Effect of Pore water expression on solid composition of cement paste

2021 ◽  
pp. 1-30
Author(s):  
Jiaxing Xu ◽  
Keren Zheng ◽  
Lou Chen ◽  
Xuejin Zhou ◽  
Qiang Yuan
Keyword(s):  
High Pressure ◽  
Cement Paste ◽  
Pore Solution ◽  
Solid Phase ◽  
Bound Water ◽  
Alkali Concentration ◽  
Interlayer Water ◽  
Before And After ◽  
Solid Phase Composition ◽  
Bound Water Content

Pore solution expression is the most commonly used method to obtain aqueous phase in cementitious material. However, the high pressure applied on the sample may affect solid phase composition. This paper presents an experimental study on the chemical and mineral composition of cement paste before and after the expression. Results indicate that a small part of the alkali contained in samples can be excluded during the pore solution expression, mainly depending on alkali concentration in the pore solution. Due to the expulsion of interlayer water in C-S-H under high pressure, the pore solution expression reduces bound water content measured by TGA. The portlandite content determined by TGA is not affected by pore solution expression, but it leads to an overestimation of portlandite in QXRD, because of the enhanced preferred orientation of the (001) plane under the applied high pressure. In addition, the size of portlandite crystal decreases to some extent due to the creep caused by pressure. The content of hemicarbonate phase is found to decrease slightly after pore solution expression, which may be aroused by the increased solubility under high pressure.

Bound Water in Cement Pastes and its Significance for Pore Solution Compositions

1986 ◽  
Vol 85 ◽  
Author(s):  
H. F. W. Taylor
Keyword(s):  
Fly Ash ◽  
Pore Solution ◽  
Bound Water ◽  
Free Water ◽  
Adsorbed Water ◽  
Interlayer Water ◽  
Structural Water ◽  
Cement Pastes ◽  
Evaporable Water ◽  
Definition Of

ABSTRACTThe problem of defining bound water in a cement paste is discussed; a reasonable definition is one that includes interlayer water in C-S-H and AFm phases, structural water in ettringite, and adsorbed water, but not water in micropores or in larger pores. On this basis, structural considerations indicate a value of around 32% on the ignited weight for a fully hydrated paste. ‘Non-evaporable’ water, typically around 22% on the ignited weight at full hydration, cannot be identified with bound water, because dehydration to the state in which only non-evaporable water remains causes major loss of interlayer water and destruction of ettringite. In the interpretation of pore solution data, the definition of bound water, and the value assumed for this quantity, are important, because the ionic concentrations in the pore solution are greatly affected by the volume of free water available to dissolve them. If cement is partially replaced by low calcium fly ash, the quantity of bound water at any given age is substantially reduced. This effect contributes to the relatively low concentrations of alkali metal and hydroxyl ions that are observed in the pore solutions of many portland-fly ash cement pastes.

ANALYSIS OF RADIOIMMUNOASSAY BY DISC ELECTROPHORESIS AND SUCROSE GRADIENT CENTRIFUGATION

1971 ◽  
Vol 66 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Lubomir Valenta ◽  
Michel L. Aubert
Keyword(s):  
Sucrose Gradient ◽  
Solid Phase ◽  
Gradient Centrifugation ◽  
Human Growth ◽  
Disc Electrophoresis ◽  
Separate Analysis ◽  
Adrenocorticotrophic Hormone ◽  
Sucrose Gradient Centrifugation ◽  
Before And After ◽  
Polypeptide Hormones

ABSTRACT Radioiodine-labelled synthetic adrenocorticotrophic hormone (ACTH), human growth hormone (HGH), human chorionic somato-mammotrophin (HCS), and human (HTSH) and bovine (BTSH) thyroid stimulating hormones were studied by disc-electrophoresis and sucrose gradient centrifugation before and after incubation with corresponding antisera. All antisera contained 7 S antibodies. After incubation, soluble antigenantibody complexes besides a small amount of precipitate were observed in the incubation mixture, characteristic of each hormone. The complexes migrated like gamma globulins or more slowly on disc-electrophoresis. and on sucrose gradient centrifugation showed patterns dependent on the time of incubation. Light 7 or 9 S, or < 12 S complexes occurred mostly after incubation for several minutes (up to 30 min) before analysis. When incubation was prolonged to 24 h and more, these relatively light complexes disappeared or diminished in favour of heavier soluble or precipitating complexes. Reproducibly obtainable sedimentation patterns of the soluble complexes suggested some definite recombination of antigen molecules with 7 S antibodies. The complexes did not occur on incubation with other sera than an antiserum to a given hormone. They were not influenced by EDTA. Displacement of the radioactivity of the complexes into the free hormone peak was obtained by addition of a non-labelled hormone identical with the labelled one. Sucrose gradient centrifugation and disc-electrophoresis are recommended for the study of immunoreaction of diluted materials and for a separate analysis of different steps of the radioimmunoassay. Radioimmunoassay was introduced for the measurement of protein hormones by Yalow & Berson (1960). The method, described originally for insulin, was later adapted to the detection of a number of protein and polypeptide hormones. On incubation of the hormone with its antiserum, a soluble antigenantibody complex is formed, which is separated from an excess of the free hormone by various methods, e. g. chromatoelectrophoresis, precipitation with a second antibody, adsorption on a solid phase etc. (Hunter 1967). Sucrose gradient centrifugation and disc-electrophoresis were occasionally used to follow some isolated aspect of radioimmunoassay (Fitschen 1965; Monjardino et al. 1968). We are demonstrating that these methods made it possible to analyze the radioimmunoassay step by step and thus may be useful for practical purposes as well as in a study of the immunoreaction of diluted materials.

Laboratory Determination of the Solid Phase Composition of Technogenically Salinized Peatlands: Possibilities and Limitations

2020 ◽  
Vol 75 (3) ◽  
pp. 131-137
Author(s):  
Yu. N. Vodyanitskii ◽  
N. A. Avetov ◽  
A. T. Savichev ◽  
S. Ya. Trofimov ◽  
E. A. Shishkonakova
Keyword(s):  
Phase Composition ◽  
Solid Phase ◽  
Laboratory Determination ◽  
Solid Phase Composition

scholarly journals Rheology of cement paste under high pressure

2017 ◽  
Vol 77 ◽  
pp. 60-67 ◽  
Author(s):  
Jae Hong Kim ◽  
Seung Hee Kwon ◽  
Shiho Kawashima ◽  
Hong Jae Yim
Keyword(s):  
High Pressure ◽  
Cement Paste

Comparative Study on Compositions of Oil-Water Transition Layer before and after ClO2-Treatment Process

2013 ◽  
Vol 652-654 ◽  
pp. 749-752
Author(s):  
Dan Dan Yuan ◽  
Hong Jun Wu ◽  
Hai Xia Sheng ◽  
Xin Sui ◽  
Bao Hui Wang
Keyword(s):  
Chemical Composition ◽  
Transition Layer ◽  
Solid Phase ◽  
Settling Tank ◽  
Physical Structure ◽  
Solid Particles ◽  
Viscosity Reduction ◽  
Insoluble Residue ◽  
Before And After ◽  
Oil Water

In order to meet the need of separating oil from water in the settling tank of the oilfield, ClO2 treatment for oil-water transition layer in settling tank is introduced. The field test displayed that the technique was achieved by a good performance. For understanding the oxidation and mechanism, compositions of oil-water transition layer were comparatively studied for before/after ClO2-treatment in this paper.The experimental results show that the compositions before and after ClO2-treatment, including physical structure and chemical composition, were varied in the great extension. The physical structure, consisting of water, oil and solid phase, was reduced to less than 5% of water and 0.5% of solid particle and increased to 95% of oil in layer compared with before-treatment, easily leading to clearly separating water from oil. The chemical composition of iron sulfide and acid insoluble substance in solid phase was decreased to more than 90% while the carbonate was reduced more than 70% . After the treatment, the viscosity reduction of the water phase in the layer was reached to 50% after oxidation demulsification with ClO2. The chemistry was discussed based on the principles and experiments. Due to ClO2 destroying (oxidizing) the rigid interface membrane structure which is supported by natural surfactant, polymer and solid particles with interface-active materials, the action accelerates the separating of water and oil and sedimentation of insoluble residue of acid in the layer. By demonstrating the experimental data and discussion, we can effectively control the oxidation performance of chlorine dioxide, which is very meaningful for oilfield on the aspect of stable production of petroleum.

Capillary suction time (CST) as a measure of sludge dewaterability

1996 ◽  
Vol 34 (3-4) ◽  
pp. 443-448 ◽  
Author(s):  
G. W. Chen ◽  
W. W. Lin ◽  
D. J. Lee
Keyword(s):  
Water Content ◽  
Specific Resistance ◽  
Bound Water ◽  
The Other ◽  
Solid Concentration ◽  
Capillary Suction ◽  
Good Index ◽  
Other Hand ◽  
Sludge Dewaterability ◽  
Bound Water Content

The feasibility of employment of capillary suction time (CST) for characterizing the dewaterability of excess activated sludges was examined. The CST was shown as a good index for sludge filterability, if only the product of solid concentration and average specific resistance is of interest. On the other hand, the bound water content cannot be directly evaluated from the CST data.

scholarly journals Effect of intraruminal infusion of potassium on the site of magnesium absorption within the digestive tract in sheep

1997 ◽  
Vol 129 (1) ◽  
pp. 99-105 ◽  
Author(s):  
D. E. DALLEY ◽  
P. ISHERWOOD ◽  
A. R. SYKES ◽  
A. B. ROBSON
Keyword(s):  
Digestive Tract ◽  
Solid Phase ◽  
Latin Square ◽  
Cerium Chloride ◽  
Faecal Excretion ◽  
Absorption Increase ◽  
High K ◽  
Before And After ◽  
Lincoln University ◽  
Female Sheep

Sixteen 2-year old female sheep were fitted with ruminal and duodenal cannulae at Johnstone Memorial Laboratory, Lincoln University during 1989–90. They were offered, at 2 hourly intervals, a pelleted concentrate diet (900 g/day) and chaffed lucerne hay (100 g/day). In a split-plot experiment they were infused, intraruminally and at four rates, with potassium (providing 16, 26, 36 or 46 g K/kg food DM/day) and magnesium (providing 1·3, 1·8, 2·3 or 3·1 g Mg/kg food DM/day) within a Latin square design and with the liquid and solid phase markers 51chromium EDTA and 141cerium chloride. Net absorption of Mg before and after the duodenum was estimated from dietary intake, duodenal flow and urinary and faecal excretion of Mg.Increasing K intake resulted in a decline in net absorption of Mg from the entire digestive tract, supporting data in the literature. Increasing K intake from 16 to 46 g/kg DM decreased urinary Mg excretion by between 0·14 and 0·30 g/day, the extent of which was independent of the level of Mg intake. At high K intake Mg absorption from the rumen was reduced, the amount absorbed ranging from 0·07 g Mg/day at intakes of 1·3 g Mg/day and 46 g K/kg DM/day to 0·66 g Mg/day at intakes of 3·1 g Mg/day and 16 g K/kg DM/day. However, at high K intake, and when Mg absorption from the rumen was reduced, net Mg absorption from sites distal to the rumen was increased to an extent which suggested compensatory absorption. Increase in K intake was associated with a consistent reduction in plasma Mg concentration which was independent of Mg intake. Increases in Mg intake resulted in increases in Mg absorption and plasma Mg concentration at all rates of K intake in direct proportion to rate of intake. The reduction in Mg absorption from the rumen at high K intake was associated with an increase (0·3 units) in pH of rumen digesta.

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