The genesis and chemistry of pore solutions in
After setting and some strength gain pore solutions can again be expressed for analysis for example by the pore solution expression equipment described by Barneyback and Diamond.2 Table 2.1 provides an illustrative set of the results of analyses of such a series of mix/pore solutions developed in a Portland cement paste that might be found in
Get PriceChanges of pore structure and chloride content in cement
Pore solution expression is a widely accepted approach to extract pore solution of cement-based materials by appllying high pressure. In this study the variations of pore solution distribution and chloride content in cement pastes before and after pore solution expression were examined. The results showed that the value of chloride concentration index N-c were mostly higher than 1.0 for
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Cement ChemistryThe Concrete Portal
The pores inside cement paste contain water (or pore solution) which can be classified into Capillary water Present in voids larger than 50 A o . Further classified into (a) free water the removal of which does not cause any shrinkage strains and (b) water held by capillary tension in small pores which causes shrinkage strains on drying.
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Ba ant Z.P. Ulm F.-J. Beltoise F. (1998
Solution of various diffusion problems of concrete is a problem of considerable interest for its durability or resistance to thermal spalling. The problem is nor mally formulated in the form of a diffusion equation whose coefficients often depend of the dependent variable such as pore humidity or concentration of var
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RESISTIVITY FORMATION FACTOR AND TRANSPORT William
Nov 17 2020 · The model uses thermodynamic calculations to predict pore solution composition pore solution resistivity pore volumes and reactions between the solid and ionic components of the cementitious
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Use of pore solution analysis in design for concrete
Pore solution analysis of hardened cement-based materials has been in increasing use over the last 30 years to determine the ionic composition of the pore fluid at various ages and after exposure to various temperature regimes. In addition it has been used to evaluate the potential for results of chemical interaction with external solutions or
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Analysis of Pore Solution of Different Cements with and
Title Analysis of Pore Solution of Different Cements with and without Admixed Chlorides Author(s) Colin B. Van Niejenhuis Ibrahim G. Oguna and Carolyn M. Hansson Publication Materials Journal Volume 117 Issue 3 Appears on pages(s) 21-28 Keywords blast furnace slag cement paste chloride pore solution silica fume Date 5/1/2020 Abstract The pore solution expressed from 28-day
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The Pore Characteristics of Geopolymer Foam Concrete and
Aug 10 2016 · The pore characteristics of geopolymer foam concretes (GFCs) manufactured in the laboratory with 0–16 foam additions were examined using image analysis (IA) and vacuum water saturation techniques. The pore size distribution pore shape and porosity were obtained. The IA method provides a suitable approach to obtain the information of large pores which are more
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Pore Solution Scientific
Based on previous studies the paper tries to explain the deformaion trend by analyzing freezing point of bulk solution and pore solution in saturated hardened cement paste. The result shows that it is critical to thermal deformation of cement-based materials at low temperature that pore solution in the pores smaller than 8 nm freezes.
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Chloride content and pH value in the pore solution of
Chloride content and the pH value of the pore solution in the neighborhood of steel reinforcement are decisive parameters for initiation and rate of corrosion. The pore solution of cement mortar and hardened cement paste has been expressed from the pore space by high pressure in the investigation. The influence of the water-cement ratio age and addition of chloride to the fresh mix on
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Solubility Behavior of the Hydration Products in the Pore
The concentrations of Ca Al Si Na K SO42- and pH value in the pore solution of Portland cement were measured during the first 28 days of hydration at room temperature. A thermodynamic analysis of the elemental concentrations was used to predict saturation indices of various solid phases known to form in normal cement system. During the first 4 h the composition of pore solution is
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The genesis and chemistry of pore solutions in
After setting and some strength gain pore solutions can again be expressed for analysis for example by the pore solution expression equipment described by Barneyback and Diamond.2 Table 2.1 provides an illustrative set of the results of analyses of such a series of mix/pore solutions developed in a Portland cement paste that might be found in
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Methods of Obtaining Pore Solution from Cement Pastes and
To test the pH value of the concrete cover layer by layer the first step was to prepare the concrete pore solution. The expression method which is the most widely recognized technique for
Get PriceChloride content and pH value in the pore solution of
Chloride content and the pH value of the pore solution in the neighborhood of steel reinforcement are decisive parameters for initiation and rate of corrosion. The pore solution of cement mortar and hardened cement paste has been expressed from the pore space by high pressure in the investigation. The influence of the water-cement ratio age and addition of chloride to the fresh mix on
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Pore Solution Chemistry and Alkali Aggregate Reaction
Study of the pore solution chemistry of mature cement pastes mortars and concretes has been possible in recent years through the development of pore solution expression techniques. This paper reviews the progress that has been made in explaining the phenomena associated with alkali-aggregate reactions in terms of pore solution composition.
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Analysis of Integral Crystalline Waterproofing Technology
an alkaline pore solution on certain types of dolomitic limestone. 2.4 Sulphate Attack The deterioration of concrete structures is accelerated when aggressive chemicals such as sulfate salts (sulfates of sodium potassium calcium or magnesium) found in soil or dissolved in groundwater and seawater penetrate concrete
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Expression of Cementitious Pore Solution and the Analysis
The pore solution is expressed from a fresh paste sample using a pressurized nitrogen gas system. The pore solution is then immediately transferred to a syringe to minimize evaporation and
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The genesis and chemistry of pore solutions in
After setting and some strength gain pore solutions can again be expressed for analysis for example by the pore solution expression equipment described by Barneyback and Diamond.2 Table 2.1 provides an illustrative set of the results of analyses of such a series of mix/pore solutions developed in a Portland cement paste that might be found in
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Analysis of total chloride content in concrete
chloride ion in a sample of concrete including bound in the solid phases and free chlorides in the pore solution. Free chloride content is the amount of chloride ion in the pore solution as obtained by squeezing con-crete samples at high pressures. Water soluble chloride content is the amount of chloride ion in a sample of concrete which can be
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RESISTIVITY FORMATION FACTOR AND TRANSPORT William
Nov 17 2020 · The model uses thermodynamic calculations to predict pore solution composition pore solution resistivity pore volumes and reactions between the solid and ionic components of the cementitious
Get Price
Methods of Obtaining Pore Solution from Cement Pastes and
The concentration of the free chloride ions has been widely determined using the pore solution expression method 4 5 6 and the water extraction method 7 8 9 10 11 12 13 14 15
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Expression of Cementitious Pore Solution and the Analysis
Sep 23 2018 · = electrical resistivity of pore solution (Ωm). The bulk electrical resistivity of concrete may be easily determined on hardened concrete using a resistivity meter following approaches outlined in AASHTO PP84-17 Appendix X2 and other literature4 5.The purpose of this article is to provide instructions for expressing the pore solution from fresh paste and analysis of the solution ionic
Get PricePrediction and Analysis of Reinforcement Corrosion in
First of all in simulated pore solution with different pH values the characteristics of Nyquist impedance spectroscopy of the whole chromium alloy under passivation stage and the damaged passivation film of reinforcing bars under initial corrosion stage have been found.
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Use of pore solution analysis in design for concrete
Pore solution analysis of hardened cement-based materials has been in increasing use over the last 30 years to determine the ionic composition of the pore fluid at various ages and after exposure to various temperature regimes. In addition it has been used to evaluate the potential for results of chemical interaction with external solutions or
Get Price
Methods of Obtaining Pore Solution from Cement Pastes and
Methods of Obtaining Pore Solution from Cement Pastes and Mortars for Chloride Analysis. Two techniques for recovery of pore solution from cement mortars are examined pore solution expression and miscible displacement using a high pressure permeameter. In the former pore solution is expressed from the mortar by crushing in the latter it is
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