Influence of Flexural Loading on Permeablility of Chloride Ion and Diffusion Coefficients in RC Beams

2010 ◽  
Vol 163-167 ◽  
pp. 3200-3205
Author(s):  
Jun Zhi Zhang ◽  
Lie Lu ◽  
Liang Ying Wang ◽  
Jian Dong Wang
Keyword(s):  
Diffusion Coefficients ◽  
Accelerated Aging ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Concrete Durability ◽  
Flexural Loading ◽  
Short Period ◽  
Bending Load ◽  
Permeability Of Chloride Ion ◽  
And Diffusion

The permeability of chloride ion in concrete can be studied using the accelerated aging method in a short period, but the influence of loading characteristic on chloride ion permeability and diffusion coefficients is not considered generally. Three RC beam (120 mm×240 mm×2400 mm) specimens with different flexural loading state are exposed in an artificial corrosion container filled with salt-fog of 5.0 % sodium chloride for 40 days, the chloride ion concentration in different depths of compressive and tensile region are measured, diffusion coefficients of different region concrete are fitted on the basis of Fick’s second law, the effect of flexural loading on chloride ion concentration and diffusion coefficients of concrete are analyzed. The results show that the effect of the flexural load influences permeability of chloride ion and diffusion coefficients of concrete, content of chloride and diffusion coefficients of concrete are controlled by loading level, and the bending load is one of the important factors that can not be ignored in the study of concrete durability.

scholarly journals Protective Mechanism of Silane on Concrete upon Marine Exposure

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 558 ◽  
Author(s):  
Shaochun Li ◽  
Wenjuan Zhang ◽  
Jun Liu ◽  
Dongshuai Hou ◽  
Yongjuan Geng ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Sol Gel ◽  
Synthesis Method ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Test Block ◽  
Protective Mechanism ◽  
Concrete Durability ◽  
Protective Effects

Due to the high chloride ion concentration in marine environments, chloride ions can penetrate into concrete, along with the transportation of water molecules, and thus, cause rebar corrosion. This is an important reason for the decrease in the concrete durability. In this paper, by means of the sol–gel synthesis method, a silane emulsion, a silane compound emulsion, and silane compound gel were prepared by using isobutyl triethoxysilane and ethyl orthosilicate (TEOS) as the main raw materials. These silane materials were coated on a concrete surface and then placed in the marine exposure sites of Wheat Island, in Qingdao, for one year. The results show that these silane materials can effectively inhibit the chloride ions transporting in concrete. Upon the increase of the exposure time, the protection ability of the silane emulsion declined gradually, while the silane compound emulsion had stable protective effects. In comparison with the permeability coefficient of chloride ions in the blank test block, the permeability coefficient of chloride ions in the test block coated with the silane emulsion, the composition of silane emulsion, and silane compound gel fell off around 20%, 30%, and 50%, respectively. The test results indicate that the three kinds of protective materials have good inhibition abilities against chloride ion transportation, on which the compound gel had the best effect.

Experimental Study on Influence of Bending Load on Chloride Ion Concentration of Concrete in Marine Environment

2014 ◽  
Vol 919-921 ◽  
pp. 460-464
Author(s):  
Han Yang Jin ◽  
Hua Xia Zhuang ◽  
Ru Tai Liu ◽  
Jia Le Shi ◽  
Jun Zhi Zhang
Keyword(s):  
Marine Environment ◽  
Concrete Beams ◽  
Chloride Ion ◽  
Load Level ◽  
Ion Concentration ◽  
Tension Zone ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Free Chloride ◽  
Bending Load

This paper mainly determined free chloride ion concentration of concrete beams of two kinds of water cement ratio (0.45and0.60) and bending load (0.00Fmax, 0.30Fmax, 0.45Fmax and 0.60Fmax) after 240 d in marine environment and compared the effect of different load conditions in the same water cement ratio on the free chloride ion concentration. The results show that the concentration of free chloride ion in tension zone of concrete increases with the increase of load level, the concentration of free chloride ion in compressed zone of concrete decreases with the increase of load level; under the same bending load level, the concentration of free chloride ion in concrete increases with water cement ratio.

Erosion-Resisting Properties for Chloride Ion of Short-Chopped Basalt Fiber Reinforced Concrete

2011 ◽  
Vol 217-218 ◽  
pp. 66-70
Author(s):  
Jun Zhi Zhang ◽  
Hua Ting Liu ◽  
Zhao Qi Fu ◽  
Liang Ying Wang ◽  
Sheng Bing Zhou
Keyword(s):  
Basalt Fiber ◽  
Chloride Ion ◽  
Fiber Reinforced Concrete ◽  
Ion Concentration ◽  
Rc Beam ◽  
Second Law Analysis ◽  
Chopped Basalt Fiber ◽  
Chlorine Ion ◽  
Ion Erosion ◽  
And Diffusion

According to a test for chloride ion erosion in concrete under designed manual climate environment, distributions of chlorine ion concentration in pure bending concrete of short-chopped basalt fiber RC beam and check RC beam without fiber with different flexural loads are analyzed in this paper, and diffusion coefficients of compression and tensile concrete are fitted on the basis of Fick’s second law. Analysis results show that erosion-resisting properties for chloride ion of the basalt fiber compression and tensile concrete in the pure flexural region are increased

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

Simulation of chloride ion transport in concrete under the coupled effects of a bending load and drying–wetting cycles

2020 ◽  
Vol 241 ◽  
pp. 118045 ◽  
Author(s):  
Cao Tongning ◽  
Zhang Lijuan ◽  
Sun Guowen ◽  
Wang Caihui ◽  
Zhang Ying ◽  
...  
Keyword(s):  
Ion Transport ◽  
Chloride Ion ◽  
Bending Load ◽  
Chloride Ion Transport

PREDICTION OF THE TRANSPORT PROPERTIES OF SF6 WITH O2, CO2, CF4, N2 AND CH4 MIXTURES AT LOW DENSITY BY THE INVERSION METHOD (PART II)

2004 ◽  
Vol 03 (01) ◽  
pp. 69-90 ◽  
Author(s):  
BEHZAD HAGHIGHI ◽  
ALIREZA HASSANI DJAVANMARDI ◽  
MOHAMAD MEHDI PAPARI ◽  
MOHSEN NAJAFI
Keyword(s):  
Potential Energy ◽  
Diffusion Coefficients ◽  
Potential Energy Function ◽  
Model Potential ◽  
Inversion Method ◽  
Low Density ◽  
Initial Model ◽  
Lennard Jones ◽  
Inversion Procedure ◽  
And Diffusion

Viscosity and diffusion coefficients for five equimolar binary gas mixtures of SF 6 with O 2, CO 2, CF 4, N 2 and CH 4 gases are determined from the extended principle of corresponding states of viscosity by the inversion technique. The Lennard–Jones 12-6 (LJ 12-6) potential energy function is used as the initial model potential required by the technique. The obtained interaction potential energies from the inversion procedure reproduce viscosity within 1% and diffusion coefficients within 5%.

scholarly journals Boundary behavior and product-form stationary distributions of jump diffusions in the orthant with state-dependent reflections

2008 ◽  
Vol 40 (02) ◽  
pp. 529-547
Author(s):  
Francisco J. Piera ◽  
Ravi R. Mazumdar ◽  
Fabrice M. Guillemin
Keyword(s):  
Random Fields ◽  
Diffusion Coefficients ◽  
Boundary Behavior ◽  
Stationary Regime ◽  
Product Form ◽  
Local Times ◽  
Nonnegative Orthant ◽  
State Dependent ◽  
The Times ◽  
And Diffusion

In this paper we consider reflected diffusions with positive and negative jumps, constrained to lie in the nonnegative orthant of ℝ n . We allow for the drift and diffusion coefficients, as well as for the directions of reflection, to be random fields over time and space. We provide a boundary behavior characterization, generalizing known results in the nonrandom coefficients and constant directions of the reflection case. In particular, the regulator processes are related to semimartingale local times at the boundaries, and they are shown not to charge the times the process expends at the intersection of boundary faces. Using the boundary results, we extend the conditions for product-form distributions in the stationary regime to the case when the drift and diffusion coefficients, as well as the directions of reflection, are random fields over space.

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