Characterization of pore structure of rice grits extrudates using mercury intrusion porosimetry, nitrogen adsorption and water vapour desorption methods

AbstractThe pore structure of low porosity cement pastes containing varying quantities of silica fume has been examined using mercury intrusion porosimetry (MIP) and nitrogen adsorption (NA) measurements. The water:solid ratio for all DSP pastes studied was 0.18. It was observed that, as for conventional pastes, removal of water by solvent replacement with methanol minimizes changes to the pore structure. Vacuum or oven drying severely reduces specific surface area and obscures important trends.It was found that capillary porosity in excess of 10 nm (100 Å) is essentially absent and that the pore volume measured can be considered an intrinsic part of the binding phase. The influence of silica fume and curing times on pore structure has been measured and the implications of the data will be discussed. Comparisons will be made with conventional cement pastes.

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The Influence of Moisture on the Expansion of Macro-Defect-Free Cements

MRS Proceedings ◽

10.1557/proc-245-173 ◽

1991 ◽

Vol 245 ◽

Cited By ~ 1

Author(s):

H. Igarashi ◽

T. Takahashi

Keyword(s):

Image Analysis ◽

Polyvinyl Alcohol ◽

Portland Cement ◽

Pore Structure ◽

Calcium Hydroxide ◽

Mercury Intrusion Porosimetry ◽

Nitrogen Adsorption ◽

Cement Pastes ◽

Alcohol Acetate ◽

Mercury Intrusion

ABSTRACTMDF(Macro-Defect-Free ) cement pastes, which consist of portland cement and polyvinyl alcohol/acetate, were prepared by varying the temperature during pressing and drying operations. We then examined the expansion of MDF cement pastes at various constant humidities. There was a large difference in expansion above 60%R.H. between samples prepared varying temperature at which samples were pressed. Samples pressed at 90 °C showed less expansion than samples pressed at 40 °C.The pore structure of MDF cement pastes before exposure to moisture was measured by nitrogen adsorption, mercury intrusion porosimetry and image analysis. The properties of a matrix containing polyvinyl alcohol/acetate and cemnt hydrates were also investigated by TEM, IR and XPS.There were not large differences in the result of IR and XPS measurement between the MDF cement pastes prepared at various temperatures. Calcium hydroxide crystal, lying perpendicular to cement particles, were often observed only in the MDF cement pastes pressed at 90 °C which occurs by water absorption, seems to be suppressed by calcium hydroxide crystal.

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Characterization of Pore Structure of Hardened Cement-Asphalt Paste by Mercury Intrusion Porosimetry

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.1589 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 1589-1593 ◽

Cited By ~ 1

Author(s):

Sheng Zhang ◽

Xi Ling Zhou ◽

Ke Ren Zheng ◽

You Jun Xie ◽

Qiang Fu

Keyword(s):

Pore Structure ◽

Pore Size ◽

Mercury Intrusion Porosimetry ◽

Total Porosity ◽

Pore Distribution ◽

Hardened Cement ◽

Volume Distribution ◽

Mercury Intrusion ◽

Two Peaks

To know the pore structure of cement-asphalt pastes, mercury intrusion porosimetry was applied to measure the total porosity, pore distribution and accumulative volume distribution of pore size and the pore structures were analyzed. The results show that the total porosities decline with increase in ages and reduction in A/C ratio. The total porosities declines from 28% at 1d, to 15.8%~17.2% at 28d; the most probable pore size declines from 20nm at 1d to 5nm at 28d.At 28d, there is an increase in the magnitude of pore size between100nm and 5μm; the volume faction of smaller than 5μm is 40~50%; and the amount of pore size smaller than 5nm account for 6%.There are two peaks (5μm & 50μm) in the curves of pore distribution.

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