the CO2 pressure on the carbonation degree and ...
Chenhui Zhu, Yonghao Fang, Hua Wei
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Predicting Cement–Admixture Incompatibilities with Cement Paste Rheology

Transportation Research Record: Journal of the Transportation Research Board, 2012
The complex interaction between cement and the chemical and mineral admixtures in concrete mixture sometimes causes unpredictable concrete performance in the field, generally defined as concrete incompatibilities. Cement paste rheology measurements—rather than traditional workability tests—can effectively detect these incompatibilities in concrete ...
Anal K. Mukhopadhyay, Sehoon Jang
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Analytical Electron Microscopy of Cement Pastes: II, Pastes of Portland Cements and Clinkers

Journal of the American Ceramic Society, 1980
Three hundred sixty‐five particles of C‐S‐H, Ca(OH) 2 , AFm phase, and AFt phase from pastes of normally ground portland cements and of finely ground cements and clinkers were analyzed. All the phases, except the Ca(OH) 2 , showed significant variation ...
E. E. LACHOWSKI, K. MOHAN, H. F. W. TAYLOR, A. E. MOORE   +3 more
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Using Dehydrated Cement Paste as New Type of Cement Additive

ACI Materials Journal, 2013
This paper presents an experimental study, including evaluation and modification, on using dehydrated cement paste (DCP) as a new type of cement additive. After a series of processes, normal DCP (N-DCP) was produced as before and a modified form of DCP (M-DCP) was produced as well. The cementitious characteristics of the groups with different kinds and
Yu, R., Shui, Z.H., Dong, J
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Fracture measurements on cement paste

Journal of Materials Science, 1976
This paper describes an investigation into the fracture behaviour of hardened cement paste. Notched specimens of the material were tested to failure in flexure and tension. In the initial flexural tests on beams of fixed overall depth, the stress intensity factor at failure as calculated from linear-elastic fracture mechanics appeared to be a material ...
D. D. Higgins, J. E. Bailey
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Heat deformations of cement paste phases and the microstructure of cement paste

Materials and Structures, 1984
The paper presents the results of an experimental investigation of the influence of thermal deformations of phases present in hardened cement paste on its microstructure. For the observation of the thermal deformation course in the range of temperature20–800°C, a method of complex thermal analysis (DTA, DTD, TD) was employed.
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Smart cement paste with carbon nanotubes

2016
Carbon nanotubes can be added to cementitious materials to create a multifunctional nanocomposite with excellent piezoresistive and strain-sensing properties. The use of carbon nanotubes provides high strain sensitivity and signal-to-noise ratio, which are ideal for fabricating self-sensing nanocomposite cement paste for applications to structural ...
UBERTINI, Filippo, Simon, Laflamme, D'ALESSANDRO, ANTONELLA   +2 more
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Dielectric amplification in cement pastes

Advanced Cement Based Materials, 1997
Dielectric amplification (dielectric constants >80) is observed in cement pastes at early ages. Standard nonlinear least squares fitting routines yield artificially large “capacitances” when constant phase elements are employed. Instead, capacitance vs. frequency analysis provides reliable evidence of dielectric amplification.
S.J. Ford, J.-H. Hwang, J.D. Shane, R.A. Olson, G.M. Moss, H.M. Jennings, T.O. Mason   +6 more
openaire   +1 more source