scholarly journals Development of Maintenance Simulation System and Prediction of Chloride Ion Permeation for Marine Concrete Structures

2013 ◽  
Vol 17 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Chang Su Lee ◽  
Meyong Won Kim
Keyword(s):  
Concrete Structures ◽  
Chloride Ion ◽  
Simulation System ◽  
Ion Permeation ◽  
Marine Concrete

scholarly journals Evaluation of Chloride-Ion Diffusion Characteristics of Wave Power Marine Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5675
Author(s):  
Changhyuck Lim ◽  
Gyuyong Kim ◽  
Gyeongtae Kim ◽  
Bokyeong Lee ◽  
Youngduck Kim ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Atmospheric Pressure ◽  
Concrete Structures ◽  
Chloride Ion ◽  
Wave Power ◽  
Ion Diffusion ◽  
Chloride Ion Penetration ◽  
Chloride Attack ◽  
Marine Concrete ◽  
Chloride Ion Diffusion

Wave power marine concrete structures generate electrical energy using waves. They are exposed to a multi-deterioration environment because of air and hydrostatic pressure and chloride attack. In this study, the effect of air pressure repeatedly generated by water level change of wave power marine concrete structures on the chloride-ion diffusion of marine concrete was analyzed. The chloride-ion diffusion of wave power marine concrete structures was evaluated. The results show that the air chamber and bypass room, which were subjected to repetitive air pressures caused by water level changes, showed a higher water-soluble chloride-ion content compared to the generator room and docking facility, which were subjected to atmospheric pressure. Field exposure tests and indoor chloride attack tests were performed using fabricated specimens to analyze the effect of pressure on chloride-ion penetration. It was confirmed that Portland blast furnace slag had a greater inhibitory effect on chloride-ion penetration than ordinary Portland cement. The concrete specimens subjected to pressure showed increased capillary pores and micro-cracks. We devised an equation for calculating the diffusion coefficient based on measured data and estimating the diffusion coefficient for the location receiving repeated air pressure by using the diffusion coefficient of the location receiving general atmospheric pressure.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

Numerical Modeling of Initiation and Propagation of Corrosion in Hollow Submerged Marine Concrete Structures

CORROSION ◽  
10.5006/0916 ◽  
2013 ◽  
Vol 69 (12) ◽  
pp. 1158-1170 ◽  
Author(s):  
A. Della Pergola ◽  
F. Lollini ◽  
E. Redaelli ◽  
L. Bertolini
Keyword(s):  
Numerical Modeling ◽  
Concrete Structures ◽  
Initiation And Propagation ◽  
Marine Concrete

Input Value Correlation in Chloride Ion Ingress Modelling and Concrete Structures Reliability

2018 ◽  
Vol 761 ◽  
pp. 127-130
Author(s):  
Martina Šomodíková ◽  
Břetislav Teplý ◽  
Dita Vořechovská
Keyword(s):  
Life Cycle ◽  
Concrete Structures ◽  
Chloride Ion ◽  
Statistical Correlation ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Engineering Systems ◽  
Special Aspect ◽  
Life Cycle Engineering ◽  
Input Variables

The assessment of service life of a structure can be performed via mathematical modelling – either analytical or numerical and it can be viewed as a necessary pre-requisite for life-cycle engineering decisions. Many works concerning the modelling and testing of degradation effects for engineering systems are reported in the literature. The present paper discusses the degradation modelling of reinforced concrete structures and concentrates on the damage they sustain due to chloride ingress, namely a special aspect: the influence of statistical correlation among input variables on the reliability.

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