Analysis of total chloride content in concrete

2002 ◽  
Vol 35 (9) ◽  
pp. 583-585 ◽  
Keyword(s):  
Chloride Content ◽  
Total Chloride

scholarly journals Chloride Binding Capacity and Its Effect on the Microstructure of Mortar Made with Marine Sand

2021 ◽  
Vol 13 (8) ◽  
pp. 4169
Author(s):  
Congtao Sun ◽  
Ming Sun ◽  
Tao Tao ◽  
Feng Qu ◽  
Gongxun Wang ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Chloride Content ◽  
Chloride Ions ◽  
Fine Aggregate ◽  
Chloride Binding ◽  
River Sand ◽  
Total Chloride ◽  
Curing Period ◽  
Marine Sand ◽  
Bound Chloride

Chloride binding capacity and its effect on the microstructure of mortar made with marine sand (MS), washed MS (WMS) and river sand (RS) were investigated in this study. The chloride contents, hydration products, micromorphology and pore structures of mortars were analyzed. The results showed that there was a diffusion trend for chloride ions from the surface of fine aggregate to cement hydrated products. During the whole curing period, the free chloride content in the mortars made by MS and WMS increased firstly, then decreased and stabilized finally with time. However, the total chloride content of three types of mortar hardly changed. The bound chloride content in the mortars made by MS and WMS slightly increased with time, and the bound chloride content included the MS, the WMS and the RS arranged from high to low. C3A·CaCl2·10H2O (Friedel’s salt) was formed at the early age and existed throughout the curing period. Moreover, the volume of fine capillary pore with a size of 10–100 nm increased in the MS and WMS mortar.

Determination of the silver concentration with ion-selective electrode potentiometry

2020 ◽  
Author(s):  
Nataliia Chupakhina ◽  
Oleg Novikov ◽  
Pavel Maslennikov ◽  
Galina Chupakhina
Keyword(s):  
Total Concentration ◽  
Equilibrium Concentration ◽  
Chloride Content ◽  
Silver Concentration ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Minimum Concentration ◽  
Total Chloride ◽  
Chloride Solutions ◽  
The Stability

<p>For technological control of hydrometallurgical processes, it is especially important to obtain data on element concentrations with an express method. Potentiometry on an ion-selective electrode makes it possible to determine concentrations in real time. We propose a method for calculation of silver concentrations for chloride solutions.</p><p>In chloride solutions, silver is present in several forms: the cation [Ag<sup>+</sup>] and the complexes [AgCl], [AgCl<sub>2</sub>]<sup>-</sup>, [AgCl<sub>3</sub>]<sup>2-</sup>, [AgCl<sub>4</sub>]<sup>3-</sup>. The ion-selective electrode is calibrated using an AgNO<sub>3</sub> solution that contains exclusively Ag<sup>+</sup> cations; therefore, it actually determines only the cation content. However, in chloride solutions the cationic form of silver is present in a minimum concentration. Complexes with chloride anions have an opposite charge and are not fixed during the analysis. The total silver concentration can be estimated by measuring the total chloride content in the sample. Using the reference data on the stability constants and information on the concentration of silver cations obtained with potentiometry on an ion-selective chlorine-silver electrode we developed a mathematical model in order to calculate the total silver concentration. Using this model, the total concentration of all the forms of silver was calculated. The data are summarized in Table 1.</p><p>Calculating the equilibrium concentration we found that in high-salinity solutions silver prevails in the form of [AgCl<sub>4</sub>]<sup>3-</sup>. All the other complexes are present in smaller quantities. This result shows that it is important to take into account the complexes formation in potentiometric measurements on ion-selective electrodes.</p><p> </p>

Study of the environment factor from Fick’s and electrical resistivity models by simulation of chloride diffusivity prediction

2020 ◽  
Vol 23 (10) ◽  
pp. 2097-2109
Author(s):  
Ronaldo A Medeiros-Junior ◽  
Diogo H Bem
Keyword(s):  
Electrical Resistivity ◽  
Service Life ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Reinforced Concrete Structures ◽  
Type Ii ◽  
Total Chloride ◽  
Chloride Diffusivity ◽  
Resistivity Model ◽  
Environment Factor

The penetration of chlorides in concrete is the main reason for the beginning of corrosion in reinforced concrete structures exposed to a marine environment, reducing their service life. This article proposes correlations between the surface chloride content ( Cs) of Fick’s model and the ambient factor ( kCl) of a resistivity model. Literature data for three types of cement were used to simulate chloride diffusivity: (1) CEM I 52.5 R; (2) CEM II/A-P 42.5 R (with 6%–20% of pozzolans); and (3) CEM type II (with 12% of pozzolans and 8% of silica fume). Concretes containing these cements were analyzed for different environmental conditions: atmosphere zone, seawater immersion, and tidal/splash zones. The surface chloride contents were determined by a combination of Fick’s and resistivity models. In this article, it was noticed that the estimated Cs value varies with the exposure class from 0.484% to 0.644% (total chloride concentration by weight of cement). An equation has been proposed to correlate Cs with the ambient factor kCl of the resistivity model.

Sign in / Sign up

Export Citation Format

Share Document