Steel reinforcement corrosion in concrete under combined actions: The role of freeze-thaw cycles, chloride ingress, and surface impregnation

2017 ◽  
Vol 148 ◽  
pp. 113-121 ◽  
Author(s):  
Peng Zhang ◽  
Yuan Cong ◽  
Michael Vogel ◽  
Zhaolin Liu ◽  
Harald S. Müller ◽  
...  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xiao-Chun Lu ◽  
Bin Guan ◽  
Bo-Fu Chen ◽  
Xin Zhang ◽  
Bo-bo Xiong

The existing studies of the corrosion of reinforced concrete have mainly focused on the interface area and chemical ion erosion, ignoring the specific service environment of the reinforced concrete. In this study, the effect of freeze-thaw damage was investigated via corrosion experiments under different freeze-thaw cycle conditions. Steel reinforcement corrosion mass, ultimate pull-out force, corrosion rate, and bond slippage were chosen as characteristic parameters in the experiments, and scanning electron microscopy (SEM) analysis was used to explain the mechanism of action of freeze-thaw damage on corrosion. The results showed that, under identical corrosion conditions, the mass of steel reinforcement corrosion and corrosion rate increased by 39.6% and 39.7% when comparing 200 freeze-thaw cycles to 0 cycles, respectively. The ultimate pull-out force and bond slippage after 200 freeze-thaw cycles decreased by 73% and 31%, respectively, compared with 0 freeze-thaw cycles. In addition, SEM analysis indicated that microstructure damage caused by freeze-thaw cycles accelerated the corrosion reaction and decreased cementitious properties, leading to decreasing ultimate pull-out force and bond slippage. The effect of freeze-thaw cycles and steel reinforcement corrosion on the macro mechanical properties of concrete is not a simple superposition.


Author(s):  
Mohamed A. Ismail ◽  
Han-Seung Lee ◽  
Mohd Warid Hussin

Corrosion of steel reinforcement embedded in concrete is one of the main causes of degradation of reinforced concrete structures. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride ingress into concrete. That degradation has a severe impact on the structure in terms of maintenance and rehabilitation costs. Therefore, early detection of reinforcement corrosion is important for efficient maintenance, repair and planning. Meanwhile, the evaluation of the corrosion of reinforcement by non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measure the polarization resistance, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. In this study, measurement of corrosion by using the mini-sensor is compared with the measured results by CM-II to verify the validity of the newly developed mini senor. Results show that there are agreement in trends of the parameters measured and as such the developed mini sensor has a promising start to be used.


2021 ◽  
pp. 1-44
Author(s):  
Samuel Adu-Amankwah ◽  
Suraj Rahmon ◽  
Leon Black

Limestone ternary cements have attracted significant research and commercial attention recently, for technical and environmental reasons. Standardization of these cements is imminent under BS EN197-5. Presently, detailed understanding of the hydration and microstructure evolution of limestone ternary cements from different alumina-rich supplementary cementitious materials (SCMs) exists in the scientific literature; improved reaction kinetics and additional phase assemblages refine the pore structure. However, understanding of the performance of these cements under exposure conditions is less prevalent. In this contribution, we review these data in a way that allows stakeholders to appreciate the capabilities of the different compositions and their performance. We focus our discussion on critically examining the interplay between the cement composition and the microstructure on durability. It is demonstrated that limestone ternary cements offer a pathway for reducing the embodied CO2 of concrete without compromising their performance. The resistance to chloride ingress, sulphate attack and ASR are significantly improved in a manner similar to binary cements. Carbonation and freeze-thaw resistance is generally lower than OPC but adequate air entrainment can offer improvement in freeze-thaw resistance. The challenge to widespread adoption of these cements is evidence of durability under field conditions. To this end, we recommend large-scale field trialling of these cements and understanding of the role of combined exposures on durability and mechanical properties.


2002 ◽  
Vol 24 (1) ◽  
pp. 127-137 ◽  
Author(s):  
M.M Al-Zahrani ◽  
S.U Al-Dulaijan ◽  
M Ibrahim ◽  
H Saricimen ◽  
F.M Sharif

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ahmad Zaki ◽  
Megat Azmi Megat Johari ◽  
Wan Muhd Aminuddin Wan Hussin ◽  
Yessi Jusman

Corrosion of steel reinforcement is a major cause of structural damage that requires repair or replacement. Early detection of steel corrosion can limit the extent of necessary repairs or replacements and costs associated with the rehabilitation works. The ground penetrating radar (GPR) method has been found to be a useful method for evaluating reinforcement corrosion in existing concrete structures. In this paper, GPR was utilized to assess corrosion of steel reinforcement in a concrete slab. A technique for accelerating reinforcement bar corrosion using direct current (DC) power supply with 5% sodium chloride (NaCl) solution was used to induce corrosion to embedded reinforcement bars (rebars) in this concrete slab. A 2 GHz GPR was used to assess the corrosion of the rebars. The analysis of the results of the GPR data obtained shows that corrosion of the rebars could be effectively localized and assessed.


2013 ◽  
Vol 357-360 ◽  
pp. 939-943 ◽  
Author(s):  
Jian Gang Niu ◽  
Liang Yan ◽  
Hai Tao Zhai

Based on the coupling testing program of freeze-thaw and carbonation, the laboratory simulation test is carried out. The laws of carbonation depth of the fly ash concrete suffered the freeze-thaw cycle in different test modes and the influence of fly ash dosage on concrete carbonation depth after the freeze-thaw cycle are studied. Defining the influence coefficient of the freeze-thaw cycles on carbonation depth of concrete, the mechanism of coupling of freeze-thaw and carbonation is analyzed,and the role of freeze-thaw and carbonation in the coupling process are obtained.


2020 ◽  
Vol 868 ◽  
pp. 57-64
Author(s):  
Vítězslav Vacek ◽  
Jiří Kolisko ◽  
Petr Pokorný ◽  
Michaela Kostelecká

Steel reinforcement made of refined maraging steel in the form of wires and strands has been for a long time used commonly for reinforcement of prestressed concrete structures. Defects on some of them and unfortunately even accidents of some cases of bridge objects, mainly recently published by media, related to corrosion of prestressed reinforcement awoke interest of both professional and wide non-professional public related to its durability. This issue also opens up a question of durability and liability of prestressed structures. In majority of existing prestressed structures the anticorrosion protection of reinforcement was traditionally secured mainly by alkalinity of the environment, i.e. concreting and/or grouting of prestressed elements in ducts. The abstract presents information related mainly to mechanical characteristics of corrosion-affected prestressed elements.


2018 ◽  
Vol 199 ◽  
pp. 04004
Author(s):  
Ze Gyang Zakka ◽  
Mike Otieno

This paper presents results of an ongoing research of the effect of 1D and 2D chloride ingress on concrete resistivity and corrosion rate of steel reinforcement. 12 concrete beams made with concrete of binder blend PC(50)/GGBS(50), w/b = 0.40, 10 mm steel reinforcement rods at concrete cover of 20 mm were used in this laboratory based experiment. The steel reinforcement bars were placed at the middle or at an orthogonal corner of the concrete beams subjected to 1D and 2D chloride ingress respectively. A single crack was induced using 3-point bending on one-half of the beams. The beams were exposed to a repeated cycle of 2 weeks ponding in 5% NaCl and then air drying in ambient laboratory condition for 2 weeks. The corrosion rate of both cracked and uncracked specimens exposed to 2D chloride ingress was significantly higher than that of beams exposed to 1D chloride ingress. The uncracked specimens had lower concrete resistivity values compared to the cracked specimens even though higher corrosion rates were measured.


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