Pore Structure Of Hydrated Cement Determined By Mercury Porosimetry And Nitrogen Sorption Techniques.

1988 ◽  
Vol 137 ◽  
Author(s):  
Yahia Abdel-Jawad ◽  
Will Hansen
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Mercury Porosimetry ◽  
Total Pore Volume ◽  
Curing Temperature ◽  
Vycor Glass ◽  
Degree Of Hydration

AbstractThe pore structure (i.e. total pore volume, surface area and pore-size distribution curves) was measured using mercury porosimetry and nitrogen sorption. Hydrated portland cement (type I) of water-cement (w/c) ratios 0.3, 0.4 and 0.6 by weight was analyzed at three degrees of hydration (i.e., 30%, 50% and 80%; 70% for the 0.3 w/c system) corresponding to low, intermediate and high levels of hydration. The effect of curing temperature (3°, 23°, and 43°C) on pore structure was also studied. The two techniques were evaluated as well on porous Vycor glass, which has a narrow pore size distribution in the size range accessible to both. Results obtained by both techniques on porous Vycor glass agreed well. However neither technique can be used alone to study the entire pore structure in well-hydrated cement due to the wide range in pore sizes and the presence of micropores. Due to the unstable pore structure in cement a specimen treatment procedure such as methanol replacement, combined with volume-thickness (V-t) analysis, is necessary in order to measure the micropores. At low hydration values the pore structure can be estimated by mercury intrusion porosimetry (MIP). At higher hydration values, however, this technique underestimates total pore volume and surface area due to the presence of micropores which MIP cannot determine. In the pore size range of overlap, higher pore volumes were obtained with MIP. Nitrogen V-t analysis shows that micropores are more pronounced with lower w/c ratios. This finding is consistent with pore size distribution curves obtained by MIP. For a given w/c ratio and degree of hydration the total pore volume measured by MIP was found to be independent of curing temperature in the temperature range studied. At any w/c ratio, capillary porosity is controlled by degree of hydration alone.

scholarly journals Microstructure and pore structure of polymer-cement composite joint sealants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chuanxin Lou ◽  
Jinyu Xu ◽  
Tengjiao Wang ◽  
Weibo Ren
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Cement Composite ◽  
Low Grade ◽  
Composite Joint ◽  
Fractal Characteristics

AbstractUtilizing methods such as scanning electron microscopy observation and mercury intrusion porosimetry, this paper investigates the basic microstructure and pore structure properties of polymer-cement composite joint sealants for pavements, and analyzes the effects and rules of various material types, ratio parameters and processing conditions. Further, the fractal characteristics and variation rules of pore size distribution are investigated for the joint sealants by introducing the fractal theory. The results show that changes in material type, ratio parameter and processing condition produce insignificant effects on the basic microstructure properties and configuration of joint sealants, with effects reflected primarily in the change of sealant pore structure. Measures like increasing the powder-liquid ratio and cement ratio, blending with sulphoaluminate cement or mica powder, adding latex powder or coupling agent, cold drawing and hot pressing, as well as ultraviolet irradiation treatment are all capable of reducing the total pore volume of joint sealants and refining their pore structure. In contrast, opposite effects are yielded when low-grade cement is used, styrene-acrylic emulsion is blended, or plasticizer is added. Additionally, after blending with talc powder or adding carbon fiber additive, the total pore volume of joint sealants remains basically unchanged or reduced, despite the coarsened pore structure. The total pore volume of joint sealants increases after wet–dry cycling treatment, while no obvious change in the pore size distribution is observed. Pore size distribution of the studied joint sealants presents distinct fractal characteristics, and the corresponding fractal dimension of pore surface area ranges between 2.6 and 2.8.

A Relationship Between Pore Structure and Residual Oil Saturation in Tertiary Surfactant Floods

1972 ◽  
Vol 12 (04) ◽  
pp. 289-296 ◽  
Author(s):  
F.A.L. Dullien ◽  
G.K. Dhawan ◽  
Nur Gurak ◽  
L. Babjak
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Cross Section ◽  
Oil Recovery ◽  
Mercury Porosimetry ◽  
Residual Oil ◽  
Pore Size Distributions ◽  
The Way

Abstract Photomicrography and mercury porosimetry have been used jointly to determine the pore-size distributions of various sandstone samples. The two curves differed drastically from each other for all samples. Two unconsolidated packs consisting of uniform 250u glass beads and mixed 44-250u beads, respectively, as well as the sinters prepared from them, were also investigated. An index, D, measuring the difficulty of recovering waterflood residuals in tertiary surfactant floods has been constructed from the two different porosimetry curves. Reasonably good correlation porosimetry curves. Reasonably good correlation bas been obtained between D and residual oil saturations found in tertiary surfactant floods. Introduction This paper presents our first results in a continuing study of pore structure and oil recovery. The problem of how pore structure might influence oil recovery has been discussed by several authors. There is, however, no known method whereby one could rank various porous media (e.g., different sandstones) on the basis of pore structure in the order of decreasing amounts of expected residual oil saturations assuming identical conditions of flooding (identical oil, water, wetting and pressure gradient for the various sands. In this pressure gradient for the various sands. In this work we have taken an initial step toward this ideal objective. The prime target of the treatment has been the problem of correlating the extent of recovery of waterflood residuals by tertiary surfactant floods with the pore structure. The degree of difficulty presented by the pore structure in the way of recovering the isolated oil masses left behind by a waterflood has been expressed in the form of an index that is calculated from a mercury porosimetry and a photomicrographic pore-size distribution curve obtained on the sample. pore-size distribution curve obtained on the sample. The degree of correlation obtained amounts to a promising start in the case of tertiary surfactant promising start in the case of tertiary surfactant floods, and there also appears to be some correlation between the residual oil saturations found in the waterfloods and the pore structure. In this paper we are considering only the case of water-wet formations and moderate viscosity ratios. THEORY The term "pore structure" ordinarily means the distribution of pore volume by some linear pore dimension (pore-size distribution) and the topographical sequence of pores. Pore-size distributions have been determined by various methods. However, for reservoir rocks the most popular method has been mercury porosimetry. In a typical reservoir rock pore necks alternate with bulges. As the meniscus of penetrating mercury advances past a pore neck, it continues to advance in a nonequilibrium manner, until it comes to an even narrower neck. Since the capillary pressure of penetration of mercury into the pore pressure of penetration of mercury into the pore space between the two necks is determined by the size of the first neck, the pore diameters corresponding to the space between the two necks remain undetected by this method. Let us consider an arbitrary pore segment in the sample and approach it from the outside surface of the sample. Somewhere between the pore segment and the outside, there is a controlling cross-section in the pore space that is defined as follows: once the meniscus of the invading mercury has passed that cross-section, there is no narrower neck in its path all the way to the segment considered. The path all the way to the segment considered. The pore neck is the segment considered the controlling pore neck is the segment considered the controlling cross-section as defined above, even if the pore neck is far removed from the controlling crosssection. Denoting the radius of the pore segment by re and that of the controlling pore neck by r'e we have re greater than r'e. JPT P. 289

Effect of air-drying and critical point drying on the porosity of clay soils

1984 ◽  
Vol 21 (1) ◽  
pp. 181-185 ◽  
Author(s):  
C. R. De Kimpe
Keyword(s):  
Organic Matter ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Critical Point ◽  
Size Distribution ◽  
Pore Volume ◽  
Organic Matter Content ◽  
Total Pore Volume ◽  
Clay Soils ◽  
Critical Point Drying

Samples from four surface and one subsurface horizons of clay-rich soils from Quebec were air-dried and critical point dried. In the latter samples, the total pore volume was 19–84% larger than in the former samples. The total pore volume, determined by mercury intrusion porosimetry and density measurements, was subdivided into large (> 8.8 μm), medium, and small (< 0.19 μm) pores. The effect of drying on these pores was estimated. Medium-sized pores were affected most by the drying technique, followed next by the large pores, and finally by the small pores. The modifications due to drying could not be explained adequately by shrinkage and it was assumed, from the pore-size distribution curves, that organic matter content had a buffer effect on particle reorganization. Keywords: critical point drying, clay soils, pore volume, pore-size distribution, organic matter.

Unified Method for the Total Pore Volume and Pore Size Distribution of Hierarchical Zeolites from Argon Adsorption and Mercury Intrusion

Langmuir ◽  
2015 ◽  
Vol 31 (4) ◽  
pp. 1242-1247 ◽  
Author(s):  
Jeffrey Kenvin ◽  
Jacek Jagiello ◽  
Sharon Mitchell ◽  
Javier Pérez-Ramírez
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Hierarchical Zeolites ◽  
Mercury Intrusion ◽  
Argon Adsorption ◽  
Unified Method

scholarly journals Pore Structural Features of Granite under Different Temperatures

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6470
Author(s):  
Hongmei Gao ◽  
Yongwei Lan ◽  
Nan Guo
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Saturation Pressure ◽  
Total Pore Volume ◽  
Structural Features ◽  
Pore Throat ◽  
Throat Radius ◽  
Median Pore

To explore the effects of thermal actions on the pore structural features of granite, scanning electron microscope (SEM) and mercury injection experiments were carried out on granite after thermal treatment (25 °C to 400 °C). The pore structure was investigated from various perspectives, including the capillary pressure curve, the pore–throat ratio, the median saturation pressure, the median pore–throat radius, the porosity, the pore volume, and the pore size distribution. Based on mercury intrusion test data, the Winland model of permeability prediction was modified for a high-temperature tight granite reservoir. The results showed that: (1) As the temperature rose, the mercury injection curve was gradually flattened, and the mercury ejection efficiency gradually increased. Meanwhile, the pore–throat ratio and the median saturation pressure decreased exponentially, and the pore connectivity was enhanced. (2) The median pore–throat radius and the porosity of granite increased exponentially as the temperature increased. Above 200 °C, the median pore–throat radius and the porosity increased substantially. (3) The pore volumes of the transitional pores, mesopores and macropores, and the total pore volume inside the granite, increased as the temperature rose. Especially above 200 °C, the transitional pores and the mesopores were prominently developed, and the pore volumes of the transitional pores and the mesopores took up a significantly greater proportion of the total pore volume. (4) As the temperature rose, the pore size distribution of granite became more extensive, the pore–throat structure was obviously developed, and the pore–throat connectivity was enhanced. (5) The relationship between the micropores’ characteristic parameters and the macro-permeability in engineering was established though a modified Winland model, and the modified Winland model had a better prediction effect. The findings provide a solid basis for rock geothermal mining projects and related geotechnical engineering.

scholarly journals Alumina/silica aerogel with zinc chloride as an alkylation catalyst

2001 ◽  
Vol 66 (10) ◽  
pp. 685-695 ◽  
Author(s):  
Aleksandar Orlovic ◽  
Djordje Janackovic ◽  
Sasa Drmanic ◽  
Zorica Marinkovic ◽  
Dejan Skala
Keyword(s):  
Catalytic Activity ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Zinc Chloride ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Chloride Content ◽  
Alkylation Catalyst

The alumina/silica with zinc chloride aerogel alkylation catalyst was obtained using a one step sol-gel synthesis, and subsequent drying with supercritical carbon dioxide. The aerogel catalyst activity was found to be higher compared to the corresponding xerogel catalyst, as a result of the higher aerogel surface area, total pore volume and favourable pore size distribution. Mixed Al-O-Si bonds were present in both gel catalyst types. Activation by thermal treatment in air was needed prior to catalytic alkylation, due to the presence of residual organic groups on the aerogel surface. The optimal activation temperature was found to be in the range 185-225 ?C, while higher temperatures resulted in the removal of zinc chloride from the surface of the aerogel catalyst with a consequential decrease in the catalytic activity. On varying the zinc chloride content, the catalytic activity of the aerogel catalyst exhibited a maximum. High zinc chloride contents decreased the catalytic activity of the aerogel catalyst as the result of the pores of the catalyst being plugged with this compound, and the separation of the alumina/silica support into Al-rich and Si-rich phases. The surface area, total pore volume, pore size distribution and zinc chloride content had a similar influence on the activity of the aerogel catalyst as was the case of xerogel catalyst and supported zinc chloride catalysts.

scholarly journals Construction of pore structure and lithology of digital rock physics based on laboratory experiments

2021 ◽  
Vol 11 (5) ◽  
pp. 2113-2125
Author(s):  
Chenzhi Huang ◽  
Xingde Zhang ◽  
Shuang Liu ◽  
Nianyin Li ◽  
Jia Kang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Laboratory Experiments ◽  
Rock Physics ◽  
Reconstruction Method ◽  
Digital Rock Physics ◽  
Digital Rock ◽  
The Core

AbstractThe development and stimulation of oil and gas fields are inseparable from the experimental analysis of reservoir rocks. Large number of experiments, poor reservoir properties and thin reservoir thickness will lead to insufficient number of cores, which restricts the experimental evaluation effect of cores. Digital rock physics (DRP) can solve these problems well. This paper presents a rapid, simple, and practical method to establish the pore structure and lithology of DRP based on laboratory experiments. First, a core is scanned by computed tomography (CT) scanning technology, and filtering back-projection reconstruction method is used to test the core visualization. Subsequently, three-dimensional median filtering technology is used to eliminate noise signals after scanning, and the maximum interclass variance method is used to segment the rock skeleton and pore. Based on X-ray diffraction technology, the distribution of minerals in the rock core is studied by combining the processed CT scan data. The core pore size distribution is analyzed by the mercury intrusion method, and the core pore size distribution with spatial correlation is constructed by the kriging interpolation method. Based on the analysis of the core particle-size distribution by the screening method, the shape of the rock particle is assumed to be a more practical irregular polyhedron; considering this shape and the mineral distribution, the DRP pore structure and lithology are finally established. The DRP porosity calculated by MATLAB software is 32.4%, and the core porosity measured in a nuclear magnetic resonance experiment is 29.9%; thus, the accuracy of the model is validated. Further, the method of simulating the process of physical and chemical changes by using the digital core is proposed for further study.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

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