Permeation Characteristics and Surface Accumulation of Chloride in Different Zones of Concrete along Altitude in Marine Environments

The accumulation characteristics of surface chloride in concrete in different zones are different in the marine environment. A series of laboratory experiments were conducted to investigate the surface chloride and permeation characteristics of concrete in a simulated marine environment. The experimental results indicated that the surface chloride and chloride profiles of concrete in different zones of marine environment decreased in the following order: tidal zone > splash zone > submerged zone > atmospheric zone. The width of the ascent zone of Cl− concentration at tidal and splash zones was far less than that of the influential depth of moisture transport (IDMT), and the range of convection zone was dependent on the IDMT. Cl− at splash and tidal zones penetrated into concrete as a bulk liquid by non-saturated permeation driven by a humidity gradient. The change of chloride profiles in concrete along the altitudinal gradient was consistent with that of the cyclic water absorption amount (CWAA). The transport rate of chloride was the highest at the highest point of the tide.

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The Chloride Ion Penetration Model Coupled with Temperature and Moisture Transfer in Marine Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.2422 ◽

2012 ◽

Vol 591-593 ◽

pp. 2422-2427

Author(s):

Juan Zhao

Keyword(s):

Marine Environment ◽

Moisture Transfer ◽

Regional Climate ◽

Chloride Ion ◽

Chloride Penetration ◽

Chloride Diffusion ◽

Tidal Zone ◽

Analog Simulation ◽

Chloride Ion Penetration ◽

Ion Penetration

Considering the complexity of the chloride ion penetration in concrete exposed to marine environment, an integrated chloride penetration model coupled with temperature and moisture transfer is proposed. The governing equations and parameters embody fully the cross-impacts among thermal conduction, moisture transfer and chloride ion penetration. Furthermore, the four exposure conditions are classified based on the different contact with the aggressive marine environment, and then the micro-climate condition on the concrete surface is investigated according to the regional climate characteristics, therefore, a comprehensive analog simulation to the chloride penetration process is proposed. To demonstrate that the proposed numerical model can correctly simulate the chloride diffusion in concrete, the integrated chloride diffusion model is applied in reproducing a real experiment, finally the model gives good agreement with the experimental profiles, and it is proved the tidal zone exposure results in a more severe attack on the reinforcement

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NUMERICAL AND LABORATORY EXPERIMENTS ON STABILITY OF GRANULAR FILTERS IN MARINE ENVIRONMENT

Coastal Engineering Proceedings ◽

10.9753/icce.v34.structures.17 ◽

2014 ◽

Vol 1 (34) ◽

pp. 17 ◽

Cited By ~ 3

Author(s):

David Schürenkamp ◽

Hocine Oumeraci ◽

Jan Kayser ◽

Fabian Karl

Keyword(s):

Marine Environment ◽

Laboratory Experiments ◽

Granular Filters

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Chloride Distribution and Steel Corrosion in a Concrete Bridge after Long-Term Exposure to Natural Marine Environment

Materials ◽

10.3390/ma13173900 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3900 ◽

Cited By ~ 1

Author(s):

Jun Liu ◽

Zhilu Jiang ◽

Yulong Zhao ◽

Hao Zhou ◽

Xiaodong Wang ◽

...

Keyword(s):

Reinforced Concrete ◽

Marine Environment ◽

Chloride Transport ◽

Steel Corrosion ◽

Concrete Bridge ◽

Reinforced Concrete Structure ◽

X Ray Diffraction ◽

Tidal Zone ◽

X Ray

Chloride-induced steel corrosion is the most concerning issue for the durability of concrete structures. Concrete and steel samples were obtained from a 30-year-old reinforced concrete bridge. The chloride content was measured by a potentiometric titration method and the microstructure of concrete was obtained by scanning electron microscopy and mercury intrusion porosimetry. The rust phases of the steel were detected by X-ray diffraction and Raman analysis. It was found that the convection depth for chloride transport in cracked concrete was significantly larger than that in uncracked concrete. The concrete in a pier column facing upstream had greater porosity due to the water impact and calcium leaching. The coefficients of variability of chloride diffusivity of concrete for the bridge deck and the pier column were significantly different. Rust phases including lepidocrocite, goethite, akaganeite, magnetite, and maghemite were detected using Raman spectroscopy and X-ray diffraction. The major phases of steel rust in the atmospheric zone were lepidocrocite and goethite, while they were lepidocrocite and maghemite in the tidal zone. The results of this study would provide information concerning the chloride-induced steel corrosion under a marine environment in order to predict long-term behaviors of a reinforced concrete structure.

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Experimental study on durability of strengthened corroded RC columns with FRP sheets in tidal zone of marine environment

Computers and Concrete ◽

10.12989/cac.2017.19.4.339 ◽

2017 ◽

Vol 19 (4) ◽

pp. 339-346 ◽

Cited By ~ 1

Author(s):

Amin Kashi ◽

Ali Akbar Ramezanianpour ◽

Faramarz Moodi

Keyword(s):

Experimental Study ◽

Marine Environment ◽

Tidal Zone ◽

Rc Columns

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Summing-up: deficiencies and future needs

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1979.0050 ◽

1979 ◽

Vol 286 (1015) ◽

pp. 625-633 ◽

Cited By ~ 2

Keyword(s):

Marine Environment ◽

Laboratory Experiments ◽

Experimental Studies ◽

Great Difficulty ◽

Organic Production ◽

Critical Examination ◽

Experimental Conditions ◽

Future Needs ◽

Significant Harm ◽

Fish And Shellfish

Although there are a great many experimental studies of particular pollutants and their effects, and some critical examination has been made of the mechanisms involved, there is great difficulty in determining whether such effects, if they are sublethal, occur in the sea. There is even more difficulty in deciding whether they produce significant harm in loss of organic production affecting, for example, the living resources of the sea: the stocks of fish and shellfish. Extrapolation from the results of laboratory experiments to the situation in the sea is hazardous because of the simplicity of experimental conditions in comparison with the complexity of the marine environment.

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