Effectiveness Protection Performance of an Internal Blending Organic Corrosion Inhibitor for Carbon Steel in Chloride Contaminated Simulated Concrete Pore Solution

et al. 2021

Materials

The objective of this study was to investigate the physico-chemical properties of concrete made with recycled brick-concrete aggregate, which was the mixture from waste concrete and waste clay brick in a 7:3 ratio. Specifically, this paper investigated the mechanical properties, freeze-thaw resistance, and distribution of water-soluble chloride ions of concrete containing RBCA and fly ash (FA) against combined freeze-thaw and sodium chloride attack. Concrete containing RBCA replacement of natural coarse aggregate and fly ash replacement of Portland cement was subjected to 45 freeze-thaw cycles containing sodium chloride solution. It was discovered that the mechanical properties and freeze-thaw resistance to sodium chloride attack gradually decreased with increasing RBCA content. At the same time, a replacement level of 15% FA by weight resulted in significant improvements in compressive strength and resistance to combined freeze-thaw and chloride attack. Furthermore, using a replacement of 30% FA by weight markedly improved the resistance to chloride ion penetration of concrete due to the lowest water-soluble chloride content.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Combined Freeze-Thaw and Chloride Attack Resistance of Concrete Made with Recycled Brick-Concrete Aggregate

et al. 2021

Materials

“…Concrete is currently the most used building material 1–7 . However, under the effect of freezing and thawing, chloride penetration, sulfate attack, etc., the reinforced concrete structure often cannot reach the designed service life 8–13 . In order to maintain the performance of the reinforced concrete structure, it needs to be repaired and strengthened.…”

Section: Introductionmentioning

confidence: 99%

Effect of chloride penetration on CFRP sheet, CFRP‐concrete interface, and CFRP‐strengthened concrete beams

Han

et al. 2023

Structural Concrete

Self Cite

Whether the performance of carbon fiber‐reinforced polymer (CFRP)‐strengthened concrete structure is affected by chloride penetration is the key to the application under chloride environments. In this paper, the effect of chloride penetration on tensile properties of CFRP sheet, bond behavior of CFRP‐concrete, and flexural performance of CFRP‐strengthened concrete beams were studied. Results show that chloride penetration has no effect on the elastic modulus of the CFRP sheet. The tensile strength and elongation of the CFRP sheet decrease with the exposure time increase, reducing by 10% and 12.7% after 240 days. The interface failure of CFRP‐concrete is likely to occur on the concrete surface. As the exposure time increases, the interface failure develops toward the epoxy resin layer; the sliding stiffness and end slip of the interface decrease. However, the ultimate bearing capacity of the interface first increases and then decreases. As the exposure time increase, the effective bonding length gradually increases, and the failure mode of CFRP‐strengthened beams changes from bending failure to shear failure. After 120 days, the ultimate bearing capacity of the beams is significantly reduced. From three parts of materials, interfaces, and components to provide an evaluation basis for the use, regular detection, and life prediction of CFRP‐strengthened reinforced concrete beams under chloride environments.

Structural Health Monitoring

“…Corrosion of reinforcements in engineering applications is regarded as one of the most key elements that reduces the service life of reinforced concrete (RC) structures. [1][2][3][4] It has been reported that 55% of the deterioration and degradation of RC structures is induced by the corrosion of steel rebars. 5 One of the major causes of corrosion of steel is ascribed to chloride ingress, especially due to the exposure of RC structures to marine or coastal environments.…”

Section: Introductionmentioning

confidence: 99%

Wave amplitude of embedded ultrasonic transducer-based damage monitoring of concrete due to steel bar corrosion

Zhang

Jia

Xiong

et al. 2021

In this research, four embedded ultrasonic piezoelectric transducers were combined to form cross pair and opposite pair monitoring schemes for continuously monitoring the damage to different strength grades of concrete caused by the corrosion of reinforcements under accelerated corrosion conditions. The damage process was analyzed by combining the electrochemical effects of steel corrosion, that is, half-cell potential and galvanic current tests. Results show that the embedded ultrasonic transducer method can detect damage of concrete during steel corrosion and that each stage of damage can be determined from the plots of ultrasonic transducer data versus corrosion rate. The results further indicate that a combination of cross pair and opposite pair testing methods can more comprehensively reflect the damage to concrete caused by the expansion of corrosion of steel bars, than a single testing method. Since electrochemical testing can only depict the corrosion state of steel rebars, it is beneficial to use embedded ultrasonic measurements to monitor the damage process of concrete. The differences in damage between different strength grades of concrete, that is, the resistance to corrosion of steel bars and brittle failure, can be obtained from the plots of ultrasonic transducer data.