scholarly journals Influence of Drying on the Microstructure of Hardened Cement Paste: A Mercury Intrusion Porosimetry, Nitrogen Sorption and SAXS Study

2020 ◽  
Vol 18 (3) ◽  
pp. 83-94
Author(s):  
Andreas Bogner ◽  
Johanna Schatz ◽  
Frank Dehn ◽  
Harald S. Müller
Keyword(s):  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Mercury Intrusion ◽  
Nitrogen Sorption

Changes of Pore Structures in Hardened Cement Paste Subjected to Flexural Loading and Wet-Dry Cycles in Seawater

2011 ◽  
Vol 374-377 ◽  
pp. 1930-1933
Author(s):  
Wu Man Zhang ◽  
Wei Sun ◽  
Jin Yang Jiang
Keyword(s):  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Coupling Effect ◽  
Great Influence ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Pore Structures ◽  
Flexural Loading ◽  
Micro Cracks ◽  
Simulated Seawater

The coupling effect of flexural loading and environmental factors has great influence on the pore structures in hardened cement paste. In this paper, Mercury intrusion porosimetry (MIP) and field emission scanning electron microscope (SEM) were used to analyze and observe the changes of pore structures in hardened cement paste subjected to flexural loading and wet-dry cycles in simulated seawater. The results show that the porosity greatly increases when the flexural loading level is raised from 0 f (the ultimate flexural loading capacity) to 0.8 f. Micro-cracks are observed and the connectivity, width and density of micro-cracks increase with the increment of flexural loading. The peaks position of pore size shifts toward greater micro-pores when the flexural loading was raised from 0 f to 0.8 f. The flexural loading and simulated seawater accelerate the degradation of pore structures.

scholarly journals On Phase Identification of Hardened Cement Pastes by Combined Nanoindentation and Mercury Intrusion Method

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3349
Author(s):  
Jingwei Ying ◽  
Xiangxin Zhang ◽  
Zhijun Jiang ◽  
Yijie Huang
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
Cement Paste ◽  
Phase Distribution ◽  
Gaussian Mixture ◽  
Hardened Cement ◽  
Phase Identification ◽  
Hardened Cement Paste ◽  
Cement Pastes ◽  
Mercury Intrusion

The micro-mechanical properties of hardened cement paste can be obtained by nanoindentation. Phases at different locations can generally be determined by using the Gaussian mixture model (GMM) method and the K-means clustering (KM) method. However, there are differences between analysis methods. In this study, pore structure and porosity of hardened cement paste aged three, seven, and 28 days were obtained by mercury intrusion porosimetry (MIP), and their micro-mechanical properties were obtained by the nanoindentation method. A new method, GMM-MIP and KM-MIP, was proposed to determine the phase of hardened cement paste based on the pore structure and nanoindentation results. The results show that GMM-MIP and KM-MIP methods are more reasonable than GMM and KM methods in determining the phase of hardened cement paste. GMM-MIP can be used to obtain reasonable phase distribution. If the micro-mechanical properties of each phase in hardened cement paste do not satisfy the normal distribution, the GMM method has significant defects.

Pore Size Distributions in Hardened Cement Paste by Sem Image Analysis

1994 ◽  
Vol 370 ◽  
Author(s):  
Sidney Diamond ◽  
Mark E. Leeman
Keyword(s):  
Image Analysis ◽  
Pore Size ◽  
Cement Paste ◽  
Hardened Cement ◽  
Size Distributions ◽  
Hardened Cement Paste ◽  
Mercury Intrusion ◽  
Sem Image ◽  
Pore Size Distributions ◽  
Sem Image Analysis

AbstractTechnical requirements for determining the size distribution of capillary pores in hardened cement paste by SEM image analysis are discussed. Results of such measurements are reported for a set of hardened cement pastes of w:c ratio 0.40 and 0.25, and of ages ranging from 1 to 28 days. Pore size distributions based on conventional mercury intrusion porisimetry are presented for the same pastes. Estimates of pore diameters by mercury intrusion are two orders of magnitude smaller than the sizes revealed by the image analysis. Diameters of air voids are even more drastically underestimated by mercury intrusion. Typical micrographs are provided to illustrate the physical reality of the image analysis results, and the technical reasons underlying the conventional misinterpretation of MIP results for hydrated cements are reviewed.

scholarly journals A numerical study of fatigue of hardened cement paste at the microscale

2021 ◽  
pp. 106401
Author(s):  
Yidong Gan ◽  
Hongzhi Zhang ◽  
Minfei Liang ◽  
Erik Schlangen ◽  
Klaas van Breugel ◽  
...  
Keyword(s):  
Cement Paste ◽  
Numerical Study ◽  
Hardened Cement ◽  
Hardened Cement Paste

Hygral stress in hardened cement paste

1999 ◽  
Vol 32 (9) ◽  
pp. 627-634 ◽  
Author(s):  
R. E. Beddoe ◽  
R. Lippok
Keyword(s):  
Cement Paste ◽  
Hardened Cement ◽  
Hardened Cement Paste
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