A numerical approach to the study of chloride ion penetration into concrete

2000 ◽  
Vol 52 (4) ◽  
pp. 243-250 ◽  
Author(s):  
O. O. Onyejekwe ◽  
N. Reddy
2015 ◽  
Vol 18 (2) ◽  
pp. 427-440 ◽  
Author(s):  
Rui Vasco Silva ◽  
Jorge de Brito ◽  
Rui Neves ◽  
Ravindra Dhir

2012 ◽  
Vol 591-593 ◽  
pp. 2422-2427
Author(s):  
Juan Zhao

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


2021 ◽  
Vol 11 (20) ◽  
pp. 9456
Author(s):  
Changjoon Lee ◽  
Andres Salas Montoya ◽  
Hoon Moon ◽  
Hyunwook Kim ◽  
Chulwoo Chung

The present study investigated the influence of the hybridization of steel and polyolefin fiber on the mechanical performance and chloride ion penetration of base concrete designed for marine shotcreting purposes. The purpose of fiber hybridization is to reduce the risk of corrosion that might occur during service life. Sets of hybrid fiber reinforced base concrete, whose water to binder ratio was 0.338, were prepared. The fiber contents in the base concrete were 0.54 and 1.08 vol%, and the volume proportion of polyolefin fiber in the hybrid fiber varied from 0 to 100%. Although the effect of fiber hybridization was not clearly observed from the compressive strength, a synergetic effect which increased both the flexural strength and toughness occurred at a fiber content of 1.08 vol%. The optimum ratio of steel and polyolefin fiber was 50:50. With respect to chloride ion penetration, an increasing amount of steel fiber increased the amount of current passing through the base concrete specimen due to the presence of electrically conductive steel fiber. However, chloride ion diffusivity was not greatly affected by the presence of steel fiber.


Lámpsakos ◽  
2018 ◽  
Vol 1 (18) ◽  
pp. 21
Author(s):  
Luz Marina Torrado-Gómez ◽  
Norma Cristina Solarte-Vanegas

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 146
Author(s):  
Jakub Hodul ◽  
Nikol Žižková ◽  
Ruben Paul Borg

Crystalline admixtures and industrial by-products can be used in cement-based materials in order to improve their mechanical properties. The research examined long-term curing and the exposure to environmental actions of polymer–cement mortars with crystalline admixture (CA) and different by-products, including Bengħisa fly ash and Globigerina limestone waste filler. The by-products were introduced as a percentage replacement of the cement. A crystallization additive was also added to the mixtures in order to monitor the improvement in durability properties. The mechanical properties of the mortar were assessed, with 20% replacement of cement with fly ash resulting in the highest compressive strength after 540 days. The performance was analyzed with respect to various properties including permeable porosity, capillary suction, rapid chloride ion penetration and chloride migration coefficient. It was noted that the addition of fly ash and crystalline admixture significantly reduced the chloride ion penetration into the structure of the polymer cement mortar, resulting in improved durability. A microstructure investigation was conducted on the samples through Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). Crystals forming through the crystalline admixture in the porous structure of the material were clearly observed, contributing to the improved properties of the cement-based polymer mortar.


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