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 Pore size distributions and pore multifractal characteristics of medium and low-rank coals

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bin Sun ◽  
Qing Yang ◽  
Jie Zhu ◽  
Tangsha Shao ◽  
Yuhang Yang ◽  
...  
Keyword(s):  
Pore Size ◽  
Pore Volume ◽  
Nitrogen Adsorption ◽  
Low Rank ◽  
Size Distributions ◽  
Confining Stress ◽  
Mercury Intrusion ◽  
Pore Size Distributions ◽  
Porosity And Permeability ◽  
Low Rank Coals

AbstractIt is of great significance to study the porosity and permeability properties of medium and low-rank coal. The porosity and permeability in confining stress experiments were used to simulate the porosity and permeability variations of coal samples under different depth conditions. The pore structure of Baoqing coal samples is greatly affected by the confining pressure, and the pores and micro cracks are more easily compressed. Based on the experimental data of mercury intrusion porosimetry (MIP) and nitrogen adsorption (NA), the pore size distributions (PSDs) of medium and low-rank coals were studied. High mercury intrusion pressure would lead to coal matrix compression. Therefore, the pore volume calculated by MIP data was corrected by NA data. The PSDs characteristics of Jixi (JX) coal and Baoqing (BQ) coal samples are obtained from the revised pore volume, and the dominant pores of medium and low-rank coals are obtained. The results show that JX coal has higher spatial heterogeneity, connectivity and pore autocorrelation. Micro fractures have an influence on the autocorrelation and heterogeneity of coal samples, especially for BQ coal samples.

Sign in / Sign up

Export Citation Format

Share Document