The Expression of Surface Chloride Concentration in Ecological Concrete and Service Life Prediction

2011 ◽  
Vol 368-373 ◽  
pp. 2204-2210 ◽  
Author(s):  
Si Feng Liu
Keyword(s):  
Fly Ash ◽  
Service Life ◽  
Life Prediction ◽  
Chloride Concentration ◽  
Total Chloride ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Diffusion Depth ◽  
Chloride Concentrations

The total chloride concentrations of concrete with 0.51 of water to cementitous from three contents of Fly ash, GGBS, two kinds of corrosion solution for one dimensional diffusion at different diffusion depth and time were measured by chemical titration. The influence of Fly ash and GGBS content on total chloride concentration and the surface chloride concentration were analyzed. The expressions of the surface chloride concentration were discussed in terms of the experimental results related with content of Fly ash, GGBS and solution. The numerical analysis results indicated that the expression of the surface chloride concentration has a significant impact on the long-term service life of concrete in chloride environments.

Analysis of Chloride Penetration into the Corner Zone of Concrete Structure Member

2007 ◽  
Vol 348-349 ◽  
pp. 397-400
Author(s):  
Xiao Yong Wang ◽  
Han Seung Lee ◽  
Hai Moon Jung
Keyword(s):  
Service Life ◽  
Diffusion Process ◽  
Concrete Structure ◽  
Chloride Concentration ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Recent Analysis ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Diffusion

Chloride penetration into concrete is the main cause of steel corrosion in concrete structures exposed to chloride-rich environments. In general, conditions on the diffusion process are dominant among various penetration mechanisms, such as ionic diffusion, capillary sorption, and so on. In recent analysis of current literature, chloride diffusion is as a simplified one-dimensional diffusion process. However, for the rebar in the corner zone of concrete beam, the diffusion belongs to a two-dimensional diffusion. Based on a galerkin finite element method, a two-dimensional diffusion differential equation is built and solved numerically and the different chloride concentration is compared to one dimensional diffusion and two-dimensional diffusion process. The service life of concrete structure members under two-dimensional chloride penetration is predicted by compared with a critical threshold chloride concentration. Compared with general one-dimensional chloride attack, the service life is considerably reduced in a corner zone due to two-dimension penetration.

Infiltration of de-icing road salts in aquifers: the Trois-Rivières-Ouest case, Quebec, Canada

1989 ◽  
Vol 26 (11) ◽  
pp. 2186-2193 ◽  
Author(s):  
Jacques Locat ◽  
Pierre Gélinas
Keyword(s):  
Unsaturated Zone ◽  
Chloride Concentration ◽  
Late Summer ◽  
Linear Source ◽  
Pumping Wells ◽  
Road Salts ◽  
Hydrogeological Investigation ◽  
Spring Snowmelt ◽  
Chloride Concentrations

The results of an extensive hydrogeological investigation of the effects of de-icing road salts on Highway 55 near Trois-Rivières-Ouest indicate that a salt lens with chloride concentrations exceeding 800 mg/L exists below the highway. Maximum chloride concentration at the nearby pumping wells, not exceeding 140 mg/L, is reached only in late summer, whereas the maximum chloride infiltration follows the spring snowmelt. About 1 year's worth of road salts is retained in the unsaturated zone. The salt lens, in the upper part of the aquifer beneath the highway, has developed to a thickness of 8 m and a width of 400 m and constitutes a linear source of salts for the aquifer. The shape of this lens is distorted by the action of the pumping wells, and the lens is partly depleted by the end of the summer. Because of the particular characteristics of the aquifer at the site studied and the exploitation methods, no long-term threat to the water quality is foreseen.

Dynamic Life Prediction of RC Structures on Multi-Environmental Time Similarity Method

2011 ◽  
Vol 255-260 ◽  
pp. 220-224 ◽  
Author(s):  
Wei Liang Jin ◽  
Zhi Yuan Li ◽  
Ju Chen ◽  
Jin Quan Wang ◽  
Xiao Zhou Wang
Keyword(s):  
Service Life ◽  
Natural Environment ◽  
Life Prediction ◽  
Indoor Environment ◽  
Prior Information ◽  
Service Life Prediction ◽  
Accelerated Tests ◽  
Rc Structures ◽  
Similarity Method

Multi-environmental time similarity (METS) stepped forward for solving the key technique of service-life correlation of reinforced concrete (RC) structures exposed in artificially accelerated and real natural environment. Artificially accelerated tests and the similarity relationship between natural and indoor environment are used to estimate the prior information. Inspections of the real structure and concrete specimens are used to update the information and reduce the uncertainty in the service-life prediction. The progress of service-life prediction becomes dynamic and long-term.

scholarly journals Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)

2020 ◽  
Author(s):  
Anna K. Tobler ◽  
Alicja Skiba ◽  
Dongyu S. Wang ◽  
Philip Croteau ◽  
Katarzyna Styszko ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Anthropogenic Activities ◽  
Chloride Concentration ◽  
Ambient Air ◽  
Aerosol Composition ◽  
Total Chloride ◽  
Ambient Aerosol ◽  
Positive Difference ◽  
The Difference

Abstract. Particulate chloride is an important component of fine particulate matter in marine air masses. Recent field studies also report elevated concentrations of gas-phase reactive chlorine species and particulate chloride related to anthropogenic activities. This work focuses on particulate chloride detection and quantification issues observed for some quadrupole aerosol chemical speciation monitors (Q-ACSM), which are designed for long-term measurement of ambient aerosol composition. The ACSM reports particle concentrations based on the difference between measurements of ambient air (sample mode) and particle-free ambient air (filter mode). For our long-term campaign in Krakow, Poland, the Q-ACSM reports apparent negative total chloride concentration for most of the campaign when analyzed with the default fragmentation table. This is the result of the difference signal from m/z 35 (35Cl+) being negative which dominates over the positive difference signal from m/z 36 (H35Cl+). Highly time-resolved experiments with NH4Cl, NaCl and KCl particles show that the signal response of m/z 35 is non-ideal, where the signal builds up and decreases slowly for all three salts, leading to a negative difference measurement. In contrast, the m/z 36 signal exhibits a near step-change response for NH4Cl during sampling and filter period, resulting in a positive difference signal. The response of m/z 36 for NaCl and KCl is not as prompt as for NH4Cl but still fast enough to have a positive difference signal. Furthermore, it is shown that this behavior is mostly temperature-independent. Based on these observations, this work presents an approach to correct the chloride concentration time series by adapting the standard fragmentation table coupled with a calibration of NH4Cl to obtain a relative ionization efficiency (RIE) based on the signal at m/z 36 (H35Cl+). This correction can be applied for measurements in environments where chloride is dominated by NH4Cl. Caution should be exercised when other chloride salts dominate the ambient aerosol.

scholarly journals Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)

2020 ◽  
Vol 13 (10) ◽  
pp. 5293-5301
Author(s):  
Anna K. Tobler ◽  
Alicja Skiba ◽  
Dongyu S. Wang ◽  
Philip Croteau ◽  
Katarzyna Styszko ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Anthropogenic Activities ◽  
Fine Particulate Matter ◽  
Chloride Concentration ◽  
Ambient Air ◽  
Aerosol Composition ◽  
Total Chloride ◽  
Positive Difference ◽  
The Difference

Abstract. Particulate chloride is an important component of fine particulate matter in marine air masses. Recent field studies also report elevated concentrations of gas-phase reactive chlorine species and particulate chloride related to anthropogenic activities. This work focuses on particulate chloride detection and quantification issues observed for some quadrupole aerosol chemical speciation monitors (Q-ACSMs) which are designed for the long-term measurement of ambient aerosol composition. The ACSM reports particle concentrations based on the difference between measurements of ambient air (sample mode) and particle-free ambient air (filter mode). For our long-term campaign in Krakow, Poland, the Q-ACSM reports apparent negative total chloride concentration for most of the campaign when analyzed with the default fragmentation table. This is the result of the difference signal from m∕z 35 (35Cl+) being negative, which dominates over the positive difference signal from m∕z 36 (H35Cl+). Highly time-resolved experiments with NH4Cl, NaCl and KCl particles show that the signal response of m∕z 35 is non-ideal when the signal builds up and decreases slowly for all three salts, leading to a negative difference measurement. In contrast, the m∕z 36 signal exhibits a near step-change response for NH4Cl during the sampling and filter period, resulting in a positive difference signal. The response of m∕z 36 for NaCl and KCl is not as prompt as for NH4Cl but still fast enough to have a positive difference signal. Furthermore, it is shown that this behavior is mostly independent of vaporizer temperature. Based on these observations, this work presents an approach to correct the chloride concentration time series by adapting the standard fragmentation table coupled with a calibration of NH4Cl to obtain a relative ionization efficiency (RIE) based on the signal at m∕z 36 (H35Cl+). This correction can be applied to measurements in environments where chloride is dominated by NH4Cl. Caution should be exercised when other chloride salts dominate the ambient particulate chloride.

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