scholarly journals Chloride Migration in Graphene Oxide Concrete

2021 ◽  
Author(s):  
Boksun Kim ◽  
Keyword(s):  
Graphene Oxide ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Noticeable Effect ◽  
Chloride Resistance ◽  
Chloride Migration ◽  
Concrete Cylinders ◽  
Chloride Penetration Resistance ◽  
Thick Disks ◽  
The University

This paper presents experimental work on the chloride penetration resistance of concrete, incorporating 0%, 2% and 3% Graphene Oxide (GO) by weight of cement. Nine 100mm diameter and 200mm high concrete cylinders were cast in the Materials Laboratory at the University of Plymouth. The cylinders were cut into 50mm thick disks and rapid chloride migration tests were carried out. After the tests, the penetration depth of the disks were measured and chloride migration coefficients were determined. It was found that compared with the control samples, the addition of 2% and 3% GO reduced the migration coefficient of concrete by about 11% and 17% respectively at 28 days after casting. This suggests that the inclusion of GO into a cementitious mix does have a noticeable effect on the increase of chloride resistance and hence the longevity of concrete.

scholarly journals The Rapid Chloride Migration Test in Assessing the Chloride Penetration Resistance of Normal and Lightweight Concrete

2021 ◽  
Vol 11 (16) ◽  
pp. 7251
Author(s):  
Jorge Pontes ◽  
José Alexandre Bogas ◽  
Sofia Real ◽  
André Silva
Keyword(s):  
Lightweight Concrete ◽  
Chloride Transport ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Simple Method ◽  
Chloride Migration ◽  
Binder Ratio ◽  
Chloride Penetration Resistance ◽  
Water Binder Ratio

Chloride-induced corrosion has been one of the main causes of reinforced concrete deterioration. One of the most used methods in assessing the chloride penetration resistance of concrete is the rapid chloride migration test (RCMT). This is an expeditious and simple method but may not be representative of the chloride transport behaviour of concrete in real environment. Other methods, like immersion (IT) and wetting–drying tests (WDT), allow for a more accurate approach to reality, but are laborious and very time-consuming. This paper aims to analyse the capacity of RCMT in assessing the chloride penetration resistance of common concrete produced with different types of aggregate (normal and lightweight) and paste composition (variable type of binder and water/binder ratio). To this end, the RCMT results were compared with those obtained from the same concretes under long-term IT and WDT. A reasonable correlation between the RCMT and diffusion tests was found, when slow-reactive supplementary materials or porous lightweight aggregates surrounded by weak pastes were not considered. A poorer correlation was found when concrete was exposed under wetting–drying conditions. Nevertheless, the RCMT was able to sort concretes in different classes of chloride penetration resistance under distinct exposure conditions, regardless of the type of aggregate and water/binder ratio.

scholarly journals Effect of graphene oxide on chloride penetration resistance of recycled concrete

2019 ◽  
Vol 8 (1) ◽  
pp. 681-689 ◽  
Author(s):  
Kai Guo ◽  
Hang Miao ◽  
Lin Liu ◽  
Jinghai Zhou ◽  
Ming Liu
Keyword(s):  
Graphene Oxide ◽  
High Strength ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Recycled Concrete ◽  
Volume Stability ◽  
Micro Cracks ◽  
Structure Morphology ◽  
Chloride Penetration Resistance ◽  
Electric Flux

Abstract Graphene oxide (GO) is a nanomaterial with ultra-high strength, good hydrophilicity, and dispersibility. To study the effect of GO on chloride penetration resistance of recycled concrete, the mechanism of action is investigated. The electric flux method is used to test the chloride penetration in recycled concrete specimens with 0, 0.03%, 0.06%, and 0.09% of GO. The volume change, microscopic pore distribution, and micro-structure morphology are characterized using laser rangefinder, and techniques such as X-ray tomography and scanning electron microscopy. The results show that the "coagulation nodule" effect of GO provides a growth basis for cement hydration,which results in a more uniform distribution of the hydrate microcrystals. It fills the micro-cracks of the recycled concrete, reduces the most probable aperture, increases the number of harmless small apertures, and enhances the volume stability of recycled concrete, thereby improving the chloride penetration resistance, which is important for improving the durability of concrete.

scholarly journals Effects of load-induced micro-cracks on chloride penetration resistance in different types of concrete

2020 ◽  
Vol 53 (6) ◽  
Author(s):  
Nicoletta Russo ◽  
Matteo Gastaldi ◽  
Pietro Marras ◽  
Luca Schiavi ◽  
Alberto Strini ◽  
...  
Keyword(s):  
Crack Width ◽  
Crack Depth ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Exposure Test ◽  
Durability Design ◽  
Micro Cracks ◽  
Chloride Migration ◽  
Chloride Penetration Resistance

AbstractChloride penetration resistance of concrete is one of the key parameters for the durability design of reinforced concrete structures located in chloride-bearing environments. In all the current available durability models, service life is evaluated considering concrete in uncracked conditions, which is rarely found in practice. This work investigates chloride penetration resistance of concrete in uncracked and micro-cracked configurations, evaluated in terms of chloride migration coefficient through non-steady state migration test (Rapid Chloride Migration test). Prismatic specimens were manufactured considering six different concrete types and two different times of curing. In micro-cracked configuration, cracks were obtained with a specifically developed loading procedure. Micro-cracks were characterized at the end of the exposure test, in terms of crack width at the exposed surface and crack depth. Results showed that cracks were 5–70 μm wide and up to 40 mm deep, always causing an increase in chloride penetration, that should be evaluated considering both crack width and crack depth, with respect to sound conditions. The effects on the chloride penetration seemed to be more pronounced on the more impervious concretes.

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