scholarly journals Effect of the Electric Field on the Distribution Law of Chloride Ions and Microstructure in Concrete with the Addition of Mineral Admixtures

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1380 ◽  
Author(s):  
Xiaoli Xie ◽  
Qingge Feng ◽  
Zheng Chen ◽  
Wei Lu
Keyword(s):  
Electric Field ◽  
Pore Structure ◽  
Chloride Ions ◽  
Mineral Admixtures ◽  
Chloride Diffusion ◽  
Electric Field Effect ◽  
Nacl Solution ◽  
Distribution Law ◽  
Chloride Migration ◽  
Chloride Profile

Migration testing of chloride under an electric field is a fast and effective method to determine the corrosion resistance of reinforced concrete against chloride. In this study, a series of admixture-involved (fly ash and slag) concrete specimens were produced for an accelerating chloride diffusion test in 3% NaCl solution under an electric field and natural chloride diffusion in 165 g/L NaCl solution under immersion conditions. Then, the chloride profile and pore structure of concretes aged 56 and 91 days were compared to investigate the effect of the electric field on chloride diffusion as well as the microstructure of the concrete. The results showed that, under accelerating electric field conditions, the degree to which chloride refined the internal pore structure of the concrete was weaker than that under natural immersion conditions. The applied electric field changed the pore structure inside the concrete, but it had little effect on the distribution of total, free, and bound chlorides and their mutual relationship. In addition, it is necessary to consider that the electric field effect on chloride migration varies with the concrete mix proportions.

Transport of Water and Chloride Ion in Cement Composites Modified with Graphene Nanoplatelet

2014 ◽  
Vol 629-630 ◽  
pp. 162-167 ◽  
Author(s):  
Hong Jian Du ◽  
Sze Dai Pang
Keyword(s):  
Chloride Ion ◽  
Chloride Ions ◽  
Chloride Diffusion ◽  
Cement Composites ◽  
Chloride Diffusion Coefficient ◽  
Barrier Effect ◽  
Graphene Nanoplatelet ◽  
Chloride Migration ◽  
Corrosion Of Steel ◽  
And Diffusion

Cement composites are vulnerable to harsh environments in which the chloride ions can ingress into concrete and thus cause corrosion of steel. In this study, the barrier effect of adding 2-D nanoparticles on the transport properties of cement-based materials was investigated. Graphene nanoplatelet (GNP), which comprises of a few layers of graphene stacked together, is chosen as a candidate in this study due to its impermeability and also its electrical conductivity which can be exploited for self-sensing functionality. Due to the large aspect ratio of the GNP, it is expected that the dispersion of these 2-D nanobarriers can contribute to the reduced permeability and diffusion of harmful agents. Experiments were carried out on cement mortar with 0%, 2.5%, 5.0% and 7.5% of GNP by weight of cement. The water penetration depth, chloride diffusion coefficient and chloride migration coefficient were reduced by 64%, 70% and 31% respectively with the addition of as little as 2.5% of GNP. This reduction can be attributed to the barrier effect of GNP which increases the tortuosity against water and chloride ions penetration, and also the refinement of the capillary pores which was revealed from the MIP tests. At GNP content exceeding 5%, the nanoparticles agglomerate, causing weak pockets which compromises the benefits of adding GNP to impede the ingress of fluids.

Compressive Strength, Chloride Diffusivity and Pore Structure of Non-Autoclaved Prestressed High-Strength Concrete with Metakaolin

2012 ◽  
Vol 450-451 ◽  
pp. 1409-1414 ◽  
Author(s):  
Jun Jie Zeng ◽  
Zhong He Shui ◽  
Wan Ru Zhang ◽  
Zheng Leng
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
High Strength Concrete ◽  
High Strength ◽  
Chloride Ions ◽  
Strength Concrete ◽  
Durability Properties ◽  
Chloride Diffusivity ◽  
Chloride Migration ◽  
Improvement Effect

The experimental study was performed on the relationship between the mechanical and durability properties of high-strength concrete with metakaolin (MK) and slag. The compressive strength, chloride penetrability and pore structure of the OPC and the concrete with MK and slag were measured. It is found that MK can significantly increase the compressive strength, decrease the chloride ions migration coefficient and improve the pore structure of the steam cured high-strength concrete. The chloride resistance is improved obviously by 5% MK and further increase of the MK dosage performs a little change of the chloride migration coefficient. Better improvement effect on the mechanical and durability properties is obtained with the incorporation of 10% MK and 10% slag. Linear relationship is found between the coarse pore porosity and the compressive strength, while the chloride migration coefficient correlates well with the capillary pore volume.

Effect of Pore Structure on the Chloride Permeability of Concrete with Mineral Admixture

2013 ◽  
Vol 690-693 ◽  
pp. 835-838 ◽  
Author(s):  
Yan Jun Hu ◽  
Yan Liang Du
Keyword(s):  
Pore Structure ◽  
Total Porosity ◽  
Chloride Ions ◽  
Mineral Admixture ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Chloride Permeability ◽  
Evaporative Water ◽  
Chloride Diffusivity ◽  
Chloride Penetration Resistance

In this paper, the effect of pore structure on the chloride ions ingress into concrete was investigated. The most probable diameter was measured by Mercury intrusion porosimetry (MIP) and the total porosity was measured by evaporative water method (EWM). The results indicate that the most probable diameter by MIP has better linear relationship with chloride diffusion coefficient than the total porosity by EWM, the most probable diameter has significant influence on chloride diffusivity, and the smaller most probable diameter will lead to higher chloride penetration resistance.

scholarly journals Electric field effect on the thermal conductivity of wurtzite GaN

2021 ◽  
Vol 118 (16) ◽  
pp. 162110
Author(s):  
Yujie Quan ◽  
Sheng-Ying Yue ◽  
Bolin Liao
Keyword(s):  
Thermal Conductivity ◽  
Electric Field ◽  
Field Effect ◽  
Electric Field Effect

Electric Field Effect on the Imaginary Part of the Dielectric Function in Highly Anisotropic Crystals

1974 ◽  
Vol 36 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Yoshiro Sasaki ◽  
Chihiro Hamaguchi ◽  
Akihiro Morotani ◽  
Junkichi Nakai
Keyword(s):  
Electric Field ◽  
Dielectric Function ◽  
Imaginary Part ◽  
Field Effect ◽  
Electric Field Effect

Antiferromagnetism and Crystalline Electric Field Effect of Ce2Pt3Si5

2008 ◽  
Vol 77 (12) ◽  
pp. 124707 ◽  
Author(s):  
Yuji Muro ◽  
Masayuki Nakano ◽  
Kiyoichiro Motoya
Keyword(s):  
Electric Field ◽  
Field Effect ◽  
Electric Field Effect ◽  
Crystalline Electric Field
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